Male CF-1 Mice Research Articles

Nutriomic Effects of Precision Lipids on Murine Hepatic Triacylglycerol Alterations Induced by High-Fat Diets.

This study aims to investigate if a mixture of functional lipids (FLs), containing conjugated linoleic acid (CLA), tocopherols (TPs), and phytosterols (PSs), prevents some lipid alterations induced by high-fat (HF) diets, without adverse effects. Male CF1 mice (n = 6/group) were fed (4 weeks) with control (C), HF, or HF + FL diets. FL prevented the overweight induced by the HF diet and reduced the adipose tissue (AT) weight, associated with lower energy efficiency. After the intervention period, the serum triacylglycerol (TAG) levels in both HF diets underwent a decrease associated with an enhanced LPL activity (mainly in muscle). The beneficial effect of the FL mixture on body weight gain and AT weight might be attributed to the decreased lipogenesis, denoted by the lower mRNA levels of SREBP1-c and ACC in AT, as well as by an exacerbated lipid catabolism, reflected by increased mRNA levels of PPARα, ATGL, HSL, and UCP2 in AT. Liver TAG levels were reduced in the HF + FL group due to an elevated lipid oxidation associated with a higher CPT-1 activity and mRNA levels of PPARα and CPT-1a. Moreover, genes linked to fatty acid biosynthesis (SREBP1-c and ACC) showed decreased mRNA levels in both HF diets, this finding being more pronounced in the HF + FL group. The administration of an FL mixture (CLA + TP + PS) prevented some lipid alterations induced by a HF diet, avoiding frequent deleterious effects of CLA in mice through the modulation of gene expression related to the regulation of lipid metabolism.

Preventive interventional strategies mitigate age-associated degeneration of dorsal hippocampal neural cells in naturally ageing mice

Objectives: The objective of this study was to investigate the effectiveness and potential protective effects of various intervention strategies, such as choline and docosahexaenoic acid (Ch-DHA) supplementation, Clitoria ternatea root extract (CTR) supplements, human embryonic kidney stem cell conditioned media (HEK-CM) treatment and exposure to enriched environments (EEs), in mitigating neural cell degeneration in dorsal hippocampal subregions of naturally ageing mice brain. Materials and Methods: Twelve–fifteen-month-old CF1 male mice were subdivided (n = 6/group) into normal age-matched control, Ch-DHA supplemented, EE exposed, HEK-CM administered and CTR-supplemented groups. Neuro morphological alterations in the dorsal hippocampus were assessed using cresyl violet staining. Results: Higher neural cell degeneration was observed in the CA1–CA3 dorsal hippocampal subregions in normal ageing mice brains. Notably, interventions such as HEK-CM administration, Ch-DHA supplementation, exposure to an EE and CTR supplementation significantly reduced degeneration, particularly in the CA3 and CA2 regions. Conclusion: Ch-DHA supplementation and HEK-CM treatment are observed to significantly reduce age-dependent degeneration of dorsal hippocampal CA3 and CA2 neurons in naturally ageing mice compared to EE exposure or CTR supplementation.

Xenobiotics Triggering Acute Intermittent Porphyria and Their Effect on Mouse Brain Respiratory Complexes.

Heme enzyme dysfunction causes a group of diseases called porphyrias. Particularly, a decrease in porphobilinogen deaminase, involved in the third step of heme biosynthesis, leads to acute intermittent porphyria (AIP). Considering our previous works demonstrating the multiplicity of brain metabolisms affected by porphyrinogenic agents, this study aimed to elucidate whether they cause any alteration on the mitochondrial respiratory chain. The activities of respiratory chain complexes (I to IV) were measured in encephalon mitochondria of CF1 male mice receiving volatile anesthetics: isoflurane (2 mL/kg) and sevoflurane (1.5 mL/kg), ethanol (30%), allylisopropylacetamide (AIA) (350 mg/kg), and barbital (167 mg/kg). Moreover, they were compared versus animals with pathological levels of 5-aminolevulinic acid (ALA, 40 mg/kg). Complex I-III activity was induced by isoflurane and decreased by AIA, ethanol, and ALA. Complex II-III activity was increased by sevoflurane and decreased by isoflurane and AIA. Complex II activity was increased by sevoflurane and barbital and decreased by AIA, ethanol, and ALA. Complex IV activity was increased by barbital and ALA and decreased by sevoflurane. The damage to the respiratory chain by ALA could be reflecting the pathophysiological condition of patients with AIP. Better understanding the broad effect of porphyrinogenic drugs and the mechanisms acting on the onset of AIP is vital in translational medicine.

Long-term behavioral and neurochemical paradoxical alterations elicited following intranasal application of a chlorpyrifos formulation in mice

The intranasal (IN) administration route represents a pathway for xenobiotics to reach the brain. The present study aimed to address the long-term consequences of IN administration of a chlorpyrifos (CPF) commercial formulation (fCPF) in mice. For this purpose, adult male CF-1 mice were intranasally administered with fCPF (10 mg/kg/day) three days a week, for 2 and 4 weeks, respectively. Behavioral and biochemical analyses were conducted 3–7, and 7.5 months after the last IN fCPF administration, respectively. Following a 6-month fCPF-free washout period, fur appearance and body injuries scores improved in the fCPF-treated groups. Notably, spatial learning and memory enhancement was observed 4 and 7 months after the last IN fCPF administration. Changes in oxidative stress markers and the activities of enzymes involved in cholinergic and glutamatergic pathways were observed in different brain areas from fCPF-treated mice, still after 7.5 months from fCPF application. Altogether, these neurochemical disturbances could be responsible for the described behavioral observations.

Exploring potential strategies to enhance memory and cognition in aging mice

Background: Aging population is rapidly expanding worldwide, and age-related cognitive impairments prove detrimental for achieving a better productive and quality of life. Lack of effective therapies for age-related cognitive impairment focuses attention on developing preventive strategies, such as nutritional interventions, cell therapies and environmental manipulations. The objective of the present study was to explore the comparative benefits of potential memory-enhancing strategies like supplementation of choline (Ch) and docosahexaenoic acid (DHA) or administration of human embryonic kidney stem cell conditioned media (HEK-CM) or exposure to environmental enrichment (EE), that attenuates cognitive impairments in aging mice. Methods: 12-month-old CF1 male mice were subdivided [n=6/group] into normal aging control (NAC), saline vehicle control (SVC), Ch-DHA, EE, heat-inactivated HEK-CM (HIHEK-CM) and HEK-CM mice. Spatial working and reference memory were assessed using an eight-arm radial maze test and cognition using a novel object recognition test (NORT). Results: Spatial memory and cognition were decreased in normal aging mice. Aged mice exposed to dietary Ch-DHA or HEK-CM showed significant enhancement in spatial learning tasks, memory and cognition compared to the same in age-matched NAC mice. Ch-DHA and HEK-CM treated mice committed significantly lesser reference memory errors and attained a higher percentage of correct choices in spatial learning and memory tasks. Moreover, on testing for cognition in NORT, significantly higher number of visits to the novel object was observed in Ch-DHA supplemented and HEK-CM administered aging mice whereas HEK-CM and EE mice groups showed significantly greater number of visits to familiar object, when compared to same in age-matched NAC and HIHEK-CM groups, respectively. Conclusion: Supplementation of Ch-DHA and HEK-CM treatment strategies have a higher potential [~ 20—30%] for enhancing spatial learning, memory and cognition in normal aged mice, whereas exposure to EE seems to enhance only their short-term memory.

Frontline Sodium Channel-Blocking Antiseizure Medicine Use Promotes Future Onset of Drug-Resistant Chronic Seizures

The mechanisms of treatment-resistant epilepsy remain unclear. We have previously shown that frontline administration of therapeutic doses of lamotrigine (LTG), which preferentially inhibits the fast-inactivation state of sodium channels, during corneal kindling of mice promotes cross-resistance to several other antiseizure medicines (ASMs). However, whether this phenomenon extends to monotherapy with ASMs that stabilize the slow inactivation state of sodium channels is unknown. Therefore, this study assessed whether lacosamide (LCM) monotherapy during corneal kindling would promote future development of drug-resistant focal seizures in mice. Male CF-1 mice (n = 40/group; 18-25 g) were administered an anticonvulsant dose of LCM (4.5 mg/kg, i.p.), LTG (8.5 mg/kg, i.p.), or vehicle (0.5% methylcellulose) twice daily for two weeks during kindling. A subset of mice (n = 10/group) were euthanized one day after kindling for immunohistochemical assessment of astrogliosis, neurogenesis, and neuropathology. The dose-related antiseizure efficacy of distinct ASMs, including LTG, LCM, carbamazepine, levetiracetam, gabapentin, perampanel, valproic acid, phenobarbital, and topiramate, was then assessed in the remaining kindled mice. Neither LCM nor LTG administration prevented kindling: 29/39 vehicle-exposed mice were kindled; 33/40 LTG-exposed mice were kindled; and 31/40 LCM-exposed mice were kindled. Mice administered LCM or LTG during kindling became resistant to escalating doses of LCM, LTG, and carbamazepine. Perampanel, valproic acid, and phenobarbital were less potent in LTG- and LCM-kindled mice, whereas levetiracetam and gabapentin retained equivalent potency across groups. Notable differences in reactive gliosis and neurogenesis were also appreciated. This study indicates that early, repeated administration of sodium channel-blocking ASMs, regardless of inactivation state preference, promotes pharmacoresistant chronic seizures. Inappropriate ASM monotherapy in newly diagnosed epilepsy may thus be one driver of future drug resistance, with resistance being highly ASM class specific.

Exploring potential strategies to enhance memory and cognition in aging mice

Background: Aging population is rapidly expanding worldwide, and age-related cognitive impairments prove detrimental for achieving a better productive and quality of life. Lack of effective therapies for age-related cognitive impairment focuses attention on developing preventive strategies, such as nutritional interventions, cell therapies and environmental manipulations. The objective of the present study was to explore the comparative benefits of potential memory-enhancing strategies like supplementation of choline (Ch) and docosahexaenoic acid (DHA) or administration of human embryonic kidney stem cell conditioned media (HEK-CM) or exposure to environmental enrichment (EE), that attenuates cognitive impairments in aging mice. Methods: 12-month-old CF1 male mice were subdivided [n=6/group] into normal aging control (NAC), saline vehicle control (SVC), Ch-DHA, EE, heat-inactivated HEK-CM (HIHEK-CM) and HEK-CM mice. Spatial working and reference memory were assessed using an eight-arm radial maze test and cognition using a novel object recognition test (NORT). Results: Spatial memory and cognition were decreased in normal aging mice. Aged mice exposed to dietary Ch-DHA or HEK-CM showed significant enhancement in spatial learning tasks, memory and cognition compared to the same in age-matched NAC mice. Ch-DHA and HEK-CM treated mice committed significantly lesser reference memory errors and attained a higher percentage of correct choices in spatial learning and memory tasks. Moreover, on testing for cognition in NORT, significantly higher number of visits to the novel object was observed in Ch-DHA supplemented and HEK-CM administered aging mice whereas HEK-CM and EE mice groups showed significantly greater number of visits to familiar object, when compared to same in age-matched NAC and HIHEK-CM groups, respectively. Conclusion: Supplementation of Ch-DHA and HEK-CM treatment strategies have a higher potential [~ 20—30%] for enhancing spatial learning, memory and cognition in normal aged mice, whereas exposure to EE seems to enhance only their short-term memory.

The effects of cannabidiol and Δ9-tetrahydrocannabinol, alone and in combination, in the maximal electroshock seizure model

In the present study, cannabidiol (CBD), Δ9-tetrahydrocannabinol (THC), and combinations of CBD and THC, were evaluated in the mouse maximal electroshock (MES) seizure test – an animal model of generalized-onset seizures. Male CF-1 mice were injected intraperitoneally (i.p.) with either CBD, THC or a combination of CBD and THC. The MES test was conducted 2 h after the injection of CBD and 1 h after the injection of THC. A wide range of doses was tested to allow the construction of dose-response curves. Toxicity was assessed using a behavioral rating scale. It was found that: 1) the ED50 for THC alone was 52 mg/kg and its therapeutic index (TI) was 1.7; 2) the ED50 for CBD alone was 190 mg/kg and its TI was 2.4; and 3) the ED50 for a 15:1 combination of CBD+THC was 130 mg/kg + 8.6 mg/kg (CBD + THC). Thus, CBD and THC were both effective in the MES model, and CBD was somewhat more effective in the presence of low (non-therapeutic) doses of THC. The improvement in CBD’s effect, however, was less dramatic than that seen in past experiments with the amygdala-kindling model (Fallah et al., 2021). Both CBD alone and CBD+THC in combination might be useful in the treatment of generalized-onset seizures. The advantage of adding THC to CBD, however, might be less than in the treatment of focal-onset seizures.

Behavioral and neurochemical impairments after intranasal administration of chlorpyrifos formulation in mice

Among the most relevant environmental factors associated with the etiology of neurodegenerative disorders are pesticides. Spray drift or volatilization generates pesticide dispersion after its application. In addition, inhalation or intranasal (IN) administration of xenobiotics constitutes a feasible route for substance delivery to the brain. This study investigates the behavioral and neurochemical effects of IN exposure to a commercial formulation of chlorpyrifos (fCPF). Adult male CF-1 mice were intranasally administered with fCPF (3–10 mg/kg/day) three days a week, for 2 weeks. Behavioral and biochemical analyses were conducted 20 and 30 days after the last IN fCPF administration, respectively. No significant behavioral or biochemical effects were observed in the 3 mg/kg fCPF IN exposure group. However, animals exposed to 10 mg/kg fCPF showed anxiogenic behavior and recognition memory impairment, with no effects on locomotor activity. In addition, the IN administration of 10 mg/kg fCPF altered the redox balance, modified the activity of enzymes belonging to the cholinergic and glutamatergic pathways, and affected glucose metabolism, and cholesterol levels in different brain areas. Taken together, these observations suggest that these biochemical imbalances could be responsible for the neurobehavioral disturbances observed after IN administration of fCPF in mice.

Evaluating the efficacy of prototype antiseizure drugs using a preclinical pharmacokinetic approach.

Pharmacokinetics (PK) of a drug drive its exposure, efficacy, and tolerability. A thorough preclinical PK assessment of antiseizure medications (ASMs) is therefore essential to evaluate the clinical potential. We tested protection against evoked seizures of prototype ASMs in conjunction with analysis of plasma and brain PK as a proof-of-principle study to enhance our understanding of drug efficacy and duration of action using rodent seizure models. In vivo seizure protection assays were performed in adult male CF-1 mice and Sprague Dawley rats. Clobazam (CLB), N-desmethyl CLB (NCLB), carbamazepine (CBZ), CBZ-10,11-epoxide (CBZE), sodium valproate (VPA), and levetiracetam (LEV) concentrations were quantified in plasma and brain using liquid chromatography-tandem mass spectrometry. Mean concentrations of each analyte were calculated and used to determine PK parameters via noncompartmental analysis in Phoenix WinNonLin. NCLB concentrations were approximately 10-fold greater than CLB in mice. The antiseizure profile of CLB was partially sustained by NCLB in mice. CLB concentrations were lower in rats than in mice. CBZE plasma exposures were approximately 70% of CBZ in both mice and rats, likely contributing to the antiseizure effect of CBZ. VPA showed a relatively short half-life in both mice and rats, which correlated with a sharp decline in efficacy. LEV had a prolonged brain and plasma half-life, associated with a prolonged duration of action in mice. The study demonstrates the utility of PK analyses for understanding the seizure protection time course in mice and rats. The data indicate that distinct PK profiles of ASMs between mice and rats likely drive differences in drug efficacy between rodent models.

Eggshell membrane treatment for the healing of superficial open wounds in mice

ResumenIntroducción. Las membranas de la cáscara de huevo presentan propiedades beneficiosas para la regeneración de tejidos y sus aplicaciones biomédicas son importantes.Objetivo.Demostrar la efectividad de las membranas de la cáscara de huevo no fecundado de gallina en el tratamiento de heridas abiertas superficiales en ratones, en comparación con el procedimiento convencional.Materiales y métodos. Se hizo una herida superficial lineal de 15 mm en la espalda de 10 ratones albinos machos. Los ratones se dividieron en cuatro grupos, uno no recibió ningún tratamiento y los otros tres sí: uno, tratamiento convencional, otro, con membranas de huevo directamente aplicadas a la herida y, el otro, con membranas en forma de polvo.La evolución de las heridas se registró en fotografías y se calculó la tasa de reducción de la longitud de la herida, así como el tiempo y el porcentaje de curación. Los porcentajes de curación se analizaron con ANOVA y la prueba de Dunnett (p<0,05).Resultados. Con los tratamientos con membranas de huevo y polvo de membrana, se logró una tasa de reducción de longitud de 1.009 y 1.020 mm/día, respectivamente, y un tiempo de curación de 12 días, en tanto que, con el tratamiento convencional, la tasa de reducción fue de 0,852 mm/día y la curación se dio en 16 días. El análisis estadístico mostró diferencias significativas entre los tratamientos con membrana de huevo y el tratamiento convencional.Conclusiones.Las membranas de la cáscara de huevo aplicadas de forma directa y en polvo resultaron más efectivas que la aplicación del procedimiento convencional en el tratamiento de heridas abiertas superficiales en ratones.

Remembering how to run: A descriptive wheel run analysis in CF1 male and female mice.

Physical exercise is known to have beneficial effects on general health and wellbeing in humans and it is also related to neuronal plasticity, increasing neurogenesis and consequently leading to improvements in processes such as learning and memory. In this sense, wheel running performance in mice appears as an extensively used behavioral approach for neurobiological studies. Here, we explored the running patterns in CF1 male and female mice allowing voluntary wheel running for 20 min along three consecutive days. We analyzed differences in the accumulated distance traveled, instant velocity, and latency to run and breaks taken in both males and females, comparing performance between days. Results revealed that after a first experience with the wheel, animals that had learnt how to run on day 1 quickly look forward to stepping into the wheel in subsequent training days, reflected by a significant increase in daily running distance and velocity. Further, no differences were found in the running performance between males and females. In summary, in a first experience with the wheel, animals get familiarized with the wheel and grow accustomed to it.

Development and biodistribution studies of 77As-labeled trithiol RM2 bioconjugates for prostate cancer: Comparison of [77As]As-trithiol-Ser-Ser-RM2 vs. [77As]As-trithiol-Glu-Ser-RM2

IntroductionRecent progress with the production of 72As (2.49 Mev β+max (64%), 3.33 Mev β+max (16%), 834 keV γ (81%), t1/2: 26 h) and 77As (0.683 Mev β−max (97%), 239 keV γ (1.59%), t1/2: 38.8 h) has facilitated their evaluation as a potential “theranostic pair” for PET imaging and radiotherapy. Our 3rd generation trithiol chelate with two carboxylic acid groups was further developed as a bifunctional chelate for radioarsenic. MethodsThe As complex with the trithiol chelate was synthesized and characterized. No carrier added (nca) [77As][H2AsO4−] was used for radiolabeling studies. The trithiol chelate was conjugated to the RM2 peptide (DPhe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2) via solid phase peptide synthesis with two different linkers, Ser-Ser and Glu-Ser. The trithiol chelate and its RM2 bioconjugates were radiolabeled with nca 77As, and the RM2 bioconjugates were compared in initial biodistribution studies. ResultsThe As diacid trithiol complex was characterized by 1H NMR, 13C NMR and HR-ESI-MS. The trithiol-RM2 precursor and As trithiol bioconjugates were characterized by HR-ESI-MS and/or LC-ESI-MS. Radiolabeling of the RM2 bioconjugates with 77As resulted in over 85% radiochemical yield for [77As]As-trithiol-Ser-Ser-RM2 ([77As]8) and 90% for [77As]As-trithiol-Glu-Ser-RM2 ([77As]9). Both radiotracers demonstrated excellent in vitro stability (≥ 90% remaining intact through 24 h in PBS buffer) and were more hydrophilic than previous analogues based on log D7.4 values. Biodistribution results of the two radiotracers in healthy CF-1 male mice demonstrated blockable pancreatic uptake at 1 h (82% for ([77As]8 and 78% for [77As]9) indicating specific gastrin-releasing peptide receptor (GRPR) uptake. The primary route of excretion was through the gastrointestinal system for both radiotracers. ConclusionsA new trithiol chelate with improved hydrophilicity was successfully conjugated to the RM2 peptide via two linkers, and high radiolabeling yield with nca 77As was achieved. In vivo biodistribution studies with both radiotracers demonstrated blockable pancreatic uptake suggestive of specific receptor uptake.

Paternal alcohol consumption has intergenerational consequences in male offspring.

Alcoholism is a heterogeneous set of disorders caused by ethanol intake. Harmful effects of paternal consumption on the offspring are poorly explored and not fully understood. We analyzed the effect of paternal alcohol consumption on both their own reproductive capacity and that of their male offspring. We used a model of ethanol consumption (15% v/v in drinking water) for 12days in adult CF-1 male mice. DNA integrity and post-translational modifications of histones were assessed in sperm; testicular weight, histology, and DNA fragmentation were analyzed. Treated or untreated male mice were mated with non-treated females to obtain two cell embryos that were cultured for 7days; morphology and embryonic cell death were evaluated. Males of both groups were mated with non-treated females. Adult male offspring was euthanized, and sperm and testicular parameters determined. Paternal ethanol consumption caused histological and epigenetic changes, as well as damage in DNA integrity in the testicular germline and sperm. These alterations gave rise to deleterious effects on embryonic development and to testicular and spermatic changes in the offspring. This study provides critical information on reproductive disturbances brought about by paternal alcohol consumption and the profound impact these could have on the male progeny. The need to explore the effects of paternal alcohol consumption in detail and warn about the importance of controlling alcohol intake for the well-being of future generations should not be underscored.

Minocycline as a therapeutic strategy against the brain dysfunctions induced by hypercholesterolemia

About 40% of adults have elevated plasma cholesterol levels, making hypercholesterolemia a critical health issue. Clinical and experimental evidence have shown that hypercholesterolemia contributes to the development of neuropathologies. Mechanisms such as blood-brain barrier dysfunction and neuroinflammation seem to connect hypercholesterolemia to brain changes related to these neuropathologies. Minocycline, an antibiotic compound of the tetracycline class, has shown significant neuroprotective effects in experimental studies, particularly on the inhibition of microglial activation. In this sense, we hypothesized that minocycline could display beneficial effects in the cognitive deficits related to hypercholesterolemia.In this study, CF-1 male and female adult young (3 months old) mice were treated with either a standard diet or a high cholesterol diet (2.5% of cholesterol). After four weeks, the animals also received minocycline or 0.9% saline by oral gavage once a day for another four weeks, totaling eight weeks of the experimental period. Next, the animals were subjected to behavioral tests, such as object recognition, splash test, and cataleptic posture. After that, the glucose tolerance test was performed, and the plasma was collected for the further performance of the biochemical analysis.Eight weeks of high cholesterol diet consumption caused an increase in the total plasma cholesterol levels of animals, which were reduced by the treatment with minocycline. Both diet and minocycline did not affect the plasma glucose levels and the glucose tolerance of animals. Also, hypercholesterolemic mice exhibited a higher body weight, weight gain, and adiposity index at the end of the experimental period. However, these parameters were not affected by the minocycline treatment. Regarding the behavioral tests, hypercholesterolemia in mice was related to a significant deficit in recognition memory and cataleptic posture, which were improved by minocycline treatment. In addition, hypercholesterolemia induced depressive-like behavior in mice, reflected by less grooming time on the splash test, which was not changed by the minocycline treatment.Therefore, our results show that administration of minocycline presented promising effects in ameliorating the cognitive and behavioral deficits related to hypercholesterolemia, demonstrating that microglial activation might play a role in the memory deficits induced by this metabolic disease.

Quantification of myocardial fibrosis using noninvasive T2-mapping magnetic resonance imaging: Preclinical models of aging and pressure overload.

Noninvasive imaging of cardiac fibrosis is important for early diagnosis and intervention in chronic heart diseases. Here, we investigated whether noninvasive, contrast agent-free MRI T2 -mapping can quantify myocardial fibrosis in preclinical models of aging and pressure overload. Myocardial fibrosis and remodeling were analyzed in two animal models: (i) aging (15-month-old male CF-1 mice vs. young 6- to 8-week-old mice), and (ii) pressure overload (PO; by transverse aortic constriction in 4- to 5-month-old male C57BL/6 mice vs. sham-operated for 14 days). In vivo T2 -mapping was performed by acquiring data during the isovolumic and early diastolic phases, with a modified respiratory and ECG-triggered multiecho TurboRARE sequence on a 7-T MRI. Cine MRI provided cardiac morphology and function. A quantitative segmentation method was developed to analyze the in vivo T2 -maps of hearts at midventricle, apex, and basal regions. The cardiac fibrosis area was analyzed ex vivo by picro sirius red (PSR) staining. Both aged and pressure-overloaded hearts developed significant myocardial contractile dysfunction, cardiac hypertrophy, and interstitial fibrosis. The aged mice had two phenotypes, fibrotic and mild-fibrotic. Notably, the aged fibrotic subgroup and the PO mice showed a marked decrease in T2 relaxation times (25.3 ± 0.6in aged vs. 29.9 ± 0.7ms in young mice, p = 0.002; and 24.3 ± 1.7in PO vs. 28.7 ± 0.7ms in shams, p = 0.05). However, no significant difference in T2 was detected between the aged mild-fibrotic subgroup and the young mice. Accordingly, an inverse correlation between myocardial fibrosis percentage (FP) and T2 relaxation time was derived (R2 = 0.98): T2 (ms)=30.45 - 1.05× FP. Thus, these results demonstrate a statistical agreement between T2 -map-quantified fibrosis and PSR staining in two different clinically relevant animal models. In conclusion, T2 -mapping MRI is a promising noninvasive contrast agent-free quantitative technique to characterize myocardial fibrosis.

Duckweed protein supports the growth and organ development of mice: A feeding study comparison to conventional casein protein.

As global population growth and meat consumption increases, sustainable alternatives to conventional protein-rich fodder crops for livestock are needed to reduce negative environmental impacts. Duckweed, a small floating aquatic plant, can generate 5 to 10 times higher protein yields than conventional land-grown crops. Although some in vivo feeding trials with duckweed have been conducted, those measuring animal weight are limited, and those examining organ development are nonexistent. To secure broad acceptance of new protein sources, such controlled studies are critical. This study measured the food intake, growth, and final organ and adipose tissue mass of male CF-1 mice fed a semi-purified diet containing casein or diets in which 10% or 25% of the casein was replaced with duckweed protein (DWP). Proximate analysis showed that the DWP preparation used contained 39.9% protein (w/w), and contained all of the essential amino acids with Met as the limiting amino acid. The average growth rates were not significantly different among the treatment groups: 0.21g/day; 0.24g/day; and 0.25g/day for the control, 10%, and 25% DWP protein diets, respectively. The daily food intake of both DWP diets was 6.5% to 8.0% higher than the control diet, but feeding efficiency did not differ among diets. The relative weight of the liver, spleen, kidneys, heart, and epidydimal fat, and colon length were not significantly different between treatment groups. The results from this study show that replacement of up to 25% dietary casein with DWP has no adverse effects on the growth rate and final organ and adipose tissue weights of laboratory mice. PRACTICAL APPLICATION: Duckweed can produce 5 to 10 times more protein per area than land-grown crops such as soybean. In this study, up to a 25% replacement of casein with duckweed protein had no observable effect on the growth or organ development of laboratory mice. Thus, duckweed has the potential to be used as a protein supplement for livestock, poultry, and fish, thereby decreasing environmental impacts from land-grown crops used for animal feed.

Glutamate transporter-1 link astrocytes with heightened aggressive behavior induced by steroid abuse in male CF1 mice

The astrocytic glutamate transporter GLT-1 performs glutamate uptake thereby mediating NMDAr responses in neurons. Ceftriaxone (CEF) upregulates astrocytic GLT-1 expression/activity, which could counteract excessive glutamate levels and aggressive behavior induced by anabolic synthetic steroids such as nandrolone decanoate (ND). Here, adult male CF-1 mice were allocated to oil (VEH), ND, CEF, and ND/CEF groups. Mice were subcutaneously (s.c.) injected with ND (15 mg/kg) or VEH for 19 days, and received intraperitoneal (i.p.) injections of CEF (200 mg/kg) or saline for 5 days. The ND/CEF group received ND for 19 days plus coadministration of CEF in the last 5 days. On the 19th day, the aggressive phenotypes were evaluated through the resident-intruder test. After 24 h, cerebrospinal fluid was collected to measure glutamate levels, and the pre-frontal cortex was used to assess GLT-1, pGluN2BTyr1472, and pGluN2ATyr1246 by Western blot. Synaptosomes from the left brain hemisphere was used to evaluate mitochondrial function including complex II-succinate dehydrogenase (SDH), Ca2+ handling, membrane potential (ΔѰm), and H2O2 production. ND decreased the latency for the first attack and increased the number of attacks by the resident mice against the intruder, mechanistically associated with an increase in glutamate levels and pGluN2BTyr1472 but not pGluN2ATyr1244, and GLT-1 downregulation. The abnormalities in mitochondrial Ca2+ influx, SDH, ΔѰm, and H2O2 implies in deficient energy support to the synaptic machinery. The ND/CEF group displayed a decreased aggressive behavior, normalization of glutamate and pGluN2BTyr1472levels, and mitochondrial function at synaptic terminals. In conclusion, the pharmacological modulation of GLT-1 highlights its relevance as an astrocytic target against highly impulsive and aggressive phenotypes.

Therapeutic Inhaled Sphingosine for Treating Lung Infection in a Mouse Model of Critical Illness.

Sphingosine, a sphingoid long chain base, is a natural lipid with antimicrobial properties. Recent animal studies have shown that preventive sphingosine inhalation can rescue susceptible mice, such as cystic fibrosis-, burn injured- or aged mice from bacterial pulmonary infection. While preventing lung infections in susceptible patients has obvious clinical merit, treatment strategies for an established infection are also direly needed, particularly in the times of rising antibiotic resistance. Here, we tested the potential of sphingosine in treating an established pulmonary infection. We used a cecal ligation and puncture (CLP) model in male CF-1 mice and a Pseudomonas aeruginosa strain that was isolated from a septic patient (P. aeruginosa 762). We determined susceptibility to intranasal infection and ascertained when the pulmonary infection was established by continuous core body temperature monitoring. We quantified sphingosine levels in the tracheal epithelium by immunohistochemistry and studied the effects on sphingosine on bacterial membrane permeabilization and intracellular acidification using fluorescent probes. We first determined that septic mice are highly susceptible to P. aeruginosa infection 2 days after indu-cing sepsis. Additionally, at this time, sphingosine levels in the tracheal epithelium are significantly reduced as compared to levels in healthy mice. Secondly, upon intranasal Pseudomonas inoculation, we ascertained that pulmonary infection was established as early as 2.5 h after inoculation as evidenced by a significant drop in core body temperature. Using these times of infection susceptibility and detection (2 days post CLP, 2.5h after inoculation) we treated with inhaled sphingosine and observed pulmonary bacterial loads reduced to levels found in infected healthy mice after inoculation and decreased infection-associated mortality. Further, our data demonstrate that sphingosine induces outer membrane permeabilization, disrupting the membrane potential and leading to intracellular acidification of the bacteria. Sphingosine shows efficacy in treating P. aeruginosa lung infections not only prophylactically, but also therapeutically.

Intranasal glyphosate-based herbicide administration alters the redox balance and the cholinergic system in the mouse brain

Pesticide exposure is associated with cognitive and psychomotor disorders. Glyphosate-based herbicides (GlyBH) are among the most used agrochemicals, and inhalation of GlyBH sprays may arise from frequent aerial pulverizations. Previously, we described that intranasal (IN) administration of GlyBH in mice decreases locomotor activity, increases anxiety, and impairs recognition memory. Then, the aim of the present study was to investigate the mechanisms involved in GlyBH neurotoxicity after IN administration. Adult male CF-1 mice were exposed to GlyBH IN administration (equivalent to 50 mg/kg/day of Gly acid, 3 days a week, during 4 weeks). Total thiol content and the activity of the enzymes catalase, acetylcholinesterase and transaminases were evaluated in different brain areas. In addition, markers of the cholinergic and the nigrostriatal pathways, as well as of astrocytes were evaluated by fluorescence microscopy in coronal brain sections. The brain areas chosen for analysis were those seen to be affected in our previous study. GlyBH IN administration impaired the redox balance of the brain and modified the activities of enzymes involved in cholinergic and glutamatergic pathways. Moreover, GlyBH treatment decreased the number of cholinergic neurons in the medial septum as well as the expression of the α7-acetylcholine receptor in the hippocampus. Also, the number of astrocytes increased in the anterior olfactory nucleus of the exposed mice. Taken together, these disturbances may contribute to the neurobehavioural impairments reported previously by us after IN GlyBH administration in mice.