Limits...
Metabolic Coupling Determines the Activity: Comparison of 11β-Hydroxysteroid Dehydrogenase 1 and Its Coupling between Liver Parenchymal Cells and Testicular Leydig Cells.

Li X, Hu G, Li X, Wang YY, Hu YY, Zhou H, Latif SA, Morris DJ, Chu Y, Zheng Z, Ge RS - PLoS ONE (2015)

Bottom Line: S3483, a G6P transporter inhibitor, reversed the G6P-mediated increases of 11β-HSD1 reductase activity.The depletion of Leydig cells eliminated Hsd11b1 (encoding 11β-HSD1) expression but did not affect the expression of H6pd (encoding H6PDH) and Slc37a4 (encoding G6P transporter).In conclusion, the availability of H6PDH determines the different direction of 11β-HSD1 in liver and Leydig cells.

View Article: PubMed Central - PubMed

Affiliation: The Second Affiliated Hospital & Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, ZJ 325000, PR China.

ABSTRACT

Background: 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) interconverts active 11β-hydroxyl glucocorticoids and inactive 11keto forms. However, its directionality is determined by availability of NADP+/NADPH. In liver cells, 11β-HSD1 behaves as a primary reductase, while in Leydig cells it acts as a primary oxidase. However, the exact mechanism is not clear. The direction of 11β-HSD1 has been proposed to be regulated by hexose-6-phosphate dehydrogenase (H6PDH), which catalyzes glucose-6-phosphate (G6P) to generate NADPH that drives 11β-HSD1 towards reduction.

Methodology: To examine the coupling between 11β-HSD1 and H6PDH, we added G6P to rat and human liver and testis or Leydig cell microsomes, and 11β-HSD1 activity was measured by radiometry.

Results and conclusions: G6P stimulated 11β-HSD1 reductase activity in rat (3 fold) or human liver (1.5 fold), but not at all in testis. S3483, a G6P transporter inhibitor, reversed the G6P-mediated increases of 11β-HSD1 reductase activity. We compared the extent to which 11β-HSD1 in rat Leydig and liver cells might be coupled to H6PDH. In order to clarify the location of H6PDH within the testis, we used the Leydig cell toxicant ethane dimethanesulfonate (EDS) to selectively deplete Leydig cells. The depletion of Leydig cells eliminated Hsd11b1 (encoding 11β-HSD1) expression but did not affect the expression of H6pd (encoding H6PDH) and Slc37a4 (encoding G6P transporter). H6pd mRNA level and H6PDH activity were barely detectable in purified rat Leydig cells. In conclusion, the availability of H6PDH determines the different direction of 11β-HSD1 in liver and Leydig cells.

No MeSH data available.


Related in: MedlinePlus

Comparison of Hsd11b1 and H6pd in rat Leydig cells and testis.Panel A, Hsd11b1 and Panel B, H6pd. Mean ± SEM, n = 4~6. *** designates significant differences between two groups at P < 0.001.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4631333&req=5

pone.0141767.g006: Comparison of Hsd11b1 and H6pd in rat Leydig cells and testis.Panel A, Hsd11b1 and Panel B, H6pd. Mean ± SEM, n = 4~6. *** designates significant differences between two groups at P < 0.001.

Mentions: Hsd11b1 signal was lower 4 days after the EDS injection, and was undetectable by 7 days after the injection of EDS (Fig 4B). 11β-HSD1 became detectable by 35 days after the EDS treatment (Fig 5E), and completely recovered by 90 days post EDS (Fig 4B). Using testis mRNA extracted from the same treatment groups, we analyzed relative amounts of mRNAs for Hsd11b1. We found that the amounts of Hsd11b1 mRNAs fell when Leydig cells were depleted, and rose during the time of Leydig cell regeneration (Fig 4B). We did not see any changes of Hsd11b2 expression levels after EDS treatment (Fig 4C). We then measured mRNAs that should be present for metabolic coupling between 11β-HSD1 and H6PDH, which are H6pd (encoding H6PDH) and Slc37a4 (encoding G6PT). On the other hand, amounts of H6pd and Slc37a4 mRNAs did not change even from 7 to 14 days post EDS when Leydig cells were completely absent in the testis (Fig 4D and 4E). This suggests that that H6pd and Slc37a4 mRNAs are other testicular non-Leydig cells since the elimination of rat Leydig cells did not affect their levels. We further compared the steady state mRNA level of Hsd11b1 and H6pd in purified rat Leydig cells from 90-day-old rat testis (Fig 6). Hsd11b1 mRNA level in rat Leydig cells was 533.0 ± 24.5 vs. 104.0 ± 10.4 copies/pg RNA in age-matched rat testis, indicating that Hsd11b1 is enriched in Leydig cells. H6pd mRNA level in rat Leydig cells was 2.26 ±0.63 vs. 10.2 ± 1.2 copies/pg RNA in age-matched rat testis, indicating that H6pd is enriched in non-Leydig cell fractions. The expression level of H6pd in rat Leydig cells is far lower than that of Hsd11b1, confirming that H6PDH cannot form an effective metabolic coupling in rat Leydig cells to render 11β-HSD1 as a primary reductase.


Metabolic Coupling Determines the Activity: Comparison of 11β-Hydroxysteroid Dehydrogenase 1 and Its Coupling between Liver Parenchymal Cells and Testicular Leydig Cells.

Li X, Hu G, Li X, Wang YY, Hu YY, Zhou H, Latif SA, Morris DJ, Chu Y, Zheng Z, Ge RS - PLoS ONE (2015)

Comparison of Hsd11b1 and H6pd in rat Leydig cells and testis.Panel A, Hsd11b1 and Panel B, H6pd. Mean ± SEM, n = 4~6. *** designates significant differences between two groups at P < 0.001.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4631333&req=5

pone.0141767.g006: Comparison of Hsd11b1 and H6pd in rat Leydig cells and testis.Panel A, Hsd11b1 and Panel B, H6pd. Mean ± SEM, n = 4~6. *** designates significant differences between two groups at P < 0.001.
Mentions: Hsd11b1 signal was lower 4 days after the EDS injection, and was undetectable by 7 days after the injection of EDS (Fig 4B). 11β-HSD1 became detectable by 35 days after the EDS treatment (Fig 5E), and completely recovered by 90 days post EDS (Fig 4B). Using testis mRNA extracted from the same treatment groups, we analyzed relative amounts of mRNAs for Hsd11b1. We found that the amounts of Hsd11b1 mRNAs fell when Leydig cells were depleted, and rose during the time of Leydig cell regeneration (Fig 4B). We did not see any changes of Hsd11b2 expression levels after EDS treatment (Fig 4C). We then measured mRNAs that should be present for metabolic coupling between 11β-HSD1 and H6PDH, which are H6pd (encoding H6PDH) and Slc37a4 (encoding G6PT). On the other hand, amounts of H6pd and Slc37a4 mRNAs did not change even from 7 to 14 days post EDS when Leydig cells were completely absent in the testis (Fig 4D and 4E). This suggests that that H6pd and Slc37a4 mRNAs are other testicular non-Leydig cells since the elimination of rat Leydig cells did not affect their levels. We further compared the steady state mRNA level of Hsd11b1 and H6pd in purified rat Leydig cells from 90-day-old rat testis (Fig 6). Hsd11b1 mRNA level in rat Leydig cells was 533.0 ± 24.5 vs. 104.0 ± 10.4 copies/pg RNA in age-matched rat testis, indicating that Hsd11b1 is enriched in Leydig cells. H6pd mRNA level in rat Leydig cells was 2.26 ±0.63 vs. 10.2 ± 1.2 copies/pg RNA in age-matched rat testis, indicating that H6pd is enriched in non-Leydig cell fractions. The expression level of H6pd in rat Leydig cells is far lower than that of Hsd11b1, confirming that H6PDH cannot form an effective metabolic coupling in rat Leydig cells to render 11β-HSD1 as a primary reductase.

Bottom Line: S3483, a G6P transporter inhibitor, reversed the G6P-mediated increases of 11β-HSD1 reductase activity.The depletion of Leydig cells eliminated Hsd11b1 (encoding 11β-HSD1) expression but did not affect the expression of H6pd (encoding H6PDH) and Slc37a4 (encoding G6P transporter).In conclusion, the availability of H6PDH determines the different direction of 11β-HSD1 in liver and Leydig cells.

View Article: PubMed Central - PubMed

Affiliation: The Second Affiliated Hospital & Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, ZJ 325000, PR China.

ABSTRACT

Background: 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) interconverts active 11β-hydroxyl glucocorticoids and inactive 11keto forms. However, its directionality is determined by availability of NADP+/NADPH. In liver cells, 11β-HSD1 behaves as a primary reductase, while in Leydig cells it acts as a primary oxidase. However, the exact mechanism is not clear. The direction of 11β-HSD1 has been proposed to be regulated by hexose-6-phosphate dehydrogenase (H6PDH), which catalyzes glucose-6-phosphate (G6P) to generate NADPH that drives 11β-HSD1 towards reduction.

Methodology: To examine the coupling between 11β-HSD1 and H6PDH, we added G6P to rat and human liver and testis or Leydig cell microsomes, and 11β-HSD1 activity was measured by radiometry.

Results and conclusions: G6P stimulated 11β-HSD1 reductase activity in rat (3 fold) or human liver (1.5 fold), but not at all in testis. S3483, a G6P transporter inhibitor, reversed the G6P-mediated increases of 11β-HSD1 reductase activity. We compared the extent to which 11β-HSD1 in rat Leydig and liver cells might be coupled to H6PDH. In order to clarify the location of H6PDH within the testis, we used the Leydig cell toxicant ethane dimethanesulfonate (EDS) to selectively deplete Leydig cells. The depletion of Leydig cells eliminated Hsd11b1 (encoding 11β-HSD1) expression but did not affect the expression of H6pd (encoding H6PDH) and Slc37a4 (encoding G6P transporter). H6pd mRNA level and H6PDH activity were barely detectable in purified rat Leydig cells. In conclusion, the availability of H6PDH determines the different direction of 11β-HSD1 in liver and Leydig cells.

No MeSH data available.


Related in: MedlinePlus