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Interleukin-1 beta-induced up-regulation of opioid receptors in the untreated and morphine-desensitized U87 MG human astrocytoma cells.

Byrne LS, Peng J, Sarkar S, Chang SL - J Neuroinflammation (2012)

Bottom Line: DOR expression was also elevated, although not significantly.Co-treatment with IL-1β and interleukin-1 receptor antagonist protein (IL-1RAP) resulted in a significant decrease in IL-1β-mediated MOR up-regulation.Our results indicate that the pro-inflammatory cytokine, IL-1β, affects opiate-dependent pathways by up-regulating the expression of the MOR in both untreated and morphine-desensitized U87 MG.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of NeuroImmune Pharmacology, Seton Hall University, 400 South Orange Ave, South Orange, NJ 07079, USA.

ABSTRACT

Background: Interleukin-1beta (IL-1β) is a pro-inflammatory cytokine that can be produced in the central nervous system during inflammatory conditions. We have previously shown that IL-1β expression is altered in the rat brain during a morphine tolerant state, indicating that this cytokine may serve as a convergent point between the immune challenge and opiate mediated biological pathways. We hypothesized that IL-1β up-regulates opioid receptors in human astrocytes in both untreated and morphine-desensitized states.

Methods: To test this hypothesis, we compared the basal expression of the mu (MOR), delta (DOR), and kappa (KOR) opioid receptors in the human U87 MG astrocytic cell line to SH-SY5Y neuronal and HL-60 immune cells using absolute quantitative real time RT-PCR (AQ-rt-RT-PCR). To demonstrate that IL-1β induced up-regulation of the MOR, DOR and KOR, U87 MG cells (2 x 105 cells/well) were treated with IL-1β (20 ng/mL or 40 ng/mL), followed by co-treatment with interleukin-1 receptor antagonist protein (IL-1RAP) (400 ng/mL or 400 ng/mL). The above experiment was repeated in the cells desensitized with morphine, where U87 MG cells were pre-treated with 100 nM morphine. The functionality of the MOR in U87 MG cells was then demonstrated using morphine inhibition of forksolin-induced intracellular cAMP, as determined by radioimmunoassay.

Results: U87 MG cells treated with IL-1β for 12 h showed a significant up-regulation of MOR and KOR. DOR expression was also elevated, although not significantly. Treatment with IL-1β also showed a significant up-regulation of the MOR in U87 MG cells desensitized with morphine. Co-treatment with IL-1β and interleukin-1 receptor antagonist protein (IL-1RAP) resulted in a significant decrease in IL-1β-mediated MOR up-regulation.

Conclusion: Our results indicate that the pro-inflammatory cytokine, IL-1β, affects opiate-dependent pathways by up-regulating the expression of the MOR in both untreated and morphine-desensitized U87 MG.

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The effects of IL-1βon opioid expression in U87 MG cells. U87 MG cells were treated with either cell culture medium (control) or IL-1β (20 ng/mL or 40 ng/mL) for 12 h. Real time RT-PCR was used to determine the levels of MOR (A), DOR (B), and KOR (C); GAPDH was used to normalize the receptor levels. Data are the mean ± SE. A Student’s t-test was used to determine significance. *P <0.05 compared to control cells.
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Figure 4: The effects of IL-1βon opioid expression in U87 MG cells. U87 MG cells were treated with either cell culture medium (control) or IL-1β (20 ng/mL or 40 ng/mL) for 12 h. Real time RT-PCR was used to determine the levels of MOR (A), DOR (B), and KOR (C); GAPDH was used to normalize the receptor levels. Data are the mean ± SE. A Student’s t-test was used to determine significance. *P <0.05 compared to control cells.

Mentions: A significant increase in MOR expression was seen in a dose dependent manner in the U87 MG cells treated with IL-1β at 20 ng/mL and 40 ng/mL for 12 h (5.35 ± 0.44 and 14.5 ± 0.32, respectively) compared to control (Figure 4A). U87 MG cells treated with 40 ng/mL, but not 20 ng/mL, IL-1β had a significant increase in DOR compared to control (1.74 ± 0.24) (Figure 4B). A significant increase in KOR was observed in a dose dependent manner with 20 ng/mL and 40 ng/mL IL-1β (1.79 ± 0.27 and 2.09 ± 0.27, respectively) compared to the control (Figure 4C).


Interleukin-1 beta-induced up-regulation of opioid receptors in the untreated and morphine-desensitized U87 MG human astrocytoma cells.

Byrne LS, Peng J, Sarkar S, Chang SL - J Neuroinflammation (2012)

The effects of IL-1βon opioid expression in U87 MG cells. U87 MG cells were treated with either cell culture medium (control) or IL-1β (20 ng/mL or 40 ng/mL) for 12 h. Real time RT-PCR was used to determine the levels of MOR (A), DOR (B), and KOR (C); GAPDH was used to normalize the receptor levels. Data are the mean ± SE. A Student’s t-test was used to determine significance. *P <0.05 compared to control cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3526549&req=5

Figure 4: The effects of IL-1βon opioid expression in U87 MG cells. U87 MG cells were treated with either cell culture medium (control) or IL-1β (20 ng/mL or 40 ng/mL) for 12 h. Real time RT-PCR was used to determine the levels of MOR (A), DOR (B), and KOR (C); GAPDH was used to normalize the receptor levels. Data are the mean ± SE. A Student’s t-test was used to determine significance. *P <0.05 compared to control cells.
Mentions: A significant increase in MOR expression was seen in a dose dependent manner in the U87 MG cells treated with IL-1β at 20 ng/mL and 40 ng/mL for 12 h (5.35 ± 0.44 and 14.5 ± 0.32, respectively) compared to control (Figure 4A). U87 MG cells treated with 40 ng/mL, but not 20 ng/mL, IL-1β had a significant increase in DOR compared to control (1.74 ± 0.24) (Figure 4B). A significant increase in KOR was observed in a dose dependent manner with 20 ng/mL and 40 ng/mL IL-1β (1.79 ± 0.27 and 2.09 ± 0.27, respectively) compared to the control (Figure 4C).

Bottom Line: DOR expression was also elevated, although not significantly.Co-treatment with IL-1β and interleukin-1 receptor antagonist protein (IL-1RAP) resulted in a significant decrease in IL-1β-mediated MOR up-regulation.Our results indicate that the pro-inflammatory cytokine, IL-1β, affects opiate-dependent pathways by up-regulating the expression of the MOR in both untreated and morphine-desensitized U87 MG.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of NeuroImmune Pharmacology, Seton Hall University, 400 South Orange Ave, South Orange, NJ 07079, USA.

ABSTRACT

Background: Interleukin-1beta (IL-1β) is a pro-inflammatory cytokine that can be produced in the central nervous system during inflammatory conditions. We have previously shown that IL-1β expression is altered in the rat brain during a morphine tolerant state, indicating that this cytokine may serve as a convergent point between the immune challenge and opiate mediated biological pathways. We hypothesized that IL-1β up-regulates opioid receptors in human astrocytes in both untreated and morphine-desensitized states.

Methods: To test this hypothesis, we compared the basal expression of the mu (MOR), delta (DOR), and kappa (KOR) opioid receptors in the human U87 MG astrocytic cell line to SH-SY5Y neuronal and HL-60 immune cells using absolute quantitative real time RT-PCR (AQ-rt-RT-PCR). To demonstrate that IL-1β induced up-regulation of the MOR, DOR and KOR, U87 MG cells (2 x 105 cells/well) were treated with IL-1β (20 ng/mL or 40 ng/mL), followed by co-treatment with interleukin-1 receptor antagonist protein (IL-1RAP) (400 ng/mL or 400 ng/mL). The above experiment was repeated in the cells desensitized with morphine, where U87 MG cells were pre-treated with 100 nM morphine. The functionality of the MOR in U87 MG cells was then demonstrated using morphine inhibition of forksolin-induced intracellular cAMP, as determined by radioimmunoassay.

Results: U87 MG cells treated with IL-1β for 12 h showed a significant up-regulation of MOR and KOR. DOR expression was also elevated, although not significantly. Treatment with IL-1β also showed a significant up-regulation of the MOR in U87 MG cells desensitized with morphine. Co-treatment with IL-1β and interleukin-1 receptor antagonist protein (IL-1RAP) resulted in a significant decrease in IL-1β-mediated MOR up-regulation.

Conclusion: Our results indicate that the pro-inflammatory cytokine, IL-1β, affects opiate-dependent pathways by up-regulating the expression of the MOR in both untreated and morphine-desensitized U87 MG.

Show MeSH
Related in: MedlinePlus