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Partial hepatectomy induces delayed hepatocyte proliferation and normal liver regeneration in ovariectomized mice.

Umeda M, Hiramoto M, Imai T - Clin Exp Gastroenterol (2015)

Bottom Line: The ovaries are one of the main organs for estradiol (E2) production.Both E2 administration and PH induced the gene expression of estrogen receptor α (ERα).The transcripts of ERα were detected specifically in periportal hepatocytes after E2 administration and PH.

View Article: PubMed Central - PubMed

Affiliation: Department of Aging Intervention, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan.

ABSTRACT
Estrogens play central roles in sexual development, reproduction, and hepatocyte proliferation. The ovaries are one of the main organs for estradiol (E2) production. Ovariectomies (OVXs) were performed on the female mice, and hepatocyte proliferation was analyzed. The ovariectomized mice exhibited delayed hepatocyte proliferation after partial hepatectomy (PH) and also exhibited delayed and reduced E2 induction. Both E2 administration and PH induced the gene expression of estrogen receptor α (ERα). The transcripts of ERα were detected specifically in periportal hepatocytes after E2 administration and PH. Moreover, the E2 concentrations and hepatocyte proliferation rates were highest in the proestrus period of the estrous cycle. Taken together, these findings indicate that E2 accelerated ERα expression in periportal hepatocytes and hepatocyte proliferation in the female mice.

No MeSH data available.


Related in: MedlinePlus

OVX did not affect liver weight recovery after PH, and the hepatocyte proliferations were delayed.Notes: (A) The time course of the OVXs and PHs are illustrated in B–D. (B and C) Control (Cont) and OVX B6 female mice underwent PH operations; the liver weight recovery (B) and hepatocyte proliferation were analyzed by BrdU-IHC (C). The values are expressed as the mean ± SEM (n=5–9). *P<0.05. (D) The livers were prepared after PH at the indicated times, and the BrdU-positive hepatocytes were counted. The values are expressed as the mean ± SEM (n=5–7). *P<0.05.Abbreviations: OVX, ovariectomy; PH, partial hepatectomy; BrdU-IHC, bromodeoxyuridine immunohistochemistry; SEM, standard error of the mean; NS, nonsignificant; OPE, operation.
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f5-ceg-8-175: OVX did not affect liver weight recovery after PH, and the hepatocyte proliferations were delayed.Notes: (A) The time course of the OVXs and PHs are illustrated in B–D. (B and C) Control (Cont) and OVX B6 female mice underwent PH operations; the liver weight recovery (B) and hepatocyte proliferation were analyzed by BrdU-IHC (C). The values are expressed as the mean ± SEM (n=5–9). *P<0.05. (D) The livers were prepared after PH at the indicated times, and the BrdU-positive hepatocytes were counted. The values are expressed as the mean ± SEM (n=5–7). *P<0.05.Abbreviations: OVX, ovariectomy; PH, partial hepatectomy; BrdU-IHC, bromodeoxyuridine immunohistochemistry; SEM, standard error of the mean; NS, nonsignificant; OPE, operation.

Mentions: No significant differences in liver weight were observed between the OVX and control mice before or after PH (Figure 5A and B). Hepatocytes are the main parenchymal cells of the liver, and DNA from the recovered livers was extracted and analyzed. The liver DNA quantities were restored by 4 days after PH in the OVX and control mice, and no significant differences were observed between the OVX and control mice (Figure 5C); these findings indicate that OVX had no significant effect on the liver regeneration. Moreover, hepatocyte proliferation following PH was analyzed based on BrdU incorporation. The rate of hepatocyte proliferation in the control mice was significantly elevated 36–44 hours after PH, but that of the OVX mice was significantly higher at 52 hours, and 60–72 hours after PH (Figure 5D). These data indicate that the OVX mice displayed slightly delayed hepatocyte proliferation (Figure 5D) but no significant change in liver weight/DNA amount recovery (Figure 5B and C).


Partial hepatectomy induces delayed hepatocyte proliferation and normal liver regeneration in ovariectomized mice.

Umeda M, Hiramoto M, Imai T - Clin Exp Gastroenterol (2015)

OVX did not affect liver weight recovery after PH, and the hepatocyte proliferations were delayed.Notes: (A) The time course of the OVXs and PHs are illustrated in B–D. (B and C) Control (Cont) and OVX B6 female mice underwent PH operations; the liver weight recovery (B) and hepatocyte proliferation were analyzed by BrdU-IHC (C). The values are expressed as the mean ± SEM (n=5–9). *P<0.05. (D) The livers were prepared after PH at the indicated times, and the BrdU-positive hepatocytes were counted. The values are expressed as the mean ± SEM (n=5–7). *P<0.05.Abbreviations: OVX, ovariectomy; PH, partial hepatectomy; BrdU-IHC, bromodeoxyuridine immunohistochemistry; SEM, standard error of the mean; NS, nonsignificant; OPE, operation.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494181&req=5

f5-ceg-8-175: OVX did not affect liver weight recovery after PH, and the hepatocyte proliferations were delayed.Notes: (A) The time course of the OVXs and PHs are illustrated in B–D. (B and C) Control (Cont) and OVX B6 female mice underwent PH operations; the liver weight recovery (B) and hepatocyte proliferation were analyzed by BrdU-IHC (C). The values are expressed as the mean ± SEM (n=5–9). *P<0.05. (D) The livers were prepared after PH at the indicated times, and the BrdU-positive hepatocytes were counted. The values are expressed as the mean ± SEM (n=5–7). *P<0.05.Abbreviations: OVX, ovariectomy; PH, partial hepatectomy; BrdU-IHC, bromodeoxyuridine immunohistochemistry; SEM, standard error of the mean; NS, nonsignificant; OPE, operation.
Mentions: No significant differences in liver weight were observed between the OVX and control mice before or after PH (Figure 5A and B). Hepatocytes are the main parenchymal cells of the liver, and DNA from the recovered livers was extracted and analyzed. The liver DNA quantities were restored by 4 days after PH in the OVX and control mice, and no significant differences were observed between the OVX and control mice (Figure 5C); these findings indicate that OVX had no significant effect on the liver regeneration. Moreover, hepatocyte proliferation following PH was analyzed based on BrdU incorporation. The rate of hepatocyte proliferation in the control mice was significantly elevated 36–44 hours after PH, but that of the OVX mice was significantly higher at 52 hours, and 60–72 hours after PH (Figure 5D). These data indicate that the OVX mice displayed slightly delayed hepatocyte proliferation (Figure 5D) but no significant change in liver weight/DNA amount recovery (Figure 5B and C).

Bottom Line: The ovaries are one of the main organs for estradiol (E2) production.Both E2 administration and PH induced the gene expression of estrogen receptor α (ERα).The transcripts of ERα were detected specifically in periportal hepatocytes after E2 administration and PH.

View Article: PubMed Central - PubMed

Affiliation: Department of Aging Intervention, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan.

ABSTRACT
Estrogens play central roles in sexual development, reproduction, and hepatocyte proliferation. The ovaries are one of the main organs for estradiol (E2) production. Ovariectomies (OVXs) were performed on the female mice, and hepatocyte proliferation was analyzed. The ovariectomized mice exhibited delayed hepatocyte proliferation after partial hepatectomy (PH) and also exhibited delayed and reduced E2 induction. Both E2 administration and PH induced the gene expression of estrogen receptor α (ERα). The transcripts of ERα were detected specifically in periportal hepatocytes after E2 administration and PH. Moreover, the E2 concentrations and hepatocyte proliferation rates were highest in the proestrus period of the estrous cycle. Taken together, these findings indicate that E2 accelerated ERα expression in periportal hepatocytes and hepatocyte proliferation in the female mice.

No MeSH data available.


Related in: MedlinePlus