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Therapeutically targeting mitochondrial redox signalling alleviates endothelial dysfunction in preeclampsia

View Article: PubMed Central - PubMed

ABSTRACT

Aberrant placentation generating placental oxidative stress is proposed to play a critical role in the pathophysiology of preeclampsia. Unfortunately, therapeutic trials of antioxidants have been uniformly disappointing. There is provisional evidence implicating mitochondrial dysfunction as a source of oxidative stress in preeclampsia. Here we provide evidence that mitochondrial reactive oxygen species mediates endothelial dysfunction and establish that directly targeting mitochondrial scavenging may provide a protective role. Human umbilical vein endothelial cells exposed to 3% plasma from women with pregnancies complicated by preeclampsia resulted in a significant decrease in mitochondrial function with a subsequent significant increase in mitochondrial superoxide generation compared to cells exposed to plasma from women with uncomplicated pregnancies. Real-time PCR analysis showed increased expression of inflammatory markers TNF-α, TLR-9 and ICAM-1 respectively in endothelial cells treated with preeclampsia plasma. MitoTempo is a mitochondrial-targeted antioxidant, pre-treatment of cells with MitoTempo protected against hydrogen peroxide-induced cell death. Furthermore MitoTempo significantly reduced mitochondrial superoxide production in cells exposed to preeclampsia plasma by normalising mitochondrial metabolism. MitoTempo significantly altered the inflammatory profile of plasma treated cells. These novel data support a functional role for mitochondrial redox signaling in modulating the pathogenesis of preeclampsia and identifies mitochondrial-targeted antioxidants as potential therapeutic candidates.

No MeSH data available.


Determination of mitochondrial biogenesis/mass in plasma treated HUVEC.(a) PGC-1α protein expression was detected by fluorescent microscopy and quantified using Image J software. Data is the mean of 5 independent experiments and are expressed as difference in percentage pixel intensity between the study groups ± SEM. *P < 0.05. (b) Mitochondrial mass was determined using fluorogenic MitoID Green reagent. Confocal microscopy of MitoID Green (green fluorescence, 1st panel) and Hoechst 33342 (blue fluorescence, 2nd panel) at 20X. Merged image localizes mitochondria (3rd panel). (c) Mitochondrial mass (MitoID Green intensity) was quantified using Image J software. Data is the mean of 3 independent experiments and are expressed as difference in percentage pixel intensity between the study groups.
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f2: Determination of mitochondrial biogenesis/mass in plasma treated HUVEC.(a) PGC-1α protein expression was detected by fluorescent microscopy and quantified using Image J software. Data is the mean of 5 independent experiments and are expressed as difference in percentage pixel intensity between the study groups ± SEM. *P < 0.05. (b) Mitochondrial mass was determined using fluorogenic MitoID Green reagent. Confocal microscopy of MitoID Green (green fluorescence, 1st panel) and Hoechst 33342 (blue fluorescence, 2nd panel) at 20X. Merged image localizes mitochondria (3rd panel). (c) Mitochondrial mass (MitoID Green intensity) was quantified using Image J software. Data is the mean of 3 independent experiments and are expressed as difference in percentage pixel intensity between the study groups.

Mentions: Given that peroxisome proliferator activated receptor γ co-activator 1-α (PGC-1α) mediates mitochondrial biogenesis and antioxidant activity in HUVEC; we determined the effect of preeclampsia plasma on protein expression of PGC-1α in HUVEC. Preeclampsia plasma stimulated a significant increase in PGC-1α protein expression (140.63% ± 13.5%, n = 5, P < 0.05) when compared with treatment with 3% plasma from uncomplicated pregnant (101.08% ± 3.97%, n = 5) and non-pregnant women (100% ± 0%, n = 5) (Fig. 2a). Additionally, we measured the effect of preeclampsia plasma on mitochondrial mass in treated HUVEC using MitoID Green by fluorescent microscopy. This fluorogenic reagent preferentially accumulates in mitochondria becoming fluorescent in their lipid environment. There was no significant difference in mitochondrial mass (89% ± 8.63, n = 3) when compared with treatment with 3% plasma from uncomplicated pregnant (94.91% ± 9.46%, n = 3) and non-pregnant women (100% ± 0%, n = 3) (Fig. 2b,c).


Therapeutically targeting mitochondrial redox signalling alleviates endothelial dysfunction in preeclampsia
Determination of mitochondrial biogenesis/mass in plasma treated HUVEC.(a) PGC-1α protein expression was detected by fluorescent microscopy and quantified using Image J software. Data is the mean of 5 independent experiments and are expressed as difference in percentage pixel intensity between the study groups ± SEM. *P < 0.05. (b) Mitochondrial mass was determined using fluorogenic MitoID Green reagent. Confocal microscopy of MitoID Green (green fluorescence, 1st panel) and Hoechst 33342 (blue fluorescence, 2nd panel) at 20X. Merged image localizes mitochondria (3rd panel). (c) Mitochondrial mass (MitoID Green intensity) was quantified using Image J software. Data is the mean of 3 independent experiments and are expressed as difference in percentage pixel intensity between the study groups.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
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getmorefigures.php?uid=PMC5015016&req=5

f2: Determination of mitochondrial biogenesis/mass in plasma treated HUVEC.(a) PGC-1α protein expression was detected by fluorescent microscopy and quantified using Image J software. Data is the mean of 5 independent experiments and are expressed as difference in percentage pixel intensity between the study groups ± SEM. *P < 0.05. (b) Mitochondrial mass was determined using fluorogenic MitoID Green reagent. Confocal microscopy of MitoID Green (green fluorescence, 1st panel) and Hoechst 33342 (blue fluorescence, 2nd panel) at 20X. Merged image localizes mitochondria (3rd panel). (c) Mitochondrial mass (MitoID Green intensity) was quantified using Image J software. Data is the mean of 3 independent experiments and are expressed as difference in percentage pixel intensity between the study groups.
Mentions: Given that peroxisome proliferator activated receptor γ co-activator 1-α (PGC-1α) mediates mitochondrial biogenesis and antioxidant activity in HUVEC; we determined the effect of preeclampsia plasma on protein expression of PGC-1α in HUVEC. Preeclampsia plasma stimulated a significant increase in PGC-1α protein expression (140.63% ± 13.5%, n = 5, P < 0.05) when compared with treatment with 3% plasma from uncomplicated pregnant (101.08% ± 3.97%, n = 5) and non-pregnant women (100% ± 0%, n = 5) (Fig. 2a). Additionally, we measured the effect of preeclampsia plasma on mitochondrial mass in treated HUVEC using MitoID Green by fluorescent microscopy. This fluorogenic reagent preferentially accumulates in mitochondria becoming fluorescent in their lipid environment. There was no significant difference in mitochondrial mass (89% ± 8.63, n = 3) when compared with treatment with 3% plasma from uncomplicated pregnant (94.91% ± 9.46%, n = 3) and non-pregnant women (100% ± 0%, n = 3) (Fig. 2b,c).

View Article: PubMed Central - PubMed

ABSTRACT

Aberrant placentation generating placental oxidative stress is proposed to play a critical role in the pathophysiology of preeclampsia. Unfortunately, therapeutic trials of antioxidants have been uniformly disappointing. There is provisional evidence implicating mitochondrial dysfunction as a source of oxidative stress in preeclampsia. Here we provide evidence that mitochondrial reactive oxygen species mediates endothelial dysfunction and establish that directly targeting mitochondrial scavenging may provide a protective role. Human umbilical vein endothelial cells exposed to 3% plasma from women with pregnancies complicated by preeclampsia resulted in a significant decrease in mitochondrial function with a subsequent significant increase in mitochondrial superoxide generation compared to cells exposed to plasma from women with uncomplicated pregnancies. Real-time PCR analysis showed increased expression of inflammatory markers TNF-&alpha;, TLR-9 and ICAM-1 respectively in endothelial cells treated with preeclampsia plasma. MitoTempo is a mitochondrial-targeted antioxidant, pre-treatment of cells with MitoTempo protected against hydrogen peroxide-induced cell death. Furthermore MitoTempo significantly reduced mitochondrial superoxide production in cells exposed to preeclampsia plasma by normalising mitochondrial metabolism. MitoTempo significantly altered the inflammatory profile of plasma treated cells. These novel data support a functional role for mitochondrial redox signaling in modulating the pathogenesis of preeclampsia and identifies mitochondrial-targeted antioxidants as potential therapeutic candidates.

No MeSH data available.