EGCG protects the mouse brain against cerebral ischemia/reperfusion injury by suppressing autophagy via the AKT/AMPK/mTOR phosphorylation pathway

Gasdermin D could be lost in the brain parenchyma infarct core and a pyroptosis-autophagy inhibition effect of Jie-Du-Huo-Xue decoction after stroke

Background

The Chinese ethnic medicine Jie-Du-Huo-Xue Decoction (JDHXD) is used to alleviate neuroinflammation in cerebral ischemia (CI). Our previous studies have confirmed that JDHXD can inhibit microglial pyroptosis in CI. However, the pharmacological mechanism of JDHXD in alleviating neuroinflammation and pyroptosis needs to be further elucidated. New research points out that there is an interaction between autophagy and inflammasome NLRP3, and autophagy can help clear NLRP3. The NLRP3 is a key initiator of pyroptosis and autophagy. The effect of JDHXD promoting autophagy to clear NLRP3 to inhibit pyroptosis on cerebral ischemia-reperfusion inflammatory injury is currently unknown. We speculate that JDHXD can inhibit pyroptosis in CI by promoting autophagy to clear NLRP3.

Methods

Chemical characterization of JDHXD was performed using LC-MS. Model of middle cerebral artery occlusion/reperfusion (MCAO/R) was established in SD rats. Neurological deficits, neuron damage, and cerebral infarct volume were evaluated. Western Blot and immunofluorescence were used to detect neuronal pyroptosis and autophagy.

Results

30 possible substance metabolites in JDHXD medicated serum were analyzed by LC-MS (Composite Score > 0.98). Furthermore, JDHXD protects rat neurological function and cerebral infarct size after CI. JDHXD inhibited the expression of pyroptosis and autophagy after CI. Our western blot and immunofluorescence results showed that JDHXD treatment can reduce the expression of autophagy-related factors ULK1, beclin1, and LC3-Ⅱ. The expression of NLRP3 protein was lower in the JDHXD group than in the I/R group. Compared with the I/R group, the expressions of pyroptosis-related factors caspase-1 P 10, GSDMD-NT, IL-18, and IL-1β decreased in the JDHXD group. Furthermore, we observed an unexpected result: immunofluorescence demonstrated that Gasdermin D (GSDMD) was significantly absent in the infarct core, and highly expressed in the peri-infarct and contralateral cerebral hemispheres. This finding challenges the prevailing view that GSDMD is elevated in the ischemic cerebral hemisphere.

Conclusion

JDHXD inhibited pyroptosis and autophagy after MCAO/R. JDHXD suppressed pyroptosis and autophagy by inhibiting NLRP3, thereby alleviating CI. In addition, we present a different observation from previous studies that the expression of GSDMD in the infarct core was lower than that in the peri-infarct and contralateral non-ischemic hemispheres on day 3 of CI.

Implantable Epigallocatechin Gallate Sustained-Release Nanofibers for the Prevention of Immobilization-Induced Muscle Atrophy

Long-term immobilization of joints can lead to disuse atrophy of the muscles in the joints. Oral nutrients are used clinically for rehabilitation and therapeutic purposes, but bioavailability and targeting are limited. Here, we report tea polyphenols (dietary polyphenols), sustained-release nanofilms that release tea polyphenols through slow local degradation of core-shell nanofibers in muscles. This dietary polyphenol does not require gastrointestinal consumption and multiple doses and can directly remove inflammatory factors and superoxide generated in muscle tissue during joint fixation. The quality of muscles is increased by 30%, and muscle movement function is effectively improved. Although nanofibers need to be implanted into muscles, they can improve bacterial infections after joint surgery. To investigate the biological mechanism of this core-shell nanomembrane prevention, we conducted further transcriptomic studies on muscle, confirming that in addition to achieving antioxidation and anti-inflammation by inhibiting TNF-α and NF-κB signaling pathways, tea polyphenol core-shell nanofibers can also promote muscle formation by activating the p-Akt signaling pathway.

A bibliometric analysis of research foci and trends in cerebral ischemia-reperfusion injury involving autophagy during 2008 to 2022

BACKGROUND

Cerebral ischemia-reperfusion injury (CIRI) is a complex pathophysiological process that typically occurs during the treatment of ischemia, with limited therapeutic options. Autophagy plays a vital role during the reperfusion phase and is a potential therapeutic target for preventing and treating cerebral ischemia-reperfusion injury.

METHODS

We conducted a comprehensive search of the Web of Science Core Collection for publications related to cerebral ischemia-reperfusion injury with autophagy, published between January 1, 2008, and January 1, 2023. We analyzed the selected publications using VOSviewer, CiteSpace, and other bibliometric tools.

RESULTS

Our search yielded 877 relevant publications. The field of autophagy in cerebral ischemia-reperfusion injury has grown rapidly since 2016. China has been the leading contributor to publications, followed by the USA and Iran. Chen Zhong and Qin Zhenghong have been influential in this field but have yet to reach all groups. In addition, there has been a shortage of collaboration among authors from different institutions. Our literature and keyword analysis identified Neurovascular protection (#11 Neuroprotective, #13 Neurovascular units, etc) and Inflammation (NLRP3 inflammasome) as popular research directions. Furthermore, the terms "Blood-Brain Barrier," "Mitophagy," and "Endoplasmic reticulum stress" have been frequently used and may be hot research topics in the future.

CONCLUSIONS

The role of autophagy in cerebral ischemia-reperfusion injury remains unclear, and the specific mechanisms of drugs used to treat ischemia-reperfusion injury still need to be explored. This work outlines the changing trends in investigating cerebral ischemia-reperfusion injury involving autophagy and suggests future lines of inquiry.