Similar Datasets
Project description:Single cell RNAseq of Old (19 month) and Young (3 month) mouse brain endothelial cells isolated from hippocampi of C57BL6 males.
2019-03-07 | GSE127963 | GEO
Project description:An aged circulatory environment can activate microglia, reduce neural precursor cell activity and impair cognition in mice. We hypothesized that brain endothelial cells (BECs) mediate at least some of these effects. We observe that BECs in the aged mouse hippocampus express an inflammatory transcriptional profile with focal upregulation of vascular cell adhesion molecule 1 (VCAM1), a protein that facilitates vascular-immune cell interactions. Concomitantly, levels of the shed, soluble form of VCAM1 are prominently increased in the plasma of aged humans and mice, and their plasma is sufficient to increase VCAM1 expression in cultured BECs and the hippocampi of young mice. Systemic administration of anti-VCAM1 antibody or genetic ablation of Vcam1 in BECs counteracts the detrimental effects of plasma from aged individuals on young brains and reverses aging aspects, including microglial reactivity and cognitive deficits, in the brains of aged mice. Together, these findings establish brain endothelial VCAM1 at the blood-brain barrier as a possible target to treat age-related neurodegeneration.
| S-EPMC6642642 | biostudies-literature
Project description:Aged blood impairs hippocampal neural precursor activity and activates microglia via brain endothelial cell VCAM1
| PRJNA525299 | ENA
Project description:Aged blood impairs hippocampal neural precursor activity and activates microglia via brain endothelial cell VCAM1
| PRJNA525880 | ENA
Project description:Discrete calcium signals within the vascular endothelium decrease with age and contribute to impaired endothelial-dependent vasodilation. Calreticulin (Calr), a multifunctional calcium binding protein and endoplasmic reticulum (ER) chaperone, can mediate calcium signals and vascular function within the endothelial cells (ECs) of small resistance arteries. We found Calr protein expression significantly decreases with age in mesenteric arteries and examined the functional role of EC Calr in vasodilation and calcium mobilization in the context of aging. Third-order mesenteric arteries from mice with or without EC Calr knockdown were examined for calcium signals and constriction to phenylephrine (PE) or vasodilation to carbachol (CCh) after 75 wk of age. PE constriction in aged mice with or without EC Calr was unchanged. However, calcium signals and vasodilation to endothelial-dependent agonist carbachol were significantly impaired in aged EC Calr knockdown mice. Ex vivo incubation of arteries with the ER stress inhibitor tauroursodeoxycholic acid (TUDCA) significantly improved vasodilation in mice lacking EC Calr. Our data suggests diminished vascular Calr expression with age can contribute to the detrimental effects of aging on endothelial calcium regulation and vasodilation.NEW & NOTEWORTHY Calreticulin (Calr) is responsible for key physiological processes in endoplasmic reticulum, especially in aging tissue. In particular, endothelial Calr is crucial to vascular function. In this study, we deleted Calr from the endothelium and aged the mice up to 75 wk to examine changes in vascular function. We found two key differences: 1) calcium events in endothelium were severely diminished after muscarinic stimulation, which 2) corresponded with a dramatic decrease in muscarinic vasodilation. Remarkably, we were able to rescue the effect of Calr deletion on endothelial-dependent vasodilatory function using tauroursodeoxycholic acid (TUDCA), an inhibitor of endoplasmic reticulum stress that is currently in clinical trials.
| S-EPMC7346539 | biostudies-literature
Project description:Alterations in adult hippocampal neurogenesis have been observed in numerous neurological diseases that contain a neuroinflammatory component. Interleukin-1? (IL-1?) is a pro-inflammatory cytokine that contributes to neuroinflammation in many CNS disorders. Our previous results reveal a severe reduction in adult hippocampal neurogenesis due to focal and chronic expression of IL-1? in a transgenic mouse model, IL-1?(XAT), that evokes a complex neuroinflammatory response. Other investigators have shown that IL-1? can bind directly to neural precursors to cause cell cycle arrest in vitro. In order to observe if IL-1 signaling is necessary in vivo, we conditionally knocked out MyD88, an adapter protein essential for IL-1 signaling, in nestin(+) neural precursor cells (NPCs) in the presence of IL-1?-dependent inflammation. Our results show that conditional knockout of MyD88 does not prevent IL-1?-induced reduction in neuroblasts using a genetic fate mapping model. Interestingly, MyD88 deficiency in nestin(+) NPCs causes an increase in the number of astrocytes in the presence of IL-1?, suggesting that MyD88-dependent signaling is important in limiting astroglial differentiation due to inflammation. MyD88 deficiency does not alter the fate of NPCs in the absence of inflammation. Furthermore, the inflammatory milieu due to IL-1? is not affected by the absence of MyD88 in nestin(+) NPCs. These results show that sustained IL-1? causes a reduction in adult hippocampal neurogenesis that is independent of MyD88-dependent signaling in nestin(+) NPCs, suggesting an indirect negative effect of IL-1? on neurogenesis.
| S-EPMC3686979 | biostudies-literature
Project description:Oxygen tension is critical for proliferation of human and murine midbrain-derived neural precursor cells (mNPCs). Here, we conditionally inactivated the hypoxia-responsive transcription factor hypoxia-inducible factor-1alpha (HIF-1alpha) in murine NPCs to determine its role in proliferation, survival, and dopaminergic differentiation in vitro as well as survival of murine dopaminergic neurons in vivo. HIF-1alpha conditional knock-out (HIF-1alpha CKO) mNPCs showed midbrain-specific impairment of survival and proliferation. Dopaminergic differentiation of HIF-1alpha CKO mNPCs in vitro was markedly reduced. Expression of vascular endothelial growth factor (VEGF) mRNA was reduced in HIF-1alpha CKO mNPCs, whereas erythropoietin signaling was not affected. Treatment of HIF-1alpha CKO mNPCs with 50 ng/ml VEGF partially recovered proliferation and dopaminergic differentiation in vitro. In substantia nigra (SN) of adult HIF-1alpha CKO mice, protein levels of dopaminergic marker molecules such as tyrosine hydroxylase (TH) and aldehyde dehydrogenase were reduced by 41 and 61%, respectively. The cell survival marker Bcl-2 was reduced by 58% while caspase-3 was activated. Nonbiased stereological cell counts of TH-positive neurons in SN of young adult HIF-1alpha CKO mice revealed a reduction of 31% compared with cre/wt mice (in which the wild-type Hif1a allele is expressed in parallel with the Cre recombinase allele). However, we found no impairment of striatal dopamine concentrations or locomotor behavior. In conclusion, HIF-1alpha seems to be a transcription factor relevant to the development and survival of substantia nigra dopaminergic neurons involving VEGF signaling.
| S-EPMC6672078 | biostudies-literature
Project description:We carried out a global survey of age-related changes in mRNA levels in the C57BL/6NIA mouse hippocampus and found a difference in the hippocampal gene expression profile between 2-month-old young mice and 15-month-old middle-aged mice correlated with an age-related cognitive deficit in hippocampal-based explicit memory formation. Middle-aged mice displayed a mild but specific deficit in spatial memory in the Morris water maze. Keywords: age comparison
2006-06-20 | GSE5078 | GEO
Project description:Obesity increases risk of age-related cognitive decline and is accompanied by peripheral inflammation. Studies in rodent models of obesity have demonstrated that impaired hippocampal function correlates with microglial activation, but the possibility that neuron/microglia interactions might be perturbed in obesity has never been directly examined. The goal of this study was to determine whether high fat diet-induced obesity promotes synaptic stripping by microglia, and whether any potential changes might be reversible by a return to low-fat diet (LFD). Time course experiments revealed that hippocampal inflammatory cytokine induction and loss of synaptic protein expression were detectable after three months of HFD, therefore subsequent groups of mice were maintained on HFD for three months before being switched to LFD for an additional two months on LFD (HFD/LFD). Additional HFD mice continued to receive HFD during this period (HFD/HFD), while another group of mice were maintained on LFD throughout the experiment (LFD/LFD). Dietary obesity impaired hippocampus-dependent memory, reduced long-term potentiation (LTP), and induced expression of the activation marker major histocompatibility complex II (MHCII) in hippocampal microglia. Diet reversal only partially attenuated increases in adiposity in HFD/LFD mice, but plasticity deficits and MHCII induction were normalized to within the range of LFD/LFD mice. Microglial activation and deficits in hippocampal function were accompanied by perturbation of spatial relationships between microglial processes and synaptic puncta. Analysis of primary microglia isolated from HFD/HFD mice revealed selective increases in internalization of synaptosomes labeled with a pH-sensitive fluorophore. Taken together, these findings indicate that dietary obesity reversibly impairs hippocampal function, and that deficits may be attributable to synaptic stripping by microglia.
| S-EPMC4679537 | biostudies-literature
Project description:Adult neurogenesis is a dynamic process by which newly activated neural stem cells (NSCs) in the subgranular zone (SGZ) of the dentate gyrus (DG) generate new neurons, which integrate into an existing neural circuit and contribute to specific hippocampal functions. Importantly, adult neurogenesis is highly susceptible to environmental stimuli, which allows for activity-dependent regulation of various cognitive functions. A vast range of neural circuits from various brain regions orchestrates these complex cognitive functions. It is therefore important to understand how specific neural circuits regulate adult neurogenesis. Here, we describe a protocol to manipulate neural circuit activity using designer receptor exclusively activated by designer drugs (DREADDs) technology that regulates NSCs and newborn progeny in rodents. This comprehensive protocol includes stereotaxic injection of viral particles, chemogenetic stimulation of specific neural circuits, thymidine analog administration, tissue processing, immunofluorescence labeling, confocal imaging, and imaging analysis of various stages of neural precursor cells. This protocol provides detailed instructions on antigen retrieval techniques used to visualize NSCs and their progeny and describes a simple, yet effective way to modulate brain circuits using clozapine N-oxide (CNO) or CNO-containing drinking water and DREADDs-expressing viruses. The strength of this protocol lies in its adaptability to study a diverse range of neural circuits that influence adult neurogenesis derived from NSCs.
| S-EPMC7365713 | biostudies-literature