TY  - JOUR
AU  - Bjelobaba, Ivana
AU  - Janjić, Marija
AU  - Prévide, Rafael Maso
AU  - Abebe, Daniel
AU  - Kucka, Marek
AU  - Stojilković, Stanko S.
PY  - 2019
UR  - https://www.frontiersin.org/articles/10.3389/fendo.2019.00248/full
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/3363
AB  - Cell-matrix interactions play important roles in pituitary development, physiology, and pathogenesis. In other tissues, a family of non-collagenous proteins, termed SIBLINGs, are known to contribute to cell-matrix interactions. Anterior pituitary gland expresses two SIBLING genes, Dmp1 (dentin matrix protein-1) and Spp1 (secreted phosphoprotein-1) encoding DMP1 and osteopontin proteins, respectively, but their expression pattern and roles in pituitary functions have not been clarified. Here we provide novel evidence supporting the conclusion that Spp1/osteopontin, like Dmp1/DMP1, are expressed in gonadotrophs in a sex- and age-specific manner. Other anterior pituitary cell types do not express these genes. In contrast to Dmp1, Spp1 expression is higher in males; in females, the expression reaches the peak during the diestrus phase of estrous cycle. In further contrast to Dmp1 and marker genes for gonadotrophs, the expression of Spp1 is not regulated by gonadotropin-releasing hormone in vivo and in vitro. However, Spp1 expression increases progressively after pituitary cell dispersion in both female and male cultures. We may speculate that gonadotrophs signal to other pituitary cell types about changes in the structure of pituitary cell-matrix network by osteopontin, a function consistent with the role of this secretory protein in postnatal tissue remodeling, extracellular matrix reorganization after injury, and tumorigenesis.
PB  - Frontiers Media S.A.
T2  - Frontiers in Endocrinology
T1  - Distinct Expression Patterns of Osteopontin and Dentin Matrix Protein 1 Genes in Pituitary Gonadotrophs
IS  - MAR
VL  - 10
VL  - 10.3389/fendo.2019.00248
DO  - 10.3389/fendo.2019.00248
SP  - 248
ER  - 

@article{
author = "Bjelobaba, Ivana and Janjić, Marija and Prévide, Rafael Maso and Abebe, Daniel and Kucka, Marek and Stojilković, Stanko S.",
year = "2019",
abstract = "Cell-matrix interactions play important roles in pituitary development, physiology, and pathogenesis. In other tissues, a family of non-collagenous proteins, termed SIBLINGs, are known to contribute to cell-matrix interactions. Anterior pituitary gland expresses two SIBLING genes, Dmp1 (dentin matrix protein-1) and Spp1 (secreted phosphoprotein-1) encoding DMP1 and osteopontin proteins, respectively, but their expression pattern and roles in pituitary functions have not been clarified. Here we provide novel evidence supporting the conclusion that Spp1/osteopontin, like Dmp1/DMP1, are expressed in gonadotrophs in a sex- and age-specific manner. Other anterior pituitary cell types do not express these genes. In contrast to Dmp1, Spp1 expression is higher in males; in females, the expression reaches the peak during the diestrus phase of estrous cycle. In further contrast to Dmp1 and marker genes for gonadotrophs, the expression of Spp1 is not regulated by gonadotropin-releasing hormone in vivo and in vitro. However, Spp1 expression increases progressively after pituitary cell dispersion in both female and male cultures. We may speculate that gonadotrophs signal to other pituitary cell types about changes in the structure of pituitary cell-matrix network by osteopontin, a function consistent with the role of this secretory protein in postnatal tissue remodeling, extracellular matrix reorganization after injury, and tumorigenesis.",
publisher = "Frontiers Media S.A.",
journal = "Frontiers in Endocrinology",
title = "Distinct Expression Patterns of Osteopontin and Dentin Matrix Protein 1 Genes in Pituitary Gonadotrophs",
number = "MAR",
volume = "10, 10.3389/fendo.2019.00248",
doi = "10.3389/fendo.2019.00248",
pages = "248"
}

Bjelobaba, I., Janjić, M., Prévide, R. M., Abebe, D., Kucka, M.,& Stojilković, S. S.. (2019). Distinct Expression Patterns of Osteopontin and Dentin Matrix Protein 1 Genes in Pituitary Gonadotrophs. in Frontiers in Endocrinology
Frontiers Media S.A.., 10(MAR), 248.
https://doi.org/10.3389/fendo.2019.00248

Bjelobaba I, Janjić M, Prévide RM, Abebe D, Kucka M, Stojilković SS. Distinct Expression Patterns of Osteopontin and Dentin Matrix Protein 1 Genes in Pituitary Gonadotrophs. in Frontiers in Endocrinology. 2019;10(MAR):248.
doi:10.3389/fendo.2019.00248 .

Bjelobaba, Ivana, Janjić, Marija, Prévide, Rafael Maso, Abebe, Daniel, Kucka, Marek, Stojilković, Stanko S., "Distinct Expression Patterns of Osteopontin and Dentin Matrix Protein 1 Genes in Pituitary Gonadotrophs" in Frontiers in Endocrinology, 10, no. MAR (2019):248,
https://doi.org/10.3389/fendo.2019.00248 . .

TY  - JOUR
AU  - Bjelobaba, Ivana
AU  - Janjić, Marija
AU  - Tavcar, Jovana S.
AU  - Kucka, Marek
AU  - Tomić, Melanija
AU  - Stojilkovic, Stanko S.
PY  - 2016
UR  - http://linkinghub.elsevier.com/retrieve/pii/S0303720716303471
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/2523
AB  - Hypothalamic GnRH together with gonadal steroids and activins/inhibin regulate its receptor gene (Gnrhr) expression in vivo, which leads to crucial changes in GnRHR numbers on the plasma membrane. This is accompanied by alterations in the gonadotroph sensitivity and responsiveness during physiologically relevant situations. Here we investigated basal and GnRH-regulated Gnrhr expression in rodent pituitary gonadotrophs in vitro. In pituitary cells from adult animals cultured in the absence of GnRH and steroid hormones, the Gnrhr expression was progressively reduced but not completely abolished. The basal Gnrhr expression was also operative in LβT2 immortalized gonadotrophs never exposed to GnRH. In both cell types, basal transcription was sufficient for the expression of functional GnRHRs. Continuous application of GnRH transiently elevated the Gnrhr expression in cultured pituitary cells followed by a sustained fall without affecting basal transcription. Both basal and regulated Gnrhr transcriptions were dependent on the protein kinase C signaling pathway. The GnRH-regulated Gnrhr expression was not operative in embryonal pituitary and LβT2 cells and was established neonatally, the sex-specific response patterns were formed at the juvenile-peripubertal stage and there was a strong correlation between basal and regulated gene expression during development. Thus, the age-dependent basal and regulated Gnrhr transcription could account for the initial blockade and subsequent activation of the reproductive system during development.
PB  - Elsevier Ireland Ltd
T2  - Molecular and Cellular Endocrinology
T1  - The relationship between basal and regulated Gnrhr expression in rodent pituitary gonadotrophs
VL  - 437
DO  - 10.1016/j.mce.2016.08.040
SP  - 302
EP  - 311
ER  - 

@article{
author = "Bjelobaba, Ivana and Janjić, Marija and Tavcar, Jovana S. and Kucka, Marek and Tomić, Melanija and Stojilkovic, Stanko S.",
year = "2016",
abstract = "Hypothalamic GnRH together with gonadal steroids and activins/inhibin regulate its receptor gene (Gnrhr) expression in vivo, which leads to crucial changes in GnRHR numbers on the plasma membrane. This is accompanied by alterations in the gonadotroph sensitivity and responsiveness during physiologically relevant situations. Here we investigated basal and GnRH-regulated Gnrhr expression in rodent pituitary gonadotrophs in vitro. In pituitary cells from adult animals cultured in the absence of GnRH and steroid hormones, the Gnrhr expression was progressively reduced but not completely abolished. The basal Gnrhr expression was also operative in LβT2 immortalized gonadotrophs never exposed to GnRH. In both cell types, basal transcription was sufficient for the expression of functional GnRHRs. Continuous application of GnRH transiently elevated the Gnrhr expression in cultured pituitary cells followed by a sustained fall without affecting basal transcription. Both basal and regulated Gnrhr transcriptions were dependent on the protein kinase C signaling pathway. The GnRH-regulated Gnrhr expression was not operative in embryonal pituitary and LβT2 cells and was established neonatally, the sex-specific response patterns were formed at the juvenile-peripubertal stage and there was a strong correlation between basal and regulated gene expression during development. Thus, the age-dependent basal and regulated Gnrhr transcription could account for the initial blockade and subsequent activation of the reproductive system during development.",
publisher = "Elsevier Ireland Ltd",
journal = "Molecular and Cellular Endocrinology",
title = "The relationship between basal and regulated Gnrhr expression in rodent pituitary gonadotrophs",
volume = "437",
doi = "10.1016/j.mce.2016.08.040",
pages = "302-311"
}

Bjelobaba, I., Janjić, M., Tavcar, J. S., Kucka, M., Tomić, M.,& Stojilkovic, S. S.. (2016). The relationship between basal and regulated Gnrhr expression in rodent pituitary gonadotrophs. in Molecular and Cellular Endocrinology
Elsevier Ireland Ltd., 437, 302-311.
https://doi.org/10.1016/j.mce.2016.08.040

Bjelobaba I, Janjić M, Tavcar JS, Kucka M, Tomić M, Stojilkovic SS. The relationship between basal and regulated Gnrhr expression in rodent pituitary gonadotrophs. in Molecular and Cellular Endocrinology. 2016;437:302-311.
doi:10.1016/j.mce.2016.08.040 .

Bjelobaba, Ivana, Janjić, Marija, Tavcar, Jovana S., Kucka, Marek, Tomić, Melanija, Stojilkovic, Stanko S., "The relationship between basal and regulated Gnrhr expression in rodent pituitary gonadotrophs" in Molecular and Cellular Endocrinology, 437 (2016):302-311,
https://doi.org/10.1016/j.mce.2016.08.040 . .

TY  - JOUR
AU  - Zemkova, Hana
AU  - Kucka, Marek
AU  - Bjelobaba, Ivana
AU  - Tomić, Melanija
AU  - Stojilković, Stanko S
PY  - 2013
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/1065
AB  - Acetylcholine (ACh) has been established as a paracrine factor in the anterior pituitary gland, but the receptors mediating ACh action and the cell types bearing these receptors have not been identified. Our results showed that the expression of the nicotinic subunits mRNAs followed the order beta 2 > beta 1 = alpha 9 > alpha 4 in cultured rat pituitary cells. The expression of the subunits in immortalized L beta T2 mouse gonadotrophs followed the order beta 2 > alpha 4 = alpha 1. M4 > M3 muscarinic receptor mRNA were also identified in pituitary and L beta T2 cells. The treatment of cultured pituitary cells with GnRH down-regulated the expression of alpha 9 and alpha 4 mRNAs, without affecting the expression of M3 and M4 receptor mRNAs, and ACh did not alter the expression of GnRH receptor mRNA. We also performed double immunostaining to show the expression of beta 2-subunit and M4 receptor proteins in gonadotrophs. Functional nicotinic channels capable of generating an inward current, facilitation of electrical activity, and Ca2+ influx were identified in single gonadotrophs and L beta T2 cells. In both cell types, the M3 receptor-mediated, phospholipase C-dependent Ca2+ mobilization activated an outward apamin-sensitive K+ current and caused hyperpolarization. The activation of M4 receptors by ACh inhibited cAMP production and GnRH-induced LH release in a pertussis toxin-sensitive manner. We concluded that multiple cholinergic receptors are expressed in gonadotrophs and that the main secretory action of ACh is inhibitory through M4 receptor-mediated down-regulation of cAMP production. The expression of nicotinic receptors in vitro compensates for the lack of regular GnRH stimulation of gonadotrophs. (Endocrinology 154: 421-433, 2013)
T2  - Endocrinology
T1  - Multiple Cholinergic Signaling Pathways in Pituitary Gonadotrophs
IS  - 1
VL  - 154
SP  - 133
EP  - 433
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_1065
ER  - 

@article{
author = "Zemkova, Hana and Kucka, Marek and Bjelobaba, Ivana and Tomić, Melanija and Stojilković, Stanko S",
year = "2013",
abstract = "Acetylcholine (ACh) has been established as a paracrine factor in the anterior pituitary gland, but the receptors mediating ACh action and the cell types bearing these receptors have not been identified. Our results showed that the expression of the nicotinic subunits mRNAs followed the order beta 2 > beta 1 = alpha 9 > alpha 4 in cultured rat pituitary cells. The expression of the subunits in immortalized L beta T2 mouse gonadotrophs followed the order beta 2 > alpha 4 = alpha 1. M4 > M3 muscarinic receptor mRNA were also identified in pituitary and L beta T2 cells. The treatment of cultured pituitary cells with GnRH down-regulated the expression of alpha 9 and alpha 4 mRNAs, without affecting the expression of M3 and M4 receptor mRNAs, and ACh did not alter the expression of GnRH receptor mRNA. We also performed double immunostaining to show the expression of beta 2-subunit and M4 receptor proteins in gonadotrophs. Functional nicotinic channels capable of generating an inward current, facilitation of electrical activity, and Ca2+ influx were identified in single gonadotrophs and L beta T2 cells. In both cell types, the M3 receptor-mediated, phospholipase C-dependent Ca2+ mobilization activated an outward apamin-sensitive K+ current and caused hyperpolarization. The activation of M4 receptors by ACh inhibited cAMP production and GnRH-induced LH release in a pertussis toxin-sensitive manner. We concluded that multiple cholinergic receptors are expressed in gonadotrophs and that the main secretory action of ACh is inhibitory through M4 receptor-mediated down-regulation of cAMP production. The expression of nicotinic receptors in vitro compensates for the lack of regular GnRH stimulation of gonadotrophs. (Endocrinology 154: 421-433, 2013)",
journal = "Endocrinology",
title = "Multiple Cholinergic Signaling Pathways in Pituitary Gonadotrophs",
number = "1",
volume = "154",
pages = "133-433",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_1065"
}

Zemkova, H., Kucka, M., Bjelobaba, I., Tomić, M.,& Stojilković, S. S.. (2013). Multiple Cholinergic Signaling Pathways in Pituitary Gonadotrophs. in Endocrinology, 154(1), 133-433.
https://hdl.handle.net/21.15107/rcub_ibiss_1065

Zemkova H, Kucka M, Bjelobaba I, Tomić M, Stojilković SS. Multiple Cholinergic Signaling Pathways in Pituitary Gonadotrophs. in Endocrinology. 2013;154(1):133-433.
https://hdl.handle.net/21.15107/rcub_ibiss_1065 .

Zemkova, Hana, Kucka, Marek, Bjelobaba, Ivana, Tomić, Melanija, Stojilković, Stanko S, "Multiple Cholinergic Signaling Pathways in Pituitary Gonadotrophs" in Endocrinology, 154, no. 1 (2013):133-433,
https://hdl.handle.net/21.15107/rcub_ibiss_1065 .

TY  - JOUR
AU  - Li, Shuo
AU  - Bjelobaba, Ivana
AU  - Yan, Zonghe
AU  - Kucka, Marek
AU  - Tomić, Melanija
AU  - Stojilković, Stanko S
PY  - 2011
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/1120
AB  - Pannexins are a newly discovered three-member family of proteins expressed in the brain and peripheral tissues that belong to the superfamily of gap junction proteins. However, in mammals pannexins do not form gap junctions, and their expression and function in the pituitary gland have not been studied. Here we show that the rat pituitary gland expresses mRNA and protein transcripts of pannexins 1 and 2 but not pannexin 3. Pannexin 1 was more abundantly expressed in the anterior lobe, whereas pannexin 2 was more abundantly expressed in the intermediate and posterior pituitary. Pannexin 1 was identified in corticotrophs and a fraction of somatotrophs, the S100-positive pituicytes of the posterior pituitary and AtT-20 (mouse pituitary adrenocorticotropin-secreting cells) and rat immortalized pituitary cells secreting prolactin, whereas pannexin 2 was detected in the S100-positive folliculostellate cells of the anterior pituitary, melanotrophs of the intermediate lobe, and vasopressin-containing axons and nerve endings in the posterior lobe. Overexpression of pannexins 1 and 2 in AtT-20 pituitary cells enhanced the release of ATP in the extracellular medium, which was blocked by the gap junction inhibitor carbenoxolone. Basal ATP release in At-T20 cells was also suppressed by down-regulating the expression of endogenous pannexin 1 but not pannexin 2 with their short interfering RNAs. These results indicate that pannexins may provide a pathway for delivery of ATP, which is a native agonist for numerous P2X cationic channels and G protein-coupled P2Y receptors endogenously expressed in the pituitary gland. (Endocrinology 152: 2342-2352, 2011)
T2  - Endocrinology
T1  - Expression and Roles of Pannexins in ATP Release in the Pituitary Gland
IS  - 6
VL  - 152
SP  - 83
EP  - 2352
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_1120
ER  - 

@article{
author = "Li, Shuo and Bjelobaba, Ivana and Yan, Zonghe and Kucka, Marek and Tomić, Melanija and Stojilković, Stanko S",
year = "2011",
abstract = "Pannexins are a newly discovered three-member family of proteins expressed in the brain and peripheral tissues that belong to the superfamily of gap junction proteins. However, in mammals pannexins do not form gap junctions, and their expression and function in the pituitary gland have not been studied. Here we show that the rat pituitary gland expresses mRNA and protein transcripts of pannexins 1 and 2 but not pannexin 3. Pannexin 1 was more abundantly expressed in the anterior lobe, whereas pannexin 2 was more abundantly expressed in the intermediate and posterior pituitary. Pannexin 1 was identified in corticotrophs and a fraction of somatotrophs, the S100-positive pituicytes of the posterior pituitary and AtT-20 (mouse pituitary adrenocorticotropin-secreting cells) and rat immortalized pituitary cells secreting prolactin, whereas pannexin 2 was detected in the S100-positive folliculostellate cells of the anterior pituitary, melanotrophs of the intermediate lobe, and vasopressin-containing axons and nerve endings in the posterior lobe. Overexpression of pannexins 1 and 2 in AtT-20 pituitary cells enhanced the release of ATP in the extracellular medium, which was blocked by the gap junction inhibitor carbenoxolone. Basal ATP release in At-T20 cells was also suppressed by down-regulating the expression of endogenous pannexin 1 but not pannexin 2 with their short interfering RNAs. These results indicate that pannexins may provide a pathway for delivery of ATP, which is a native agonist for numerous P2X cationic channels and G protein-coupled P2Y receptors endogenously expressed in the pituitary gland. (Endocrinology 152: 2342-2352, 2011)",
journal = "Endocrinology",
title = "Expression and Roles of Pannexins in ATP Release in the Pituitary Gland",
number = "6",
volume = "152",
pages = "83-2352",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_1120"
}

Li, S., Bjelobaba, I., Yan, Z., Kucka, M., Tomić, M.,& Stojilković, S. S.. (2011). Expression and Roles of Pannexins in ATP Release in the Pituitary Gland. in Endocrinology, 152(6), 83-2352.
https://hdl.handle.net/21.15107/rcub_ibiss_1120

Li S, Bjelobaba I, Yan Z, Kucka M, Tomić M, Stojilković SS. Expression and Roles of Pannexins in ATP Release in the Pituitary Gland. in Endocrinology. 2011;152(6):83-2352.
https://hdl.handle.net/21.15107/rcub_ibiss_1120 .

Li, Shuo, Bjelobaba, Ivana, Yan, Zonghe, Kucka, Marek, Tomić, Melanija, Stojilković, Stanko S, "Expression and Roles of Pannexins in ATP Release in the Pituitary Gland" in Endocrinology, 152, no. 6 (2011):83-2352,
https://hdl.handle.net/21.15107/rcub_ibiss_1120 .