Adult Mice Research Articles

Ablation of oligodendrogenesis in adult mice alters brain microstructure and activity independently of behavioral deficits.

Oligodendrocytes continue to differentiate from their precursor cells even in adulthood, a process that can be modulated by neuronal activity and experience. Previous work has indicated that conditional ablation of oligodendrogenesis in adult mice leads to learning and memory deficits in a range of behavioral tasks. The current study replicated and re-evaluated evidence for a role of oligodendrogenesis in motor learning, using a complex running wheel task. Further, we found that ablating oligodendrogenesis alters brain microstructure (ex vivo MRI) and brain activity (in vivo EEG) independent of experience with the task. This suggests a role for adult oligodendrocyte formation in the maintenance of brain function and indicates that task-independent changes due to oligodendrogenesis ablation need to be considered when interpreting learning and memory deficits in this model.

Differential regulation by CD47 and thrombospondin-1 of extramedullary erythropoiesis in mouse spleen.

Extramedullary erythropoiesis is not expected in healthy adult mice, but erythropoietic gene expression was elevated in lineage-depleted spleen cells from Cd47-/- mice. Expression of several genes associated with early stages of erythropoiesis was elevated in mice lacking CD47 or its signaling ligand thrombospondin-1, consistent with previous evidence that this signaling pathway inhibits expression of multipotent stem cell transcription factors in spleen. In contrast, cells expressing markers of committed erythroid progenitors were more abundant in Cd47-/- spleens but significantly depleted in Thbs1-/- spleens. Single-cell transcriptome and flow cytometry analyses indicated that loss of CD47 is associated with accumulation and increased proliferation in spleen of Ter119-CD34+ progenitors and Ter119+CD34- committed erythroid progenitors with elevated mRNA expression of Kit, Ermap, and Tfrc. Induction of committed erythroid precursors is consistent with the known function of CD47 to limit the phagocytic removal of aged erythrocytes. Conversely, loss of thrombospondin-1 delays the turnover of aged red blood cells, which may account for the suppression of committed erythroid precursors in Thbs1-/- spleens relative to basal levels in wild-type mice. In addition to defining a role for CD47 to limit extramedullary erythropoiesis, these studies reveal a thrombospondin-1-dependent basal level of extramedullary erythropoiesis in adult mouse spleen.

Glutamine metabolism improves left ventricular function but not macrophage-mediated inflammation following myocardial infarction.

Glutamine is a critical amino acid that serves as an energy source, building block, and signaling molecule for the heart tissue and the immune system. However, the role of glutamine metabolism in regulating cardiac remodeling following myocardial infarction (MI) is unknown. In this study, we show in adult male mice that glutamine metabolism is altered both in the remote (contractile) area and in infiltrating macrophages in the infarct area after permanent left anterior descending artery occlusion. We found that metabolites related to glutamine metabolism were differentially altered in macrophages at days 1, 3, and 7 after MI using untargeted metabolomics. Glutamine metabolism in live cells was increased after MI relative to no MI controls. Gene expression in the remote area of the heart indicated a loss of glutamine metabolism. Glutamine administration improved LV function at days 1, 3, and 7 after MI, which was associated with improved contractile and metabolic gene expression. Conversely, administration of BPTES, a pharmacological inhibitor of glutaminase-1, worsened LV function after MI. Neither glutamine nor BPTES administration impacted gene expression or bioenergetics of macrophages isolated from the infarct area. Our results indicate that glutamine metabolism plays a critical role in maintaining LV contractile function following MI, and that glutamine administration improves LV function. Glutamine metabolism may also play a role in regulating macrophage function, but macrophages are not responsive to exogenous pharmacological manipulation of glutamine metabolism.

Discovery of antimalarial drugs from secondary metabolites in actinomycetes culture library

BackgroundNatural products play a key role as potential sources of biologically active substances for the discovery of new drugs. This study aimed to identify secondary metabolites from actinomycete library extracts that are potent against the asexual stages of Plasmodiumfalciparum (P.falciparum).MethodsSecondary metabolites from actinomycete library extracts were isolated from culture supernatants by ethyl acetate extraction. Comprehensive screening was performed to identify novel antimalarial compounds from the actinomycete library extracts (n = 28). The antimalarial activity was initially evaluated in vitro against chloroquine/mefloquine-sensitive (3D7) and-resistant (Dd2) lines of P.falciparum. The cytotoxicity was then evaluated in primary adult mouse brain (AMB) cells.ResultsOut of the 28 actinomycete extracts, 17 showed parasite growth inhibition > 50% at a concentration of 50 µg/mL, nine were identified with an IC50 value < 10 µg/mL, and seven suppressed the parasite significantly with an IC50 value < 5 µg/mL. The extracts from Streptomycesaureus strains HUT6003 (Extract ID number: 2), S.antibioticus HUT6035 (8), and Streptomyces sp. strains GK3 (26) and GK7 (27), were found to have the most potent antimalarial activity with IC50 values of 0.39, 0.09, 0.97, and 0.36 µg/mL (against 3D7), and 0.26, 0.22, 0.72, and 0.21 µg/mL (against Dd2), respectively. Among them, Streptomycesantibioticus strain HUT6035 (8) showed the highest antimalarial activity with an IC50 value of 0.09 µg/mL against 3D7 and 0.22 µg/mL against Dd2, and a selective index (SI) of 188 and 73.7, respectively.ConclusionSecondary metabolites obtained from the actinomycete extracts showed promising antimalarial activity in vitro against 3D7 and Dd2 cell lines of P.falciparum with minimal toxicity. Therefore, secondary metabolites obtained from actinomycete extracts represent an excellent starting point for the development of antimalarial drug leads.

Effects of non-rapid eye movement sleep on the cortical synaptic expression of GluA1-containing AMPA receptors.

Converging electrophysiological, molecular and ultrastructural evidence supports the hypothesis that sleep promotes a net decrease in excitatory synaptic strength, counteracting the net synaptic potentiation caused by ongoing learning during waking. However, several outstanding questions about sleep-dependent synaptic weakening remain. Here, we address some of these questions by using two established molecular markers of synaptic strength, the levels of the AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors containing the GluA1 subunit and the phosphorylation of GluA1 at serine 845 (p-GluA1(845)). We previously found that, in the rat cortex and hippocampus, these markers are lower after 6-8h of sleep than after the same time spent awake. Here, we measure GluA1 and p-GluA1(845) levels in synaptosomes of mouse cortex after 5h of either sleep, sleep deprivation, recovery sleep after sleep deprivation or selective REM sleep deprivation (32 C57BL/B6 adult mice, 16 females). We find that relative to after sleep deprivation, these synaptic markers are lower after sleep independent of whether the mice were allowed to enter REM sleep. Moreover, 5h of recovery sleep following acute sleep deprivation is enough to renormalize their expression. Thus, the renormalization of GluA1 and p-GluA1(845) expression crucially relies on NREM sleep and can occur in a few hours of sleep after acute sleep deprivation.

West Nile Virus-Induced Expression of Senescent Gene Lgals3bp Regulates Microglial Phenotype within Cerebral Cortex

Microglia, the resident macrophages of the central nervous system, exhibit altered gene expression in response to various neurological conditions. This study investigates the relationship between West Nile Virus infection and microglial senescence, focusing on the role of LGALS3BP, a protein implicated in both antiviral responses and aging. Using spatial transcriptomics, RNA sequencing and flow cytometry, we characterized changes in microglial gene signatures in adult and aged mice following recovery from WNV encephalitis. Additionally, we analyzed Lgals3bp expression and generated Lgals3bp-deficient mice to assess the impact on neuroinflammation and microglial phenotypes. Our results show that WNV-activated microglia share transcriptional signatures with aged microglia, including upregulation of genes involved in interferon response and inflammation. Lgals3bp was broadly expressed in the CNS and robustly upregulated during WNV infection and aging. Lgals3bp-deficient mice exhibited reduced neuroinflammation, increased homeostatic microglial numbers, and altered T cell populations without differences in virologic control or survival. These data indicate that LGALS3BP has a role in regulating neuroinflammation and microglial activation and suggest that targeting LGALS3BP might provide a potential route for mitigating neuroinflammation-related cognitive decline in aging and post-viral infections.

Sex-specific resilience of neocortex to food restriction.

Mammals have evolved sex-specific adaptations to reduce energy usage in times of food scarcity. These adaptations are well described for peripheral tissue, though much less is known about how the energy-expensive brain adapts to food restriction, and how such adaptations differ across the sexes. Here, we examined how food restriction impacts energy usage and function in the primary visual cortex (V1) of adult male and female mice. Molecular analysis and RNA sequencing in V1 revealed that in males, but not in females, food restriction significantly modulated canonical, energy-regulating pathways, including pathways associated waith AMP-activated protein kinase, peroxisome proliferator-activated receptor alpha, mammalian target of rapamycin, and oxidative phosphorylation. Moreover, we found that in contrast to males, food restriction in females did not significantly affect V1 ATP usage or visual coding precision (assessed by orientation selectivity). Decreased serum leptin is known to be necessary for triggering energy-saving changes in V1 during food restriction. Consistent with this, we found significantly decreased serum leptin in food-restricted males but no significant change in food-restricted females. Collectively, our findings demonstrate that cortical function and energy usage in female mice are more resilient to food restriction than in males. The neocortex, therefore, contributes to sex-specific, energy-saving adaptations in response to food restriction.

Sex-specific resilience of neocortex to food restriction

Mammals have evolved sex-specific adaptations to reduce energy usage in times of food scarcity. These adaptations are well described for peripheral tissue, though much less is known about how the energy-expensive brain adapts to food restriction, and how such adaptations differ across the sexes. Here, we examined how food restriction impacts energy usage and function in the primary visual cortex (V1) of adult male and female mice. Molecular analysis and RNA sequencing in V1 revealed that in males, but not in females, food restriction significantly modulated canonical, energy-regulating pathways, including pathways associated waith AMP-activated protein kinase, peroxisome proliferator-activated receptor alpha, mammalian target of rapamycin, and oxidative phosphorylation. Moreover, we found that in contrast to males, food restriction in females did not significantly affect V1 ATP usage or visual coding precision (assessed by orientation selectivity). Decreased serum leptin is known to be necessary for triggering energy-saving changes in V1 during food restriction. Consistent with this, we found significantly decreased serum leptin in food-restricted males but no significant change in food-restricted females. Collectively, our findings demonstrate that cortical function and energy usage in female mice are more resilient to food restriction than in males. The neocortex, therefore, contributes to sex-specific, energy-saving adaptations in response to food restriction.

Moderate India Pale Ale beer consumption promotes antigenotoxic and non-mutagenic effects in ex vivo and in vivo mice models.

Discussion of the benefits of moderate alcohol consumption is ongoing. Broadly, research focusing on ethanol consumption tends to report no benefits. However, studies that distinguish between different types of alcoholic beverages, particularly beers, often reveal positive effects. The present study evaluated the genotoxic and mutagenic effects of moderate chronic consumption of India Pale Ale (IPA) craft beer. Sixty-four adult male Swiss mice were used and divided into control and treatment groups receiving water, IPA beer with 55.23 g of ethanol per liter of beer, aqueous solution with 55.23 g of ethanol per liter, and hop infusion ad libitum for 30 days. After this period, the animals were genetically evaluated with a comet assay. For the ex vivo comet assay, blood was collected and exposed to hydrogen peroxide (H2O2). For the in vivo assay, the alkylating agent cyclophosphamide (CP) was administered to the groups after blood collection and sacrificed after 24 h. Brain, liver, and heart tissues were analyzed. Bone marrow was collected and submitted to the micronucleus test. The groups treated with IPA beer, ethanol, and hops did not show genotoxic and mutagenic action in the blood, brain, heart, or liver. The antigenotoxic action of IPA beer and hops was observed in both in vivo and ex vivo models, showing a similar reduction in DNA damage caused by CP. There was no significant difference between the groups with regard to the formation of micronuclei by CP. Moderate chronic consumption of IPA beer and hops infusion showed antigenotoxic effects in mice but no antimutagenic action. © 2024 Society of Chemical Industry.

A single-cell atlas of chromatin accessibility in mouse organogenesis.

Organogenesis is a highly complex and precisely regulated process. Here we profiled the chromatin accessibility in >350,000 cells derived from 13 mouse embryos at four developmental stages from embryonic day (E) 10.5 to E13.5 by SPATAC-seq in a single experiment. The resulting atlas revealed the status of 830,873 candidate cis-regulatory elements in 43 major cell types. By integrating the chromatin accessibility atlas with the previous transcriptomic dataset, we characterized cis-regulatory sequences and transcription factors associated with cell fate commitment, such as Nr5a2 in the development of gastrointestinal tract, which was preliminarily supported by the in vivo experiment in zebrafish. Finally, we integrated this atlas with the previous single-cell chromatin accessibility dataset from 13 adult mouse tissues to delineate the developmental stage-specific gene regulatory programmes within and across different cell types and identify potential molecular switches throughout lineage development. This comprehensive dataset provides a foundation for exploring transcriptional regulation in organogenesis.

MMP-3 Knockout Induces Global Transcriptional Changes and Reduces Cerebral Infarction in Both Male and Female Models of Ischemic Stroke

Ischemic stroke followed by reperfusion (IR) leads to extensive cerebrovascular injury characterized by neuroinflammation and brain cell death. Inhibition of matrix metalloproteinase-3 (MMP-3) emerges as a promising therapeutic approach to mitigate IR-induced stroke injury. We employed middle cerebral artery occlusion with subsequent reperfusion (MCAO/R) to model ischemic stroke in adult mice. Specifically, we investigated the impact of MMP-3 knockout (KO) on stroke pathophysiology using RNA sequencing (RNA-seq) of stroke brains harvested 48 h post-MCAO. MMP-3 KO significantly reduced brain infarct size following stroke. Notably, RNA-seq analysis showed that MMP-3 KO altered expression of 333 genes (252 downregulated) in male stroke brains and 3768 genes (889 downregulated) in female stroke brains. Functional pathway analysis revealed that inflammation, integrin cell surface signaling, endothelial- and epithelial-mesenchymal transition (EndMT/EMT), and apoptosis gene signatures were decreased in MMP-3 KO stroke brains. Intriguingly, MMP-3 KO downregulated gene signatures more profoundly in females than in males, as indicated by greater negative enrichment scores. Our study underscores MMP-3 inhibition as a promising therapeutic strategy, impacting multiple cellular pathways following stroke.

Parkinson’s-linked LRRK2-G2019S derails AMPAR trafficking, mobility, and composition in striatum with cell-type and subunit specificity

Parkinson's disease (PD) is a multifactorial disease that affects multiple brain systems and circuits. While defined by motor symptoms caused by degeneration of brainstem dopamine neurons, debilitating non-motor abnormalities in fronto-striatal-based cognitive function are common, appear early, and are initially independent of dopamine. Young adult mice expressing the PD-associated G2019S missense mutation in Lrrk2 also exhibit deficits in fronto-striatal-based cognitive tasks. In mice and humans, cognitive functions require dynamic adjustments in glutamatergic synapse strength through cell-surface trafficking of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptors (AMPARs), but it is unknown how LRRK2 mutation impacts dynamic features of AMPAR trafficking in striatal projection neurons (SPNs). Here, we used Lrrk2G2019S knockin mice to show that surface AMPAR subunit stoichiometry is altered biochemically and functionally in mutant SPNs in dorsomedial striatum to favor the incorporation of GluA1 over GluA2. GluA1-containing AMPARs were resistant to internalization from the cell surface, leaving an excessive accumulation of GluA1 on the surface within and outside synapses. This negatively impacted trafficking dynamics that normally support synapse strengthening, as GluA1-containing AMPARs failed to increase at synapses in response to a potentiating stimulus and showed significantly reduced surface mobility. Surface GluA2-containing AMPARs were expressed at normal levels in synapses, indicating subunit-selective impairment. Abnormal surface accumulation of GluA1 was independent of PKA activity and was limited to D1R SPNs. Since LRRK2 mutation is thought to be part of a common PD pathogenic pathway, our data suggest that sustained, striatal cell-type specific changes in AMPAR composition and trafficking contribute to cognitive or other impairments associated with PD.

Parkinson’s-linked LRRK2-G2019S derails AMPAR trafficking, mobility, and composition in striatum with cell-type and subunit specificity

Parkinson's disease (PD) is a multifactorial disease that affects multiple brain systems and circuits. While defined by motor symptoms caused by degeneration of brainstem dopamine neurons, debilitating non-motor abnormalities in fronto-striatal-based cognitive function are common, appear early, and are initially independent of dopamine. Young adult mice expressing the PD-associated G2019S missense mutation in Lrrk2 also exhibit deficits in fronto-striatal-based cognitive tasks. In mice and humans, cognitive functions require dynamic adjustments in glutamatergic synapse strength through cell-surface trafficking of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptors (AMPARs), but it is unknown how LRRK2 mutation impacts dynamic features of AMPAR trafficking in striatal projection neurons (SPNs). Here, we used Lrrk2G2019S knockin mice to show that surface AMPAR subunit stoichiometry is altered biochemically and functionally in mutant SPNs in dorsomedial striatum to favor the incorporation of GluA1 over GluA2. GluA1-containing AMPARs were resistant to internalization from the cell surface, leaving an excessive accumulation of GluA1 on the surface within and outside synapses. This negatively impacted trafficking dynamics that normally support synapse strengthening, as GluA1-containing AMPARs failed to increase at synapses in response to a potentiating stimulus and showed significantly reduced surface mobility. Surface GluA2-containing AMPARs were expressed at normal levels in synapses, indicating subunit-selective impairment. Abnormal surface accumulation of GluA1 was independent of PKA activity and was limited to D1R SPNs. Since LRRK2 mutation is thought to be part of a common PD pathogenic pathway, our data suggest that sustained, striatal cell-type specific changes in AMPAR composition and trafficking contribute to cognitive or other impairments associated with PD.

Inducible Deletion of the Prostaglandin EP3 Receptor in Kidney Tubules of Male and Female Mice Has No Major Effect on Water Homeostasis.

The prostaglandin E2 (PGE2) receptor EP3 has been detected in the thick ascending limb (TAL) and the collecting duct of the kidney, where its actions are proposed to inhibit water reabsorption. However, EP3 is also expressed in other cell types, including vascular endothelial cells. The aim here was to determine the contribution of EP3 in renal water handling in male and female adult mice by phenotyping a novel mouse model with doxycycline-dependent deletion of EP3 throughout the kidney tubule (EP3-/- mice). RNAscope demonstrated that EP3 was highly expressed in the cortical and medullary TAL of adult mice. Compared to controls EP3 mRNA expression was reduced by >80% in whole kidney (RT-qPCR) and non-detectable (RNAscope) in renal tubules of EP3-/- mice. Under basal conditions, there were no significant differences in control and EP3-/- mice of both genders in food and water intake, bodyweight, urinary output or clinical biochemistries. No differences were detectable between genotypes in handling of an acute water load, or in their response to the vasopressin analogue dDAVP. No differences in water handling were observed when PGE2 production was enhanced using a 1% NaCl load. Expression of proteins involved in kidney water handling were not different between genotypes. This study demonstrates that renal tubular EP3 is not essential for body fluid homeostasis in males or females, even when PGE2 levels are high. The mouse model is a novel tool for examining the role of EP3 in kidney function independently of potential developmental abnormalities or systemic effects.

P-235 Lipid profile changes during neurodevelopment (ND) of mouse embryos cultured in vitro

Abstract Study question Does in vitro culture (IVC) induce changes in lipid profile of the embryo? Summary answer IVC induces changes in embryonic lipid homeostasis that subsequently affect placenta-brain axis (PBA) function and are then maintained in the brain of adult mice. What is known already During ART, embryos are exposed to oxidative stress (OS)-prone environment. Cellular lipids are particularly sensitive to OS. Lipids are a crucial component for proper brain development and any aberrancies in lipid profile of the embryo can affect neurodevelopment (ND) through the PBA, leading to functional and behavioural deficits during adulthood. In particular, deficiencies of ether-linked glicerophospolipids (e.g. plasmalogens), which are highly abundant in the brain, and polyunsaturated fatty acids (PUFAs), have been associated with psychiatric and ND disorders. Study design, size, duration C57BL6 mouse embryos were cultured in vitro for 72hs, and analysed or transferred to 25 recipient females for further development. From 6 pregnant mice, conceptuses (placentae and brain) were collected at near-term pregnancy (19dpc, n &amp;gt; 8/group). Remaining 8 pregnant mice were allowed to deliver and raise litters. Subsequently, brain was collected from male offspring at 4 month of age for lipid homeostasis evaluation. Control group consisted of embryos and offspring obtained from naturally mated C57BL6 mice. Participants/materials, setting, methods C57BL6 blastocysts (n &amp;gt; 15/group) were fixed and subjected to lipid analysis by Fourier transform infra-red (FTIR) and Coherent antistokes Raman spectroscopies (CARS). To reveal lipid changes indicative for ND disorders, selected PUFAs were analyzed by liquid chromatography-mass spectrometry (LC-MS) (n &amp;gt; 8/group) in placenta and brains from prenatal and adult mice. Additionally, placental expression of genes regulating biosynthesis of plasmalogens and proteome of adult males brain, was performed. Values were considered different when p &amp;lt; 0.05, Mean±SEM; Mann-Whitney test. Main results and the role of chance Our results show that IVC induced lipid composition changes in blastocyst, characterised by increased proportion of phospholipids, fatty amides and cholesterol (59±8.2 vs.44.7±8.8; 149±4.5vs. 104±12; 44±2.9vs. 27±4.6 sum of absorbance, p &amp;lt; 0.05); and lipid droplets (LDs) distribution changes, such as, increase size (2.3±0.11 vs 1.8±0.07 µm2, p = 0.0021), and number of large LDs (5.5±0.7 vs. 3.3±0.2, p = 0.006). LC-MS revealed increased levels of linolenic (LA), arachidonic (AA) and docosahexaenoic (DHA) acids in placenta (LA:15.49±1.7 vs. 6.92±2; AA:263.6±29.1 vs. 62.7±14.7 DHA:0±2.5 vs. 2.7±0.8 pmol/mg; p &amp;lt; 0.03) and foetal brain (LA:13.6±5.5 vs. 1.5±0.9; AA:240.5±100 vs. 39.3±9.6; 13.9±6.9 vs. 2.11±0.6 pmol/mg; p &amp;lt; 0.03) of IVC conceptuses, which may condition brain development and function. Conversely, levels of LA and AA were low in adult brain from IVC offspring (LA:4.4±1.5 vs 14.5±3.8; AA: 581±95 vs 1842±454 pmol/mg, p &amp;lt; 0.04). Additionally, the expression of genes regulating biosynthesis of plasmalogens was reduced in IVC placentae (Gnpat:0.2±0.04 vs 1.2±03; Tmem189:0.3±0.1 vs. 1.3±0.3 fold change; p ≤ 0.01). Proteome analysis demonstrated that pathways regulating lipid homeostasis, such as fatty acid oxidation and phospholipid binding and those involved in IL-17a signaling and neurogenesis were upregulated in brain of adult IVC offspring. Limitations, reasons for caution Our results may not entirely reflect what occurs in human embryo, as mouse oocytes have a higher lipid content than human oocyte. Differences in lipid content may cause an increased or decreased penetrance and exhibition of developmental changes of the embryos. Wider implications of the findings Being of non-genetic background, lipid changes induced by IVC may similarly threaten embryos regardless of species causing ND disorders. Our study sheds new light on non-genetic origins of ND disorders and will likely ignite further studies on embryonic lipid changes and their consequences, relevant for human pregnancy and neuropsychiatry. Trial registration number not applicable

P-011 Maternal gestational methyl donor deficiency affects reproductive development and fertility of mice offspring

Abstract Study question Is maternal methyl donor deficiency during gestation affects offspring’s reproductive health at adulthood? Summary answer Maternal gestational methyl donor deficiency affects reproductive development and fertility of F1 offspring and also leads to increased post implantation loss What is known already Reproductive disorders and their exact mechanisms are scarce in “The developmental origins of health and disease” (DOHaD) hypothesis which well explains the metabolic complications such as obesity, type 2 diabetes and hypertension that may take root during early development. The maternal nutritional environment during early development has important implications on offspring’s health later in life including reproductive health. The gestational period is of critical importance during which major epigenetic reprogramming occurs. The maternal methyl donor deficiency during gestational period may affect this process and epigenetic signatures of developing gametes and the fertility potential Study design, size, duration Pregnant female OCT4-GFP mice, fed on control chow diet (CCD) &amp; 40% methyl-donors (Folate, Methionine &amp; Vitamin B12) deficient diet (MDD) from gestation day (GD) 5 to GD 20. The gonadal development of F1 offsprings was studied on gestation day GD 18, post-natal day (PND) 22 and PND 60. Fertility study was done by mating adult F1 male offspring with adult female mice fed on standard diet Participants/materials, setting, methods Homocysteine levels in dams (F0) at GD18 were estimated by ELISA. Testosterone levels in F1 offsprings at PND 60 were estimated by ELISA. Furthermore, Serum glucose levels in F1 offsprings were measured at PND 60 and PND 75 by glucometer. Testicular histology, quantitative histomorphometry, immunofluorescence and TUNEL assay was performed at PND 60. Main results and the role of chance Fetal weight was reduced at GD13 and GD18 but postnatal body weight at PND 22 and 60 was not significantly affected in MDD group. Teratological defects were observed in pups of 40% MDD group as compared to CDD. Testosterone levels were significantly reduced in F1 offsprings of 40% MDD group. Glucose levels were similar in both the groups at PND 60 but at PND 75 it is significantly higher in case of F1 offsprings of 40% MDD. Maternal serum homocysteine levels and global DNA methylation levels of fetal gonads were affected. Testicular histology was significantly impaired in 40% MDD group at GD18, PND22 and PND60. Quantitative histomorphometry and immunofluorescence study showed the loss of spermatogonia and spermatocytes with significant increase in germ cells sloughing and seminiferous tubules atrophy. Apoptosis is also observed in seminiferous tubules. Copulation index, sperm count and motility was significantly reduced in case of 40% MDD group at adulthood. The F1 offspring of this group were sub-fertile with significant post implantation loss. Limitations, reasons for caution Although mice share ∼90% genome with humans, they may not resemble all aspect of physiology or pathology in humans hence it could limit the findings to extrapolate to humans. Wider implications of the findings The knowledge gained from this work could be helpful in highlighting the need of gestational micronutrient interventions specially methyl donors, which could help improving maternal and child health as well as reducing the future disease burden of reproductive disorders Trial registration number not applicable

Gas5 regulates early-life stress-induced anxiety and spatial memory.

Early-life stress (ES) induced by maternal separation (MS) remains a proven causality of anxiety and memory deficits at later stages of life. Emerging studies have shown that MS-induced gene expression in the hippocampus is operated at the level of transcription. However, the extent of involvement of non-coding RNAs in MS-induced behavioural deficits remains unexplored. Here, we have investigated the role of synapse-enriched long non-coding RNAs (lncRNAs) in anxiety and memory upon MS. We observed that MS led to an enhancement of expression of the lncRNA growth arrest specific 5 (Gas5) in the hippocampus; accompanied by increased levels of anxiety and deficits in spatial memory. Gas5 knockdown in early life was able to reduce anxiety and partially rescue the spatial memory deficits of maternally separated adult mice. However, the reversal of MS-induced anxiety and memory deficits is not attributed to Gas5 activity during neuronal development as Gas5 RNAi did not influence spine development. Gene Ontology analysis revealed that Gas5 exerts its function by regulating RNA metabolism and translation. Our study highlights the importance of MS-regulated lncRNA in anxiety and spatial memory.

P-349 Impact of an Aurora kinase inhibitor on AML cells and mouse ovarian follicles in vitro

Abstract Study question Can an aurora kinase B/C inhibitor suppress AML cell line proliferation while not impacting on mouse follicles in vitro? Summary answer Exposure to an aurora kinase inhibitor at a predetermined cytotoxic concentration suppressed AML cell proliferation but had no impact on subsequent follicle health in vitro. What is known already There is a risk that cryopreserved ovarian tissue from young women with a leukaemia diagnosis harbours leukemic cells, which on grafting could transfer disease. Novel chemotherapy agents, specifically aurora kinase inhibitors [ e.g. GSK 1070916 (GSK) ], target proteins involved in chromosomal alignment and segregation during mitosis and meiosis. It is anticipated that aurora kinase inhibitors would have an impact on the development of all somatic cells, including granulosa cells proliferating during follicle growth, however a previous study using ovarian tissue pieces indicated no impact on follicles. Study design, size, duration Primary and secondary follicles (diameter ≤ 100 µm) were manually dissected from adult mouse ovaries and embedded in an extracellular scaffold together with &amp;gt;1,000 AML cells. Individual follicles and AML cells were cultured for 7 days followed by exposure to GSK for 24 hours. GSK was removed by washing and the culture continued for another two days at which time cells were assessed for normal morphology and survival with live/dead staining (Calcein AM/ Ethidium Homodimer-1). Participants/materials, setting, methods The leukemic cell line OC1-AML-3 (DSMZ) was cultured in RPMI-1640 +10% FCS and routinely passaged as recommended. Cell proliferation and cytotoxicity were assessed using the Alamar Blue assay. 20% DMSO was used as a positive control in the cytotoxicity assays and live/dead evaluation. Follicles were cultured in αMEM, ITS, FSH, ascorbic acid and 10% FCS under oil in 5%CO2 : 95% air. Survival and growth were evaluated in two extracellular scaffolds; UltiMatrix and Hystem™-HP. Main results and the role of chance Follicle survival and growth was better (p &amp;lt; 0.05) in UltiMatrix (84.7%; 61/72) compared to Hystem™-HP (72.0%;77/107) with an average increase of 20 µm in diameter at day 7. When OCI-AML-3 cells (0.7 x105/ml) were exposed to a range of concentrations of GSK (10nM to 10µM) for 24hr in an in vitro cytotoxicity assessment, survival was reduced to 0% at a concentration of 10µM. The 20% DMSO positive control also resulted in 0% survival. However, in the 3- dimensional scaffold culture, exposure to 10 µM GSK for 24hr resulted in a mean survival of OCI-AML-3 cells of 27% (100 cells counted/ well) which was similar to the 20% DMSO positive control (32%) and significantly different to the negative (no GSK) control (95%; p &amp;lt; 0.01). Follicles exposed to GSK appeared alive, emitting a strong green fluorescence for both oocyte and granulosa cells, although some of the surface follicular cells were dead. Live/dead staining of GSK exposed follicles was similar to follicles not exposed to GSK. In contrast, the majority of the follicular cells were dead following exposure to 20% DMSO. Limitations, reasons for caution Due to whole mount assessment of the follicles for live/dead staining, it is difficult to determine whether the oocyte is alive. In scaffold culture some of the free cells present may be of follicular origin, potentially resulting in overestimation of the proportion of AML cells alive after GSK treatment. Wider implications of the findings This 3- dimensional culture system, incorporating a follicle and a leukemic cell line within a scaffold provides a good model to assess the impact of chemotherapy on both cell types and could be applicable for human follicles. Trial registration number Not applicable

Single-cell transcriptomic profiling unveils insights into ovarian fibrosis in obese mice

BackgroundAdiposity profoundly impacts reproductive health in both humans and animals. However, the precise subpopulations contributing to infertility under obese conditions remain elusive.ResultsIn this study, we established an obese mouse model through an eighteen-week high-fat diet regimen in adult female mice. Employing single-cell RNA sequencing (scRNA-seq), we constructed a comprehensive single-cell atlas of ovarian tissues from these mice to scrutinize the impact of obesity on the ovarian microenvironment. ScRNA-seq revealed notable alterations in the microenvironment of ovarian tissues in obese mice. Granulosa cells, stromal cells, T cells, and macrophages exhibited functional imbalances compared to the control group. We observed heightened interaction strength in the SPP1-CD44 pairing within lgfbp7+ granulosa cell subtypes and Il1bhigh monocyte subtypes in the ovarian tissues of obese mice. Moreover, the interaction strength between Il1bhigh monocyte subtypes and Pdgfrb+ stromal cell subtypes in the form of TNF − TNFrsf1α interaction was also enhanced subsequently to obesity, potentially contributing to ovarian fibrosis pathogenesis.ConclusionsWe propose a model wherein granulosa cells secrete SPP1 to activate monocytes, subsequently triggering TNF-α secretion by monocytes, thereby activating stromal cells and ultimately leading to the development of ovarian fibrosis. Intervening in this process may represent a promising avenue for improving clinical outcomes in fertility treatments for obese women.

Rapamycin-encapsulated nanoparticle delivery in polycystic kidney disease mice

Rapamycin slows cystogenesis in murine models of polycystic kidney disease (PKD) but failed in clinical trials, potentially due to insufficient drug dosing. To improve drug efficiency without increasing dose, kidney-specific drug delivery may be used. Mesoscale nanoparticles (MNP) selectively target the proximal tubules in rodents. We explored whether MNPs can target cystic kidney tubules and whether rapamycin-encapsulated-MNPs (RapaMNPs) can slow cyst growth in Pkd1 knockout (KO) mice. MNP was intravenously administered in adult Pkd1KO mice. Serum and organs were harvested after 8, 24, 48 or 72 h to measure MNP localization, mTOR levels, and rapamycin concentration. Pkd1KO mice were then injected bi-weekly for 6 weeks with RapaMNP, rapamycin, or vehicle to determine drug efficacy on kidney cyst growth. Single MNP injections lead to kidney-preferential accumulation over other organs, specifically in tubules and cysts. Likewise, one RapaMNP injection resulted in higher drug delivery to the kidney compared to the liver, and displayed sustained mTOR inhibition. Bi-weekly injections with RapaMNP, rapamycin or vehicle for 6 weeks resulted in inconsistent mTOR inhibition and little change in cyst index, however. MNPs serve as an effective short-term, kidney-specific delivery system, but long-term RapaMNP failed to slow cyst progression in Pkd1KO mice.