The maturational breakdown of mitochondria in reticulocytes

Rapoport, S.; Schewe, Tankred

doi:10.1016/0304-4157(86)90006-7

Cited by 140 publications

(104 citation statements)

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“…In the human airway epithelium, the expression of 15-LO is observed during retinoid-induced cell differentiation (25). Furthermore, increased expression of rabbit reticulocyte 15-LO is observed during reticulocyte maturation (51). The overexpression of peroxisome proliferator-activated receptor (PPAR)␥ in rat intestinal tumors was recently reported, and Caco-2 cells were found to express the highest levels of PPAR␥ of all the human colorectal cell lines tested (52).…”

Section: Discussionmentioning

confidence: 97%

Expression of 15-Lipoxygenase by Human Colorectal Carcinoma Caco-2 Cells during Apoptosis and Cell Differentiation

Kamitani

Geller

Eling

1998

Journal of Biological Chemistry

130

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We studied arachidonic acid metabolism and the expression of cyclooxygenase (Cox) and 15-lipoxygenase (15-LO) in the human colorectal carcinoma cell line, Caco-2, which undergo apoptosis and cell differentiation in the presence of sodium butyrate (NaBT). Caco-2 cells expressed very low levels of Cox-1 but highly expressed Cox-2. NaBT treatment shifted the arachidonic acid metabolites by cell lysates from prostaglandins to 15-hydroxyeicosatetraenoic acid, indicating the presence of a 15-LO. Linoleic acid, an excellent substrate for 15-LO, was metabolized poorly by the Caco-2 cells, but NaBT treatment shifted metabolism to 15-LO metabolite, 13(S)-hydroxyoctadecadienoic acid. Caco-2 cells expressed a 15-LO but only after treatment with NaBT, as determined by Northern blotting. Immunoblotting with anti-human 15-LO antibody detected a 72-kDa band in NaBT-treated Caco-2 cells. Expression of 15-LO mRNA was dependent on the duration of NaBT treatment, with the highest expression observed between 10 and 24 h. Results from expression and metabolism studies with arachidonic and linoleic acid cells indicated Cox-2 was responsible for the lipid metabolism in control cells, whereas 15-LO was the major enzyme responsible after NaBT induction of apoptosis and cell differentiation. The 15-LO in Caco-2 cells was characterized as human reticulocyte 15-LO by reverse transcription-polymerase chain reaction and restriction enzyme analysis. The expression of 15-LO and 15-hydroxyeicosatetraenoic acid or 13(S)-hydroxyoctadecadienoic acid formation correlates with cell differentiation or apoptosis in Caco-2 cells induced by NaBT. The addition of nordihydroguaiaretic acid, a lipoxygenase inhibitor, significantly increased NaBT-induced apoptosis, whereas the addition of indomethacin did not alter NaBT-induced apoptosis in the Caco-2 cells. However, indomethacin treatment decreased the expression of Cox-2 in NaBT-treated cells and significantly increased the expression of 15-LO during NaBT treatment. These studies suggest a role for 15-LO, in addition to Cox-2, in modulating NaBT-induced apoptosis and cell differentiation in human colorectal carcinoma cells.The first genetic alteration in the multistep process that leads to the development of colon carcinogenesis seems to be the loss of APC gene function. Investigations of APC function and its mutations have provided important clues in understanding colon cancer (1). One of the important changes that results from the loss of the APC gene function is the overexpression of prostaglandin H synthase-2 (cyclooxygenase-2, Cox-2), 1 an inducible enzyme that converts arachidonic acid to prostaglandins. The link between APC, Cox-2, and polyp formation was firmly established in studies using APC (Apc ⌬716 ) and Cox-2 knockout mice (2). Mice carrying the APC mutation overexpress Cox-2 and develop intestinal polyps. When bred to mice with the disrupted Cox-2 gene, the offspring, homozygously deficient for Cox-2, had significantly less polyps than the mice with wild-type Cox-2. These results confirmed C...

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Section: Discussionmentioning

confidence: 97%

Expression of 15-Lipoxygenase by Human Colorectal Carcinoma Caco-2 Cells during Apoptosis and Cell Differentiation

Kamitani

Geller

Eling

1998

Journal of Biological Chemistry

130

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“…In the reticulocyte, another cell that eliminates organelles during development, the enzyme lipoxygenase is believed to play a crucial role by damaging mitochondrial membranes and permitting the ATP-ubiquitin proteolytic system to break down the mitochondrial components (Rapoport and Schewe, 1986). However, the reticulocyte lipoxygenase appears to be a cell-type specific enzyme, as lipoxygenases from other cells are apparently incapable of priming mitochondrial degradation (Rapoport and Schewe, 1986). Thus, even though lipoxygenase activity has recently been demonstrated in the rat lens (Lysz et al, 1991) it may not play a role in mitochondrial breakdown.…”

Section: Discussionmentioning

confidence: 99%

Coincident loss of mitochondria and nuclei during lens fiber cell differentiation

Bassnett

Beebe

1992

Developmental Dynamics

200

153

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During normal differentiation, lens fiber cells lose their nuclei, mitochondria, and other membrane-bound organelles. In the present study, a slice preparation of the embryonic chicken lens was used with laser scanning confocal microscopy to study the spatial and temporal patterns of organelle breakdown during embryonic development. At all stages examined, mitochondria in lens epithelial cells were present in perinuclear clusters. In contrast, early in development, lens fiber cells contained extremely elongated mitochondria (>lo0 pm) that were distributed throughout the cytoplasm and oriented along the long axis of the cells. By the 8th day of embryonic development (E8), the mitochondria in the central fiber cells began to fragment. At the same time, the nuclei in these cells became smaller and more spherical. By E 10, mitochondria1 staining in the central fibers became punctate. Electron microscopy of this region revealed swollen mitochondria with disrupted cristae. By E12, cells in the central region of the lens lacked mitochondria and nuclei. The loss of nuclei and mitochondria from a given cell was coincident and abrupt (2-4 hr), occurring in a previously unsuspected domain situated about 300 pm from the anterior surface of the lens. A cytoskeletal component, actin, persisted in the central cells indicating that organelle degradation represents a selective process and not simply the global degradation of supramolecular structures. Throughout embryonic development, the organelle-free region grew at approximately the same rate as the lens and, by the time of hatching, had expanded to match the diameter of the pupil. The present results suggest that the embryonic lens will be a useful model system with which to study mechanisms of organelle degradation. o 1992 WiIey-Liss, Inc.

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“…This enzyme, together with vitamin E, which slows down the oxidative chain reaction driven by lipid peroxyl radicals (R-OO · ), plays an important protective role by preventing lipid decomposition (241). In addition to spontaneous lipid peroxidation, several physiological processes, e.g., recycling of mitochondria in reticulocytes, depend on enzymatic activity of 12/15-lipoxygenase (LOX) (291). By converting phospholipid hydroperoxides (R-OOH) to corresponding alcohols (R-OH), GPx4 prevents initiation of new chain reactions and serves as antagonist of 12/15-LOX preventing nonenzymatic lipid peroxidation (305).…”

Section: Selenoprotein Functionmentioning

confidence: 99%

Selenoproteins: Molecular Pathways and Physiological Roles

Labunskyy

Hatfield

Gladyshev³

2014

Physiological Reviews

1,063

835

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Selenium is an essential micronutrient with important functions in human health and relevance to several pathophysiological conditions. The biological effects of selenium are largely mediated by selenium-containing proteins (selenoproteins) that are present in all three domains of life. Although selenoproteins represent diverse molecular pathways and biological functions, all these proteins contain at least one selenocysteine (Sec), a seleniumcontaining amino acid, and most serve oxidoreductase functions. Sec is cotranslationally inserted into nascent polypeptide chains in response to the UGA codon, whose normal function is to terminate translation. To decode UGA as Sec, organisms evolved the Sec insertion machinery that allows incorporation of this amino acid at specific UGA codons in a process requiring a cis-acting Sec insertion sequence (SECIS) element. Although the basic mechanisms of Sec synthesis and insertion into proteins in both prokaryotes and eukaryotes have been studied in great detail, the identity and functions of many selenoproteins remain largely unknown. In the last decade, there has been significant progress in characterizing selenoproteins and selenoproteomes and understanding their physiological functions. We discuss current knowledge about how these unique proteins perform their functions at the molecular level and highlight new insights into the roles that selenoproteins play in human health.

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The maturational breakdown of mitochondria in reticulocytes

Cited by 140 publications

References 117 publications

Expression of 15-Lipoxygenase by Human Colorectal Carcinoma Caco-2 Cells during Apoptosis and Cell Differentiation

Expression of 15-Lipoxygenase by Human Colorectal Carcinoma Caco-2 Cells during Apoptosis and Cell Differentiation

Coincident loss of mitochondria and nuclei during lens fiber cell differentiation

Selenoproteins: Molecular Pathways and Physiological Roles

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