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Hyaluronan synthase-2 upregulation protects smpd3-deficient fibroblasts against cell death induced by nutrient deprivation, but not against apoptosis evoked by oxidized LDL.

Garoby-Salom S, Rouahi M, Mucher E, Auge N, Salvayre R, Negre-Salvayre A - Redox Biol (2014)

Bottom Line: The resistance of fro/fro cells to starvation-induced apoptosis is associated with an increased expression of hyaluronan synthase 2 (HAS2) mRNAs and protein, which is inhibited by ceramide.In wt fibroblasts, this HAS2 rise and its protective effect did not occur, but exogenously added HA exhibited a protective effect against starvation-induced apoptosis.Taken together, these results highlight the role of nSMase2 in apoptosis evoked by nutrient starvation that could contribute to the delayed apoptosis of hypertrophic chondrocytes in the growth plate, and emphasize the antiapoptotic properties of HAS2.

View Article: PubMed Central - PubMed

Affiliation: INSERM UMR-1048, BP 84225, 31432 Toulouse Cedex 4, France; University of Toulouse, Toulouse, France.

No MeSH data available.


Related in: MedlinePlus

HAS2 expression is dependent on nSMase2/Cer and is involved in the resistance of fro/fro to nutrient deprivation-induced apoptosis. (A) Western blot of HAS2 in wt and fro/fro fibroblasts grown in complete medium (compl) and nutrient deprivation conditions (depriv). (B) HAS2 mRNA expression evaluated by q-PCR experiments, and normalized to HPRT, in fro/fro and wt fibroblasts grown in complete medium (compl), nutrient derivation conditions (depriv). The effect of C2-ceramide (C2Cer, 5 µM), was tested in fro/fro fibroblasts, as indicated. (C) Western blot of HAS2 in fro/fro fibroblasts grown in complete medium and treated with scrambled siRNA or with specific HAS2 siRNA (upper panel) or in complete (compl) or nutrient deprivation (depriv) medium with or without methylumbelliferone (MU, 1 mM) (lower panel). (D) After 48 h incubation, the cytotoxicity was evaluated by the MTT test. Data are mean±SEM of 5 separate experiments, ⁎p<0.05.
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f0020: HAS2 expression is dependent on nSMase2/Cer and is involved in the resistance of fro/fro to nutrient deprivation-induced apoptosis. (A) Western blot of HAS2 in wt and fro/fro fibroblasts grown in complete medium (compl) and nutrient deprivation conditions (depriv). (B) HAS2 mRNA expression evaluated by q-PCR experiments, and normalized to HPRT, in fro/fro and wt fibroblasts grown in complete medium (compl), nutrient derivation conditions (depriv). The effect of C2-ceramide (C2Cer, 5 µM), was tested in fro/fro fibroblasts, as indicated. (C) Western blot of HAS2 in fro/fro fibroblasts grown in complete medium and treated with scrambled siRNA or with specific HAS2 siRNA (upper panel) or in complete (compl) or nutrient deprivation (depriv) medium with or without methylumbelliferone (MU, 1 mM) (lower panel). (D) After 48 h incubation, the cytotoxicity was evaluated by the MTT test. Data are mean±SEM of 5 separate experiments, ⁎p<0.05.

Mentions: As expected, HAS2 expression was much higher in fro/fro fibroblasts than in wt fibroblasts (Fig. 4A and B), in agreement with Qin et al. [29], but HAS2 expression was not (or only slightly) dependent on culture conditions, since HAS2 was high in fro/fro cells grown in complete medium and in nutrient starvation conditions, while HAS2 of wt fibroblasts was low in both culture media (Fig. 4A and B). HAS2 expression was dependent on Cer generated by nSMase2, as shown by treatment with C2-ceramide (5 µM) that decreased HAS2 expression in fro/fro fibroblasts (Fig. 4B).


Hyaluronan synthase-2 upregulation protects smpd3-deficient fibroblasts against cell death induced by nutrient deprivation, but not against apoptosis evoked by oxidized LDL.

Garoby-Salom S, Rouahi M, Mucher E, Auge N, Salvayre R, Negre-Salvayre A - Redox Biol (2014)

HAS2 expression is dependent on nSMase2/Cer and is involved in the resistance of fro/fro to nutrient deprivation-induced apoptosis. (A) Western blot of HAS2 in wt and fro/fro fibroblasts grown in complete medium (compl) and nutrient deprivation conditions (depriv). (B) HAS2 mRNA expression evaluated by q-PCR experiments, and normalized to HPRT, in fro/fro and wt fibroblasts grown in complete medium (compl), nutrient derivation conditions (depriv). The effect of C2-ceramide (C2Cer, 5 µM), was tested in fro/fro fibroblasts, as indicated. (C) Western blot of HAS2 in fro/fro fibroblasts grown in complete medium and treated with scrambled siRNA or with specific HAS2 siRNA (upper panel) or in complete (compl) or nutrient deprivation (depriv) medium with or without methylumbelliferone (MU, 1 mM) (lower panel). (D) After 48 h incubation, the cytotoxicity was evaluated by the MTT test. Data are mean±SEM of 5 separate experiments, ⁎p<0.05.
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f0020: HAS2 expression is dependent on nSMase2/Cer and is involved in the resistance of fro/fro to nutrient deprivation-induced apoptosis. (A) Western blot of HAS2 in wt and fro/fro fibroblasts grown in complete medium (compl) and nutrient deprivation conditions (depriv). (B) HAS2 mRNA expression evaluated by q-PCR experiments, and normalized to HPRT, in fro/fro and wt fibroblasts grown in complete medium (compl), nutrient derivation conditions (depriv). The effect of C2-ceramide (C2Cer, 5 µM), was tested in fro/fro fibroblasts, as indicated. (C) Western blot of HAS2 in fro/fro fibroblasts grown in complete medium and treated with scrambled siRNA or with specific HAS2 siRNA (upper panel) or in complete (compl) or nutrient deprivation (depriv) medium with or without methylumbelliferone (MU, 1 mM) (lower panel). (D) After 48 h incubation, the cytotoxicity was evaluated by the MTT test. Data are mean±SEM of 5 separate experiments, ⁎p<0.05.
Mentions: As expected, HAS2 expression was much higher in fro/fro fibroblasts than in wt fibroblasts (Fig. 4A and B), in agreement with Qin et al. [29], but HAS2 expression was not (or only slightly) dependent on culture conditions, since HAS2 was high in fro/fro cells grown in complete medium and in nutrient starvation conditions, while HAS2 of wt fibroblasts was low in both culture media (Fig. 4A and B). HAS2 expression was dependent on Cer generated by nSMase2, as shown by treatment with C2-ceramide (5 µM) that decreased HAS2 expression in fro/fro fibroblasts (Fig. 4B).

Bottom Line: The resistance of fro/fro cells to starvation-induced apoptosis is associated with an increased expression of hyaluronan synthase 2 (HAS2) mRNAs and protein, which is inhibited by ceramide.In wt fibroblasts, this HAS2 rise and its protective effect did not occur, but exogenously added HA exhibited a protective effect against starvation-induced apoptosis.Taken together, these results highlight the role of nSMase2 in apoptosis evoked by nutrient starvation that could contribute to the delayed apoptosis of hypertrophic chondrocytes in the growth plate, and emphasize the antiapoptotic properties of HAS2.

View Article: PubMed Central - PubMed

Affiliation: INSERM UMR-1048, BP 84225, 31432 Toulouse Cedex 4, France; University of Toulouse, Toulouse, France.

No MeSH data available.


Related in: MedlinePlus