Changes with Development in the Expression of Cathepsin E in the Fetal Rat Stomach

Yonezawa, Satoshi; Maejima, Yukari; Hagiwara, Naoki; Aratani, Tomoko; Shoji, Ryujiro; Kageyama, Takashi; Tsukada, Sachiyuki; Ichinose, Masakazu

doi:10.1111/j.1440-169x.1993.00349.x

Cited by 14 publications

(12 citation statements)

References 42 publications

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“…Pepsin or pepsinogen, as mentioned above, may be transported into the yolk together with the egg white. Another possible candidate is cathepsin E, which is known to be expressed in the fetal rat stomach until pepsinogen C appears (Yonezawa et al 1993). When the turnover of stomach epithelium takes place, the enzyme also may be transported along with the egg white.…”

Section: Discussionmentioning

confidence: 99%

Absorption, transportation and digestion of egg white in quail embryos

et al. 2002

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The present study was done to reveal how egg white is taken up by embryonic tissues, the pathway through which egg white is transported, and the location where it is digested during the development of the quail Coturnix japonica. Antiserum against quail ovalbumin was raised in rabbit and used as a probe. By immunoelectron microscopy, the uptake of ovalbumin on a small scale by receptor-mediated endocytosis was observed in the ectodermal cells of the yolk sac on days four to seven of incubation. The uptake of egg white on a large scale by fluid-phase endocytosis took place in the cells generally referred to collectively as the 'albumen sac'. The ovalbumin was transported through the albumen sac into the extraembryonic cavity during days eight to 10, and then into the amniotic cavity through the amnion approximately on day 10. Ovalbumin was present in the intestinal lumen on days 11 and 14, but it was not digested in the intestinal epithelial cells. The ovalbumin was detected in the yolk of embryos after day 10. Immunoblot testing, as well as a fluoroimmunoassay, revealed that the location where the amount of ovalbumin was highest changed chronologically from the extraembryonic cavity on day 10 to the amniotic cavity on day 11, the intestinal lumen on day 12 and then to the yolk on day 13. Several low molecular proteins which cross-reacted with the antiserum were observed in the extracts of the yolk. The reaction producing these proteins depended on low pH (approximately 3.0) and was inhibited by pepstatin A. The ovotransferrin was similarly digested. These results indicate that egg white is, for the most part, transported through the albumen sac to the yolk via the extraembryonic cavity, the amniotic cavity, and the intestinal lumen, and is digested in the yolk by aspartic proteinases.

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Section: Discussionmentioning

confidence: 99%

Absorption, transportation and digestion of egg white in quail embryos

et al. 2002

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“…These results suggest that CE is increasingly expressed in these rat brain tissues with aging and greatly processed to the mature CE. On the other hand, CE in most rat tissues such as spleen and stomach has been shown to be predominantly present as the enzymatically inactive proform (Yonezawa et al, 1993;Okamoto et al, 199S). This protein is also known to exist in normal human erythrocyte membranes in the proform, which can be easily activated by cell aging or oxidant challenge .…”

Section: Discussionmentioning

confidence: 99%

Increased Expression of Cathepsins E and D in Neurons of the Aged Rat Brain and Their Colocalization with Lipofuscin and Carboxy‐Terminal Fragments of Alzheimer Amyloid Precursor Protein

Nakanishi¹,

Amano²,

Sastradipura³

et al. 1997

Journal of Neurochemistry

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Age‐related changes in the expression and localization of two distinct intracellular aspartic proteinases, cathepsin E (CE) and cathepsin D (CD), were investigated in the rat cerebral cortex and the brainstem by immunocytochemical and quantitative methods using discriminative antibodies specific for each enzyme. Non‐lysosomal CE was barely detectable in these two brain tissues in the embryonic stages, whereas relatively high expression of lysosomal CD was observed in embryonic tissues. After birth, CE was increasingly expressed in these tissues with aging to attain maximal levels at 30 months of age. Western blot analyses revealed that CE existed predominantly as the mature enzyme at 2 and 17 months of age, whereas it was present as not only the mature enzyme but also the proenzyme at 30 months of age. On the other hand, CD was mainly present in the mature form throughout development, although its level in these tissues was also significantly increased with aging. The CE‐positive cortical and brainstem neurons of the aged rat corresponded well with cells emitting autofluorescence for lipopigments. By the double‐staining technique, most of the CE‐positive cortical and brainstem neurons of the aged rat were also positive for antibody to the carboxyl‐terminal fragments of amyloid precursor protein (APP634–695), intracellular accumulation of which is thought to be associated with age‐related changes in the endosome/lysosome system. It is important that electron microscopy revealed that CE in brainstem neurons of the aged rat colocalized with CD in the lipofuscin‐containing lysosomes. These results indicate that aging results in the increased expression and lysosomal localization of CE in cortical and brainstem neurons and changes in the endosomal/lysosomal proteolytic system, which may be related to lipofuscinogenesis and altered intracellular APP metabolism.

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“…The developmental change of acid protease activity in fetal rat glandular stomach tissues has been described in detail elsewhere [31]. The Table 1.…”

Section: Enzyme Assaymentioning

confidence: 99%