Zebrafish aussicht mutant embryos exhibit widespread overexpression of ace (fgf8) and coincident defects in CNS development

Development ◽  
1999 ◽  
Vol 126 (10) ◽  
pp. 2129-2140 ◽  
Author(s):  
C.P. Heisenberg ◽  
C. Brennan ◽  
S.W. Wilson

During the development of the zebrafish nervous system both noi, a zebrafish pax2 homolog, and ace, a zebrafish fgf8 homolog, are required for development of the midbrain and cerebellum. Here we describe a dominant mutation, aussicht (aus), in which the expression of noi and ace is upregulated. In aus mutant embryos, ace is upregulated at many sites in the embryo, while noi expression is only upregulated in regions of the forebrain and midbrain which also express ace. Subsequent to the alterations in noi and ace expression, aus mutants exhibit defects in the differentiation of the forebrain, midbrain and eyes. Within the forebrain, the formation of the anterior and postoptic commissures is delayed and the expression of markers within the pretectal area is reduced. Within the midbrain, En and wnt1 expression is expanded. In heterozygous aus embryos, there is ectopic outgrowth of neural retina in the temporal half of the eyes, whereas in putative homozygous aus embryos, the ventral retina is reduced and the pigmented retinal epithelium is expanded towards the midline. The observation that aus mutant embryos exhibit widespread upregulation of ace raised the possibility that aus might represent an allele of the ace gene itself. However, by crossing carriers for both aus and ace, we were able to generate homozygous ace mutant embryos that also exhibited the aus phenotype. This indicated that aus is not tightly linked to ace and is unlikely to be a mutation directly affecting the ace locus. However, increased Ace activity may underly many aspects of the aus phenotype and we show that the upregulation of noi in the forebrain of aus mutants is partially dependent upon functional Ace activity. Conversely, increased ace expression in the forebrain of aus mutants is not dependent upon functional Noi activity. We conclude that aus represents a mutation involving a locus normally required for the regulation of ace expression during embryogenesis.

2021 ◽  
Vol 7 (9) ◽  
pp. eabc4898
Author(s):  
Yvette Zarb ◽  
Sucheta Sridhar ◽  
Sina Nassiri ◽  
Sebastian Guido Utz ◽  
Johanna Schaffenrath ◽  
...  

Microglia participate in central nervous system (CNS) development and homeostasis and are often implicated in modulating disease processes. However, less is known about the role of microglia in the biology of the neurovascular unit (NVU). In particular, data are scant on whether microglia are involved in CNS vascular pathology. In this study, we use a mouse model of primary familial brain calcification, Pdgfbret/ret, to investigate the role of microglia in calcification of the NVU. We report that microglia enclosing vessel calcifications, coined calcification-associated microglia, display a distinct activation phenotype. Pharmacological ablation of microglia with the CSF1R inhibitor PLX5622 leads to aggravated vessel calcification. Mechanistically, we show that microglia require functional TREM2 for controlling vascular calcification. Our results demonstrate that microglial activity in the setting of pathological vascular calcification is beneficial. In addition, we identify a previously unrecognized function of microglia in halting the expansion of vascular calcification.


2004 ◽  
Vol 286 (2) ◽  
pp. H498-H506 ◽  
Author(s):  
María Paz Ocaranza ◽  
Guillermo Díaz-Araya ◽  
Juan E. Carreño ◽  
David Muñoz ◽  
Juan Pablo Riveros ◽  
...  

In humans, the effect of angiotensin-converting enzyme (ACE) gene polymorphisms in cardiovascular disease is still controversial. In the rat, a microsatellite marker in the ACE gene allows differentiation of the ACE gene polymorphism among strains with different ACE levels. We tested the hypothesis that this ACE gene polymorphism determines the extent of cardiac fibrosis induced by isoproterenol (Iso) in the rat. We used a male F2 generation (homozygous LL and BB ACE genotypes determined by polymerase chain reaction) derived from two rat strains [Brown-Norway (BB) and Lewis (LL)] that differ with respect to their plasma ACE activities. For induction of left ventricular (LV) hypertrophy (LVH) and cardiac fibrosis, rats were infused with Iso (5 mg·kg–1·day–1) or saline (control) for 10 days and euthanized at day 1 after the last injection. The interstitial collagen volumetric fraction (ICVF), collagen I, and fibronectin content, but not collagen III content, were significantly higher in the homozygous BB rats than in homozygous LL rats. Differences in metalloprotease (MMP)-9, but not in MMP-2 activities as well as in cardiac cell proliferation, were also detected between LL and BB rats treated with Iso. LV ACE activity was higher in BB rats than LL rats and correlated with ICVF ( r = 0.61, P < 0.002). No changes were observed in plasma ACE activities, ANG II plasma or LV levels, plasma renin activity, and ACE and ANG II type 1 receptor (AT1R) mRNA levels in the LV of rats with the two different ACE polymorphisms. Iso induced a similar degree of LVH [assessed by an increase in LV weight 100 per body weight, LV-to-right ventricle (RV) ratio, and LV protein content] in LL and BB rats. We concluded that rats in the F2 generation with high plasma ACE activity developed more fibrosis but to a similar degree of LVH compared with rats with low plasma ACE activity.


Physiology ◽  
2003 ◽  
Vol 18 (3) ◽  
pp. 130-136 ◽  
Author(s):  
Fernando de Castro

Different molecules (netrins, semaphorins, slits) with chemotropic functions and their receptors (neogenin, DCC, neuropilins, plexins, robos) have been identified that guide axons during development of the nervous system to establish the complex pattern of connections among a large number of neurons. These molecules have been recently identified to play a role in cell migration of the central nervous system during development.


Hypertension ◽  
2013 ◽  
Vol 62 (suppl_1) ◽  
Author(s):  
Nadia S Bertoncello ◽  
Roseli P Moreira ◽  
Rodrigo Yokota ◽  
Rodolfo M Rosa ◽  
Danielle Y Arita ◽  
...  

The mechanisms underlying the link between high constitutive levels of ACE and diabetic nephropathy has not been completely understood, but an imbalance between angiotensin I (ACE) and II (ACE2) converting enzymes homeostasis has been described in diabetic kidney disease. The aim of this study was to evaluate ACE/ACE2 homeostasis in kidney from diabetic mice presenting increased dosage of ACE gene. Male mice (3 months old) genetically engineered to harbor one or three copies of the ACE gene were made diabetic (streptozotocin - STZ, 50 mg/Kg) and randomly assigned into: 1-copy control (1CC), 1-copy diabetic (1CD), 3-copy control (3CC) and 3-copy diabetic. At the end of experimental period body weight was evaluated and kidney was excised. Kidney-to-body weight ratio and ACE and ACE 2 activities were determined using specific substrates (ZPhe-HL and 7-Mca-APK(Dnp), respectively) (Two way ANOVA + Tukey test; P<0.05). Diabetes increased blood glucose (1CD : 436 ± 25 vs. 1CC: 90 ± 2; 3CD: 556 ± 6 vs. 3CC: 112 ± 4 mg/dL) and kidney-to-body weight ratio (1CD: 7.5 ± 0.2 vs. 1CC: 5.8 ± 0.2; 3CD: 7.8 ± 0.1 vs. 3CC: 5.8 ± 0.1 mg/g) with no influence of ACE genotype. As expected, renal ACE activity was directly related to ACE gene copy number in control group (3CC: 9.4 ± 2.11 vs. 1CC:5.6 ± 0.9 mU/mg protein). Renal ACE activity was decreased in diabetic groups (1CD: 3.6 ± 0.2 vs. 1CC: 5.6 ± 0.9; 3CD: 2.3 ± 0.4 vs. 3CC: 9.4 ± 2.1 mU/mg protein) with no influence of ACE genotype. Under physiological condition, renal ACE2 activity remained unchanged regardless of the ACE genotype (1CC: 1.9 ± 0.2 = 3CC: 1.4 ± 0.1 μM/min/mg). However upon a pathological stimulus, renal ACE2 activity was efficiently increased only in 1CD group, but not in 3CD, as compared with the others (1CD: 5.1 ± 0.9 vs. 1CC: 1.9 ± 0.2 = 3CC: 1.4 ± 0.1 = 3CD: 2.2 ± 0.2 μM/min/mg). Taken together, our results show for the first time, that susceptibility for the development of diabetic nephropathy associated with increased ACE gene dosage may be, at least in part, caused by a decrease on renal ACE2 activity. This may result in increased local levels of angiotensin II and decreased angiotensin (1-7), leading to altered glomerular permeability and albuminuria, functional alterations presented by 3CD animals. Financial Support: FAPESP, CAPES, CNPq.


Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 730
Author(s):  
Clara Forrer Charlier ◽  
Rodrigo A. P. Martins

The precise replication of DNA and the successful segregation of chromosomes are essential for the faithful transmission of genetic information during the cell cycle. Alterations in the dynamics of genome replication, also referred to as DNA replication stress, may lead to DNA damage and, consequently, mutations and chromosomal rearrangements. Extensive research has revealed that DNA replication stress drives genome instability during tumorigenesis. Over decades, genetic studies of inherited syndromes have established a connection between the mutations in genes required for proper DNA repair/DNA damage responses and neurological diseases. It is becoming clear that both the prevention and the responses to replication stress are particularly important for nervous system development and function. The accurate regulation of cell proliferation is key for the expansion of progenitor pools during central nervous system (CNS) development, adult neurogenesis, and regeneration. Moreover, DNA replication stress in glial cells regulates CNS tumorigenesis and plays a role in neurodegenerative diseases such as ataxia telangiectasia (A-T). Here, we review how replication stress generation and replication stress response (RSR) contribute to the CNS development, homeostasis, and disease. Both cell-autonomous mechanisms, as well as the evidence of RSR-mediated alterations of the cellular microenvironment in the nervous system, were discussed.


2003 ◽  
Vol 81 (4) ◽  
pp. 371-384 ◽  
Author(s):  
S Harvey ◽  
M Kakebeeke ◽  
A E Murphy ◽  
E J Sanders

Growth hormone (GH) is primarily produced in the pituitary gland, although GH gene expression also occurs in the central and autonomic nervous systems. GH-immunoreactive proteins are abundant in the brain, spinal cord, and peripheral nerves. The appearance of GH in these tissues occurs prior to the ontogenic differentiation of the pituitary gland and prior to the presence of GH in systemic circulation. Neural GH is also present in neonates, juveniles, and adults and is independent of changes in pituitary GH secretion. Neural GH is therefore likely to have local roles in neural development or neural function, especially as GH receptors (GHRs) are widespread in the nervous system. In recent studies, GH mRNA and GH immunoreactive proteins have been identified in the neural retina of embryonic chicks. GH immunoreactivity is present in the optic cup of chick embryos at embryonic day (ED) 3 of the 21-d incubation period. It is widespread in the neural retina by ED 7 but also present in the nonpigmented retina, choroid, sclera, and cornea. This immunoreactivity is associated with proteins in the neural retina comparable in size with those in the adult pituitary gland, although it is primarily associated with 15–16 kDa moieties rather than with the full-length molecule of approximately 22 kDa. These small GH moieties may reflect proteolytic fragments of "monomer" GH and (or) the presence of different GH gene transcripts, since full-length and truncated GH cDNAs are present in retinal tissue extracts. The GH immunoreactivity in the retina persists throughout embryonic development but is not present in juvenile birds (after 6 weeks of age). This immunoreactivity is also associated with the presence of GH receptor (GHR) immunoreactivity and GHR mRNA in ocular tissues of chick embryos. The retina is thus an extrapituitary site of GH gene expression during early development and is probably an autocrine or paracrine site of GH action. The marked ontogenic pattern of GH immunoreactivity in the retina suggests hitherto unsuspected roles for GH in neurogenesis or ocular development.Key words: growth hormone, growth hormone receptor, nervous system, retina, autocrine, paracrine.


Author(s):  
Sanaa K. Bardaweel ◽  
Muhammed Alzweiri ◽  
Aman A. Ishaqat

Homochirality is fundamental for life. L-Amino acids are exclusively used as substrates for the polymerization and formation of peptides and proteins in living systems. However, D- amino acids were recently detected in various living organisms, including mammals. Of these D-amino acids, D-serine has been most extensively studied. D-Serine was found to play an important role as a neurotransmitter in the human central nervous system (CNS) by binding to the N-methyl- D-aspartate receptor (NMDAr). D-Serine binds with high affinity to a co-agonist site at the NMDAr and, along with glutamate, mediates several vital physiological and pathological processes, including NMDAr transmission, synaptic plasticity and neurotoxicity. Therefore, a key role for D-serine as a determinant of NMDAr mediated neurotransmission in mammalian CNS has been suggested. In this context, we review the known functions of D-serine in human physiology, such as CNS development, and pathology, such as neuro-psychiatric and neurodegenerative diseases related to NMDAr dysfunction.


2008 ◽  
Vol 19 (1) ◽  
pp. 1-31 ◽  
Author(s):  
R.K. POOH ◽  
K.H. POOH

Imaging technologies have been remarkably improved and contribute to prenatal evaluation of fetal central nervous system (CNS) development and assessment of CNS abnormalities in utero.


2021 ◽  
Vol 15 ◽  
Author(s):  
Yongliang Wang ◽  
Ruxia Han ◽  
Zhejun Xu ◽  
Xiahui Sun ◽  
Chunxue Zhou ◽  
...  

Toxoplasma gondii is neurotropic and affects the function of nerve cells, while the mechanism is unclear. LncRNAs are abundantly enriched in the brain and participated in the delicate regulation of the central nervous system (CNS) development. However, whether these lncRNAs are involved in the regulation of microglia activation during the process of T. gondii infection is largely unknown. In this study, the upregulation of a novel lncRNA147410.3 (ENSMUST00000147410.3) was identified as a key factor to influence this process. The target gene of lncRNA147410.3 was predicted and identified as Hoxb3. The localization of lncRNA147410.3 in the brain and cells was proved in the nucleus of neuroglia through FISH assay. Furthermore, the function of lncRNA147410.3 on neuronal cell was confirmed that lncRNA147410.3 could affect proliferation, differentiation, and apoptosis of mouse microglia by positively regulating Hoxb3. Thus, our study explored the modulatory action of lncRNA147410.3 in T. gondii infected mouse brain, providing a scientific basis for using lncRNA147410.3 as a therapeutic target to treat neurological disorder induced by T. gondii.


Author(s):  
Kohei Shiota

Abstract In this paper, the process of CNS development in human embryos and fetuses is described. The primordium of the nervous system appears as early as during the third week after fertilization, but its differentiation and maturation require a considerably long period of time until after birth. Therefore, the developing brain is vulnerable to various kinds of deleterious environmental effects during the preand perinatal life. This paper aims at giving an overview of the major organogenesis of the brain in human embryos and fetuses.


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