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The loss of Tm7sf gene accelerates skin papilloma formation in mice.

Bellezza I, Gatticchi L, del Sordo R, Peirce MJ, Sidoni A, Roberti R, Minelli A - Sci Rep (2015)

Bottom Line: The 3β-hydroxysterol Δ14-reductase, encoded by the Tm7sf2 gene, is an enzyme involved in cholesterol biosynthesis.Interestingly, the genotype showed reduced expression of nur77, a gene associated with resistance to neoplastic transformation.In conclusion, the loss of Tm7sf2 alters the expression of proteins involved in epidermal differentiation by reducing the levels of cholesterol sulfate.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Medicina Sperimentale, Università di Perugia, Polo Unico Sant'Andrea delle Fratte, p.le Gambuli, Perugia, 06132; Italia.

ABSTRACT
The 3β-hydroxysterol Δ14-reductase, encoded by the Tm7sf2 gene, is an enzyme involved in cholesterol biosynthesis. Cholesterol and its derivatives control epidermal barrier integrity and are protective against environmental insults. To determine the role of the gene in skin cholesterol homeostasis, we applied 12-o-tetradecanoylphorbol-13-acetate (TPA) to the skin of Tm7sf2(+/+) and Tm7sf2(-/-) mice. TPA increased skin cholesterol levels by inducing de novo synthesis and up-take only in Tm7sf2(+/+) mouse, confirming that the gene maintains cholesterol homeostasis under stress conditions. Cholesterol sulfate, one of the major players in skin permeability, was doubled by TPA treatment in the skin of wild-type animals but this response was lost in Tm7sf2(-/-) mice. The expression of markers of epidermal differentiation concomitant with farnesoid-X-receptor and p38 MAPK activation were also disrupted in Tm7sf2(-/-) mice. We then subjected Tm7sf2(+/+) and Tm7sf2(-/-) mice to a classical two-stage skin carcinogenesis protocol. We found that the loss of Tm7sf2 increased incidence and multiplicity of skin papillomas. Interestingly, the genotype showed reduced expression of nur77, a gene associated with resistance to neoplastic transformation. In conclusion, the loss of Tm7sf2 alters the expression of proteins involved in epidermal differentiation by reducing the levels of cholesterol sulfate.

No MeSH data available.


Related in: MedlinePlus

Tm7sf2 gene drives cholesterol accumulation after TPA exposure.WT and Tm7sf2 KO mice were subjected to a single skin topical application of TPA and sacrificed at the indicated time. The skin was removed and used to determine: (A) cholesterol levels by TLC analysis (n = 3); expression of (B) Abca1, (C) Hmgcr, (D) Ldlr, (F) SREB-2 by Real Time RT- PCR analyses. Expression of each gene was normalized to Gapdh and reported as 2−ΔΔCt. Relative mRNA level of WT untreated mice skin was assumed as 1. Results are given as mean ± S.D. (n = 4), *p < 0.05 vs. untreated WT, # p < 0.05 vs. the respective WT. (E) Whole skin lysates (pooled samples from n = 5 mice) were analyzed by western blotting with the indicated antibodies. Anti β-actin was used as loading control.
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f1: Tm7sf2 gene drives cholesterol accumulation after TPA exposure.WT and Tm7sf2 KO mice were subjected to a single skin topical application of TPA and sacrificed at the indicated time. The skin was removed and used to determine: (A) cholesterol levels by TLC analysis (n = 3); expression of (B) Abca1, (C) Hmgcr, (D) Ldlr, (F) SREB-2 by Real Time RT- PCR analyses. Expression of each gene was normalized to Gapdh and reported as 2−ΔΔCt. Relative mRNA level of WT untreated mice skin was assumed as 1. Results are given as mean ± S.D. (n = 4), *p < 0.05 vs. untreated WT, # p < 0.05 vs. the respective WT. (E) Whole skin lysates (pooled samples from n = 5 mice) were analyzed by western blotting with the indicated antibodies. Anti β-actin was used as loading control.

Mentions: Cholesterol and/or its derivatives may play a direct role in epidermal homeostasis and TPA is known to change the metabolism of sterols in mouse skin17. To analyse the role of Tm7sf2 gene in cholesterol epidermal homeostasis we topically treated Tm7sf2+/+ and Tm7sf2−/− mice with 20 nmol of TPA and determined cholesterol levels at 72 h. We found that the skin of Tm7sf2+/+ and Tm7sf2−/− mice contained comparable basal amounts of cholesterol (0.88 ± 0.02 vs. 0.73 ± 0.01 mg g of tissue−1) and that TPA increased cholesterol levels only in the skin of Tm7sf2+/+ mice (Fig. 1A). It is to note that treatment with acetone did not affect skin cholesterol levels (Fig. S1 A and B).


The loss of Tm7sf gene accelerates skin papilloma formation in mice.

Bellezza I, Gatticchi L, del Sordo R, Peirce MJ, Sidoni A, Roberti R, Minelli A - Sci Rep (2015)

Tm7sf2 gene drives cholesterol accumulation after TPA exposure.WT and Tm7sf2 KO mice were subjected to a single skin topical application of TPA and sacrificed at the indicated time. The skin was removed and used to determine: (A) cholesterol levels by TLC analysis (n = 3); expression of (B) Abca1, (C) Hmgcr, (D) Ldlr, (F) SREB-2 by Real Time RT- PCR analyses. Expression of each gene was normalized to Gapdh and reported as 2−ΔΔCt. Relative mRNA level of WT untreated mice skin was assumed as 1. Results are given as mean ± S.D. (n = 4), *p < 0.05 vs. untreated WT, # p < 0.05 vs. the respective WT. (E) Whole skin lysates (pooled samples from n = 5 mice) were analyzed by western blotting with the indicated antibodies. Anti β-actin was used as loading control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4372794&req=5

f1: Tm7sf2 gene drives cholesterol accumulation after TPA exposure.WT and Tm7sf2 KO mice were subjected to a single skin topical application of TPA and sacrificed at the indicated time. The skin was removed and used to determine: (A) cholesterol levels by TLC analysis (n = 3); expression of (B) Abca1, (C) Hmgcr, (D) Ldlr, (F) SREB-2 by Real Time RT- PCR analyses. Expression of each gene was normalized to Gapdh and reported as 2−ΔΔCt. Relative mRNA level of WT untreated mice skin was assumed as 1. Results are given as mean ± S.D. (n = 4), *p < 0.05 vs. untreated WT, # p < 0.05 vs. the respective WT. (E) Whole skin lysates (pooled samples from n = 5 mice) were analyzed by western blotting with the indicated antibodies. Anti β-actin was used as loading control.
Mentions: Cholesterol and/or its derivatives may play a direct role in epidermal homeostasis and TPA is known to change the metabolism of sterols in mouse skin17. To analyse the role of Tm7sf2 gene in cholesterol epidermal homeostasis we topically treated Tm7sf2+/+ and Tm7sf2−/− mice with 20 nmol of TPA and determined cholesterol levels at 72 h. We found that the skin of Tm7sf2+/+ and Tm7sf2−/− mice contained comparable basal amounts of cholesterol (0.88 ± 0.02 vs. 0.73 ± 0.01 mg g of tissue−1) and that TPA increased cholesterol levels only in the skin of Tm7sf2+/+ mice (Fig. 1A). It is to note that treatment with acetone did not affect skin cholesterol levels (Fig. S1 A and B).

Bottom Line: The 3β-hydroxysterol Δ14-reductase, encoded by the Tm7sf2 gene, is an enzyme involved in cholesterol biosynthesis.Interestingly, the genotype showed reduced expression of nur77, a gene associated with resistance to neoplastic transformation.In conclusion, the loss of Tm7sf2 alters the expression of proteins involved in epidermal differentiation by reducing the levels of cholesterol sulfate.

View Article: PubMed Central - PubMed

Affiliation: Dipartimento di Medicina Sperimentale, Università di Perugia, Polo Unico Sant'Andrea delle Fratte, p.le Gambuli, Perugia, 06132; Italia.

ABSTRACT
The 3β-hydroxysterol Δ14-reductase, encoded by the Tm7sf2 gene, is an enzyme involved in cholesterol biosynthesis. Cholesterol and its derivatives control epidermal barrier integrity and are protective against environmental insults. To determine the role of the gene in skin cholesterol homeostasis, we applied 12-o-tetradecanoylphorbol-13-acetate (TPA) to the skin of Tm7sf2(+/+) and Tm7sf2(-/-) mice. TPA increased skin cholesterol levels by inducing de novo synthesis and up-take only in Tm7sf2(+/+) mouse, confirming that the gene maintains cholesterol homeostasis under stress conditions. Cholesterol sulfate, one of the major players in skin permeability, was doubled by TPA treatment in the skin of wild-type animals but this response was lost in Tm7sf2(-/-) mice. The expression of markers of epidermal differentiation concomitant with farnesoid-X-receptor and p38 MAPK activation were also disrupted in Tm7sf2(-/-) mice. We then subjected Tm7sf2(+/+) and Tm7sf2(-/-) mice to a classical two-stage skin carcinogenesis protocol. We found that the loss of Tm7sf2 increased incidence and multiplicity of skin papillomas. Interestingly, the genotype showed reduced expression of nur77, a gene associated with resistance to neoplastic transformation. In conclusion, the loss of Tm7sf2 alters the expression of proteins involved in epidermal differentiation by reducing the levels of cholesterol sulfate.

No MeSH data available.


Related in: MedlinePlus