Molecular mechanisms of neurogenic aging in the adult mouse subventricular zone

In the adult rodent brain, the continuous production of new neurons by neural stem/progenitor cells (NSPCs) residing in specialized neurogenic niches and their subsequent integration into pre-existing cerebral circuitries supports odour discrimination, spatial learning, and contextual memory capabilities. Aging is recognized as the most potent negative regulator of adult neurogenesis. The neurogenic process markedly declines in the aged brain, due to the reduction of the NSPC pool and the functional impairment of the remaining NSPCs. This decline has been linked to the progressive cognitive deficits of elderly individuals and it may also be involved in the onset/progression of neurological disorders. Since the human lifespan has been dramatically extended, the incidence of age-associated neuropsychiatric conditions in the human population has increased. This has prompted efforts to shed light on the mechanisms underpinning the age-related decline of adult neurogenesis, whose knowledge may foster therapeutic approaches to prevent or delay cognitive alterations in elderly patients. In this review, we summarize recent progress in elucidating the molecular causes of neurogenic aging in the most abundant NSPC niche of the adult mouse brain: the subventricular zone (SVZ). We discuss the age-associated changes occurring both in the intrinsic NSPC molecular networks and in the extrinsic signalling pathways acting in the complex environment of the SVZ niche, and how all these changes may steer young NSPCs towards an aged phenotype

Molecular signatures of the aging brain: finding the links between genes and phenotypes

Aging is associated with cognitive decline and increased vulnerability to neurodegenerative diseases. The progressive extension of the average human lifespan is bound to lead to a corresponding increase in the fraction of cognitively impaired elderly individuals among the human population, with an enormous societal and economic burden. At the cellular and tissue levels, cognitive decline is linked to a reduction in specific neuronal subpopulations, a widespread decrease in synaptic plasticity and an increase in neuroinflammation due to an enhanced activation of astrocytes and microglia, but the molecular mechanisms underlying these functional changes during normal aging and in neuropathological conditions remain poorly understood. In this review, we summarize very recent and outstanding progress in elucidating the molecular changes associated with cognitive decline through the genome-wide profiling of aging brain cells at different molecular levels (genomic, epigenomic, transcriptomic, proteomic). We discuss how the correlation of different molecular and phenotypic traits driven by mathematical and computational analyses of large datasets has led to the prediction of key molecular nodes of neurodegenerative pathways, and provide a few examples of candidate regulators of cognitive decline identified with these approaches. Furthermore, we highlight the dysregulation of the synaptic transcriptome in neuronal cells and of the inflammatory transcriptome in glial cells as some of the key events during normal and neuropathological human brain aging

Neuroserpin polymers cause oxidative stress in a neuronal model of the dementia FENIB

The serpinopathies are human pathologies caused by mutations that promote polymerisation and intracellular deposition of proteins of the serpin superfamily, leading to a poorly understood cell toxicity. The dementia FENIB is caused by polymerisation of the neuronal serpin neuroserpin (NS) within the endoplasmic reticulum (ER) of neurons. With the aim of understanding the toxicity due to intracellular accumulation of neuroserpin polymers, we have generated transgenic neural progenitor cell (NPC) cultures from mouse foetal cerebral cortex, stably expressing the control protein GFP (green fluorescent protein), or human wild type, G392E or delta NS. We have characterised these cell lines in the proliferative state and after differentiation to neurons. Our results show that G392E NS formed polymers that were mostly retained within the ER, while wild type NS was correctly secreted as a monomeric protein into the culture medium. Delta NS was absent at steady state due to its rapid degradation, but it was easily detected upon proteasomal block. Looking at their intracellular distribution, wild type NS was found in partial co-localisation with ER and Golgi markers, while G392E NS was localised within the ER only. Furthermore, polymers of NS were detected by ELISA and immunofluorescence in neurons expressing the mutant but not the wild type protein. We used control GFP and G392E NPCs differentiated to neurons to investigate which cellular pathways were modulated by intracellular polymers by performing RNA sequencing. We identified 747 genes with a significant upregulation (623) or downregulation (124) in G392E NS-expressing cells, and we focused our attention on several genes involved in the defence against oxidative stress that were up-regulated in cells expressing G392E NS (Aldh1b1, Apoe, Gpx1, Gstm1, Prdx6, Scara3, Sod2). Inhibition of intracellular anti-oxidants by specific pharmacological reagents uncovered the damaging effects of NS polymers. Our results support a role for oxidative stress in the cellular toxicity underlying the neurodegenerative dementia FENIB

Cul3 regulates cytoskeleton protein homeostasis and cell migration during a critical window of brain development

De novo loss of function mutations in the ubiquitin ligase-encoding gene Cullin3 (CUL3) lead to autism spectrum disorder (ASD). Here, we used Cul3 mouse models to evaluate the consequences of Cul3 mutations in vivo. Our results show that Cul3 haploinsufficient mice exhibit deficits in motor coordination as well as ASD-relevant social and cognitive impairments. Cul3 mutant brain displays cortical lamination abnormalities due to defective neuronal migration and reduced numbers of excitatory and inhibitory neurons. In line with the observed abnormal columnar organization, Cul3 haploinsufficiency is associated with decreased spontaneous excitatory and inhibitory activity in the cortex. At the molecular level, employing a quantitative proteomic approach, we show that Cul3 regulates cytoskeletal and adhesion protein abundance in mouse embryos. Abnormal regulation of cytoskeletal proteins in Cul3 mutant neuronal cells results in atypical organization of the actin mesh at the cell leading edge, likely causing the observed migration deficits. In contrast to these important functions early in development, Cul3 deficiency appears less relevant at adult stages. In fact, induction of Cul3 haploinsufficiency in adult mice does not result in the behavioral defects observed in constitutive Cul3 haploinsufficient animals. Taken together, our data indicate that Cul3 has a critical role in the regulation of cytoskeletal proteins and neuronal migration and that ASD-associated defects and behavioral abnormalities are primarily due to Cul3 functions at early developmental stages

Pengaruh Pemberian Bunga Rosella Terhadap Perubahan Tekanan Darah Penderita Hipertensi Dengan Terapi Captopril Di Desa Kamiwangi Kecamatan Toili Barat Kabupaten Luwuk Banggai

Hypertension is a cardiovasculer disturbance which is mostly founded in society. in healing hypertension, it needs continually Treatments. Rosella flower is a plant that has many good Components to heal hypertension. This research uses Quasy experiment design with control group. the amout of population in this research are 40 people. The method in taking sample uses purposive sampling and it got 30 respondents as the sample. The information of blood pressure was taken from the clients by using spygmomanometer, then it was displayed in table and processed by using SPSS program (statistic program for society science), used coupling T test, uncoupling T test with interpretation level 95%(a<0.05). The result of the research shows that the hypertension patients with captopril therapy which were given boiled dry rosella, got faster reduction of blood pressure after 2 hours than the hypertension patients with only captopril therapy. By using coupling T test, p-value was 0,00 . With mean value of the difference of reduction of sistolik blood pressure on the first day in intervention group was 28 mmHg while the control group was 11mmHg. on the second day, the reduction of sistolik blood pressure in intervention group was 13,33 l, and for control group, it was 5 mmHg. The diastolic blood pressure on the first day, the mean of the reduction of blood pressure in intervention group was 14mmHg while in control group was 6mmHg. On the second day, the mean of sistolic blood pressure in intervention group was 6 mmHg, and 2mmHg for control group. Key words: hypertension, rosella flower, captopril therapy Hipertensi merupakan penyakit gangguan kardiovaskuler. Bunga rosella adalah tumbuhan herbal untuk mengobati hipertensi. Tujuan penelitian melihat pengaruh bunga rosella terhadap tekanan darah penderita hipertensi dengan terapi captopril. Metode : quasi eksperiment design with control group, purposive sampling, 30 subyek (15 kelompok intervensi, 15 kelompok kontrol). Intervensi, subyek dengan captopril ditambahkan seduhan kering bunga rosella. Kontrol subyek mendapatkan dengan captopril saja. Sistolik pre kelompok intervensi, pada kategori hipertensi grade I, II, III. Sistolik post masuk pada kategori normal, pre hipertensi, hipertensi grade I, II, III. Diastolik pre kelompok intervensi terbesar kategori pre hipertensi, post diastolik terbesar berada pada kategori normal. Kelompok kontrol sistolik pre terbesar pada hipertensi grade II, post berada pada hipertensi grade I. Diastolik kelompok kontrol pre terbesar pada hipertensi grade I, post terbesar hipertensi grade I. Dianalisis dengan uji T berpasangan, dan uji T tidak berpasangan, α ≤ 0,05. Hasil Uji T berpasangan tekanan darah pre-post sistolik p-value 0,000, diastolik p-value 0,004, didapatkan pengaruh bunga rosella terhadap penderita hipertensi dengan captopril, penurunan tekanan darah kelompok intervensi sistolik 19,333, diastolik 10,000 mmHg, kelompok kontrol sistolik 9,000 mmHg, diastolik 4,333 mmHg. Hasil Uji T tidak berpasangan di dapatkan perbedaan penurunan tekanan darah kelompok intervensi lebih besar dibadingkan kelompok kontrol, dengan p-value, sistolik 0,000, diastolik 0,025. Perbedaan penurunan sistolik sebesar 12,333 mmHg, diastolik 6,333 mmHg. Kesimpulan didapatkan pengaruh pemberian bunga rosella terhadap Perubahan tekanan darah penderita hipertensi dengan terapi captopri

Molecular profiling of aged neural progenitors identifies Dbx2 as a candidate regulator of age-associated neurogenic decline.

Adult neurogenesis declines with aging due to the depletion and functional impairment of neural stem/progenitor cells (NSPCs). An improved understanding of the underlying mechanisms that drive age-associated neurogenic deficiency could lead to the development of strategies to alleviate cognitive impairment and facilitate neuroregeneration. An essential step towards this aim is to investigate the molecular changes that occur in NSPC aging on a genomewide scale. In this study, we compare the transcriptional, histone methylation and DNA methylation signatures of NSPCs derived from the subventricular zone (SVZ) of young adult (3 months old) and aged (18 months old) mice. Surprisingly, the transcriptional and epigenomic profiles of SVZ-derived NSPCs are largely unchanged in aged cells. Despite the global similarities, we detect robust age-dependent changes at several hundred genes and regulatory elements, thereby identifying putative regulators of neurogenic decline. Within this list, the homeobox gene Dbx2 is upregulated in vitro and in vivo, and its promoter region has altered histone and DNA methylation levels, in aged NSPCs. Using functional in vitro assays, we show that elevated Dbx2 expression in young adult NSPCs promotes age-related phenotypes, including the reduced proliferation of NSPC cultures and the altered transcript levels of age-associated regulators of NSPC proliferation and differentiation. Depleting Dbx2 in aged NSPCs caused the reverse gene expression changes. Taken together, these results provide new insights into the molecular programmes that are affected during mouse NSPC aging, and uncover a new functional role for Dbx2 in promoting age-related neurogenic decline.This work was supported by grants to P.J.R.-G. from the 6 Wellcome Trust (WT093736) and the BBSRC (BB/P013406/1, BB/M022285/1), by funding from 7 Sapienza University of Rome (G.L, S.B., E.C) and by a grant from the Spanish Ministry of 8 Economy to P.B. (BFU2016-75412-R, co-financed by FEDER). The Babraham Institute Biological 9 Services Unit is supported by Campus Capability Grant funding from the BBSRC

X-ray irradiated cultures of mouse cortical neural stem/progenitor cells recover cell viability and proliferation with dose-dependent kinetics

Exposure of the developing or adult brain to ionizing radiation (IR) can cause cognitive impairment and/ or brain cancer, by targeting neural stem/progenitor cells (NSPCs). IR effects on NSPCs include transient cell cycle arrest, permanent cell cycle exit/differentiation, or cell death, depending on the experimental conditions. In vivo studies suggest that brain age influences NSPC response to IR, but whether this is due to intrinsic NSPC changes or to niche environment modifications remains unclear. Here, we describe the dose-dependent, time-dependent effects of X-ray IR in NSPC cultures derived from the mouse foetal cerebral cortex. We show that, although cortical NSPCs are resistant to low/moderate IR doses, high level IR exposure causes cell death, accumulation of DNA double-strand breaks, activation of p53- related molecular pathways and cell cycle alterations. Irradiated NSPC cultures transiently upregulate differentiation markers, but recover control levels of proliferation, viability and gene expression in the second week post-irradiation. These results are consistent with previously described in vivo effects of IR in the developing mouse cortex, and distinct from those observed in adult NSPC niches or in vitro adult NSPC cultures, suggesting that intrinsic differences in NSPCs of different origins might determine, at least in part, their response to IR

Cul3 regulates cytoskeleton protein homeostasis and cell migration during a critical window of brain development

De novo loss of function mutations in the ubiquitin ligase-encoding gene Cullin3 lead to autism spectrum disorder (ASD). In mouse, constitutive haploinsufficiency leads to motor coordination deficits as well as ASD-relevant social and cognitive impairments. However, induction of Cul3 haploinsufficiency later in life does not lead to ASD-relevant behaviors, pointing to an important role of Cul3 during a critical developmental window. Here we show that Cul3 is essential to regulate neuronal migration and, therefore, constitutive Cul3 heterozygous mutant mice display cortical lamination abnormalities. At the molecular level, we found that Cul3 controls neuronal migration by tightly regulating the amount of Plastin3 (Pls3), a previously unrecognized player of neural migration. Furthermore, we found that Pls3 cell-autonomously regulates cell migration by regulating actin cytoskeleton organization, and its levels are inversely proportional to neural migration speed. Finally, we provide evidence that cellular phenotypes associated with autism-linked gene haploinsufficiency can be rescued by transcriptional activation of the intact allele in vitro, offering a proof of concept for a potential therapeutic approach for ASDs

Colture di cellule staminali neurali come modello per lo studio di patologie del sistema nervoso, studi farmacologici e di neurotossicità

Neural stem cell coltures as model to study neurological diseases and evaluate drug neurotoxicity. New effec- tive therapies are required to treat chronic and acute brain pathologies. Clinical intervention strategies aimed to increase mobilization of neural stem cells (NSC) located in the adult mammalian brain and to strengthen neurogen- esis have been proposed as possible regenerative therapy in several brain pathologies. Though in vivo studies are mandatory, human and rodents NSC cultures constitute an important complementary model to identify the effects of endogenous (e.g. pro-inflammatory cytokines produced in the lesioned brain) and exogenous molecules (e.g. drugs) on neurogenesis. In this review we illustrate the use of NSC as a cellular model to clarify mechanisms implicated in brain disease and to screen the efficacy of new drugs. We will also present some studies that highlight the rising inter- est around embryonic inducible pluripotent cells (iPS) as cellular models for studying brain pathologies in vitro