Melanoma growth stimulatory activity is a mitogenic polypeptide secreted by human melanoma cells. The mature form is maximally 73 amino acids long. MGSA is structurally related to the platelet-derived beta-thromboglobulin. It is the product of the gene GRO isolated by Anisowicz et al. (1987). Horuk et al. (1993) indicated that structurally MGSA belongs to a superfamily of proteins that includes interleukin-8 and platelet factor-4. These proteins are involved in inflammatory processes.A cytokine-induced neutrophil chemoattractant (CINC/gro), an interleukin (IL)-8-like neutrophil chemoattractant, has been purified and cloned from the culture fluid of a rat kidney epitheloid cell line NRK-52E . The primary structure of CINC/gro indicates that it is the rat counterpart of human GRO and therefore belongs to the IL-8 family, which acts as a functional chemoattractant for neutrophils in vivo.
General function
Ligand, Hormone
Comment
Cellular localization
Secreted
Comment
Ovarian function
Ovulation, Luteinization
Comment
Ovulation is an inflammation-like reaction in which leukocytes are postulated to have a central role. The abundance of leukocytes in the ovary varies with the stage of the cycle and a marked influx of neutrophils and monocytes into the interior of the follicle during ovulation has been observed. The intraovarian
signals causing this preovulatory influx are not known. Ushigoe K et al 2000 examined whether CINC/gro contributes to the
ovulation process in the rat ovulation system. They found that CINC/gro protein did not increase as a result of PMSG injection. However, it increased rapidly after hCG injection and
peaked at 6 h after hCG. CINC/gro mRNA was also strongly expressed after hCG injection. The increase of CINC/gro
protein followed increases in IL-1beta and tumor necrosis factor (TNF). In the whole ovarian dispersate culture, FSH,
hCG, IL-1beta, and TNF stimulated the production of CINC/gro protein in a dose-dependent manner. In particular, the
stimulatory effects of IL-1beta and TNF were stronger than those of gonadotropins. These results suggest that CINC/gro
plays an important role in the rat ovulation process by attracting neutrophils.
The Role of Bone Morphogenetic Protein 6 in Accumulation and Regulation of Neutrophils in the Human Ovary. Akiyama I 2014 et al.
Bone morphogenetic protein (BMP) cytokine is known to regulate ovulation, as BMP-6 null mice exhibit a decrease in the number of ovulatory follicles without effect on either the morphology or the dynamics of follicular development. In the present study, the role of BMP-6 in ovulatory process was investigated using human granulosa-lutein cells (GCs). Granulosa-lutein cells, obtained from in vitro fertilization patients, were cultured with BMP-6 followed by RNA extraction. The neutrophil-chemotactic activity of the supernatant of cultured GC was investigated. Bone morphogenetic protein 6 significantly increased growth-regulated oncogene a (GRO-a) messenger RNA (mRNA) and protein expression in GC. In the neutrophil-chemotaxis assay, the GC supernatant cultured with BMP-6 attracted more neutrophils than control samples, which was negated with anti-GRO-a neutralizing antibody. Bone morphogenetic protein 6 also suppressed the relative expression of the protease inhibitors, secretory leukocyte peptidase inhibitor, and whey acid protein 14 mRNA in GC. Bone morphogenetic protein 6 might play a role in ovulation by increasing the accumulation of neutrophils in the ovulatory follicle and suppressing the effect of protease inhibitors.
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The Effects of Epidermal Growth Factor and Transforming Growth Factor-a on Secretion of Interleukin-8 and Growth-Regulated Oncogene-a in Human Granulosa-Lutein Cells. Kawano Y et al. Background: In order to investigate the roles of epidermal growth factor (EGF) and transforming growth factor (TGF)-a in ovulation, we studied the production of interleukin (IL)-8 and growth-regulated oncogene (GRO)-a in cultured human granulosa-lutein cells. Methods: Granulosa-lutein cells obtained from the follicular fluids of in vitro fertilization and embryo transfer patients were cultured and treated with EGF, TGF-a, tumor necrosis factor (TNF)-a or 12-O-tetradecanoylphorbol 13-acetate (TPA). An immortalized granulosa cell line (GC1a) was also cultured and treated with EGF, TGF-a or mitogen-activated protein kinase kinase inhibitor. The supernatants were collected, and IL-8 and GRO-a were measured by ELISA. Results: The levels of IL-8 and GRO-a were significantly increased after treatment with EGF, TGF-a, TNF-a and TPA by primary cultured granulosa-lutein cells. The levels of IL-8 and GRO-a were also significantly increased after treatment with EGF or TGF-a in a dose-dependent manner by GC1a. When GC1a was treated with EGF, TGF-a or U0126, the levels of IL-8 and GRO-a were significantly decreased. Conclusion: Our data indicate that the production of IL-8 and GRO-a is upregulated by EGF and TGF-a. It is suggested that EGF and TGF-a may play an important role in luteinization processes involving IL-8 and GRO-a production.
Karstrom-Encrantz et al reported that the concentrations of GROalpha in the cell culture medium were increased by the presence of the proinflammatory cytokine interleukin (IL)-1beta, with ~10-fold higher concentrations in the medium, compared with the controls.
Oral E et al hypothesized that growth-regulated alpha (GRO alpha), a neutrophil chemoat-tractant/activating factor, may be a modulator of periovulatory neutrophil chemotaxis. They showed that in human follicular fluids the mean pre-hCG GRO alpha level was 51 pg/ml, post-hCG it was 210 pg/ml. GRO was produced constitutively by ovarian stromal and granulosa-lutein cells. Interleukin-alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF-alpha) further stimulated GRO alpha production. Treatment of stromal cells with hCG also stimulated GRO alpha production.
Interleukin (IL)-1{alpha}-Induced Chemokines in Mouse Granulosa Cells: Impact on Keratinocyte Chemoattractant (KC) Chemokine, a CXC Subfamily. Son DS et al. Interleukin-1 (IL-1) is well known to be involved in the immune system and have a role in ovarian inflammation as well as exhibiting inhibitory effects on steroidogenesis and folliculogenesis. Since multiple ascpects of ovarian function have also been shown to involve cytokine/chemokine networks, IL-1alpha-induced chemokine gene expression in mouse granulosa cells was investigated. Granulosa cells from immature mice at 28 days of age were cultured with IL-1alpha (10 ng/ml). IL-1alpha induced abundantly and specifically keratinocyte chemoattractant (KC) chemokine, (CXCL1 homology)a CXC subfamily. KC chemokine mRNA and protein were increased 1-2 h after IL-1alpha and then gradually decreased. The KC promoter (-701/+30) containing three nuclear factor (NF)-kappaB sites was fully responsive to IL-1alpha whereas deletions and mutants of the NF-kappaB sites lowered the responsiveness to IL-1alpha. The proximal NF-kappaB site (-69/-59) played a critical role in regulating IL-1alpha-induced KC chemokine promoter activity. Overexpression of the inhibitor of NF-kappaB (IkappaB) blocked KC promoter activity induced by IL-1alpha whereas overexpression of p65, a component of NF-kappaB, increased promoter activity and mRNA of KC chemokine. In addition, FSH (FSH) did not affect NF-kappaB signaling or IL-1alpha-induced KC chemokine promoter activity. Within 1-3 h after ip injection of lipopolysaccharide (LPS, 100 microg/mouse), a product known to stimulate release of IL-1, KC chemokine was localized in the ovary to granulosa cells as well as the thecal-interstitial layer. The results of this study indicate that KC gene is a chemokine induced acutely by IL-1alpha via NF-kappaB signaling in mouse granulosa cells.
Ovarian localization
Granulosa, Theca, Luteal cells
Comment
GROalpha was localized by immunohistochemistry predominantly in the theca layer but also in the granulosa layer of the dominant follicle during the late follicular phase. Ushigoe K et al 2000 found that In rat ovaries, CINC/gro was immunohistochemically recognized in the theca layer of the antral follicle but not in the granulosa cells. While Karstrom-Encrantz et al found cultured granulosa-lutein cells secreted detectable amounts of GROalpha.
Follicle stages
Preovulatory, Corpus luteum
Comment
Ushigoe K et al examined whether CINC/gro contributes to the ovulation process in the rat ovulation system. In rat ovaries, CINC/gro was immunohistochemically recognized in the theca layer of the antral follicle but not in the granulosa cells. To clarify the role of CINC/gro in the ovulation process, CINC/gro protein and mRNA were examined during pregnant mare serum gonadotropin (PMSG)-hCG treatment. CINC/gro protein did not increase as a result of PMSG injection. However, it increased rapidly after hCG injection and peaked at 6 h after hCG. CINC/gro mRNA was also strongly expressed after hCG injection. The increase of CINC/gro protein followed increases in IL-1beta and tumor necrosis factor alpha (TNFalpha). In the whole ovarian dispersate culture, FSH, hCG, IL-1beta, and TNFalpha stimulated the production of CINC/gro protein in a dose-dependent manner. In particular, the stimulatory effects of IL-1beta and TNFalpha were stronger than those of gonadotropins. These results suggest that CINC/gro plays an important role in the rat ovulation process by attracting neutrophils. CINC/gro increased just prior to ovulation, and it may be regulated directly by cytokines such as IL-1beta and TNFalpha and indirectly by gonadotropins.