A Genome-Wide Expression Profile of Steroidogenic Cells Selectively Derived from Adrenal Glands of Knockout Mice Lacking Steroidogenic Acute Regulatory Protein by Targeted Expression of Enhanced Green Fluorescent Protein.

Steroidogenic acute regulatory protein (StAR) facilitates cholesterol transfer into the inner mitochondrial membrane in the acute phase of steroidogenesis. Mice lacking StAR (Star−/−) share phenotypes with human individuals having congenital lipoid adrenal hyperplasia including compromised production of steroid hormones and florid accumulation of cholesterol esters in adrenal glands and gonads. To define a specific pattern of molecular changes with StAR deficiency, we performed transcriptome analysis of adrenal cells selectively isolated by fluorescent-activated cell sorting at embryonic d 17.5 or 18.5 in seven wild-type (Star+/+) or four Star−/− mice having the transgene targeting the enhanced green fluorescent protein to cell lineages that express StAR. A gene expression profile was obtained by whole-mouse genome microarray and confirmed by quantitative real-time PCR, identifying 1206 and 767 significantly up-regulated and down-regulated genes, respectively, in Star−/− mice compared with Star+/+ mice (fold difference ≥ 2 and P value < 0.05 with false discovery rate < 0.2). In Star−/− mice, expression levels of genes involved in cholesterol efflux and the inflammatory response were significantly up-regulated, whereas those related to steroid hormone biosynthesis or cholesterol biosynthesis and influx were not significantly changed. Immunoreactive Iba1 or F4/80 (macrophage marker) in adrenal glands of Star−/− mice was detected not only in an increased number of resident macrophages but also in most adrenocortical cells. These findings expand our understanding of the pathophysiology of adrenal glands with the disruption of StAR and propose a reciprocal interaction between adrenocortical cells and resident macrophages inside adrenal glands of Star−/− mice.

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Complex Role of the Mitochondrial Targeting Signal in the Function of Steroidogenic Acute Regulatory Protein Revealed by Bacterial Artificial Chromosome Transgenesis in Vivo

Molecular Endocrinology ◽

10.1210/me.2007-0493 ◽

2008 ◽

Vol 22 (4) ◽

pp. 951-964 ◽

Cited By ~ 38

Author(s):

Goro Sasaki ◽

Tomohiro Ishii ◽

Pancharatnam Jeyasuria ◽

Youngah Jo ◽

Assaf Bahat ◽

...

Keyword(s):

Bacterial Artificial Chromosome ◽

Adrenal Cortex ◽

Regulatory Protein ◽

Artificial Chromosome ◽

Steroidogenic Acute Regulatory Protein ◽

Mitochondrial Targeting ◽

Targeting Signal ◽

Steroidogenic Cells ◽

Steroidogenic Acute Regulatory

The steroidogenic acute regulatory protein (StAR) stimulates the regulated production of steroid hormones in the adrenal cortex and gonads by facilitating the delivery of cholesterol to the inner mitochondrial membrane. To explore key aspects of StAR function within bona fide steroidogenic cells, we used a transgenic mouse model to explore the function of StAR proteins in vivo. We first validated this transgenic bacterial artificial chromosome reconstitution system by targeting enhanced green fluorescent protein to steroidogenic cells of the adrenal cortex and gonads. Thereafter, we targeted expression of either wild-type StAR (WT-StAR) or a mutated StAR protein lacking the mitochondrial targeting signal (N47-StAR). In the context of mice homozygous for a StAR knockout allele (StAR−/−), all StAR activity derived from the StAR transgenes, allowing us to examine the function of the proteins that they encode. The WT-StAR transgene consistently restored viability and steroidogenic function to StAR−/− mice. Although the N47-StAR protein was reportedly active in transfected COS cells and mitochondrial reconstitution experiments, the N47-StAR transgene rescued viability in only 40% of StAR−/− mice. Analysis of lipid deposits in the primary steroidogenic tissues revealed a hierarchy of StAR function provided by N47-StAR: florid lipid deposits were seen in the adrenal cortex and ovarian theca region, with milder deposits in the Leydig cells. Our results confirm the ability of StAR lacking its mitochondrial targeting signal to perform some essential functions in vivo but also demonstrate important functional defects that differ from in vitro studies obtained in nonsteroidogenic cells.

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Genome-wide analysis ofSaccharomyces cerevisiaeidentifies cellular processes affecting intracellular aggregation of Alzheimer's amyloid-β42: importance of lipid homeostasis

Molecular Biology of the Cell ◽

10.1091/mbc.e13-04-0216 ◽

2014 ◽

Vol 25 (15) ◽

pp. 2235-2249 ◽

Cited By ~ 18

Author(s):

S. Nair ◽

M. Traini ◽

I. W. Dawes ◽

G. G. Perrone

Keyword(s):

Fluorescent Protein ◽

Amyloid Β ◽

Major Effect ◽

Early Event ◽

Cellular Mechanisms ◽

Data Set ◽

Cellular Processes ◽

Genome Wide ◽

A Genome ◽

Green Fluorescent

Amyloid-β (Aβ)–containing plaques are a major neuropathological feature of Alzheimer's disease (AD). The two major isoforms of Aβ peptide associated with AD are Aβ40 and Aβ42, of which the latter is highly prone to aggregation. Increased presence and aggregation of intracellular Aβ42 peptides is an early event in AD progression. Improved understanding of cellular processes affecting Aβ42 aggregation may have implications for development of therapeutic strategies. Aβ42 fused to green fluorescent protein (Aβ42-GFP) was expressed in ∼4600 mutants of a Saccharomyces cerevisiae genome-wide deletion library to identify proteins and cellular processes affecting intracellular Aβ42 aggregation by assessing the fluorescence of Aβ42-GFP. This screening identified 110 mutants exhibiting intense Aβ42-GFP–associated fluorescence. Four major cellular processes were overrepresented in the data set, including phospholipid homeostasis. Disruption of phosphatidylcholine, phosphatidylserine, and/or phosphatidylethanolamine metabolism had a major effect on intracellular Aβ42 aggregation and localization. Confocal microscopy indicated that Aβ42-GFP localization in the phospholipid mutants was juxtaposed to the nucleus, most likely associated with the endoplasmic reticulum (ER)/ER membrane. These data provide a genome-wide indication of cellular processes that affect intracellular Aβ42-GFP aggregation and may have important implications for understanding cellular mechanisms affecting intracellular Aβ42 aggregation and AD disease progression.

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Von Hermaphroditos der griechischen Mythologie bis zu DSD der Moderne

Praxis ◽

10.1024/1661-8157.98.1.31 ◽

2008 ◽

Vol 98 (1) ◽

pp. 31-34

Author(s):

Oestmann ◽

Mullis ◽

Stanga

Keyword(s):

Regulatory Protein ◽

Steroidogenic Acute Regulatory Protein ◽

Sich Eine ◽

Fand Sich ◽

Steroidogenic Acute Regulatory

Wir berichten über eine heute 34-jährige Frau, die im Alter von 6 Monaten wegen rezidivierendem Erbrechen hospitalisiert werden musste. Als Ursache fand sich eine Nebenniereninsuffizienz mit Verminderung sämtlicher Hormone der Steroidhormonbiosynthese. Die weiteren Abklärungen ergaben bei dem phänotypisch weiblichen Säugling eine lipoide kongenitale adrenale Hyperplasie mit 46,XY DSD. 24 Jahre später konnte in der DNS-Sequenzanalyse ein homozygoter, in der Schweiz vorkommender Basenaustausch des steroidogenic acute regulatory protein-Gens gefunden werden, welcher zu einem Aminosäurenaustausch Leucin 260 Prolin (L260P) führt.

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