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Metabolic changes and inflammation in cultured astrocytes from the 5xFAD mouse model of Alzheimer ’ s disease: Alleviation by pantethine

View Article: PubMed Central - PubMed

ABSTRACT

Astrocytes play critical roles in central nervous system homeostasis and support of neuronal function. A better knowledge of their response may both help understand the pathophysiology of Alzheimer’s disease (AD) and implement new therapeutic strategies. We used the 5xFAD transgenic mouse model of AD (Tg thereafter) to generate astrocyte cultures and investigate the impact of the genotype on metabolic changes and astrocytes activation. Metabolomic analysis showed that Tg astrocytes exhibited changes in the glycolytic pathway and tricarboxylic acid (TCA) cycle, compared to wild type (WT) cells. Tg astrocytes displayed also a prominent basal inflammatory status, with accentuated reactivity and increased expression of the inflammatory cytokine interleukin-1 beta (IL-1β). Compensatory mechanisms were activated in Tg astrocytes, including: i) the hexose monophosphate shunt with the consequent production of reducing species; ii) the induction of hypoxia inducible factor-1 alpha (HIF-1α), known to protect against amyloid-β (Aβ) toxicity. Such events were associated with the expression by Tg astrocytes of human isoforms of both amyloid precursor protein (APP) and presenilin-1 (PS1). Similar metabolic and inflammatory changes were induced in WT astrocytes by exogenous Aβ peptide. Pantethine, the vitamin B5 precursor, known to be neuroprotective and anti-inflammatory, alleviated the pathological pattern in Tg astrocytes as well as WT astrocytes treated with Aß. In conclusion, our data enlighten the dual pathogenic/protective role of astrocytes in AD pathology and the potential protective role of pantethine.

No MeSH data available.


Related in: MedlinePlus

APP is expressed in astrocytes.(A) Western blot analysis of full-length APP, C99 and C83 CTF fragments in Tg and WT cortices (upper panel) and in astrocytes (bottom panel), using a CTF (C-terminal fragment) antibody specifically recognizing the C-terminal end of APP. Graphs on the right represent the mean ± SD of actin-normalized values of the percentage of variation in optical density (O.D.) relative to WT. (B) mRNA expression levels of human APP (APP) and presenilin-1 (PS1) in Tg and WT astrocytes. Values were obtained from three independent experiments (n = 3 per group) (*, significant difference between Tg and WT groups; p<0.05).
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pone.0175369.g005: APP is expressed in astrocytes.(A) Western blot analysis of full-length APP, C99 and C83 CTF fragments in Tg and WT cortices (upper panel) and in astrocytes (bottom panel), using a CTF (C-terminal fragment) antibody specifically recognizing the C-terminal end of APP. Graphs on the right represent the mean ± SD of actin-normalized values of the percentage of variation in optical density (O.D.) relative to WT. (B) mRNA expression levels of human APP (APP) and presenilin-1 (PS1) in Tg and WT astrocytes. Values were obtained from three independent experiments (n = 3 per group) (*, significant difference between Tg and WT groups; p<0.05).

Mentions: We found that the levels of full length APP underwent a significant 2.75-fold increase in Tg cortex compared to WT, as revealed by western blot probed with an antibody (APP-CTF) that specifically recognizes the APP C-terminal end (Fig 5A). Moreover, we observed a significant 4.75-fold increase of APP-derived C99 fragment. Using the same antibody, we found the levels of full length APP increased by 1.75-fold in Tg astrocytes compared with WT (Fig 5B). We confirmed this difference between Tg and WT astrocytes using the 22C11 antibody directed against the N-terminal domain of APP (not shown). We detected expression of both human APP and PS1 mRNAs in Tg astrocytes but not in WT (Fig 5B). These results may suggest higher levels of APP in Tg astrocytes compared to WT. Nevertheless, under our experimental conditions, we failed to detect human APP in the cortex and astrocytes using the human specific 6E10 antibody. In the astrocytes, neither the APP-derived C99 fragment nor the Aß peptide have been detected.


Metabolic changes and inflammation in cultured astrocytes from the 5xFAD mouse model of Alzheimer ’ s disease: Alleviation by pantethine
APP is expressed in astrocytes.(A) Western blot analysis of full-length APP, C99 and C83 CTF fragments in Tg and WT cortices (upper panel) and in astrocytes (bottom panel), using a CTF (C-terminal fragment) antibody specifically recognizing the C-terminal end of APP. Graphs on the right represent the mean ± SD of actin-normalized values of the percentage of variation in optical density (O.D.) relative to WT. (B) mRNA expression levels of human APP (APP) and presenilin-1 (PS1) in Tg and WT astrocytes. Values were obtained from three independent experiments (n = 3 per group) (*, significant difference between Tg and WT groups; p<0.05).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC5391924&req=5

pone.0175369.g005: APP is expressed in astrocytes.(A) Western blot analysis of full-length APP, C99 and C83 CTF fragments in Tg and WT cortices (upper panel) and in astrocytes (bottom panel), using a CTF (C-terminal fragment) antibody specifically recognizing the C-terminal end of APP. Graphs on the right represent the mean ± SD of actin-normalized values of the percentage of variation in optical density (O.D.) relative to WT. (B) mRNA expression levels of human APP (APP) and presenilin-1 (PS1) in Tg and WT astrocytes. Values were obtained from three independent experiments (n = 3 per group) (*, significant difference between Tg and WT groups; p<0.05).
Mentions: We found that the levels of full length APP underwent a significant 2.75-fold increase in Tg cortex compared to WT, as revealed by western blot probed with an antibody (APP-CTF) that specifically recognizes the APP C-terminal end (Fig 5A). Moreover, we observed a significant 4.75-fold increase of APP-derived C99 fragment. Using the same antibody, we found the levels of full length APP increased by 1.75-fold in Tg astrocytes compared with WT (Fig 5B). We confirmed this difference between Tg and WT astrocytes using the 22C11 antibody directed against the N-terminal domain of APP (not shown). We detected expression of both human APP and PS1 mRNAs in Tg astrocytes but not in WT (Fig 5B). These results may suggest higher levels of APP in Tg astrocytes compared to WT. Nevertheless, under our experimental conditions, we failed to detect human APP in the cortex and astrocytes using the human specific 6E10 antibody. In the astrocytes, neither the APP-derived C99 fragment nor the Aß peptide have been detected.

View Article: PubMed Central - PubMed

ABSTRACT

Astrocytes play critical roles in central nervous system homeostasis and support of neuronal function. A better knowledge of their response may both help understand the pathophysiology of Alzheimer&rsquo;s disease (AD) and implement new therapeutic strategies. We used the 5xFAD transgenic mouse model of AD (Tg thereafter) to generate astrocyte cultures and investigate the impact of the genotype on metabolic changes and astrocytes activation. Metabolomic analysis showed that Tg astrocytes exhibited changes in the glycolytic pathway and tricarboxylic acid (TCA) cycle, compared to wild type (WT) cells. Tg astrocytes displayed also a prominent basal inflammatory status, with accentuated reactivity and increased expression of the inflammatory cytokine interleukin-1 beta (IL-1&beta;). Compensatory mechanisms were activated in Tg astrocytes, including: i) the hexose monophosphate shunt with the consequent production of reducing species; ii) the induction of hypoxia inducible factor-1 alpha (HIF-1&alpha;), known to protect against amyloid-&beta; (A&beta;) toxicity. Such events were associated with the expression by Tg astrocytes of human isoforms of both amyloid precursor protein (APP) and presenilin-1 (PS1). Similar metabolic and inflammatory changes were induced in WT astrocytes by exogenous A&beta; peptide. Pantethine, the vitamin B5 precursor, known to be neuroprotective and anti-inflammatory, alleviated the pathological pattern in Tg astrocytes as well as WT astrocytes treated with A&szlig;. In conclusion, our data enlighten the dual pathogenic/protective role of astrocytes in AD pathology and the potential protective role of pantethine.

No MeSH data available.


Related in: MedlinePlus