Search Results (176)

The purpose of this work was to study the effects of lactoferrin (Lf) on acute (days 3 and 15) and early-delayed (day 30) changes in the dentate gyrus of mouse hippocampus caused by whole-body gamma-irradiation. Male C57BL/6 mice received Lf (4 mg per mouse, i.p. injection) immediately after whole-body gamma-irradiation at a dose of 7.5 Gy from a ⁶⁰Co source. The effect of Lf on mouse behavior was evaluated using “Open field” and “Elevated plus-maze” tests. The proportion of cells with DNA replication was determined by 5-ethynyl-2′-deoxyuridine incorporation (thymidine analog) and detected by a click reaction with azide Alexa Fluor 568. Lf treatment increased animal survival during the experiment (30 days), compensated for radiation-induced body weight loss, and prevented suppression of motor and exploratory activities. A pronounced anti-radiation effect of Lf on mouse brain cells has been demonstrated. A single injection of the protein allowed preserving 2-fold more proliferating cells and immature neurons in the dentate gyrus of the hippocampus of irradiated animals during the acute period of post-radiation injury development. Full article

Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is a severe X-linked neurodevelopmental condition characterized by early-onset, intractable epilepsy, motor and cognitive impairment, and autistic-like features. Although constitutive Cdkl5 knockout (KO) models have established the importance of CDKL5 during early brain development, CDKL5’s role in the mature brain remains poorly defined. Here, we employed an inducible, conditional KO model in which Cdkl5 is selectively deleted from forebrain glutamatergic neurons in adult mice to investigate the postdevelopmental functions of CDKL5. Using a total of 48 adult male mice, including Cdkl5^flox/Y(Cre⁺) (n = 30) and Cdkl5^flox/Y(Cre⁻) littermate controls (n = 18), we found that tamoxifen-induced Cdkl5 deletion led to prominent behavioral impairments, including deficits in motor coordination, reduced sociability, and impaired hippocampus-dependent spatial memory, while behavioral features such as hyperactivity and stereotypic jumping, typically present in germline KOs, were absent. Sensory functions, including olfaction and pain perception, were also preserved. At the cellular level, the loss of Cdkl5 resulted in a marked reduction in excitatory synapse density in the cortex and hippocampus, accompanied by increased numbers of immature dendritic spines and decreased mature spines. Neuronal loss in the hippocampal CA1 region and selective microglial activation in the cortex were also observed. These alterations closely resemble those seen in constitutive KO models, underscoring the ongoing requirement for CDKL5 expression in excitatory neurons for maintaining synaptic integrity and neuronal homeostasis in the adult brain. This study underscores the importance of temporally controlled models for investigating the mechanisms underlying CDD pathophysiology in the adult brain. Full article

Familial hypercholesterolemia leads to the early development of cardiovascular diseases at a young age due to the prolonged exposure of the arterial vessel wall to high concentrations of atherogenic lipids. Serotonin plays a significant role in the development and progression of atherosclerotic processes. Monoamine has a damaging effect on the vascular wall, stimulates the proliferation of vascular smooth muscle cells and fibroblasts, and participates in platelet activation and aggregation. The aim of the work was the demonstration of the importance of serotonin, transporters, and receptors in the pathogenesis of atherosclerotic plaque formation. The study was performed on immature mice of the C57BL/6JGpt-Ldlr^em1Cd82/Gpt (Ldlr^+/−) line (main group) and C57BL/6 mice of comparable age and sex demographics (control group). Morphological manifestations of early signs of atherosclerosis (pre-lipid stage and lipoidosis stage, which were confirmed by Sudan III staining) in the gene-modified mice’s aorta were determined. Morphological changes in the aorta correlated with changes in the left ventricle of the heart, where lipid content also increased. No atherosclerotic changes in the control-group mice were detected. A statistically significant increase in the expression of the membrane serotonin transporter and 5HT2A and 5HT2B receptors in both the aorta and left ventricle was also found in the animals of the main group. Serotonin and its receptors and transporter may become new therapeutic targets for the treatment and prevention of atherosclerotic vascular lesion progression in children and adults. Full article

Mature dendritic cells (DCs) are known to activate effector immune responses, whereas steady state immature DCs can induce tolerance. Several studies have targeted immature murine quiescent DCs in vivo with antigen, including donor alloantigens, for the induction of tolerance. Receptors expressed by specific DC subsets have been also targeted with antibodies linked with antigens to induce tolerance; for instance, in vivo targeting of the DCIR2⁺ DC subset with donor alloantigen resulted in long-term survival of heart and skin transplants. DCs also express sialic acid immunoglobulin-like lectin (Siglec) receptors, and these have been successfully targeted with myelin oligiodendrocyte glycoprotein (MOG) antigen to induce tolerance in experimental autoimmune encephalomyelitis (EAE). We investigated, in a mismatched model of skin transplant (B6K^d into B6 recipient mice), whether targeting a sialylated alloantigen K^d (Sia-K^d) to Siglecs on recipient DCs promoted transplant survival. The injection of α2,3 Sia-K^d into B6 recipient mice prior to B6K^d skin transplantation, by binding to Batf3 dependent DCs, resulted in prolonged skin graft survival and an increase in CD4⁺CD62L⁺Foxp3⁺ Tregs. Targeting Siglecs on DC subsets in vivo represents a novel way of improving transplant survival. Full article

Background: Myeloid-derived suppressor cells (MDSCs) contribute to immune suppression observed in chronic lymphocytic leukemia (CLL). MDSCs are immature myeloid cells that are hijacked during development and further reprogrammed by the tumor microenvironment (TME) to harbor immune-suppressive properties and inhibit T-cell functions. Bromodomain and extraterminal domain (BET) proteins, including BRD4, are epigenetic modulators that regulate genes implicated in CLL pathogenesis and TME interactions. Previously, we investigated how the novel BET inhibitor OPN-51107 (OPN5) prevents CLL disease expansion, modulates T-cell immune function, and alters gene expression related to MDSCs. In turn, we hypothesize that BET proteins such as BRD4 regulate MDSC functions, and subsequent pharmacological inhibition of BRD4 will alleviate MDSC-mediated immune suppression in CLL. Methods: Utilizing the Eµ-TCL1 mouse model of CLL, we evaluated BRD4 protein expression in MDSCs derived from the bone marrow of transgenic and age-matched wild-type (WT) mice. We then investigated the ex vivo functionality of OPN5-treated MDSCs, expanded from Eµ-TCL1 and WT bone marrow in MDSC-supportive medium. Finally, we conducted an in vivo study utilizing the Eµ-TCL1 adoptive transfer mouse model to determine the in vivo effects of OPN5 on MDSCs and other immune populations. Results: Through the course of this study, we found that MDSCs isolated from Eμ-TCL1 mice upregulate BRD4 expression and are more immune-suppressive than their WT counterparts. Furthermore, we demonstrated ex vivo OPN5 treatment reverses the immune-suppressive capacity of MDSCs isolated from leukemic mice, evident via enhanced T-cell proliferation and IFNγ production. Finally, we showed in vivo OPN5 treatment slows CLL disease progression and modulates immune cell populations, including MDSCs. Conclusions: Altogether, these data support BET inhibition as a useful therapeutic approach to reverse MDSC-mediated immune suppression in CLL. Full article

In adults, expressed in renal cancer (ERC)/mesothelin is exclusively expressed in the mesothelial cells lining the pleural, pericardial, and peritoneal cavities, yet its function under physiological conditions is unknown. To explore this, we studied ERC expression in wild-type (WT) mice at different developmental stages by immunohistochemistry and analyzed the ultrastructure of the mesothelium in WT and Erc-knockout (KO) mice via electron microscopy. Additionally, cardiopulmonary function in adult WT and Erc-KO mice was assessed using echocardiography and the forced oscillation technique (FOT). During embryonic development in WT mice, ERC expression was detected in the epicardium as early as embryonic day (E)12.5 but was absent in the pleura until E18.5. The timing of expression appeared to coincide with the active maturation of these organs, which implied a potential role in cardiopulmonary development. Electron microscopy revealed that microvilli on the mesothelium of Erc-KO mice were immature compared to those of WT mice. Based on these findings, we hypothesized that ERC might contribute to cardiopulmonary function; however, echocardiography and FOT did not reveal any functional differences between WT and Erc-KO mice. This suggests that ERC has limited functional relevance under physiological conditions. Full article

Background: GABAergic signaling plays a crucial role in modulating neuronal proliferation, migration, and the formation of neural network connections. The termination of GABA transmission primarily occurs through the action of GABA transporter 1 (GAT1), encoded by the SLC6A1 gene. Multiple SLC6A1 mutations have been implicated in neurodevelopmental disorders, but their effects on the nervous system are unclear. Methods: We estimated the expression pattern of the GAT1 (S295L) protein using the Slc6a1^S295L/S295L mouse model via RT-PCR, Western blotting, and confocal immunofluorescence. The effect of GAT1 (S295L) on hippocampal neurogenesis was investigated by neuronal marker staining (Sox2, Tbr2, NeuroD1, DCX, NeuN) and BrdU label experiments. The dendritic complexity was mapped through Sholl analysis. RNA-Seq was utilized to explore the signaling pathways and molecules associated with neurodevelopmental disorders. Results: We detected a remarkable decline in the quantity of type-2b intermediate progenitor cells, neuroblasts, and immature neurons in the dentate gyrus (DG) of Slc6a1^S295L/S295L mice at 4 weeks. These abnormalities were exacerbated in adulthood, as evidenced by compromised dendritic length and height as well as the complexity of immature neurons. Immunofluorescence staining showed the abnormal aggregation of GAT1 (S295L) protein in neurons. RNA-seq analysis identified pathways associated with neurodevelopment, neurological disorders, protein homeostasis, and neuronutrition. The neurotrophin Bdnf decreased at all ages in the Slc6a1^S295L/S295L mice. Conclusions: Our data provide new evidence that GAT1 (S295L) causes impaired neurogenesis in the DG. GAT1 mutation not only disrupts GABA homeostasis but also impairs the neurotrophic support necessary for normal hippocampal development, which may be one of the factors contributing to impaired neurogenesis. Full article

Host microbiota may impact disease vector behavior and pathogen transmission, but little is known about associations between ectoparasites and microbial communities in wildlife reservoir species. We used Illumina metagenomic sequencing to explore the impacts of tick parasitism on the rodent fecal microbiome in both a field and laboratory setting. We found that tick parasitism on wild hosts was associated with variation in the fecal microbiota of both the white-footed deermouse, Peromyscus leucopus, and the southern cotton rat, Sigmodon hispidus. In a lab experiment, we detected significant changes to the fecal microbiome after experimental exposure to immature ticks in treated versus control BALB/c mice. Whereas there is variation in the fecal microbiome associated with each of the host species we tested, some of the same microbial taxa, notably members of the family Muribaculaceae, occurred at higher relative abundance in tick-parasitized hosts in both the field and laboratory studies, suggesting that there are consistent impacts of tick parasitism on the host gut microbiome. We recommend future studies to test the hypothesis that epithelial cell secretions, generated as part of the host’s immune response to tick parasitism, could provide resources that allow particular microbial lineages in the mammalian gut to flourish. Full article

Schistosoma japonicum eggs in the host liver form granuloma and liver fibrosis and then lead to portal hypertension and cirrhosis, seriously threatening human health. Natural killer (NK) cells can kill activated hepatic stellate cells (HSCs) against hepatic fibrosis. We used single-cell sequencing to screen hepatic NK cell subsets against schistosomiasis liver fibrosis. Hepatic NK cells were isolated from uninfected mice and mice infected for four and six weeks. The NK cells underwent single-cell sequencing. The markers’ expression in the NK subsets was detected through Reverse Transcription–Quantitative PCR (RT-qPCR). The proportion and granzyme B (Gzmb) expression of the total NK and Thy1⁺NK were detected. NK cells overexpressing Thy1 (Thy1-OE) were constructed, and functions were detected. The results revealed that the hepatic NK cells could be divided into mature, immature, regulatory-like, and memory-like NK cells and re-clustered into ten subsets. C3 (Cx3cr1⁺NK) and C4 (Thy1⁺NK) increased at week four post-infection, and other subsets decreased continuously. The successfully constructed Thy1-OE NK cells had significantly higher effector molecules and induced greater HSC apoptosis than the control NK cells. It revealed a pattern of hepatic NK cells in a mouse model of schistosomiasis. The Thy1⁺NK cells could be used as target cells against hepatic fibrosis. Full article

Our recent study revealed that continuous prenatal low-dose-rate irradiation did not induce cellular changes in the dentate gyrus of the hippocampus in male B6C3F1 mice exposed to gamma rays during prenatal development. However, changes in body weight, body mass index (BMI), locomotor ability, and mRNA and miRNA expressions in the hippocampus and blood were observed. To investigate potential sex differences in the effects of prenatal gamma irradiation, we conducted a parallel study on female B6C3F1 mice. The results showed significant reductions in the weight of the lungs and left kidney in prenatally irradiated female offspring, accompanied by significantly increased fat deposits in the mesentery, retroperitoneal, and left perigonadal areas. Despite these systemic changes, no cellular alterations were observed in the subgranular zone (immature neurons) or the hilus of the dentate gyrus (mature neurons and glial cells, including astrocytes, microglia, and oligodendrocyte progenitor cells). However, significant increases in hippocampal mRNA expression were detected for genes such as H2bc24, Fos, Cd74, Tent5a, Traip, and Sap25. Conversely, downregulation of mRNAs Inpp5j and Gdf3 was observed in whole blood. A Venn diagram highlighted the differential expression of two mRNAs, Ttn and Slc43a3, between the hippocampus and whole blood. Comparisons between prenatally irradiated male and female B6C3F1 mice revealed sex-specific differences. In whole blood, 4 mRNAs (Scd1, Cd59b, Vmn1r58, and Gm42427) and 1 miRNA (mmu-miR-8112) exhibited differential expression. In the hippocampus, 12 mRNAs and 2 novel miRNAs were differentially expressed between the sexes. qRT-PCR analysis validated the upregulation of H2bc24, Fos, Cd74, and Tent5a in the female hippocampus. These gene expression changes may be associated with the increased fat deposition observed following chronic low-dose-rate gamma irradiation exposure. This study underscores the importance of investigating sex-specific biological responses to prenatal gamma irradiation and highlights potential molecular pathways linked to observed physiological changes. Full article

Background: Epilepsy is a neurological disorder defined by the occurrence of epileptic seizures, which can significantly affect children, often leading to learning and cognitive impairments. Microglia, the resident immune cells of the central nervous system, are essential in clearing damaged neurons through phagocytosis. Notably, GAB_BR-associated microglia have been implicated in regulating phagocytic activity. Since the phagocytic function of microglia is critical in the pathogenesis of epilepsy, this study aims to investigate the role of GAB_BR-associated microglia in the development of the immature brain following epileptic seizures. Methods: Epilepsy was induced in a mouse model by the intraperitoneal injection of KA. Changes in the expression of the GAB_BR-related gene, GAB_BR2, in hippocampal microglia were analyzed using single-nucleus RNA sequencing (snRNA-seq). Cognitive and emotional changes in the mice were assessed through behavioral analyses. The expression of GAB_BR2 was semi-quantitatively measured using Western blotting, quantitative reverse transcription PCR, and immunofluorescence. Additionally, the spatial relationship between GAB_BR2 and hippocampal neurons was evaluated using Imaris software. Results: The snRNA-seq analysis revealed that GAB_BR2 expression was elevated in activated microglia in the hippocampus during chronic epilepsy compared to the early phase of seizures. Behavioral assessments demonstrated heightened anxiety levels and learning and memory impairments in the chronic epilepsy group compared to the control group. GAB_BR2 expression was upregulated in chronic epilepsy. Three-dimensional reconstruction analyses revealed a significantly increased contact volume between GAB_BR-associated microglia and neurons in the chronic epilepsy group compared to the control group. Conclusions: GAB_BR-associated microglia significantly contribute to the progression of immature brain diseases by promoting neuronal phagocytic activity. Full article

Background/Objectives: Hyperlipidemia is a serious risk factor for cardiovascular diseases and liver steatosis. In this work, we explored the effect of an herbal formula (CBF) containing immature Ceratonia siliqua pods and Ocimum basilicum extracts on lipid metabolism disorders and lipoprotein-rich plasma (LRP) oxidation in mice. Methods: The phenolic composition was determined using HPLC-DAD analysis. The antioxidant activity was studied using various in vitro methods. Acute toxicity was evaluated in mice. Importantly, the effect of the CBF on lipid metabolism disorders was investigated in a high-fat diet (HFD) hyperlipidemia mouse model. An in silico study was carried out to predict underlying mechanisms. Results: The HPLC analysis revealed gallic acid, cinnamic acid, and naringenin as major phenolics of the carob pod aqueous extract. Concerning the basil hydro-ethanolic extract, rosmarinic, chicoric, caftaric, and caffeic acids were the main phenolics. Accordingly, the CBF prevented LRP oxidation in a concentration-dependent manner. This formula is not toxic in mice (LD₅₀ > 2000 mg/kg body weight). Moreover, animals administered the CBF at 200 mg/kg/day presented a significant decline in their body weight gain, adipose tissue weight, plasma total cholesterol, low-density lipoprotein cholesterol (LDL-C) level, and glycaemia after 10 weeks’ treatment. Accordingly, the CBF decreased the plasma atherogenic index and the LDL-C to HDL-C ratio and reduced the level of fats accumulated in the liver. The molecular docking study revealed that chicoric, rosmarinic, and caftaric acids, and naringenin bound particularly strongly to many proteins involved in the regulation of lipid and cholesterol metabolism. This includes the HMG-CoA reductase, PPARα/γ, PCSK9, Cyp7a1, and ATP-citrate lyase. Conclusions: The CBF could be a good source of natural supplements, functional foods, and pharmaceuticals effective in managing hyperlipidemia and oxidative stress and preventing their related cardiovascular disorders. Full article

We previously reported that membrane-type 5-matrix metalloproteinase (MT5-MMP) deficiency not only reduces pathological hallmarks of Alzheimer’s disease (AD) in 5xFAD (Tg) mice in vivo but also impairs interleukin-1 beta (IL-1β)-mediated neuroinflammation and Aβ production in primary Tg immature neural cell cultures after 11 days in vitro. We now investigate the effect of MT5-MMP on incipient pathogenic pathways that are activated in cortical primary cultures at 21–24 days in vitro (DIV), during which time neurons are organized into a functional mature network. Using wild-type (WT), MT5-MMP^−/− (MT5^−/−), 5xFAD (Tg), and 5xFADxMT5-MMP^−/− (TgMT5^−/−) mice, we generated primary neuronal cultures that were exposed to IL-1β and/or different proteolytic system inhibitors. We assessed neuroinflammation, APP metabolism, synaptic integrity, and electrophysiological properties using biochemical, imaging and whole-cell patch-clamp approaches. The absence of MT5-MMP impaired the IL-1β-mediated induction of inflammatory genes in TgMT5^−/− cells compared to Tg cells. Furthermore, the reduced density of dendritic spines in Tg neurons was also prevented in TgMT5^−/− neurons. IL-1β caused a strong decrease in the dendritic spine density of WT neurons, which was prevented in MT5^−/− neurons. However, the latter exhibited fewer spines than the WT under untreated conditions. The spontaneous rhythmic firing frequency of the network was increased in MT5^−/− neurons, but not in TgMT5^−/− neurons, and IL-1β increased this parameter only in Tg neurons. In terms of induced somatic excitability, Tg and TgMT5^−/− neurons exhibited lower excitability than WT and MT5^−/−, while IL-1β impaired excitability only in non-AD backgrounds. The synaptic strength of miniature global synaptic currents was equivalent in all genotypes but increased dramatically in WT and MT5^−/− neurons after IL-1β. MT5-MMP deficiency decreased endogenous and overexpressed C83 and C99 levels but did not affect Aβ levels. C99 appears to be cleared by several pathways, including γ-secretase, the autophagolysosomal system, and also α-secretase, via its conversion to C83. In summary, this study confirms that MT5-MMP is a pivotal factor affecting not only neuroinflammation and APP metabolism but also synaptogenesis and synaptic activity at early stages of the pathology, and reinforces the relevance of targeting MT5-MMP to fight AD. Full article

Laboratory mice are instrumental for preclinical research but there are serious concerns that the use of a clean standardized environment for specific-pathogen-free (SPF) mice results in poor bench-to-bedside translation due to their immature immune system. The aim of the present study was to test the importance of the gut microbiota in wild vs. SPF mice for evaluating host immune responses in a house-dust-mite-induced allergic airway inflammation model without the influence of pathogens. The wild mouse microbiome reduced histopathological changes and TNF-α in the lungs and serum when transplanted to microbiota-depleted mice compared to mice transplanted with the microbiome from SPF mice. Moreover, the colonic gene expression of Gata3 was significantly lower in the wild microbiome-associated mice, whereas Muc1 was more highly expressed in both the ileum and colon. Intestinal microbiome and metabolomic analyses revealed distinct profiles associated with the wild-derived microbiome. The wild-mouse microbiome thus partly reduced sensitivity to house-dust-mite-induced allergic airway inflammation compared to the SPF mouse microbiome, and preclinical studies using this model should consider using both ‘dirty’ rewilded and SPF mice for testing new therapeutic compounds due to the significant effects of their respective microbiomes and derived metabolites on host immune responses. Full article

Multiple sclerosis (MS) is a chronic neurodegenerative disorder involving demyelination. The cuprizone model is commonly used to study MS by inducing oligodendrocyte stress and demyelination. The subventricular zone (SVZ) plays a key role in neurogenesis, while the neuronal/glial antigen 2 (NG2) is a marker for immature glial cells, involved in oligodendrocyte differentiation. The apelin receptor (APLNR) is linked to neurogenesis and behavior modulation. This study explores the role of APLNR in NG2-positive cells during de- and remyelination phases in the experimental cuprizone mouse model. Thirty male C57BL/6 mice were divided into control (not treated), demyelination (5 weeks cuprizone administration), and remyelination (5 weeks cuprizone administration + 5 weeks recovery) groups. Histological examinations, immunohistochemistry, and immunofluorescence on serial coronal sections were conducted to evaluate corpus callosum (CC) morphology and APLNR and NG2 expression in the SVZ, in addition to behavioral assessments. The histological analysis showed a significant reduction in the CC’s thickness and area after five weeks of cuprizone exposure, followed by recovery five weeks post-exposure. During the demyelination phase, APLNR-expressing cells peaked while NG2-positive cells decreased. In the remyelination phase, APLNR-expressing cells declined, and NG2-positive cells increased. Confocal microscopy confirmed the co-localization of NG2 and APLNR markers. Statistically significant differences were observed across experimental groups. Correlation analyses highlighted associations between APLNR/NG2 cell counts and CC changes. Behavioral tests revealed impaired motor coordination and memory during demyelination, with gradual recovery during remyelination. Significant changes in the CC structure and the number of APLNR and NG2-positive cells were observed during de- and remyelination, suggesting that NG2-positive cells expressing APLNR may play a key role in remyelination. Full article