Dexmedetomidine Provides Protection to Neurons Against OGD/R-Induced Oxidative Stress and Neuronal Apoptosis
Background: Dexmedetomidine, a potent α2-adrenoceptor (α2-AR) agonist, is extensively used in the operating room (OR) and intensive care unit (ICU) and has applied in several diseases. However, the precise role of dexmedetomidine in oxygen and glucose deprivation/reoxygenation (OGD/R)-treated neurons, and the mechanisms underlying its effect, has yet to be elucidated.
Methods: OGD/R-treated neurons served as a cellular model in our study. Western blotting was used to investigate the protein levels of α-adrenergic receptor (α-AR) in OGD/R-treated neurons, apoptosis related proteins (Bcl-2, Bax and Cleaved Caspase 3) and a range of proteins associated with the Nrf2/ARE pathway (Nrf2, HO-1, NQO-1, SOD). The CCK-8 assay was used to determine cell survival rates while Co-IP was used to determine the interactions between α2-AR and Nrf2. The TUNEL assay was used to detect the levels of apoptosis in neurons.
Results: OGD/R treatment reduced the level of α2-AR protein in neurons and reduced neuronal survival in a time-dependent manner. However, treatment with dexmedetomidine led to an elevation of α2-AR protein expression in OGD/R-treated neurons and the survival rate of OGD/R-treated neurons. These results indicated that dexmedetomidine treatment promoted the viability of OGD/R-treated neurons but inhibited OGD/R-mediated oxidative stress and neuronal apoptosis. From a mechanistic point-of-view, Nrf2 can bind effectively with α2-AR. We believe that dexmedetomidine exerted effect on the Nrf2/ARE pathway in OGD/R-treated neurons. Silencing the expression of Nrf2 reversed the effects of dexmedetomidine on cell viability, oxidative stress, and neuronal apoptosis in OGD/R-treated neurons.
Conclusion: Collectively, our data indicate that elucidated that the activation of α2-AR by dexmedetomidine had a protective effect in neurons against OGD/R-triggered oxidative stress and neuronal apoptosis by modulating the Nrf2/ARE pathway, thus providing a novel way forward to develop clinical therapies to reduce oxidative stress induced by neuronal injury.
Figure 1
Figure 2
Figure 3
Figure 4
This is a list of supplementary files associated with this preprint. Click to download.
Posted 22 Sep, 2020
On 08 Dec, 2020
Received 11 Nov, 2020
On 24 Oct, 2020
Received 21 Oct, 2020
Invitations sent on 19 Oct, 2020
On 19 Oct, 2020
On 03 Sep, 2020
On 02 Sep, 2020
On 02 Sep, 2020
On 31 Aug, 2020
Dexmedetomidine Provides Protection to Neurons Against OGD/R-Induced Oxidative Stress and Neuronal Apoptosis
Posted 22 Sep, 2020
On 08 Dec, 2020
Received 11 Nov, 2020
On 24 Oct, 2020
Received 21 Oct, 2020
Invitations sent on 19 Oct, 2020
On 19 Oct, 2020
On 03 Sep, 2020
On 02 Sep, 2020
On 02 Sep, 2020
On 31 Aug, 2020
Background: Dexmedetomidine, a potent α2-adrenoceptor (α2-AR) agonist, is extensively used in the operating room (OR) and intensive care unit (ICU) and has applied in several diseases. However, the precise role of dexmedetomidine in oxygen and glucose deprivation/reoxygenation (OGD/R)-treated neurons, and the mechanisms underlying its effect, has yet to be elucidated.
Methods: OGD/R-treated neurons served as a cellular model in our study. Western blotting was used to investigate the protein levels of α-adrenergic receptor (α-AR) in OGD/R-treated neurons, apoptosis related proteins (Bcl-2, Bax and Cleaved Caspase 3) and a range of proteins associated with the Nrf2/ARE pathway (Nrf2, HO-1, NQO-1, SOD). The CCK-8 assay was used to determine cell survival rates while Co-IP was used to determine the interactions between α2-AR and Nrf2. The TUNEL assay was used to detect the levels of apoptosis in neurons.
Results: OGD/R treatment reduced the level of α2-AR protein in neurons and reduced neuronal survival in a time-dependent manner. However, treatment with dexmedetomidine led to an elevation of α2-AR protein expression in OGD/R-treated neurons and the survival rate of OGD/R-treated neurons. These results indicated that dexmedetomidine treatment promoted the viability of OGD/R-treated neurons but inhibited OGD/R-mediated oxidative stress and neuronal apoptosis. From a mechanistic point-of-view, Nrf2 can bind effectively with α2-AR. We believe that dexmedetomidine exerted effect on the Nrf2/ARE pathway in OGD/R-treated neurons. Silencing the expression of Nrf2 reversed the effects of dexmedetomidine on cell viability, oxidative stress, and neuronal apoptosis in OGD/R-treated neurons.
Conclusion: Collectively, our data indicate that elucidated that the activation of α2-AR by dexmedetomidine had a protective effect in neurons against OGD/R-triggered oxidative stress and neuronal apoptosis by modulating the Nrf2/ARE pathway, thus providing a novel way forward to develop clinical therapies to reduce oxidative stress induced by neuronal injury.
Figure 1
Figure 2
Figure 3
Figure 4