Curcumin Rescues Oxidative Stress-Induced Impairment of PINK1/Parkin Pathway-Mediated Mitophagy in APOE4-Expressing Astrocytes

 Will your competent? doctor and hospital GUARANATEE that human testing occurs? Why not?

Laziness? Incompetence? Or just don't care? NO leadership? NO strategy? Not my job? Not my Problem!

Curcumin Rescues Oxidative Stress-Induced Impairment of PINK1/Parkin Pathway-Mediated Mitophagy in APOE4-Expressing Astrocytes

Jia-Xin Yu 1, Wen-Xuan Zhang 1, Pu-Yu Li 1, Yi-Liang Yang 1 2, Han-Chang Huang 3 4 5

Affiliations 

• PMID: 41706344
 
• DOI: 10.1007/s12035-026-05744-9

Abstract

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized primarily by deterioration in memory, cognition, and learning ability. Its etiology is complex and influenced by multiple factors, including genetics and environment. With advancing research into mitochondrial function and mechanisms, impaired mitophagy has been proposed as a significant mechanism contributing to AD. The ApoE ε4 allele, a high-risk genetic factor for AD, may play a key role in disease pathogenesis by inducing mitophagy dysfunction and apoptosis. From the perspective of APOE gene polymorphisms, this study investigates abnormal changes in mitochondrial function and autophagy in humanized APOE4 mice primary astrocytes under oxidative stress, as well as the regulatory effect of curcumin (Cur) on mitophagy and oxidative stress-induced apoptosis, thereby exploring its potential to ameliorate AD through targeting mitophagy. Mitochondrial function analysis revealed that APOE4 expression reduced the antioxidant capacity and respiratory function of primary astrocytes, leading to mitochondrial membrane damage, intracellular reactive oxygen species (ROS) accumulation, and decreased ATP production. Curcumin effectively protected mitochondrial integrity, reduced the number of damaged mitochondria, improved overall mitochondrial function, and helped maintain mitochondrial homeostasis involving in PINK1/Parkin pathway. Regarding autophagy and apoptosis, curcumin was shown to restore autophagic flux, mitigate autophagy disruption caused by oxidative stress, and reverse early-stage apoptosis.

Timosaponin B-II attenuates cerebral ischemia injury by enhancing Parkin-mediated mitophagy

 

Sounds important for our recovery. Do you really think your incompetent? doctor and hospital will ensure human testing gets done? Competent entities would do that!

Timosaponin B-II attenuates cerebral ischemia injury by enhancing Parkin-mediated mitophagy

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https://doi.org/10.1016/j.phymed.2025.157580Get rights and content

Abstract

Background

Ischemic stroke (IS) is linked to dysregulated mitophagy. Timosaponin B-II (TBII), a complex furostan steroid saponin extracted from Anemarrhena asphodeloides Bunge, has been demonstrated to play a crucial role in regulating autophagy. However, whether TBII exerts therapeutic effects in cerebral ischemia through the regulation of autophagy, particularly Parkin-dependent pathways remained unexplored.

Purpose

The present study investigated whether TBII can alleviate cerebral ischemic injury by enhancing Parkin-dependent mitophagy.

Methods

We evaluated TBII’s effects on cerebral ischemic injury using permanent middle cerebral artery occlusion (pMCAO) in mice and oxygen-glucose deprivation (OGD)-treated neurons. Mitophagy and mitochondrial function were assessed by Western blot, transmission electron microscopy (TEM), and immunofluorescence techniques. Parkin knockdown (shPrkn lentivirus) and the mitophagy inhibitor Mdivi-1 were employed to validate TBII’ mechanisms.

Results

Intragastrical (i.g.) administration of TBII (10, 20, 40 mg/kg) for 7 days significantly reduced cerebral infarction volume, brain water content, and neurological deficits in pMCAO mice, while attenuating neuronal death in vivo and in vitro. Molecular docking, cellular thermal shift assays (CETSA), drug affinity responsive target stability (DARTS), and molecular dynamics simulations confirmed that TBII specifically binds and stabilizes to Parkin, suggesting its potential to enhance mitophagy. TBII mitigated the impairment of mitophagy by upregulating Parkin and p-Parkin (Ser65), promoting the ubiquitination of mitochondria, the degradation of autophagy substrate SQSTM1 and damaged mitochondria after IS. TBII also preserved mitochondrial membrane potential (MMP), suppressed oxidative stress, and restored mitochondrial function and ultrastructure. These benefits were reversed by the mitophagy inhibitor Mdivi-1 and Parkin knockdown.

Conclusion

The present study demonstrates that TBII reduces oxidative stress, preserves mitochondrial function, and ultimately attenuates ischemic brain injure by enhancing Parkin-dependent mitophagy. Our study provides the first evidence supporting TBII as a promising therapeutic agent for IS.

Graphical abstract

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USP7 promotes PINK1/Parkin-dependent mitophagy to ameliorate cerebral ischemia–reperfusion injury by deubiquitinating and stabilizing SIRT1

Sounds important for our recovery. Do you really think your incompetent doctor and hospital will ensure human testing gets done? Competent entities would do that!

USP7 promotes PINK1/Parkin-dependent mitophagy to ameliorate cerebral ischemia–reperfusion injury by deubiquitinating and stabilizing SIRT1

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,

https://doi.org/10.1016/j.brainres.2025.149638

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Highlights

• •
  USP7 stabilizes SIRT1 via deubiquitination, enhancing mitophagy.
• •
  USP7-SIRT1 axis activates PINK1/Parkin pathway post-ischemia.
• •
  USP7 mitigates brain injury by promoting damaged mitochondria clearance.
• •
  SIRT1 upregulation by USP7 reduces cerebral ischemia–reperfusion damage.
• •
  USP7-mediated mitophagy offers neuroprotection in stroke models.

neuroprotection(Wrong terminology, neuroprotection gives no sense of urgency! Call it by its' correct name; the neuronal cascade of death! Sounds important to immediately get fixed, neuroprotection is a milquetoast term saying nothing!)

If your doctor tells you they did nothing to stop the neuronal cascade of death in the first week thus letting hundreds of millions to billions of neurons die, you'd sue them for malpractice. Neuroprotection doesn't give any sense of urgency.

Abstract

Background

Cerebral ischemia–reperfusion (CI/R) injury, a major complication of ischemic stroke, is characterized by mitochondrial dysfunction and neuronal apoptosis, and understanding its underlying molecular mechanisms is essential for the development of effective therapeutic strategies. This study aimed to investigate the role of ubiquitin-specific protease 7 (USP7) in CI/R injury and elucidate its regulatory mechanisms.

Methods

A rat model of middle cerebral artery occlusion/reperfusion (MCAO/R) and an in vitro neuronal model subjected to oxygen-glucose deprivation/reperfusion (OGD/R) was used to mimic CI/R injury. USP7 was overexpressed or knocked down, with or without co-treatment, using the autophagy inhibitor 3-methyladenine (3-MA). Neurological function was evaluated using standardized scoring systems, and cerebral infarct volume was quantified by TTC staining. Histopathological alterations in the cortex and hippocampus were assessed using hematoxylin-eosin (HE) and Nissl staining. Neuronal viability and apoptosis were measured by CCK-8 assay, TUNEL staining, and flow cytometry. To assess cellular metabolism and oxidative stress, ATP and LDH levels, along with antioxidant markers including SOD, GSH, and GSH-Px, were analyzed using commercial biochemical kits. Mitochondrial morphology and autophagosome formation were visualized using transmission electron microscopy. Gene and protein expression levels were quantified by qRT-PCR and Western blotting, respectively. Immunofluorescence microscopy was performed to evaluate subcellular localization of target proteins and co-localization with mitochondrial membrane markers. Lastly, protein–protein interactions and ubiquitination modification were analyzed by co-immunoprecipitation assays.

Results

USP7 overexpression significantly alleviated neurological deficits, reduced infarct volume, attenuated histological damage, and decreased neuronal apoptosis in the MCAO/R model. In parallel, in the OGD/R model, USP7 overexpression markedly enhanced neuronal viability, suppressed apoptosis, restored ATP production, improved antioxidant capacity (as indicated by increased levels of SOD, GSH, and GSH-Px), and reduced LDH release. Mechanistically, USP7 stabilized SIRT1 protein expression through deubiquitination, which in turn activated the PINK1/Parkin pathway and enhanced mitophagy. This activation was demonstrated by an increased LC3II/LC3I ratio, elevated ATG5 expression, enhanced co-localization of Tomm20 and Parkin, and increased autophagosome formation. Moreover, these protective effects could be abolished when either 3-MA treatment was applied or SIRT1/PINK1 expression was knocked down.

Conclusion

USP7 mitigates CI/R injury by promoting PINK1/Parkin-dependent mitophagy through SIRT1 deubiquitination and stabilization, supporting USP7 as a potential therapeutic target for ischemic stroke.

Graphical abstract

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PA2G4/EBP1 ubiquitination by PRKN/PARKIN promotes mitophagy protecting neuron death in cerebral ischemia

Neuroprotection doesn't specify urgency, CASCADE OF DEATH does!

Will your incompetent doctor and hospital do nothing to get human testing done? NO? Then fire the whole hospital because they aren't a viable hospital.

 

PA2G4/EBP1 ubiquitination by PRKN/PARKIN promotes mitophagy protecting neuron death in cerebral ischemia

Inwoo Hwang

,

Byeong-Seong Kim

,

Ho Yun Lee

,

Sung-Woo Cho

,

Seung Eun Lee

&

Jee-Yin Ahn

Received 05 Jan 2023, Accepted 11 Sep 2023, Accepted author version posted online: 15 Sep 2023

• Cite this article
• https://doi.org/10.1080/15548627.2023.2259215
• CrossMark

 

Accepted author version

ABSTRACT

Cerebral ischemia induces massive mitochondrial damage, leading to neuronal death. The elimination of damaged mitochondria via mitophagy is critical for neuroprotection.(neuronal cascade of death is a much better term, suggesting immediacy.) Here we show that the level of PA2G4/EBP1 (proliferation-associated 2G4) was notably increased early during transient middle cerebral artery occlusion and prevented neuronal death by eliciting cerebral ischemia-reperfusion (IR)-induced mitophagy. Neuron-specific knockout of Pa2g4 increased infarct volume and aggravated neuron loss with impaired mitophagy and was rescued by introduction of adeno-associated virus serotype 2 expressing PA2G4/EBP1. We determined that PA2G4/EBP1 is ubiquitinated on lysine 376 by PRKN/PARKIN on the damaged mitochondria and interacts with receptor protein SQSTM1/p62 for mitophagy induction. Thus, our study suggests that PA2G4/EBP1 ubiquitination following cerebral IR-injury promotes mitophagy induction, which may be implicated in neuroprotection.

KEYWORDS:

• Ischemia
• mitophagy
• PA2G4/EBP1
• PRKN/PARKIN
• SQSTM1/p62

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