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SUMO-specific protease 2 is essential for modulating p53-Mdm2 in development of trophoblast stem cell niches and lineages.

Chiu SY, Asai N, Costantini F, Hsu W - PLoS Biol. (2008)

Bottom Line: Reintroducing SENP2 into the mutants can reduce the sumoylation of Mdm2, diminish the p53 level and promote trophoblast development.Furthermore, downregulation of p53 alleviates the SENP2- phenotypes and stimulation of p53 causes abnormalities in trophoblast proliferation and differentiation, resembling those of the SENP2 mutants.Our data reveal a key genetic pathway, SENP2-Mdm2-p53, underlying trophoblast lineage development, suggesting its pivotal role in cell cycle progression of mitosis and endoreduplication.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Genetics, Center for Oral Biology, James P Wilmot Cancer Center, University of Rochester Medical Center, Rochester, New York, USA.

ABSTRACT
SUMO-specific protease 2 (SENP2) modifies proteins by removing SUMO from its substrates. Although SUMO-specific proteases are known to reverse sumoylation in many defined systems, their importance in mammalian development and pathogenesis remains largely elusive. Here we report that SENP2 is highly expressed in trophoblast cells that are required for placentation. Targeted disruption of SENP2 in mice reveals its essential role in development of all three trophoblast layers. The mutation causes a deficiency in cell cycle progression. SENP2 has a specific role in the G-S transition, which is required for mitotic and endoreduplication cell cycles in trophoblast proliferation and differentiation, respectively. SENP2 ablation disturbs the p53-Mdm2 pathway, affecting the expansion of trophoblast progenitors and their maturation. Reintroducing SENP2 into the mutants can reduce the sumoylation of Mdm2, diminish the p53 level and promote trophoblast development. Furthermore, downregulation of p53 alleviates the SENP2- phenotypes and stimulation of p53 causes abnormalities in trophoblast proliferation and differentiation, resembling those of the SENP2 mutants. Our data reveal a key genetic pathway, SENP2-Mdm2-p53, underlying trophoblast lineage development, suggesting its pivotal role in cell cycle progression of mitosis and endoreduplication.

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Related in: MedlinePlus

SENP2 Is Critical for the G1–S Transition of Mitotic Division in TS Cells(A) BrdU labeling for 1 h measured the proliferation rate of the SENP2+/+ and SENP2–/– TS cells in vitro. The graph shows the average percentages of the BrdU-positive cells in three independent experiments (p = 0.0013, n = 3).(B,C) Flow cytometric analysis of the PI-stained SENP2+/+ and SENP2–/– TS cells to determine their cell cycle profiles. The result shown in (B) is a representative of four independent experiments, and the graph in (C) shows the average percentage of the G0–G1 and S populations (n = 4). A consistent increase in the G0–G1 population (p < 0.0001) and decrease in the S population (p = 0.0024) was detected in the SENP2 mutants.(D) The SENP2+/+ and SENP2–/– TS cells were treated with nocodazole for 0, 3 and 6 h as indicated. Flow cytometric analyses showed that there was a delay in synchronizing the SENP2–/– cells upon the nocodazole treatment.
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pbio-0060310-g007: SENP2 Is Critical for the G1–S Transition of Mitotic Division in TS Cells(A) BrdU labeling for 1 h measured the proliferation rate of the SENP2+/+ and SENP2–/– TS cells in vitro. The graph shows the average percentages of the BrdU-positive cells in three independent experiments (p = 0.0013, n = 3).(B,C) Flow cytometric analysis of the PI-stained SENP2+/+ and SENP2–/– TS cells to determine their cell cycle profiles. The result shown in (B) is a representative of four independent experiments, and the graph in (C) shows the average percentage of the G0–G1 and S populations (n = 4). A consistent increase in the G0–G1 population (p < 0.0001) and decrease in the S population (p = 0.0024) was detected in the SENP2 mutants.(D) The SENP2+/+ and SENP2–/– TS cells were treated with nocodazole for 0, 3 and 6 h as indicated. Flow cytometric analyses showed that there was a delay in synchronizing the SENP2–/– cells upon the nocodazole treatment.

Mentions: To further examine stem cell expansion and development, we derived a number of SENP2–/– TS cell lines from blastocysts. Immunostaining analyses of Oct4 (an ES cell marker) [27] and Cdx2 (a TS cell marker) [20] confirmed that we were able to successfully establish the SENP2- TS cell lines (Figure S3). The proliferation rate (BrdU labeling for 1 h) of the SENP2- TS cells in vitro was also reduced, compared to that of the wild-type cells (p = 0.013, n = 3) (Figure 7A). Although the deficiency in cell cycle progression was also demonstrated using the TS cells in vitro, the degree of severity was reduced compared with that seen in the in vivo studies. As we were aware, the in vitro system does not always recapitulate the dynamic developmental processes that occur in vivo. Nevertheless, because of the limited materials available from the early stages of placenta, the TS cell culture does provide a valuable system to further those of our investigations that are otherwise impossible to perform in vivo.


SUMO-specific protease 2 is essential for modulating p53-Mdm2 in development of trophoblast stem cell niches and lineages.

Chiu SY, Asai N, Costantini F, Hsu W - PLoS Biol. (2008)

SENP2 Is Critical for the G1–S Transition of Mitotic Division in TS Cells(A) BrdU labeling for 1 h measured the proliferation rate of the SENP2+/+ and SENP2–/– TS cells in vitro. The graph shows the average percentages of the BrdU-positive cells in three independent experiments (p = 0.0013, n = 3).(B,C) Flow cytometric analysis of the PI-stained SENP2+/+ and SENP2–/– TS cells to determine their cell cycle profiles. The result shown in (B) is a representative of four independent experiments, and the graph in (C) shows the average percentage of the G0–G1 and S populations (n = 4). A consistent increase in the G0–G1 population (p < 0.0001) and decrease in the S population (p = 0.0024) was detected in the SENP2 mutants.(D) The SENP2+/+ and SENP2–/– TS cells were treated with nocodazole for 0, 3 and 6 h as indicated. Flow cytometric analyses showed that there was a delay in synchronizing the SENP2–/– cells upon the nocodazole treatment.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2602722&req=5

pbio-0060310-g007: SENP2 Is Critical for the G1–S Transition of Mitotic Division in TS Cells(A) BrdU labeling for 1 h measured the proliferation rate of the SENP2+/+ and SENP2–/– TS cells in vitro. The graph shows the average percentages of the BrdU-positive cells in three independent experiments (p = 0.0013, n = 3).(B,C) Flow cytometric analysis of the PI-stained SENP2+/+ and SENP2–/– TS cells to determine their cell cycle profiles. The result shown in (B) is a representative of four independent experiments, and the graph in (C) shows the average percentage of the G0–G1 and S populations (n = 4). A consistent increase in the G0–G1 population (p < 0.0001) and decrease in the S population (p = 0.0024) was detected in the SENP2 mutants.(D) The SENP2+/+ and SENP2–/– TS cells were treated with nocodazole for 0, 3 and 6 h as indicated. Flow cytometric analyses showed that there was a delay in synchronizing the SENP2–/– cells upon the nocodazole treatment.
Mentions: To further examine stem cell expansion and development, we derived a number of SENP2–/– TS cell lines from blastocysts. Immunostaining analyses of Oct4 (an ES cell marker) [27] and Cdx2 (a TS cell marker) [20] confirmed that we were able to successfully establish the SENP2- TS cell lines (Figure S3). The proliferation rate (BrdU labeling for 1 h) of the SENP2- TS cells in vitro was also reduced, compared to that of the wild-type cells (p = 0.013, n = 3) (Figure 7A). Although the deficiency in cell cycle progression was also demonstrated using the TS cells in vitro, the degree of severity was reduced compared with that seen in the in vivo studies. As we were aware, the in vitro system does not always recapitulate the dynamic developmental processes that occur in vivo. Nevertheless, because of the limited materials available from the early stages of placenta, the TS cell culture does provide a valuable system to further those of our investigations that are otherwise impossible to perform in vivo.

Bottom Line: Reintroducing SENP2 into the mutants can reduce the sumoylation of Mdm2, diminish the p53 level and promote trophoblast development.Furthermore, downregulation of p53 alleviates the SENP2- phenotypes and stimulation of p53 causes abnormalities in trophoblast proliferation and differentiation, resembling those of the SENP2 mutants.Our data reveal a key genetic pathway, SENP2-Mdm2-p53, underlying trophoblast lineage development, suggesting its pivotal role in cell cycle progression of mitosis and endoreduplication.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical Genetics, Center for Oral Biology, James P Wilmot Cancer Center, University of Rochester Medical Center, Rochester, New York, USA.

ABSTRACT
SUMO-specific protease 2 (SENP2) modifies proteins by removing SUMO from its substrates. Although SUMO-specific proteases are known to reverse sumoylation in many defined systems, their importance in mammalian development and pathogenesis remains largely elusive. Here we report that SENP2 is highly expressed in trophoblast cells that are required for placentation. Targeted disruption of SENP2 in mice reveals its essential role in development of all three trophoblast layers. The mutation causes a deficiency in cell cycle progression. SENP2 has a specific role in the G-S transition, which is required for mitotic and endoreduplication cell cycles in trophoblast proliferation and differentiation, respectively. SENP2 ablation disturbs the p53-Mdm2 pathway, affecting the expansion of trophoblast progenitors and their maturation. Reintroducing SENP2 into the mutants can reduce the sumoylation of Mdm2, diminish the p53 level and promote trophoblast development. Furthermore, downregulation of p53 alleviates the SENP2- phenotypes and stimulation of p53 causes abnormalities in trophoblast proliferation and differentiation, resembling those of the SENP2 mutants. Our data reveal a key genetic pathway, SENP2-Mdm2-p53, underlying trophoblast lineage development, suggesting its pivotal role in cell cycle progression of mitosis and endoreduplication.

Show MeSH
Related in: MedlinePlus