Puerarin protects rat brain against ischemia/reperfusion injury by suppressing autophagy  via  the AMPK-mTOR-ULK1 signaling pathway

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Puerarin suppresses autophagy to alleviate cerebral ischemia/reperfusion injury, and accumulating evidence indicates that the AMPK-mTOR signaling pathway regulates the activation of the autophagy pathway through the coordinated phosphorylation of ULK1. In this study, we investigated the mechanisms underlying the neuroprotective effect of puerarin and its role in modulating autophagy via the AMPK-mTOR-ULK1 signaling pathway in the rat middle cerebral artery occlusion model of cerebral ischemia/reperfusion injury. Rats were intraperitoneally injected with puerarin, 50 or 100 mg/kg, daily for 7 days. Then, 30 minutes after the final administration, rats were subjected to transient middle cerebral artery occlusion for 90 minutes. Then, after 24 hours of reperfusion, the Longa score and infarct volume were evaluated in each group. Autophagosome formation was observed by transmission electron microscopy. LC3, Beclin-1 p62, AMPK, mTOR and ULK1 protein expression levels were examined by immunofluorescence and western blot assay. Puerarin substantially reduced the Longa score and infarct volume, and it lessened autophagosome formation in the hippocampal CA1 area following cerebral ischemia/reperfusion injury in a dose-dependent manner. Pretreatment with puerarin (50 or 100 mg/kg) reduced Beclin-1 expression and the LC3-II/LC3-I ratio, as well as p-AMPK and pS317-ULK1 levels. In comparison, it increased p62 expression. Furthermore, puerarin at 100 mg/kg dramatically increased the levels of p-mTOR and pS757-ULK1 in the hippocampus on the ischemic side. Our findings suggest that puerarin alleviates autophagy by activating the APMK-mTOR-ULK1 signaling pathway. Thus, puerarin might have therapeutic potential for treating cerebral ischemia/reperfusion injury.

Related collections

Most cited references 40

Record: found
Abstract: found
Article: not found

Guidelines for the use and interpretation of assays for monitoring autophagy.

C N Estevez, S M Lee, Qing Zhong … (2012)

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.

0 comments Cited 785 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Beclin-phosphatidylinositol 3-kinase complex functions at the trans-Golgi network.

A Kihara, Y Kabeya, Y Ohsumi … (2001)

Autophagy is an intracellular bulk protein degradation system. Beclin is known to be involved in this process; however, its role is unclear. In this study, we showed that Beclin was co-immunoprecipitated with phosphatidylinositol (PtdIns) 3-kinase, which is also required for autophagy, suggesting that Beclin is a component of the PtdIns 3-kinase complex. Quantitative analyses using a cross-linker showed that all Beclin forms a complex with PtdIns 3-kinase, whereas approximately 50% of PtdIns 3-kinase remains free from Beclin. Indirect immunofluorescence microscopy demonstrated that the majority of Beclin and PtdIns 3-kinase localize to the trans-Golgi network (TGN). Some PtdIns 3-kinase is also distributed in the late endosome. These results suggest that Beclin and PtdIns 3-kinase control autophagy as a complex at the TGN.

0 comments Cited 206 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Hemorrhagic transformation after ischemic stroke in animals and humans.

Boryana Stamova, DaZhi Liu, Glen Jickling … (2014)

Hemorrhagic transformation (HT) is a common complication of ischemic stroke that is exacerbated by thrombolytic therapy. Methods to better prevent, predict, and treat HT are needed. In this review, we summarize studies of HT in both animals and humans. We propose that early HT ( 18 to 24 hours after stroke) that relates to ischemia activation of brain proteases (MMP-2, MMP-3, MMP-9, and endogenous tissue plasminogen activator), neuroinflammation, and factors that promote vascular remodeling (vascular endothelial growth factor and high-moblity-group-box-1). Processes that mediate BBB repair and reduce HT risk are discussed, including transforming growth factor beta signaling in monocytes, Src kinase signaling, MMP inhibitors, and inhibitors of reactive oxygen species. Finally, clinical features associated with HT in patients with stroke are reviewed, including approaches to predict HT by clinical factors, brain imaging, and blood biomarkers. Though remarkable advances in our understanding of HT have been made, additional efforts are needed to translate these discoveries to the clinic and reduce the impact of HT on patients with ischemic stroke.

0 comments Cited 196 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Journal

Journal ID (nlm-ta): Neural Regen Res

Journal ID (iso-abbrev): Neural Regen Res

Journal ID (publisher-id): NRR

Title: Neural Regeneration Research

Publisher: Medknow Publications & Media Pvt Ltd (India )

ISSN (Print): 1673-5374

ISSN (Electronic): 1876-7958

Publication date (Print): June 2018

Volume: 13

Issue: 6

Pages: 989-998

Affiliations

[1 ]Third-Grade Pharmacological Laboratory on Chinese Medicine Approved by State Administration of Traditional Chinese Medicine, Medical College of China Three Gorges University, Yichang, Hubei Province, China

[2 ]Xiangyang Hospital of Traditional Chinese Medicine, Xiangyang, Hubei Province, China

[3 ]Yichang Hospital of Traditional Chinese Medicine, Clinical Medical College of Traditional Chinese Medicine, China Three Gorges University, Yichang, Hubei Province, China

[4 ]Department of Medicine and Therapeutics, the Chinese University of Hong Kong, Hong Kong Special Administrative Region, China

[5 ]The Institute of Neurology, the First College of Clinical Medical Sciences, China Three Gorges University, Yichang, Hubei Province, China

Author notes

[* ] Correspondence to: Zhi-Gang Mei or Zhi-Tao Feng, meizhigang@ 123456ctgu.edu.cn or fengzhitao2008@ 123456126.com .

Author contributions: Conception and design: ZGM and ZTF. Implement of experiments: JFW, WT, and WFH. Data analysis: JFW, YF, and HJZ. Administrative, technical or material support: SBY and SZZ. Technical and information support: LX. Draft of manuscript: JFW. Study supervision: ZGM and ZTF. All authors approved the final version of the paper.

Author information

Zhi-Gang Mei http://orcid.org/0000-0002-9099-7099

Zhi-Tao Feng http://orcid.org/0000-0003-1107-944X

Article

Publisher ID: NRR-13-989

DOI: 10.4103/1673-5374.233441

PMC ID: 6022469

PubMed ID: 29926825

SO-VID: 72e97198-17c6-4147-89b6-774dac5e0cb5

License:

This is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms.

Puerarin protects rat brain against ischemia/reperfusion injury by suppressing autophagy via the AMPK-mTOR-ULK1 signaling pathway

Read this article at

Abstract

Abstract

Related collections

Neuronal Signaling

Most cited references 40

Guidelines for the use and interpretation of assays for monitoring autophagy.

Beclin-phosphatidylinositol 3-kinase complex functions at the trans-Golgi network.

Hemorrhagic transformation after ischemic stroke in animals and humans.

Author and article information

Journal

Affiliations

Author notes

Author information

Article

History

Categories

Comments

Comment on this article

Similar content 1,840

Cited by 52

Most referenced authors 4,381