Transgene expression of prion protein induces crinophagy in intermediate pituitary cells

2007 ◽  
Vol 67 (1) ◽  
pp. 81-96 ◽  
Author(s):  
Jos W.G. van Rosmalen ◽  
Gerard J.M. Martens
Keyword(s):  
Prion Protein ◽  
Transgene Expression ◽  
Pituitary Cells

scholarly journals Cell type-specific transgene expression of the prion protein in Xenopus intermediate pituitary cells

FEBS Journal ◽  
2006 ◽  
Vol 273 (4) ◽  
pp. 847-862 ◽  
Author(s):  
Jos W. G. van Rosmalen ◽  
Gerard J. M. Martens
Keyword(s):  
Prion Protein ◽  
Transgene Expression ◽  
Pituitary Cells ◽  
Cell Type ◽  
Cell Type Specific

Transgene expression of prion protein induces crinophagy in intermediate pituitary cells

2006 ◽  
Vol 67 (1) ◽  
pp. 81-96 ◽  
Author(s):  
Jos W.G. van Rosmalen ◽  
Gerard J.M. Martens
Keyword(s):  
Prion Protein ◽  
Transgene Expression ◽  
Pituitary Cells

scholarly journals The Promoter of the Rat Gonadotropin-Releasing Hormone Receptor Gene Directs the Expression of the Human Placental Alkaline Phosphatase Reporter Gene in Gonadotrope Cells in the Anterior Pituitary Gland as well as in Multiple Extrapituitary Tissues

Endocrinology ◽  
2004 ◽  
Vol 145 (2) ◽  
pp. 983-993 ◽  
Author(s):  
Anne Granger ◽  
Valérie Ngô-Muller ◽  
Christian Bleux ◽  
Céline Guigon ◽  
Hanna Pincas ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Reporter Gene ◽  
Transgene Expression ◽  
Pituitary Cells ◽  
Placental Alkaline Phosphatase ◽  
R Gene ◽  
Glycoprotein Hormone ◽  
Steroidogenic Factor 1 ◽  
Functional Sites ◽  
Human Placental Alkaline Phosphatase

Abstract Previous studies dealing with the mechanisms underlying the tissue-specific and regulated expression of the GnRH receptor (GnRH-R) gene led us to define several cis-acting regulatory sequences in the rat GnRH-R gene promoter. These include functional sites for steroidogenic factor 1, activator protein 1, and motifs related to GATA and LIM homeodomain response elements as demonstrated primarily in transient transfection assays in mouse gonadotrope-derived cell lines. To understand these mechanisms in more depth, we generated transgenic mice bearing the 3.3-kb rat GnRH-R promoter linked to the human placental alkaline phosphatase reporter gene. Here we show that the rat GnRH-R promoter drives the expression of the reporter gene in pituitary cells expressing the LHβ and/or FSHβ subunit but not in TSHβ- or GH-positive cells. Furthermore, the spatial and temporal pattern of the transgene expression during the development of the pituitary was compatible with that characterizing the emergence of the gonadotrope lineage. In particular, transgene expression is colocalized with the expression of the glycoprotein hormone α-subunit at embryonic day 13.5 and with that of steroidogenic factor 1 at later stages of pituitary development. Transgene expression was also found in specific brain areas, such as the lateral septum and the hippocampus. A single promoter is thus capable of directing transcription in highly diverse tissues, raising the question of the different combinations of transcription factors that lead to such a multiple, but nevertheless cell-specific, expressions of the GnRH-R gene.

scholarly journals Doxycycline control of prion protein transgene expression modulates prion disease in mice

1998 ◽  
Vol 95 (21) ◽  
pp. 12580-12585 ◽  
Author(s):  
P. Tremblay ◽  
Z. Meiner ◽  
M. Galou ◽  
C. Heinrich ◽  
C. Petromilli ◽  
...  
Keyword(s):  
Prion Protein ◽  
Prion Disease ◽  
Transgene Expression

Ultrastructural Aspects of Golgi Complex Function in Parathyroid Cells of Winter Frogs

1973 ◽  
Vol 31 ◽  
pp. 680-681
Author(s):  
William J. Dougherty
Keyword(s):  
Golgi Complex ◽  
Secretory Granules ◽  
Complex Function ◽  
Secretory Activity ◽  
Secretory Proteins ◽  
Perivascular Spaces ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
Ca Ions ◽  
Regulation Of Secretion

The regulation of secretion in exocrine and endocrine cells has long been of interest. Electron microscopic and other studies have demonstrated that secretory proteins synthesized on ribosomes are transported by the rough ER to the Golgi complex where they are concentrated into secretory granules. During active secretion, secretory granules fuse with the cell membrane, liberating and discharging their contents into the perivascular spaces. When secretory activity is suppressed in anterior pituitary cells, undischarged secretory granules may be degraded by lysosomes. In the parathyroid gland, evidence indicates that the level of blood Ca ions regulates both the production and release of parathormone. Thus, when serum Ca is low, synthesis and release of parathormone are both stimulated; when serum Ca is elevated, these processes are inhibited.

The Ultrastructure of Lymphocytic Hypophysitis

1981 ◽  
Vol 39 ◽  
pp. 466-467
Author(s):  
S.L. Asa ◽  
K. Kovacs ◽  
J. M. Bilbao ◽  
R. G. Josse ◽  
K. Kreines
Keyword(s):  
Electron Microscopy ◽  
Plasma Cells ◽  
Secretory Granules ◽  
Sella Turcica ◽  
Uranyl Acetate ◽  
Lymphocytic Hypophysitis ◽  
Pituitary Cells ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
Mass Lesions

Seven cases of lymphocytic hypophysitis in women have been reported previously in association with various degrees of hypopituitarism. We report two pregnant patients who presented with mass lesions of the sella turcica, clinically mimicking pituitary adenoma. However, pathologic examination revealed extensive infiltration of the anterior pituitary by lymphocytes and plasma cells with destruction of the gland. To our knowledge, the ultrastructural features of lymphocytic hypophysitis have not been studied so far.For transmission electron microscopy, tissue from surgical specimens was fixed in glutaraldehyde, postfixed in OsO4, dehydrated and embedded in epoxy-resin. Ultrathin sections were stained with uranyl acetate and lead citrate and examined with a Philips 300 electron microscope.Electron microscopy revealed adenohypophysial cells of all types exhibiting varying degrees of injury. In the areas of most dense inflammatory cell infiltration pituitary cells contained large lysosomal bodies fusing with secretory granules (Fig. 1), as well as increased numbers of swollen mitochondria, indicating oncocytic transformation (Fig. 2).

Measurement of spontaneous neuronal membrane activity by time lapse confocal microscopy

1995 ◽  
Vol 53 ◽  
pp. 972-973
Author(s):  
R H. Selinfreund ◽  
A. H. Cornell-Bell
Keyword(s):  
Membrane Potential ◽  
Confocal Microscopy ◽  
Patch Clamp ◽  
Electrical Activity ◽  
Time Lapse ◽  
Neuronal Firing ◽  
Neuronal Membrane ◽  
Pituitary Cells ◽  
Patch Clamp Recording ◽  
Spontaneous Electrical Activity

Cellular electrophysiological properties are normally monitored by standard patch clamp techniques . The combination of membrane potential dyes with time-lapse laser confocal microscopy provides a more direct, least destructive rapid method for monitoring changes in neuronal electrical activity. Using membrane potential dyes we found that spontaneous action potential firing can be detected using time-lapse confocal microscopy. Initially, patch clamp recording techniques were used to verify spontaneous electrical activity in GH4\C1 pituitary cells. It was found that serum depleted cells had reduced spontaneous electrical activity. Brief exposure to the serum derived growth factor, IGF-1, reconstituted electrical activity. We have examined the possibility of developing a rapid fluorescent assay to measure neuronal activity using membrane potential dyes. This neuronal regeneration assay has been adapted to run on a confocal microscope. Quantitative fluorescence is then used to measure a compounds ability to regenerate neuronal firing.The membrane potential dye di-8-ANEPPS was selected for these experiments. Di-8- ANEPPS is internalized slowly, has a high signal to noise ratio (40:1), has a linear fluorescent response to change in voltage.

Correlative transmission and high-resolution scanning electron microscopic studies on pituitary cells

1990 ◽  
Vol 48 (3) ◽  
pp. 20-21
Author(s):  
S. Tai
Keyword(s):  
Cell Types ◽  
Depth Of Field ◽  
Secretory Cells ◽  
Specific Cell ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
3 Dimensional ◽  
Microscopic Studies ◽  
Structure And Activity ◽  
Intracellular Structure

Extensive cytological and histological research, correlated with physiological experimental analysis, have been done on the anterior pituitaries of many different vertebrates which have provided the knowledge to create the concept that specific cell types synthesize, store and release their specific hormones. These hormones are stored in or associated with granules. Nevertheless, there are still many doubts - that need further studies, specially on the ultrastructure and physiology of these endocrine cells during the process of synthesis, transport and secretion, whereas some new methods may provide the information about the intracellular structure and activity in detail.In the present work, ultrastructural study of the hormone-secretory cells of chicken pituitaries have been done by using TEM as well as HR-SEM, to correlate the informations obtained from 2-dimensional TEM micrography with the 3-dimensional SEM topographic images, which have a continous surface with larger depth of field that - offers the adventage to interpretate some intracellular structures which were not possible to see using TEM.

Metallic prions

2004 ◽  
Vol 71 ◽  
pp. 193-202 ◽  
Author(s):  
David R Brown
Keyword(s):  
Prion Protein ◽  
Binding Capacity ◽  
Normal Function ◽  
Transmissible Spongiform Encephalopathies ◽  
Published Data ◽  
Normal Brain ◽  
Copper Binding ◽  
Loss Of Function ◽  
Spongiform Encephalopathies ◽  
The Brain

Prion diseases, also referred to as transmissible spongiform encephalopathies, are characterized by the deposition of an abnormal isoform of the prion protein in the brain. However, this aggregated, fibrillar, amyloid protein, termed PrPSc, is an altered conformer of a normal brain glycoprotein, PrPc. Understanding the nature of the normal cellular isoform of the prion protein is considered essential to understanding the conversion process that generates PrPSc. To this end much work has focused on elucidation of the normal function and activity of PrPc. Substantial evidence supports the notion that PrPc is a copper-binding protein. In conversion to the abnormal isoform, this Cu-binding activity is lost. Instead, there are some suggestions that the protein might bind other metals such as Mn or Zn. PrPc functions currently under investigation include the possibility that the protein is involved in signal transduction, cell adhesion, Cu transport and resistance to oxidative stress. Of these possibilities, only a role in Cu transport and its action as an antioxidant take into consideration PrPc's Cu-binding capacity. There are also more published data supporting these two functions. There is strong evidence that during the course of prion disease, there is a loss of function of the prion protein. This manifests as a change in metal balance in the brain and other organs and substantial oxidative damage throughout the brain. Thus prions and metals have become tightly linked in the quest to understand the nature of transmissible spongiform encephalopathies.

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