A note on alkaline phosphatase activity of germ cells in Amblystoma and chick embryos

Duodenal differentiation in normal chick embryos between 15·75 and 20·5 days of incubation was characterized by the following changes: 1. The dry weight increases from 4·1 to 12·4 mg. 2. The alkaline phosphatase activity increases from less than 12 to 426 units. 3. The length of the villi increases sixfold. 4. The height of the epithelial cells at the villous tips increases from 12·9 to 25·9 μ. 5. The shape of the mucosal cells changes from low columnar, to cuboidal, to high columnar. 6. The shape of the nuclei progresses from round to ovoid. 7. At first mitotic figures are distributed throughout the epithelium but become restricted to the crypts of Lieberkühn. 8. Cytoplasmic glycogen appears by day 15·75 and is mobilized by 20·5 days. 9. A mucopolysaccharide at the brush border of the mucosal cells progressively appears at 16·75 days and increases in amount. 10. Alkaline phosphatase activity (Gomori technique) at the brush border appears in low levels at 16·75 days and becomes more intense. 11. Fresh body weights and third toe lengths at 19·75 and 20·5 days of incubation were recorded as indices of body growth. In ‘hypophysectomized’ embryos at 19·75–21·5 days of age: 12. The level of duodenal differentiation approximated that of normal 16·75–17·75 day embryos. 13. In ‘phypophysectomized’ embryos which received a pars distalis chorioallantoic homograft at 9·5 days of incubation the duodena were normal. 14. In ‘hypophysectomized’ embryos with grafts which became atrophic the level of duodenal differentiation was not different from that of untreated ‘hypophysectomized’ embryos. 15. In chick embryos duodenal differentiation depends on pars distalis hormones.

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Ectopic FGF23 production induces mineral changes, osteogenic transdifferentiation, and cancer associated microcalcifications

10.1101/2020.06.25.171355 ◽

2020 ◽

Author(s):

Ida Marie Boisen ◽

John Erik Nielsen ◽

Ireen Kooij ◽

Jovana Kaludjerovic ◽

Peter J. O’Shaughnessy ◽

...

Keyword(s):

Alkaline Phosphatase ◽

Germ Cell ◽

Phosphatase Activity ◽

Sertoli Cell ◽

Germ Cells ◽

Alkaline Phosphatase Activity ◽

Cell Cancer ◽

Seminiferous Tubules ◽

Testicular Germ Cell ◽

Increased Risk

AbstractTesticular microcalcifications consist of hydroxyapatite and their demonstration by ultrasound has been associated with increased risk of testicular germ cell cancer (TGCT). Here, we show that fibroblast growth factor 23 (FGF23), a bone-specific regulator of phosphate homeostasis, is expressed in testicular germ cell neoplasia in situ (GCNIS), embryonal carcinoma (EC), and human embryonic stem cells. FGF23 is not glycosylated in TGCTs and thus rapidly cleaved into a C-terminal fragment that serves as a competitive antagonist for full-length FGF23. High levels of C-terminal FGF23 occupy the receptor formed by Klotho and FGF receptor 1 (FGFR1) in the germ cells facilitating a shift in the expression of phosphate transport proteins from SLC34A2 to SLC34A1 in seminiferous tubules adjacent to GCNIS. Fgf23 knockout mice have a marked epididymal deposition of hydroxyapatite, while the testicular phenotype is milder with spermatogenic arrest and focal germ-cell-specific expression of the bone-like markers runt-related transcription factor 2 (RUNX2) and bone gamma-carboxyglutamic acid-containing protein (BGLAP). In accordance, mice with no functional androgen receptor and lack of circulating gonadotropins develop microcalcifications in 94% of cases and have lower Slc34a2, and higher Slc34a1 and Bglap expression. In accordance, human testicular specimens with microcalcifications also have lower SLC34A2, and focally germ cells express SLC34A1, BGLAP, and RUNX2. Importantly, calcium or phosphate induced osteogenic transdifferentiation of a spermatogonial cell line in vitro demonstrated by induction of alkaline phosphatase activity and deposition of hydroxyapatite, which could be fully rescued by pyrophosphate (PPi). Severe microcalcifications were also found in a mouse model with Sertoli-cell ablation particularly when Sertoli-ablation was conducted prepubertally where the germ cells retain stem cell potential. In conclusion, cancer-related microcalcifications may arise secondary to gonadal mineral alterations, which in combination with impaired Sertoli cell function and reduced PPi due to high alkaline phosphatase activity in GCNIS and TGCTs, facilitates osteogenic transdifferentiation of testicular germ cells and deposition of hydroxyapatite.

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The maturation of cortisone-treated embryonic duodenum in vitro. II. The striated border

Development ◽

10.1242/dev.14.2.169 ◽

1965 ◽

Vol 14 (2) ◽

pp. 169-179

Author(s):

Raymond L. Hayes

Keyword(s):

Alkaline Phosphatase ◽

Phosphatase Activity ◽

Alkaline Phosphatase Activity ◽

Duodenal Mucosa ◽

Cortisone Acetate ◽

Chick Embryos ◽

Adrenal Steroids ◽

Pituitary Glands ◽

In Vitro Maintenance

Regulation of the morphological and physiological maturation of embryonic duodenal mucosa by adrenocorticoid hormones has been demonstrated with a variety of techniques. Single injections of cortisone acetate (Moog & Richardson, 1955; Moog & Thomas, 1957); multiple daily administrations of cortisone (Moog & Ford, 1957; Moog, 1959); or in vitro maintenance of duodenal fragments with adrenal steroids (Moog & Nehari, 1954; Moog & Kirsch, 1955) all accelerate morphogenesis and the onset of alkaline phosphatase activity in this tissue. The differentiation of the duodenal mucosa is not only responsive to hormonal application but is dependent on it. Hinni & Watterson (1963) have ablated pituitary glands from chick embryos, hence interrupting the hypophysealadrenal axis and arresting adrenal function. Following this procedure, morphogenesis is retarded and alkaline phosphatase activity in the epithelium diminished. Release from adrenocortical influence does not modify the course of differentiation, but does affect the rate of cellular maturation.

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LEUCOCYTE METABOLISM IN PREGNANCY

Acta Endocrinologica ◽

10.1530/acta.0.xxxv0575 ◽

1960 ◽

Vol XXXV (IV) ◽

pp. 575-584 ◽

Cited By ~ 2

Author(s):

C. Borel ◽

J. Frei ◽

A. Vannotti

Keyword(s):

Alkaline Phosphatase ◽

Oxygen Consumption ◽

Pregnant Women ◽

Phosphatase Activity ◽

Alkaline Phosphatase Activity ◽

Lactate Production ◽

Glucose Consumption ◽

In Pregnancy

ABSTRACT Enzymatic studies, on leucocytes of pregnant women, show an increase of the alkaline phosphatase activity and a decrease of the glucose consumption and lactate production, as well as of proteolysis. The oxygen consumption, with succinate as substrate, does not vary.

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