Minocycline Suppresses NLRP3 Inflammasome Activation in Experimental Ischemic Stroke

Abstract

Objective: Minocycline, a tetracycline antibiotic, has shown anti-inflammatory effects in cerebral ischemia and neurodegenerative disease; however, the molecular mechanisms underlying this effect have not been clearly identified. Since NLRP3 inflammasome activation controls the maturation and release of proinflammatory cytokines, especially interleukin-1β (IL-1β) and IL-18 in ischemia stroke, we suppose that minocycline may be involved in the regulation of NLRP3 inflammasome activation. Methods: We investigated the effects of minocycline on NLRP3 inflammasome activation using the transient middle cerebral artery occlusion (tMCAO) mouse model and an in vitro oxygen-glucose deprivation/reoxygenation injury model in BV2 microglial cells. Results: We found that minocycline administrated 1 h after reperfusion can improve neurological disorder, reduce infarct volume, and alleviate cerebral edema. Meanwhile, we showed that minocycline prevented the activation of microglias and attenuated NLRP3 inflammasome signaling after tMCAO injury. Furthermore, we found that the pretreatment of minocycline significantly inhibited signal 1 and signal 2 of NLRP3 inflammasome activation in BV2 cells. Conclusion: We demonstrated that minocycline can ameliorate ischemia-induced brain damage via inhibiting NLRP3 inflammasome activation.

Nano-chemically Modified Tetracycline-3 (nCMT-3) Attenuates Acute Lung Injury via Blocking sTREM-1 Release and NLRP3 Inflammasome Activation

“…Our findings have revealed that both of NLRP3 and caspase-1 are reduced by nCMT-3. A study using the tetracycline derivate minocycline by Lu et al in ischemia-induced brain damage reports similar results to our findings (38). The activation of NLRP3 inflammasome triggers caspase-1 activation and IL-1b/IL-18 secretion, eventually resulting in an inflammatory and pyroptotic cell death.…”

Nano-chemically Modified Tetracycline-3 (nCMT-3) Attenuates Acute Lung Injury via Blocking sTREM-1 Release and NLRP3 Inflammasome Activation

“…Our findings have revealed that both of NLRP3 and caspase-1 are reduced by nCMT-3. A study using the tetracycline derivate minocycline by Lu et al in ischemia-induced brain damage reports similar results to our findings (38). The activation of NLRP3 inflammasome triggers caspase-1 activation and IL-1b/IL-18 secretion, eventually resulting in an inflammatory and pyroptotic cell death.…”

Acute minocycline treatment inhibits microglia activation, reduces infarct volume, and has domain-specific effects on post-stroke cognition in rats

“…Given that previous studies using minocycline post-stroke have largely focused on microglia in the infarct acutely, we sought to investigate the chronic anti-in ammatory effects of minocycline in both the infarct and remote brain regions. We found that post-stroke minocycline treatment reduced chronic total microglia (Iba1 + ) expression in the infarct, aligning with previous studies that reported decreases in total microglia in the infarct acutely [26][27][28][29] . Our results differed from one study that found minocycline decreased Iba1 expression in the infarct at 1-and 2-weeks post-stroke but not 4-weeks 28 .…”

Microglial activation in the motor cortex mediated NLRP3-related neuroinflammation and neuronal damage following spinal cord injury

“…We successfully cultured primary cortical microglia and neurons with >95% positive cells of landmark protein ( Supplementary Figures S2 , S3 ). To determine the effect of minocycline on cell viability of primary microglia, a dose-response experiment was performed on microglia treated with minocycline for 12 h. Similar to previous studies (Lu et al, 2016 ; Piotrowska et al, 2017 ), cell viability was not changed in response to minocycline (10–100 μM) ( Figure 5B ). And, we chose 50 μM minocycline treatment for 12 h at subsequent experiments.…”

Nano-chemically Modified Tetracycline-3 (nCMT-3) Attenuates Acute Lung Injury via Blocking sTREM-1 Release and NLRP3 Inflammasome Activation

“…Our findings have revealed that both of NLRP3 and caspase-1 are reduced by nCMT-3. A study using the tetracycline derivate minocycline by Lu et al in ischemia-induced brain damage reports similar results to our findings (38). The activation of NLRP3 inflammasome triggers caspase-1 activation and IL-1b/IL-18 secretion, eventually resulting in an inflammatory and pyroptotic cell death.…”

Acute minocycline treatment inhibits microglia activation, reduces infarct volume, and has domain-specific effects on post-stroke cognition in rats

“…Given that previous studies using minocycline post-stroke have largely focused on microglia in the infarct acutely, we sought to investigate the chronic anti-in ammatory effects of minocycline in both the infarct and remote brain regions. We found that post-stroke minocycline treatment reduced chronic total microglia (Iba1 + ) expression in the infarct, aligning with previous studies that reported decreases in total microglia in the infarct acutely [26][27][28][29] . Our results differed from one study that found minocycline decreased Iba1 expression in the infarct at 1-and 2-weeks post-stroke but not 4-weeks 28 .…”

Microglial activation in the motor cortex mediated NLRP3-related neuroinflammation and neuronal damage following spinal cord injury

“…We successfully cultured primary cortical microglia and neurons with >95% positive cells of landmark protein ( Supplementary Figures S2 , S3 ). To determine the effect of minocycline on cell viability of primary microglia, a dose-response experiment was performed on microglia treated with minocycline for 12 h. Similar to previous studies (Lu et al, 2016 ; Piotrowska et al, 2017 ), cell viability was not changed in response to minocycline (10–100 μM) ( Figure 5B ). And, we chose 50 μM minocycline treatment for 12 h at subsequent experiments.…”

Nano-chemically Modified Tetracycline-3 (nCMT-3) Attenuates Acute Lung Injury via Blocking sTREM-1 Release and NLRP3 Inflammasome Activation

“…Our findings have revealed that both of NLRP3 and caspase-1 are reduced by nCMT-3. A study using the tetracycline derivate minocycline by Lu et al in ischemia-induced brain damage reports similar results to our findings (38). The activation of NLRP3 inflammasome triggers caspase-1 activation and IL-1b/IL-18 secretion, eventually resulting in an inflammatory and pyroptotic cell death.…”

Acute minocycline treatment inhibits microglia activation, reduces infarct volume, and has domain-specific effects on post-stroke cognition in rats

“…Given that previous studies using minocycline post-stroke have largely focused on microglia in the infarct acutely, we sought to investigate the chronic anti-in ammatory effects of minocycline in both the infarct and remote brain regions. We found that post-stroke minocycline treatment reduced chronic total microglia (Iba1 + ) expression in the infarct, aligning with previous studies that reported decreases in total microglia in the infarct acutely [26][27][28][29] . Our results differed from one study that found minocycline decreased Iba1 expression in the infarct at 1-and 2-weeks post-stroke but not 4-weeks 28 .…”

Microglial activation in the motor cortex mediated NLRP3-related neuroinflammation and neuronal damage following spinal cord injury

“…We successfully cultured primary cortical microglia and neurons with >95% positive cells of landmark protein ( Supplementary Figures S2 , S3 ). To determine the effect of minocycline on cell viability of primary microglia, a dose-response experiment was performed on microglia treated with minocycline for 12 h. Similar to previous studies (Lu et al, 2016 ; Piotrowska et al, 2017 ), cell viability was not changed in response to minocycline (10–100 μM) ( Figure 5B ). And, we chose 50 μM minocycline treatment for 12 h at subsequent experiments.…”