Limits...
ZBTB20 is required for anterior pituitary development and lactotrope specification.

Cao D, Ma X, Cai J, Luan J, Liu AJ, Yang R, Cao Y, Zhu X, Zhang H, Chen YX, Shi Y, Shi GX, Zou D, Cao X, Grusby MJ, Xie Z, Zhang WJ - Nat Commun (2016)

Bottom Line: Disruption of Zbtb20 leads to anterior pituitary hypoplasia, hypopituitary dwarfism and a complete loss of mature lactotropes.Furthermore, endogenous ZBTB20 protein binds to Prl promoter, and its knockdown decreases PRL expression and secretion in a lactotrope cell line MMQ.In addition, ZBTB20 overexpression enhances the transcriptional activity of Prl promoter in vitro.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China.

ABSTRACT
The anterior pituitary harbours five distinct hormone-producing cell types, and their cellular differentiation is a highly regulated and coordinated process. Here we show that ZBTB20 is essential for anterior pituitary development and lactotrope specification in mice. In anterior pituitary, ZBTB20 is highly expressed by all the mature endocrine cell types, and to some less extent by somatolactotropes, the precursors of prolactin (PRL)-producing lactotropes. Disruption of Zbtb20 leads to anterior pituitary hypoplasia, hypopituitary dwarfism and a complete loss of mature lactotropes. In ZBTB20- mice, although lactotrope lineage commitment is normally initiated, somatolactotropes exhibit profound defects in lineage specification and expansion. Furthermore, endogenous ZBTB20 protein binds to Prl promoter, and its knockdown decreases PRL expression and secretion in a lactotrope cell line MMQ. In addition, ZBTB20 overexpression enhances the transcriptional activity of Prl promoter in vitro. In conclusion, our findings point to ZBTB20 as a critical regulator of anterior pituitary development and lactotrope specification.

No MeSH data available.


Related in: MedlinePlus

Impaired postnatal cell proliferation in Zbtb20−/− pituitary.(a) Immunohistochemical staining of BrdU was performed on E18.5 to P21 pituitaries of Zbtb20+/+ and Zbtb20−/− littermates to assess cell proliferation. The percentage of BrdU-positive cells in anterior lobe was determined from counting serial sections of each pituitary. E18.5: n=20 sections from four animals; P0: n=26 sections from seven animals; P7: n=31 sections from five animals; P14: n=34 sections from five animals; and P21: n=27 sections from four animals. Values represent mean±s.e.m. *P<0.05, **P<0.01 (Student's t-test). (b,c) Immunohistochemical double staining of BrdU (red) and PRL (b) or GH (c) (green) was performed on the pituitary at the indicated age (P7 to P21). Arrowheads indicate double-positive cells, and inserts show the enlargement of double-positive cells. The percentage of double-positive cells among the GH-positive cells was determined by counting serial sections of each pituitary. P7: n=8 sections from three animals; P14: n=12 sections from three animals; and P21: n=9 sections from three animals. Values represent mean±s.e.m. *P<0.05 (Student's t-test). Scale bar, (a) 200 μm; (b,c) 100 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4835541&req=5

f4: Impaired postnatal cell proliferation in Zbtb20−/− pituitary.(a) Immunohistochemical staining of BrdU was performed on E18.5 to P21 pituitaries of Zbtb20+/+ and Zbtb20−/− littermates to assess cell proliferation. The percentage of BrdU-positive cells in anterior lobe was determined from counting serial sections of each pituitary. E18.5: n=20 sections from four animals; P0: n=26 sections from seven animals; P7: n=31 sections from five animals; P14: n=34 sections from five animals; and P21: n=27 sections from four animals. Values represent mean±s.e.m. *P<0.05, **P<0.01 (Student's t-test). (b,c) Immunohistochemical double staining of BrdU (red) and PRL (b) or GH (c) (green) was performed on the pituitary at the indicated age (P7 to P21). Arrowheads indicate double-positive cells, and inserts show the enlargement of double-positive cells. The percentage of double-positive cells among the GH-positive cells was determined by counting serial sections of each pituitary. P7: n=8 sections from three animals; P14: n=12 sections from three animals; and P21: n=9 sections from three animals. Values represent mean±s.e.m. *P<0.05 (Student's t-test). Scale bar, (a) 200 μm; (b,c) 100 μm.

Mentions: To investigate the cellular basis of pituitary hypoplasia in ZBTB20- mice, we detected cell apoptosis and proliferation in postnatal pituitary. TUNEL staining revealed that very rare TUNEL-positive apoptotic cells were detected in the developing pituitaries from P7 to P21, with no significant difference between control and mutant mice (Supplementary Fig. 5). Then the proliferation rate was evaluated by measuring bromodeoxyuridine (BrdU) incorporation after a single intraperitoneal injection. There was no significant difference of BrdU incorporation into anterior pituitary cells between the two genotypes at E18.5 or P0 (Supplementary Fig. 6a). However, in comparison with control, the density of BrdU-positive cells was reduced in the mutant anterior pituitary by ∼27% (n=31–34 slices from five animals) at P7 and P14, and more dramatically, by about 67% (n=27 slices from four animals, P<0.01, Student's t-test) at P21 (Fig. 4a), indicating a defect of cell proliferation in the mutant pituitary.


ZBTB20 is required for anterior pituitary development and lactotrope specification.

Cao D, Ma X, Cai J, Luan J, Liu AJ, Yang R, Cao Y, Zhu X, Zhang H, Chen YX, Shi Y, Shi GX, Zou D, Cao X, Grusby MJ, Xie Z, Zhang WJ - Nat Commun (2016)

Impaired postnatal cell proliferation in Zbtb20−/− pituitary.(a) Immunohistochemical staining of BrdU was performed on E18.5 to P21 pituitaries of Zbtb20+/+ and Zbtb20−/− littermates to assess cell proliferation. The percentage of BrdU-positive cells in anterior lobe was determined from counting serial sections of each pituitary. E18.5: n=20 sections from four animals; P0: n=26 sections from seven animals; P7: n=31 sections from five animals; P14: n=34 sections from five animals; and P21: n=27 sections from four animals. Values represent mean±s.e.m. *P<0.05, **P<0.01 (Student's t-test). (b,c) Immunohistochemical double staining of BrdU (red) and PRL (b) or GH (c) (green) was performed on the pituitary at the indicated age (P7 to P21). Arrowheads indicate double-positive cells, and inserts show the enlargement of double-positive cells. The percentage of double-positive cells among the GH-positive cells was determined by counting serial sections of each pituitary. P7: n=8 sections from three animals; P14: n=12 sections from three animals; and P21: n=9 sections from three animals. Values represent mean±s.e.m. *P<0.05 (Student's t-test). Scale bar, (a) 200 μm; (b,c) 100 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835541&req=5

f4: Impaired postnatal cell proliferation in Zbtb20−/− pituitary.(a) Immunohistochemical staining of BrdU was performed on E18.5 to P21 pituitaries of Zbtb20+/+ and Zbtb20−/− littermates to assess cell proliferation. The percentage of BrdU-positive cells in anterior lobe was determined from counting serial sections of each pituitary. E18.5: n=20 sections from four animals; P0: n=26 sections from seven animals; P7: n=31 sections from five animals; P14: n=34 sections from five animals; and P21: n=27 sections from four animals. Values represent mean±s.e.m. *P<0.05, **P<0.01 (Student's t-test). (b,c) Immunohistochemical double staining of BrdU (red) and PRL (b) or GH (c) (green) was performed on the pituitary at the indicated age (P7 to P21). Arrowheads indicate double-positive cells, and inserts show the enlargement of double-positive cells. The percentage of double-positive cells among the GH-positive cells was determined by counting serial sections of each pituitary. P7: n=8 sections from three animals; P14: n=12 sections from three animals; and P21: n=9 sections from three animals. Values represent mean±s.e.m. *P<0.05 (Student's t-test). Scale bar, (a) 200 μm; (b,c) 100 μm.
Mentions: To investigate the cellular basis of pituitary hypoplasia in ZBTB20- mice, we detected cell apoptosis and proliferation in postnatal pituitary. TUNEL staining revealed that very rare TUNEL-positive apoptotic cells were detected in the developing pituitaries from P7 to P21, with no significant difference between control and mutant mice (Supplementary Fig. 5). Then the proliferation rate was evaluated by measuring bromodeoxyuridine (BrdU) incorporation after a single intraperitoneal injection. There was no significant difference of BrdU incorporation into anterior pituitary cells between the two genotypes at E18.5 or P0 (Supplementary Fig. 6a). However, in comparison with control, the density of BrdU-positive cells was reduced in the mutant anterior pituitary by ∼27% (n=31–34 slices from five animals) at P7 and P14, and more dramatically, by about 67% (n=27 slices from four animals, P<0.01, Student's t-test) at P21 (Fig. 4a), indicating a defect of cell proliferation in the mutant pituitary.

Bottom Line: Disruption of Zbtb20 leads to anterior pituitary hypoplasia, hypopituitary dwarfism and a complete loss of mature lactotropes.Furthermore, endogenous ZBTB20 protein binds to Prl promoter, and its knockdown decreases PRL expression and secretion in a lactotrope cell line MMQ.In addition, ZBTB20 overexpression enhances the transcriptional activity of Prl promoter in vitro.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathophysiology, Second Military Medical University, 800 Xiangyin Road, Shanghai 200433, China.

ABSTRACT
The anterior pituitary harbours five distinct hormone-producing cell types, and their cellular differentiation is a highly regulated and coordinated process. Here we show that ZBTB20 is essential for anterior pituitary development and lactotrope specification in mice. In anterior pituitary, ZBTB20 is highly expressed by all the mature endocrine cell types, and to some less extent by somatolactotropes, the precursors of prolactin (PRL)-producing lactotropes. Disruption of Zbtb20 leads to anterior pituitary hypoplasia, hypopituitary dwarfism and a complete loss of mature lactotropes. In ZBTB20- mice, although lactotrope lineage commitment is normally initiated, somatolactotropes exhibit profound defects in lineage specification and expansion. Furthermore, endogenous ZBTB20 protein binds to Prl promoter, and its knockdown decreases PRL expression and secretion in a lactotrope cell line MMQ. In addition, ZBTB20 overexpression enhances the transcriptional activity of Prl promoter in vitro. In conclusion, our findings point to ZBTB20 as a critical regulator of anterior pituitary development and lactotrope specification.

No MeSH data available.


Related in: MedlinePlus