Limits...
Insulin promotes survival of amyloid-beta oligomers neuroblastoma damaged cells via caspase 9 inhibition and Hsp70 upregulation.

Di Carlo M, Picone P, Carrotta R, Giacomazza D, San Biagio PL - J. Biomed. Biotechnol. (2010)

Bottom Line: By TUNEL and biochemical assays we demonstrate that the recovery of the cell viability is obtained by inhibition of intrinsic apoptotic program, triggered by A-beta and involving caspase 9 and 3 activation.Furthermore, A-beta activates the stress inducible Hsp70 protein in LAN5 cells and an overexpression is detectable after the addition of insulin, suggesting that this major induction is the necessary condition to activate a cell survival program.Together, these results may provide opportunities for the design of preventive and therapeutic strategies against AD.

View Article: PubMed Central - PubMed

Affiliation: Istituto di Biomedicina e Immunologia Molecolare A. Monroy, Consiglio Nazionale delle Ricerche, 90146 Palermo, Italy. di-carlo@ibim.cnr.it

ABSTRACT
Alzheimer's disease (AD) and type 2 diabetes are connected in a way that is still not completely understood, but insulin resistance has been implicated as a risk factor for developing AD. Here we show an evidence that insulin is capable of reducing cytotoxicity induced by Amyloid-beta peptides (A-beta) in its oligomeric form in a dose-dependent manner. By TUNEL and biochemical assays we demonstrate that the recovery of the cell viability is obtained by inhibition of intrinsic apoptotic program, triggered by A-beta and involving caspase 9 and 3 activation. A protective role of insulin on mitochondrial damage is also shown by using Mito-red vital dye. Furthermore, A-beta activates the stress inducible Hsp70 protein in LAN5 cells and an overexpression is detectable after the addition of insulin, suggesting that this major induction is the necessary condition to activate a cell survival program. Together, these results may provide opportunities for the design of preventive and therapeutic strategies against AD.

Show MeSH

Related in: MedlinePlus

Dose dependence of protective effect of insulin against rAβ42 oligomers induced cell death. (a) LAN5 neuroblastoma cells were untreated (control) or incubated with insulin 50 or 100 or 200 μM of insulin alone or after incubation with 25 or 40 μM of rAβ42. After incubation treated and untreated cells were submitted to viability MTS assay. Cell viability is significantly lower in rAβ42 25 μM *P < .01, rAβ42 25 μM + insulin 50 μM *P < .01 versus control, whereas it is not significantly lower with rAβ42 25 μM + insulin 100 μM versus control. Cell viability is significantly lower in rAβ42 40 μM *P < .003, rAβ42  40 μM + insulin 50 μM *P < .003, whereas it is not significantly lower with Aβ 40 μM + insulin 100 μM versus control. Percentage of viability is referred to control, the data are the mean ±  SD of three separate experiments. (b) Representative morphological images of LAN5 untreated cells (control), treated with rAβ42 40 μM, rAβ42 40 μM, and insulin 100 μM, insulin alone 100 μM. Bar 20 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2871552&req=5

fig1: Dose dependence of protective effect of insulin against rAβ42 oligomers induced cell death. (a) LAN5 neuroblastoma cells were untreated (control) or incubated with insulin 50 or 100 or 200 μM of insulin alone or after incubation with 25 or 40 μM of rAβ42. After incubation treated and untreated cells were submitted to viability MTS assay. Cell viability is significantly lower in rAβ42 25 μM *P < .01, rAβ42 25 μM + insulin 50 μM *P < .01 versus control, whereas it is not significantly lower with rAβ42 25 μM + insulin 100 μM versus control. Cell viability is significantly lower in rAβ42 40 μM *P < .003, rAβ42 40 μM + insulin 50 μM *P < .003, whereas it is not significantly lower with Aβ 40 μM + insulin 100 μM versus control. Percentage of viability is referred to control, the data are the mean ±  SD of three separate experiments. (b) Representative morphological images of LAN5 untreated cells (control), treated with rAβ42 40 μM, rAβ42 40 μM, and insulin 100 μM, insulin alone 100 μM. Bar 20 μm.

Mentions: As shown in Figure 1(a), cells treated with rAβ42, 25 μM or 40 μM showed a mortality of about 60% and 85%, respectively, if compared to the control. When insulin was added, in the sample previously treated with oligomers, a recovery of cell viability of about 20% for the minor concentration and 100% for the higher concentration was observed, indicating that insulin plays a protective effect against A-beta toxicity (Figure 1(a)).


Insulin promotes survival of amyloid-beta oligomers neuroblastoma damaged cells via caspase 9 inhibition and Hsp70 upregulation.

Di Carlo M, Picone P, Carrotta R, Giacomazza D, San Biagio PL - J. Biomed. Biotechnol. (2010)

Dose dependence of protective effect of insulin against rAβ42 oligomers induced cell death. (a) LAN5 neuroblastoma cells were untreated (control) or incubated with insulin 50 or 100 or 200 μM of insulin alone or after incubation with 25 or 40 μM of rAβ42. After incubation treated and untreated cells were submitted to viability MTS assay. Cell viability is significantly lower in rAβ42 25 μM *P < .01, rAβ42 25 μM + insulin 50 μM *P < .01 versus control, whereas it is not significantly lower with rAβ42 25 μM + insulin 100 μM versus control. Cell viability is significantly lower in rAβ42 40 μM *P < .003, rAβ42  40 μM + insulin 50 μM *P < .003, whereas it is not significantly lower with Aβ 40 μM + insulin 100 μM versus control. Percentage of viability is referred to control, the data are the mean ±  SD of three separate experiments. (b) Representative morphological images of LAN5 untreated cells (control), treated with rAβ42 40 μM, rAβ42 40 μM, and insulin 100 μM, insulin alone 100 μM. Bar 20 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2871552&req=5

fig1: Dose dependence of protective effect of insulin against rAβ42 oligomers induced cell death. (a) LAN5 neuroblastoma cells were untreated (control) or incubated with insulin 50 or 100 or 200 μM of insulin alone or after incubation with 25 or 40 μM of rAβ42. After incubation treated and untreated cells were submitted to viability MTS assay. Cell viability is significantly lower in rAβ42 25 μM *P < .01, rAβ42 25 μM + insulin 50 μM *P < .01 versus control, whereas it is not significantly lower with rAβ42 25 μM + insulin 100 μM versus control. Cell viability is significantly lower in rAβ42 40 μM *P < .003, rAβ42 40 μM + insulin 50 μM *P < .003, whereas it is not significantly lower with Aβ 40 μM + insulin 100 μM versus control. Percentage of viability is referred to control, the data are the mean ±  SD of three separate experiments. (b) Representative morphological images of LAN5 untreated cells (control), treated with rAβ42 40 μM, rAβ42 40 μM, and insulin 100 μM, insulin alone 100 μM. Bar 20 μm.
Mentions: As shown in Figure 1(a), cells treated with rAβ42, 25 μM or 40 μM showed a mortality of about 60% and 85%, respectively, if compared to the control. When insulin was added, in the sample previously treated with oligomers, a recovery of cell viability of about 20% for the minor concentration and 100% for the higher concentration was observed, indicating that insulin plays a protective effect against A-beta toxicity (Figure 1(a)).

Bottom Line: By TUNEL and biochemical assays we demonstrate that the recovery of the cell viability is obtained by inhibition of intrinsic apoptotic program, triggered by A-beta and involving caspase 9 and 3 activation.Furthermore, A-beta activates the stress inducible Hsp70 protein in LAN5 cells and an overexpression is detectable after the addition of insulin, suggesting that this major induction is the necessary condition to activate a cell survival program.Together, these results may provide opportunities for the design of preventive and therapeutic strategies against AD.

View Article: PubMed Central - PubMed

Affiliation: Istituto di Biomedicina e Immunologia Molecolare A. Monroy, Consiglio Nazionale delle Ricerche, 90146 Palermo, Italy. di-carlo@ibim.cnr.it

ABSTRACT
Alzheimer's disease (AD) and type 2 diabetes are connected in a way that is still not completely understood, but insulin resistance has been implicated as a risk factor for developing AD. Here we show an evidence that insulin is capable of reducing cytotoxicity induced by Amyloid-beta peptides (A-beta) in its oligomeric form in a dose-dependent manner. By TUNEL and biochemical assays we demonstrate that the recovery of the cell viability is obtained by inhibition of intrinsic apoptotic program, triggered by A-beta and involving caspase 9 and 3 activation. A protective role of insulin on mitochondrial damage is also shown by using Mito-red vital dye. Furthermore, A-beta activates the stress inducible Hsp70 protein in LAN5 cells and an overexpression is detectable after the addition of insulin, suggesting that this major induction is the necessary condition to activate a cell survival program. Together, these results may provide opportunities for the design of preventive and therapeutic strategies against AD.

Show MeSH
Related in: MedlinePlus