scholarly journals The N-myc proto-oncogene and IGF-II growth factor mRNAs are expressed by distinct cells in human fetal kidney and brain.

1989 ◽  
Vol 108 (3) ◽  
pp. 1093-1104 ◽  
Author(s):  
H Hirvonen ◽  
M Sandberg ◽  
H Kalimo ◽  
V Hukkanen ◽  
E Vuorio ◽  
...  

We studied the expression of the N-myc proto-oncogene and the insulin-like growth factor-II (IGF-II) gene in human fetuses of 16-19 gestational wk. Both genes have specific roles in the growth and differentiation of embryonic tissues, such as the kidney and neural tissue. Since continued expression of N-myc and IGF-II mRNAs is also a characteristic feature of Wilms' tumor, a childhood neoplasm of probable fetal kidney origin, we were particularly interested in the possibility that their expression might be linked or coordinately regulated in the developing kidney. Expression of N-myc mRNA was observed in the brain and in the kidney by Northern hybridization analysis. In in situ hybridization of the kidney, N-myc autoradiographic grains were primarily located over epithelially differentiating mesenchyme while most of the mesenchymal stromal cells showed only a background signal with the N-myc probe. N-myc mRNA was detectable throughout the developing brain with a slight accentuation in the intermediate zone cells in between the subependymal and cortical layers. Thus, even postmitotic neuroepithelial cells of the fetal cerebrum expressed N-myc mRNA. In Northern hybridization, IGF-II mRNA signal was abundant in the kidney but much weaker, though definite, in the brain. The regional distribution of IGF-II mRNA in the kidney was largely complementary to that of N-myc. IGF-II autoradiographic grains were located predominantly over the stromal and blastemal cells with a relative lack of hybridization over the epithelial structures. In the brain, IGF-II mRNA was about two- to threefold more abundant in the subependymal and intermediate layers than in the cortical plate and ependymal zone, respectively. The fetal expression patterns of the N-myc and IGF-II mRNAs are reflected by the types of tumors known to express the corresponding genes during postnatal life such as Wilms' tumor. However, the apparent coexpression of the IGF-II and N-myc genes in immature kidneys occurs largely in distinct cell types.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Karthik Shekhar ◽  
Joshua R. Sanes

It has been known for over a century that the basic organization of the retina is conserved across vertebrates. It has been equally clear that retinal cells can be classified into numerous types, but only recently have methods been devised to explore this diversity in unbiased, scalable, and comprehensive ways. Advances in high-throughput single-cell RNA-sequencing (scRNA-seq) have played a pivotal role in this effort. In this article, we outline the experimental and computational components of scRNA-seq and review studies that have used them to generate retinal atlases of cell types in several vertebrate species. These atlases have enabled studies of retinal development, responses of retinal cells to injury, expression patterns of genes implicated in retinal disease, and the evolution of cell types. Recently, the inquiry has expanded to include the entire eye and visual centers in the brain. These studies have enhanced our understanding of retinal function and dysfunction and provided tools and insights for exploring neural diversity throughout the brain. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2010 ◽  
Vol 108 (5) ◽  
pp. 1069-1076 ◽  
Author(s):  
Elisabeth R. Barton ◽  
J DeMeo ◽  
Hanqin Lei

Insulin-like growth factor I (IGF-I) coordinates proliferation and differentiation in a wide variety of cell types. The igf1 gene not only produces IGF-I, but also generates multiple carboxy-terminal extensions, the E-peptides, through alternative splicing leading to different isoforms. It is not known if the IGF-I isoforms share a common pathway for their actions, or if there are specific actions of each protein. Viral administration of murine IGF-IA, IGF-IB, and mature IGF, which lacked an E-peptide extension, was utilized to identify IGF-I isoform-specific responsive genes in muscles of young growing mice. Microarray analysis revealed responses that were driven by increased IGF-I regardless of the presence of E-peptide, such as Bcl-XL. In contrast, distinct expression patterns were observed after viral delivery of IGF-IA or IGF-IB, which included matrix metalloproteinase 13 (MMP13). Expression of Bcl-XL was prevented when viral administration of the IGF-I isoforms was performed into muscles of MKR mice, which lack functional IGF-I receptors on the muscle fibers. However, MMP13 expression persisted under the same conditions after viral injection of IGF-IB. At 4 mo after viral delivery, expression of IGF-IA or IGF-IB promoted muscle hypertrophy, but viral delivery of mature IGF-I failed to increase muscle mass. These studies provide evidence that local production of IGF-I requires the E-peptides to drive hypertrophy in growing muscle and that both common and unique pathways exist for the IGF-I isoforms to promote biological effects.


2021 ◽  
Author(s):  
Ricardo Melo Ferreira ◽  
Angela R. Sabo ◽  
Seth Winfree ◽  
Kimberly S. Collins ◽  
Danielle Janosevic ◽  
...  

AbstractDespite important advances in studying experimental and clinical acute kidney injury (AKI), the pathogenesis of this disease remains incompletely understood. Single cell sequencing studies have closed this knowledge gap by characterizing the transcriptomic signature of different cell types within the kidney. However, the spatial distribution of injury can be regional and affect cells heterogeneously. We first optimized coordination of spatial transcriptomics and single nuclear sequencing datasets, mapping 30 dominant cell types to a human nephrectomy sample. The predicted cell type spots corresponded with the underlying hematoxylin and eosin histopathology. To study the implications of acute kidney injury on the distribution of transcript expression, we then characterized the spatial transcriptomic signature of two murine AKI models: ischemia reperfusion injury (IRI) and cecal ligation puncture (CLP). Localized regions of reduced overall expression were found associated with tissue injury pathways. Using single cell sequencing, we deconvoluted the signature of each spatial transcriptomic spot, identifying patterns of colocalization between immune and epithelial cells. As expected, neutrophils infiltrated the renal medullary outer stripe in the ischemia model. Atf3 was identified as a chemotactic factor in S3 proximal tubule cells. In the CLP model, infiltrating macrophages dominated the outer cortical signature and Mdk was identified as a corresponding chemotactic factor. The regional distribution of these immune cells was validated with multiplexed CO-Detection by inDEXing (CODEX) immunofluorescence. Spatial transcriptomic sequencing can aid in uncovering the mechanisms driving immune cell infiltration and allow detection of relevant subpopulations in single cell sequencing. The complementarity of these technologies facilitates the development of a transcriptomic kidney atlas in health and disease.


2021 ◽  
Vol 7 (1) ◽  
pp. 73-103
Author(s):  
Ulrike Grünert ◽  
Paul R. Martin

The eye sends information about the visual world to the brain on over 20 parallel signal pathways, each specialized to signal features such as spectral reflection (color), edges, and motion of objects in the environment. Each pathway is formed by the axons of a separate type of retinal output neuron (retinal ganglion cell). In this review, we summarize what is known about the excitatory retinal inputs, brain targets, and gene expression patterns of ganglion cells in humans and nonhuman primates. We describe how most ganglion cell types receive their input from only one or two of the 11 types of cone bipolar cell and project selectively to only one or two target regions in the brain. We also highlight how genetic methods are providing tools to characterize ganglion cells and establish cross-species homologies.


Development ◽  
1991 ◽  
Vol 112 (3) ◽  
pp. 821-832 ◽  
Author(s):  
K. Hatta ◽  
R. Bremiller ◽  
M. Westerfield ◽  
C.B. Kimmel

We have studied developmental expression of zebrafish engrailed-like (Eng) antigens. Many cell types are reproducibly labeled by two antibodies that recognize the Eng homeodomain, but other cells are labeled by only one or the other, suggesting a hitherto unrecognized complexity of Eng proteins. Expression patterns vary remarkably according to cell type and location. In the undifferentiated primordia of the brain and of each myotome, expression by a stripe of cells spatially subdivides the primordium at a location where a morphological boundary forms later, suggesting expression may be required for development of the boundaries. Supporting this hypothesis, trunk myotomal cells that express Eng are absent in spt-1 mutant embryos, just where the myotomal boundaries fail to form. Another pattern is present in rhombomeres, pharyngeal arches, and the pectoral girdle. In each of these cases, cells (neuron, muscle, cartilage) generating a subset of a series of repeated elements selectively express Eng. These subsets then form specialized derivatives, suggesting Eng homeoproteins are involved in determining the specializations. Epidermal expression is present in the ventral half of the pectoral fin rudiment, precisely ‘compartmentalizing’ the fin. Neuronal cells at a certain dorsoventral level in each hindbrain and spinal cord segment selectively express Eng, suggesting segmental control of neuronal identity. Specific expression patterns are observed in taste buds, otic vesicles and teeth. Thus we propose that eng genes function in diverse cell types in zebrafish, but play selector roles that can be classified into a few basic types.


1987 ◽  
Vol 133 (1) ◽  
pp. 169-174 ◽  
Author(s):  
Gail E. Fraizer ◽  
Daniel F. Bowen-Pope ◽  
Arthur M. Vogel

2016 ◽  
Vol 57 (2) ◽  
pp. 97-111 ◽  
Author(s):  
Giampaolo Trivellin ◽  
Ivana Bjelobaba ◽  
Adrian F Daly ◽  
Darwin O Larco ◽  
Leonor Palmeira ◽  
...  

We recently showed that Xq26.3 microduplications cause X-linked acrogigantism (X-LAG). X-LAG patients mainly present with growth hormone and prolactin-secreting adenomas and share a minimal duplicated region containing at least four genes. GPR101 was the only gene highly expressed in their pituitary lesions, but little is known about its expression patterns. In this work, GPR101 transcripts were characterized in human tissues by 5′-Rapid Amplification of cDNA Ends (RACE) and RNAseq, while the putative promoter was bioinformatically predicted. We investigated GPR101 mRNA and protein expression by RT-quantitative PCR (qPCR), whole-mount in situ hybridization, and immunostaining, in human, rhesus monkey, rat and zebrafish. We identified four GPR101 isoforms characterized by different 5′-untranslated regions (UTRs) and a common 6.1kb long 3′UTR. GPR101 expression was very low or absent in almost all adult human tissues examined, except for specific brain regions. Strong GPR101 staining was observed in human fetal pituitary and during adolescence, whereas very weak/absent expression was detected during childhood and adult life. In contrast to humans, adult monkey and rat pituitaries expressed GPR101, but in different cell types. Gpr101 is expressed in the brain and pituitary during rat and zebrafish development; in rat pituitary, Gpr101 is expressed only after birth and shows sexual dimorphism. This study shows that different GPR101 transcripts exist and that the brain is the major site of GPR101 expression across different species, although divergent species- and temporal-specific expression patterns are evident. These findings suggest an important role for GPR101 in brain and pituitary development and likely reflect the very different growth, development and maturation patterns among species.


Development ◽  
2001 ◽  
Vol 128 (12) ◽  
pp. 2233-2241 ◽  
Author(s):  
Fabrizio C. Serluca ◽  
Mark C. Fishman

Vertebrate embryos use a series of transient kidneys to regulate fluid balance, osmolarity and metabolic waste during development. The first kidney to form in the embryo is the pronephros. This kidney is composed of several cell types with very different functions and is organized into discrete segments: glomerulus, tubules and nephric duct. The site of origin of these cells is poorly understood, as are their lineage relationships. We have defined regions of the intermediate mesoderm as candidates for the pronephric field by expression patterns of the Wilms’ Tumor suppressor gene (wt1), single-minded 1 (sim1) and pax2.1. All of these potential kidney markers are expressed in a stripe of intermediate mesoderm, with distinct, overlapping antero-posterior borders. We labeled small groups of cells in this area by laser uncaging of a fluorescent dextran, and then tracked their fates. We found that there was a bounded contiguous region of the intermediate mesoderm that provides pronephric progenitors. As is true for other organ fields, the pronephric field regulates after focal destruction, such that a normal pronephros forms after laser-mediated removal of the wt1 domain. The progenitors for podocytes, tubular cells and duct are restricted to subdomains within the pronephric field. The most anterior cells in the pronephric field give rise to podocytes. This corresponds to the wt1-expressing region. The next more posterior cells contribute to the tubule, and express both wt1 and pax2.1. The most posterior cells contribute to the nephric duct, and these express pax2.1 and sim1, but not wt1. Thus, there is a field for the pronephric kidney with classical attributes of defined border, pre-pattern and regulation. The pattern of the fate map reflects particular combinations of transcription factors.


2015 ◽  
Vol 38 (1) ◽  
pp. 54-73 ◽  
Author(s):  
Tracey A. Quinn ◽  
Udani Ratnayake ◽  
Hayley Dickinson ◽  
Margie Castillo-Melendez ◽  
David W. Walker

The androgen dehydroepiandrosterone (DHEA) has trophic and anti-glucocorticoid actions on brain growth. The adrenal gland of the spiny mouse (Acomys cahirinus) synthesizes DHEA. The aim of this study was to determine whether the brain of this precocial species is also able to produce DHEA de novo during fetal, neonatal and adult life. The expression of P450c17 and cytochrome b5 (Cytb5), the enzyme and accessory protein responsible for the synthesis of DHEA, was determined in fetal, neonatal and adult brains by immunocytochemistry, and P450c17 bioactivity was determined by the conversion of pregnenolone to DHEA. Homogenates of fetal brain produced significantly more DHEA after 48 h in culture (22.46 ± 2.0 ng/mg tissue) than adult brain homogenates (5.04 ± 2.0 ng/mg tissue; p < 0.0001). P450c17 and Cytb5 were co-expressed in fetal neurons but predominantly in oligodendrocytes and white matter tracts in the adult brain. Because DHEA modulates glucocorticoids actions, the expression of the glucocorticoid receptor (GR) was also determined. In the brainstem, medulla, midbrain, and cerebellum, the predominant GR localization changed from neurons in the fetal brain to oligodendrocytes and white matter tracts in the adult brain. The change of expression of P450c17, Cytb5 and GR proteins with cell type, brain region and developmental age indicates that DHEA is an endogenous neurosteroid in this species that may have important trophic and stress-modifying actions during both prenatal and postnatal life.


2010 ◽  
Vol 391 (7) ◽  
Author(s):  
Barbara Haigl ◽  
Christoph-Erik Mayer ◽  
Gerald Siegwart ◽  
Hedwig Sutterlüty

Abstract Sprouty (Spry) proteins are well-known negative regulators of receptor tyrosine kinase-mediated signalling. Their expression is controlled by mitogens, implying a negative feedback loop. Correspondingly, the different members of the family fulfil important roles during organogenesis by adjustment of growth factor-induced processes. In addition, Spry4, one member of this protein family, has been shown to regulate angiogenesis by inhibiting vascular endothelial cell growth factor-induced extracellular signalling-regulated kinase (ERK) activation. Because oxygen is an important regulator of angiogenesis, we investigated Spry4 expression patterns under hypoxic conditions. Our data demonstrate that both hypoxia and desferrioxamine (DFO) treatment increased Spry4 expression. Following iron depletion, elevated Spry4 levels were detected in several cell types independent of tissue origin, presence of mitogens, cell differentiation and malignancy. Evaluation of the underlying regulative mechanisms revealed that augmented transcription and increased mRNA stability enhance mRNA levels of Spry4 in response to DFO. This study unveils a growth factor-independent regulation mechanism of Spry4 expression. Because increased Spry4 levels are accompanied by disappearing ERK phosphorylation, Spry4 might be involved in the timely restriction of MAPK signals under hypoxic conditions, similar to its role in mitogen-regulated processes. However, the functional significance of the observed upregulation of Spry4 during iron depletion remains to be clarified.


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