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Increased DJ-1 expression under oxidative stress and in Alzheimer's disease brains.

Baulac S, Lu H, Strahle J, Yang T, Goldberg MS, Shen J, Schlossmacher MG, Lemere CA, Lu Q, Xia W - Mol Neurodegener (2009)

Bottom Line: We found that DJ-1 was expressed early during zebrafish development and throughout adulthood.While a slight reduction in staining for islet-1 positive neurons was observed in both DJ-1 KD and H2O2 treated embryos, the number of apoptotic cells was significantly increased in both KD and H2O2 treated embryos.Therefore, our results strongly suggest that DJ-1 expression is not necessary during zebrafish development but can be induced in zebrafish exposed to oxidative stress and is present in human AD brains.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Harvard University, Boston, MA 02115, USA. wxia@rics.bwh.harvard.edu.

ABSTRACT
Mutations in the DJ-1 gene have been linked to autosomal recessive familial Parkinson's disease. To understand the function of DJ-1, we determined the DJ-1 expression in both zebrafish and post mortem human brains. We found that DJ-1 was expressed early during zebrafish development and throughout adulthood. Knock down (KD) of DJ-1 by injection of morpholino did not cause dramatic morphologic alterations during development, and no loss of dopaminergic neurons was observed in embryos lacking DJ-1. However, DJ-1 KD embryos were more susceptible to programmed cell death. While a slight reduction in staining for islet-1 positive neurons was observed in both DJ-1 KD and H2O2 treated embryos, the number of apoptotic cells was significantly increased in both KD and H2O2 treated embryos. Interestingly, DJ-1 expression was increased in brains of zebrafish under conditions of oxidative stress, indicating that DJ-1 is a part of stress-responsive machinery. Since oxidative stress is one of the major contributors to the development of Alzheimer's disease (AD), we also examined DJ-1 expression in AD brains. Using DJ-1 specific antibodies, we failed to detect a robust staining of DJ-1 in brain tissues from control subjects. However, DJ-1 immunoreactivity was detected in hippocampal pyramidal neurons and astrocytes of AD brains. Therefore, our results strongly suggest that DJ-1 expression is not necessary during zebrafish development but can be induced in zebrafish exposed to oxidative stress and is present in human AD brains.

No MeSH data available.


Related in: MedlinePlus

Lack of changes in DJ-1 expression in the presenceof Aβ. Conditioned media from CHO and CHO+APP cells were collected for the measurement of Aβ levels and treatment of PC-12 cells. A. High levels of Aβ40 were found in the media from CHO+APP cells before (white bar) and after (black bar) the treatment of PC-12 cells (the standard error of means was illustrated). B. High levels of Aβ42 were found in the media from CHO+APP cells before (white) and after (black) the treatment of PC-12 cells, compared to undetectable amount of Aβ in the media from CHO cells. C. Conditioned media from CHO or CHO+APP cells were applied to PC-12 cells for 24 hr, and cells were collected for the quantification of DJ-1 by Western blot using antibody DJ-1-N. Cells from two independent experiments were collected, and the expression levels of DJ-1 in both sets of PC-12 cells maintained at similar levels.
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Figure 7: Lack of changes in DJ-1 expression in the presenceof Aβ. Conditioned media from CHO and CHO+APP cells were collected for the measurement of Aβ levels and treatment of PC-12 cells. A. High levels of Aβ40 were found in the media from CHO+APP cells before (white bar) and after (black bar) the treatment of PC-12 cells (the standard error of means was illustrated). B. High levels of Aβ42 were found in the media from CHO+APP cells before (white) and after (black) the treatment of PC-12 cells, compared to undetectable amount of Aβ in the media from CHO cells. C. Conditioned media from CHO or CHO+APP cells were applied to PC-12 cells for 24 hr, and cells were collected for the quantification of DJ-1 by Western blot using antibody DJ-1-N. Cells from two independent experiments were collected, and the expression levels of DJ-1 in both sets of PC-12 cells maintained at similar levels.

Mentions: To search for any mechanistic cause for DJ-1 expression in AD brains, we examined the effect of Aβ on the regulation of DJ-1 expression. We have used two cell lines, CHO that expresses endogenous levels of APP, and CHO+APP that expresses high levels of APP and generates a large amount of Aβ. When we measured the conditioned media from CHO and CHO+APP cells, we found elevated levels of Aβ40 (Fig. 7A, before treatment) and Aβ42 (Fig. 7B, before treatment) in the media from CHO+APP cells, compared to undetectable level of Aβ in the media from CHO cells (Fig. 7A and 7B). We applied conditioned media to PC-12 cells for 24 hrs, and collected media and cells for the quantification of Aβ and DJ-1. We found that the conditioned media continued to carry high levels of Aβ40 (Fig. 7A, after treatment) and Aβ42 (Fig. 7B, after treatment). Despite of the Aβ exposure, the expression levels of DJ-1 in PC-12 cells maintained at similar levels (Fig. 7C). Therefore, endogenous DJ-1 expression in PC-12 cells did not change in the presence of extracellular Aβ.


Increased DJ-1 expression under oxidative stress and in Alzheimer's disease brains.

Baulac S, Lu H, Strahle J, Yang T, Goldberg MS, Shen J, Schlossmacher MG, Lemere CA, Lu Q, Xia W - Mol Neurodegener (2009)

Lack of changes in DJ-1 expression in the presenceof Aβ. Conditioned media from CHO and CHO+APP cells were collected for the measurement of Aβ levels and treatment of PC-12 cells. A. High levels of Aβ40 were found in the media from CHO+APP cells before (white bar) and after (black bar) the treatment of PC-12 cells (the standard error of means was illustrated). B. High levels of Aβ42 were found in the media from CHO+APP cells before (white) and after (black) the treatment of PC-12 cells, compared to undetectable amount of Aβ in the media from CHO cells. C. Conditioned media from CHO or CHO+APP cells were applied to PC-12 cells for 24 hr, and cells were collected for the quantification of DJ-1 by Western blot using antibody DJ-1-N. Cells from two independent experiments were collected, and the expression levels of DJ-1 in both sets of PC-12 cells maintained at similar levels.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2654450&req=5

Figure 7: Lack of changes in DJ-1 expression in the presenceof Aβ. Conditioned media from CHO and CHO+APP cells were collected for the measurement of Aβ levels and treatment of PC-12 cells. A. High levels of Aβ40 were found in the media from CHO+APP cells before (white bar) and after (black bar) the treatment of PC-12 cells (the standard error of means was illustrated). B. High levels of Aβ42 were found in the media from CHO+APP cells before (white) and after (black) the treatment of PC-12 cells, compared to undetectable amount of Aβ in the media from CHO cells. C. Conditioned media from CHO or CHO+APP cells were applied to PC-12 cells for 24 hr, and cells were collected for the quantification of DJ-1 by Western blot using antibody DJ-1-N. Cells from two independent experiments were collected, and the expression levels of DJ-1 in both sets of PC-12 cells maintained at similar levels.
Mentions: To search for any mechanistic cause for DJ-1 expression in AD brains, we examined the effect of Aβ on the regulation of DJ-1 expression. We have used two cell lines, CHO that expresses endogenous levels of APP, and CHO+APP that expresses high levels of APP and generates a large amount of Aβ. When we measured the conditioned media from CHO and CHO+APP cells, we found elevated levels of Aβ40 (Fig. 7A, before treatment) and Aβ42 (Fig. 7B, before treatment) in the media from CHO+APP cells, compared to undetectable level of Aβ in the media from CHO cells (Fig. 7A and 7B). We applied conditioned media to PC-12 cells for 24 hrs, and collected media and cells for the quantification of Aβ and DJ-1. We found that the conditioned media continued to carry high levels of Aβ40 (Fig. 7A, after treatment) and Aβ42 (Fig. 7B, after treatment). Despite of the Aβ exposure, the expression levels of DJ-1 in PC-12 cells maintained at similar levels (Fig. 7C). Therefore, endogenous DJ-1 expression in PC-12 cells did not change in the presence of extracellular Aβ.

Bottom Line: We found that DJ-1 was expressed early during zebrafish development and throughout adulthood.While a slight reduction in staining for islet-1 positive neurons was observed in both DJ-1 KD and H2O2 treated embryos, the number of apoptotic cells was significantly increased in both KD and H2O2 treated embryos.Therefore, our results strongly suggest that DJ-1 expression is not necessary during zebrafish development but can be induced in zebrafish exposed to oxidative stress and is present in human AD brains.

View Article: PubMed Central - HTML - PubMed

Affiliation: Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Harvard University, Boston, MA 02115, USA. wxia@rics.bwh.harvard.edu.

ABSTRACT
Mutations in the DJ-1 gene have been linked to autosomal recessive familial Parkinson's disease. To understand the function of DJ-1, we determined the DJ-1 expression in both zebrafish and post mortem human brains. We found that DJ-1 was expressed early during zebrafish development and throughout adulthood. Knock down (KD) of DJ-1 by injection of morpholino did not cause dramatic morphologic alterations during development, and no loss of dopaminergic neurons was observed in embryos lacking DJ-1. However, DJ-1 KD embryos were more susceptible to programmed cell death. While a slight reduction in staining for islet-1 positive neurons was observed in both DJ-1 KD and H2O2 treated embryos, the number of apoptotic cells was significantly increased in both KD and H2O2 treated embryos. Interestingly, DJ-1 expression was increased in brains of zebrafish under conditions of oxidative stress, indicating that DJ-1 is a part of stress-responsive machinery. Since oxidative stress is one of the major contributors to the development of Alzheimer's disease (AD), we also examined DJ-1 expression in AD brains. Using DJ-1 specific antibodies, we failed to detect a robust staining of DJ-1 in brain tissues from control subjects. However, DJ-1 immunoreactivity was detected in hippocampal pyramidal neurons and astrocytes of AD brains. Therefore, our results strongly suggest that DJ-1 expression is not necessary during zebrafish development but can be induced in zebrafish exposed to oxidative stress and is present in human AD brains.

No MeSH data available.


Related in: MedlinePlus