Both cellular senescence and organismic aging are known to be dynamic processes that start early in life and progress constantly during the whole life of the individual. In this work, with the objective of identifying signatures of age-related progressive change at the transcriptomic level, we have performed a whole-genome gene expression analysis of peripheral blood leukocytes in a group of healthy individuals with ages ranging from 14 to 93 years. A set of genes with progressively changing gene expression (either increase or decrease with age) has been identified and contextualized in a coexpression network. A modularity analysis has been performed on this network and biological-term and pathway enrichment analyses have been used for biological interpretation of each module. In summary, the results of the present work reveal the existence of a transcriptomic component that shows progressive expression changes associated to age in peripheral blood leukocytes, highlighting both the dynamic nature of the process and the need to complement young vs. elder studies with longitudinal studies that includes middle aged individuals. From the transcriptional point of view, immunosenescence seems to be occurring from a relatively early age, at least from the late 20s/early 30s, and the 49 56 y/o age-range appears to be critical. In general, the genes that, according to our results, show progressive expression changes with aging are involved in pathogenic/cellular processes that have classically been linked to aging in humans: cancer, immune processes and cellular growth vs. maintenance.
Age gene expression and coexpression progressive signatures in peripheral blood leukocytes.
Age, Specimen part
View SamplesMyotonic dystrophes (DM), the most common adult muscular dystrophy, are the first recognized examples of RNA-mediated diseases in which expression of mutant RNAs containing expanded CUG or CCUG repeats interfere with the splicing of other mRNAs. Using whole-genome microarrays, we found that alternative splicing of the BIN1 mRNA is altered in DM skeletal muscle tissues, resulting in the expression of an inactive form of BIN1 deprived of phosphoinositide-binding and membrane-tubulating activities. BIN1 is involved in tubular invaginations of the plasma membrane and is essential for biogenesis of the muscle T-tubules, which are specialized skeletal muscle membrane structures essential to correct excitation-contraction (E-C) coupling. Mutations in the BIN1 gene cause centronuclear myopathy (CNM) that shares some histopathological features with DM, and both diseases are characterized by muscle weakness. Consistent with a loss-of-function of BIN1, muscle T-tubules were altered in DM patients, and membrane tubulation was restored upon expression of the correct splicing form of BIN1 in DM muscle cells. By deciphering the mechanism of BIN1 splicing mis-regulation we demonstrate that the splicing regulator, MBNL1, which is sequestered by expanded CUG and CCUG in DM, binds the BIN1 pre-mRNA and regulates directly its alternative splicing. Finally, reproducing BIN1 splicing alteration in mice is sufficient to reproduce the DM features of T-tubule alterations and muscle weakness. We propose that alteration of BIN1 alternative splicing regulation leads to muscle weakness, a predominant pathological feature of DM.
Misregulated alternative splicing of BIN1 is associated with T tubule alterations and muscle weakness in myotonic dystrophy.
Specimen part
View SamplesAging is a major risk factor for many neurological pathologies, including Alzheimer's disease (AD). However, the mechanisms underlying brain aging and cognitive decline remain elusive. Body tissues are perfused by interstitial fluid (ISF), which is locally reabsorbed via the lymphatic vascular network. In contrast, the parenchyma of the central nervous system (CNS) is devoid of lymphatic vasculature; in the brain, removal of cellular debris and toxic molecules, such as amyloid beta (A?) peptides, is mediated by a combination of transcellular mechanisms of transport across the blood-brain and blood-cerebrospinal fluid (CSF) barriers, phagocytosis and digestion by resident microglia and recruited monocytes/macrophages, and CSF influx and ISF efflux through a paravascular route. The recent characterization of meningeal lymphatic vessels prompted a reassessment of the conventional pathways of CNS waste clearance. The role of this vasculature in brain function, specifically in the context of aging and AD, is still poorly understood. Here we show that meningeal lymphatic vessels play an essential role in maintaining brain homeostasis by draining macromolecules from the CNS (CSF and ISF) into the cervical lymph nodes. Using pharmacological, surgical, and genetic models we show that impairment of meningeal lymphatic function in adult mice slows paravascular influx of CSF macromolecules and efflux of ISF macromolecules, and induces cognitive impairment. Treatment with a lymphangiogenic factor, vascular endothelial growth factor C (VEGF-C), enhances meningeal lymphatic drainage of CSF macromolecules, improving brain perfusion and learning and memory performance in aged mice. Disruption of meningeal lymphatic vessels in transgenic mouse models of AD promotes amyloid deposition in the meninges, which closely correlates with human meningeal pathology, and aggravates overall disease severity. Our findings suggest that meningeal lymphatic dysfunction may be an aggravating factor in AD pathology and in age-associated cognitive decline. Thus, augmentation of meningeal lymphatic function might be a promising therapeutic target for preventing or delaying age-associated neurological diseases. Overall design: Male C57BL/6J mice (2 months-old) were injected (intra-cisterna magna) with Visudyne (verteporfin for injection), or vehicle as control, and submitted to a step of photoconversion, to induce meningeal lymphatic vessel ablation. This procedure was repeated 2 weeks later to ensure prolonged meningeal lymphatic dysfunction. 2 weeks after the last surgical procedure, mice were subjected to the MWM test. 3 days after, whole hippocampus was macrodissected and total RNA was extracted for sequencing.
Functional aspects of meningeal lymphatics in ageing and Alzheimer's disease.
Age, Specimen part, Cell line, Treatment, Subject
View SamplesAging is a major risk factor for many neurological pathologies, including Alzheimer's disease (AD). However, the mechanisms underlying brain aging and cognitive decline remain elusive. Body tissues are perfused by interstitial fluid (ISF), which is locally reabsorbed via the lymphatic vascular network. In contrast, the parenchyma of the central nervous system (CNS) is devoid of lymphatic vasculature; in the brain, removal of cellular debris and toxic molecules, such as amyloid beta (A?) peptides, is mediated by a combination of transcellular mechanisms of transport across the blood-brain and blood-cerebrospinal fluid (CSF) barriers, phagocytosis and digestion by resident microglia and recruited monocytes/macrophages, and CSF influx and ISF efflux through a paravascular route. The recent characterization of meningeal lymphatic vessels prompted a reassessment of the conventional pathways of CNS waste clearance. The role of this vasculature in brain function, specifically in the context of aging and AD, is still poorly understood. Here we show that meningeal lymphatic vessels play an essential role in maintaining brain homeostasis by draining macromolecules from the CNS (CSF and ISF) into the cervical lymph nodes. Using pharmacological, surgical, and genetic models we show that impairment of meningeal lymphatic function in adult mice slows paravascular influx of CSF macromolecules and efflux of ISF macromolecules, and induces cognitive impairment. Treatment with a lymphangiogenic factor, vascular endothelial growth factor C (VEGF-C), enhances meningeal lymphatic drainage of CSF macromolecules, improving brain perfusion and learning and memory performance in aged mice. Disruption of meningeal lymphatic vessels in transgenic mouse models of AD promotes amyloid deposition in the meninges, which closely correlates with human meningeal pathology, and aggravates overall disease severity. Our findings suggest that meningeal lymphatic dysfunction may be an aggravating factor in AD pathology and in age-associated cognitive decline. Thus, augmentation of meningeal lymphatic function might be a promising therapeutic target for preventing or delaying age-associated neurological diseases. Overall design: Male C57BL/6J mice (2 months-old) were injected (intra-cisterna magna) with Visudyne (verteporfin for injection), or vehicle as control, and submitted to a step of photoconversion, to induce meningeal lymphatic vessel ablation. This procedure was repeated 2 weeks later to ensure prolonged meningeal lymphatic dysfunction. 2 weeks after the last surgical procedure, whole hippocampus was macrodissected and total RNA was extracted for sequencing.
Functional aspects of meningeal lymphatics in ageing and Alzheimer's disease.
Age, Specimen part, Cell line, Treatment, Subject
View SamplesAging is a major risk factor for many neurological pathologies, including Alzheimer's disease (AD). However, the mechanisms underlying brain aging and cognitive decline remain elusive. Body tissues are perfused by interstitial fluid (ISF), which is locally reabsorbed via the lymphatic vascular network. In contrast, the parenchyma of the central nervous system (CNS) is devoid of lymphatic vasculature; in the brain, removal of cellular debris and toxic molecules, such as amyloid beta (A?) peptides, is mediated by a combination of transcellular mechanisms of transport across the blood-brain and blood-cerebrospinal fluid (CSF) barriers, phagocytosis and digestion by resident microglia and recruited monocytes/macrophages, and CSF influx and ISF efflux through a paravascular route. The recent characterization of meningeal lymphatic vessels prompted a reassessment of the conventional pathways of CNS waste clearance. The role of this vasculature in brain function, specifically in the context of aging and AD, is still poorly understood. Here we show that meningeal lymphatic vessels play an essential role in maintaining brain homeostasis by draining macromolecules from the CNS (CSF and ISF) into the cervical lymph nodes. Using pharmacological, surgical, and genetic models we show that impairment of meningeal lymphatic function in adult mice slows paravascular influx of CSF macromolecules and efflux of ISF macromolecules, and induces cognitive impairment. Treatment with a lymphangiogenic factor, vascular endothelial growth factor C (VEGF-C), enhances meningeal lymphatic drainage of CSF macromolecules, improving brain perfusion and learning and memory performance in aged mice. Disruption of meningeal lymphatic vessels in transgenic mouse models of AD promotes amyloid deposition in the meninges, which closely correlates with human meningeal pathology, and aggravates overall disease severity. Our findings suggest that meningeal lymphatic dysfunction may be an aggravating factor in AD pathology and in age-associated cognitive decline. Thus, augmentation of meningeal lymphatic function might be a promising therapeutic target for preventing or delaying age-associated neurological diseases. Overall design: Lymphatic endothelial cells (LECs) were isolated from meninges of adult (2-3 months-old) or old (20-24 months-old) male C57BL/6 mice. Cells were sorted by FACS according to the following phenotype: CD45-CD31+PDPN+.
Functional aspects of meningeal lymphatics in ageing and Alzheimer's disease.
Specimen part, Cell line, Subject
View SamplesWhile VEGF-targeted therapies are showing promise in clinical studies, new angiogenesis targets are needed to make additional gains. Here, we show that increased Zeste homologue 2 (EZH2) expression in either tumor cells or in tumor vasculature is predictive of poor clinical outcome. The increase in endothelial EZH2 is a direct result of VEGF stimulation and indicates the presence of a paracrine circuit that promotes angiogenesis by methylating and silencing vasohibin 1 (VASH1). EZH2 silencing in the tumor-associated endothelial cells resulted in inhibition of angiogenesis mediated by reactivation of VASH1, and reduced ovarian cancer growth. Combined, these data provide a new understanding of the regulation of tumor angiogenesis and support the potential for targeting EZH2 as a novel therapeutic approach.
Regulation of tumor angiogenesis by EZH2.
No sample metadata fields
View SamplesOver the last years, evidence has grown that exposure to air pollution, in addition to impairing lung function and health in individuals of all age, can be linked to negative effects in newborn when present during pregnancy. Data suggests that intrauterine exposure of fetuses (exposure of the mother to air pollution during pregnancy) in fact exerts a negative impact on lung development. However, the means by which exposure during pregnancy affects lung development, have not been studied in depth yet. In this study, we investigated alterations of the transcriptome of the developing lung in a mouse model of gestational and early-life postnatal exposure to urban PM2.5 (from Sao Paulo, Brazil).
Pre- and postnatal exposure of mice to concentrated urban PM<sub>2.5</sub> decreases the number of alveoli and leads to altered lung function at an early stage of life.
Specimen part
View SamplesDynamic gene expression in the PSM of vertebrates is critical for the spatial and temporal patterning of somites.
Dynamic CREB family activity drives segmentation and posterior polarity specification in mammalian somitogenesis.
Specimen part
View SamplesPublic information is widely available at low cost to animals living in social groups. For instance, bystanders may eavesdrop on signaling interactions between conspecifics and use it to adapt their subsequent behavior towards the observed individuals. This social eavesdropping ability is expected to require specialized mechanisms such as social attention, which selects social information available for learning. To begin exploring the genetic basis of social eavesdropping, we used a previously established attention paradigm in the lab to study the brain gene expression profile of male zebrafish in relation to the attention they have paid towards conspecifics involved or not involved in agonistic interactions. Microarray gene chips were used to characterize their brain transcriptomes based on differential expression of single genes and gene sets. These analyses were complemented by promoter region-based techniques. Using data from both approaches, we further drafted protein interaction networks. Our results suggest that attentiveness towards conspecifics, whether interacting or not, activates pathways linked to neuronal plasticity and memory formation. The network analyses suggested that fos and jun are key players on this response, and that npas4a, nr4a1 and egr4 may also play an important role.
Brain Transcriptomic Response to Social Eavesdropping in Zebrafish (Danio rerio).
Sex, Specimen part, Treatment
View SamplesHistone acetylation and other modifications of the chromatin are important regulators of gene expression and, consequently, may contribute to drug-induced behaviors and neuroplasticity. Previous studies have shown that a reduction on histone deacetylase (HDAC) activity results on the enhancement of some psychostimulant-induced behaviors. In the present study, we extend those seminal findings by showing that the administration of the HDAC inhibitor sodium butyrate enhances morphine-induced locomotor sensitization and conditioned place preference. In contrast, this compound has no effects on the development of morphine tolerance and dependence. Similar effects were observed for cocaine and ethanol-induced behaviors. These behavioral changes were accompanied by a selective boosting of a component of the transcriptional program activated by chronic morphine administration that included circadian clock genes and other genes relevant in addictive behavior. Our results support an specific role for histone acetylation and the epigenetic modulation of transcription at a reduced number of biologically relevant loci on non-homeostatic, long lasting, drug-induced behavioral plasticity. To further investigate the molecular bases of sodium butyrate action on long-lasting behavioral responses to morphine, we screened for potential substrates of their interaction by performing a genome-wide comparison of the striatal transcriptome after chronic administration of morphine in the absence or presence of sodium butyrate.
Selective boosting of transcriptional and behavioral responses to drugs of abuse by histone deacetylase inhibition.
Sex, Age, Specimen part
View Samples