Role of Pink1-mediated mitophagy in adenomyosis

Regulation on mitophagy in adenomyosis by Guizhi Fuling Wan

ETHNOPHARMACOLOGICAL RELEVANCE

Guizhi Fuling Wan (GZFLW), a canonical herbal formulation originating from Synopsis of the Golden Chamber, has been widely utilized in managing pain-associated disorders. While its therapeutic efficacy in adenomyosis (AM) characterized by severe dysmenorrhea is well-documented, the underlying pharmacological mechanisms remain elusive. Emerging evidence suggests that hypoxic mitochondrial damage in endometrial tissue constitutes a pathological hallmark of AM, wherein mitophagy regulation through the PINK1/Parkin signaling pathway plays a pivotal role in mitochondrial quality control. Although certain phytomedicines have demonstrated mitophagy-modulating properties under hypoxic conditions, the specific regulatory effects of GZFLW on this process in AM pathogenesis warrant systematic investigation.

AIM OF THE STUDY

To elucidate the mitophagy-modulating mechanism of GZFLW in AM through integrated in vivo and in vitro approaches.

MATERIALS AND METHODS

An allogeneic pituitary transplantation-induced AM mouse model was established. Pharmacodynamic assessment included hotplate testing and serum cancer antigen 125 (CA125) quantification, while blood urea nitrogen (BUN) and alanine aminotransferase (ALT) levels were monitored for hepatorenal toxicity screening. Histopathological characterization employed hematoxylin-eosin (H&E) staining and transmission electron microscopy (TEM) for ultrastructural analysis. Protein expression of PINK1/Parkin pathway components (PINK1, Parkin, OPTIN, NDP52, P62) were determined by Western blot. Primary endometrial stromal cells (ESCs) isolated from clinical AM specimens underwent functional assessment via transwell migration/invasion assays, complemented by flow cytometric quantification of mitochondrial membrane potential (MMP) and reactive oxygen species (ROS). Molecular docking simulations evaluated ligand-receptor interactions between GZFLW bioactive constituents and PINK1/Parkin proteins. This study protocol was approved by the Medical Ethics Committee of China Three Gorges University (No. 2022CA002).

RESULTS

Histopathological validation confirmed successful AM model establishment. ELISA revealed significantly elevated CA125 levels in AM mice versus controls (P < 0.05), with notable reductions in GZFLW-treated groups (GET: P < 0.05, GZFLW-L: P < 0.01). No intergroup differences emerged in ALT/BUN levels, indicating absence of hepatorenal toxicity. Post-modeling pain threshold depression (P < 0.05 vs control) was attenuated by GZFLW treatment (P < 0.05). TEM analysis demonstrated mitochondrial pathology in AM endometrium, including structural deformation, reduced mitochondrial quantity, and autophagosome accumulation, all ameliorated by GZFLW-L intervention. Western blot showed upregulated PINK1 (P < 0.01), Parkin, OPTIN, and NDP52 (P < 0.05) in AM group, with subsequent downregulation following GZFLW-L administration (P < 0.05). In vitro, AM ESCs exhibited MMP depolarization (P < 0.05), reversed by GZFLW treatment alongside suppressed migratory/invasive capacity (P < 0.01, P < 0.05), ROS reduction (P < 0.05), and attenuated PINK1/Parkin pathway activation. Molecular docking confirmed strong binding affinities (binding energy < -5.0 kcal/mol) between GZFLW phytoconstituents and PINK1/Parkin targets.

CONCLUSION

This investigation reveals that GZFLW exerts its therapeutic effects on AM via targeted modulation of the PINK1/Parkin-mediated mitophagy axis, supporting its potential as a mitochondria-targeted therapeutic strategy for AM management.

The involvement of mitochondrial dysfunction during the development of adenomyosis

The etiology of adenomyosis remains unclear. The association between epithelial-mesenchymal transition (EMT) and mitochondrial dysfunction has been proposed to be involved in fibrotic diseases. Adenomyosis is defined as the existence of endometrial glands and stroma in the myometrium with EMT and ultimate fibrosis. Thus, we aimed to investigate the involvement of mitochondrial dysfunction in fibrotic adenomyosis. Mitochondrial integrity was examined in mouse and human adenomyotic tissues. Control and tamoxifen-treated mice were treated with 3-nitropropionic acid (3-NPA, a mitochondrial dysfunction inducer) and NG-nitro-L-arginine methyl ester (L-NAME, a mitochondrial dysfunction inhibitor), respectively, at postnatal day (PND) 21 followed by an evaluation of adenomyosis, EMT and fibrosis as well as the expression of mitophagy, oxidative stress, transforming growth factor beta-1 (TGF-β1). The gene profiles of adenomyotic uteri were examined at PND42. Adenomyotic mice exhibited increased development of EMT and fibrosis. Adenomyotic tissues showed consistent mitochondrial destruction with increased fission, mitophagosomes, and lysosomes. Besides, mitophagy, oxidative stress, and TGF-β1 levels were consistently increased. The mitochondrial dysfunction, the development of mitophagy and fibrosis, and TGF-β1 expression were induced by 3-NPA in control uteri. In contrast, L-NAME attenuated mitochondrial dysfunction, mitophagy, fibrosis, and TGF-β1 in adenomyotic uteri. Gene profiling demonstrated increased expression of mitochondrial dysfunction-related genes in adenomyotic uteri. We showed that mitochondrial dysfunction-induced TGF-β1 dysregulation and fibrosis were associated with the development of adenomyosis.

Controversial Roles of Autophagy in Adenomyosis and Its Implications for Fertility Outcomes-A Systematic Review

Background/Objectives: Adenomyosis is a benign condition where ectopic endometrial glandular tissue is found within the uterine myometrium. Its impact on women's reproductive outcomes is substantial, primarily due to defective decidualization, impaired endometrial receptivity, and implantation failure. The exact pathogenesis of the disease remains unclear, and the role of autophagy in adenomyosis and its associated infertility is not well understood. The aim of this systematic review was to conduct an exhaustive search of the literature to clarify the role of autophagy in the pathogenesis of adenomyosis. Methods: A systematic search was conducted in Medline, Embase, and Scopus databases up to the date of 20 August 2024. We included all English-written publications assessing the role of autophagy in the pathogenesis of adenomyosis. Results: Seventeen eligible articles were identified, including reviews and experimental studies involving human samples and murine models. The results showed that the role of autophagy in adenomyosis is controversial, with studies showing both increased and decreased levels of autophagy in adenomyosis. Conclusions: Autophagy plays a dual role in cell survival and death. Increased autophagy might support the survival and proliferation of ectopic endometrial cells, while decreased autophagy could prevent cell death, leading to abnormal growth. Oxidative stress may trigger pro-survival autophagy, mitigating apoptosis and promoting cellular homeostasis. Hormonal imbalances disrupt normal autophagic activity, potentially impairing endometrial receptivity and decidualization and contributing to infertility. The balance of autophagy is crucial in adenomyosis, with its dual role contributing to the complexity of the disease. Limitations: A few studies have been conducted with heterogeneous populations, limiting comparative analyses.

The cGAS-STING pathway and female reproductive system diseases

The cGAS-STING pathway has become a crucial role in the detection of cytosolic DNA and the initiation of immune responses. The cGAS-STING pathway not only mediates protective immune defense against various DNA-containing pathogens but also detects tumor-derived DNA to generate intrinsic anti-tumor immunity. However, abnormal activation of the cGAS-STING pathway by self-DNA can also lead to autoimmune diseases and inflammatory disorders. This article reviews the mechanisms and functions of the cGAS-STING pathway, as well as the latest research progress in female reproductive-related diseases. We focus on the regulatory mechanisms and roles of this pathway in common female reproductive disorders, discuss the clinical potential of the cGAS-STING pathway as biomarkers and therapeutic agents for female reproductive diseases, as well as the research controversies, technical issues, and biological knowledge gaps that need to be resolved. Furthermore, we provide new ideas for the treatment and prevention of these diseases.

mtDNA regulates cGAS-STING signaling pathway in adenomyosis

In various hyperproliferative disorders, damaged mitochondria can release mitochondrial DNA (mtDNA) into the cytoplasm, activating the cGAS-STING signaling pathway and subsequent immune imbalances. Our previous research has demonstrated that hypoxia plays a role in the development of adenomyosis (AM) by inducing mitochondrial dysfunction. However, the precise involvement of the cGAS-STING signaling pathway and mtDNA in AM remains unclear. Therefore, this study aims to investigate the relationship between mtDNA secretion, changes in the cGAS-STING signaling pathway, and the abnormal cellular proliferation observed in AM. We found the cGAS, STING, TBK1, p-TBK1, IRF3, and p-IRF3 proteins levels were significantly elevated in the tissues of patients with AM compared to the control group. Additionally, there was an increase in the expression of the pro-inflammatory cytokines IL-6 and IFN-α in the AM tissues. Hypoxia-induced an increase in the proliferation and migration abilities of endometrial stromal cells (ESCs), accompanied by the activation of the cGAS-STING signaling pathway and elevated levels of IFN-α. Furthermore, hypoxia promoted the leakage of mtDNA into the cytoplasm in AM ESCs, and the deletion of mtDNA reduced the activation of the cGAS-STING pathway. Moreover, knockdown of the STING gene inhibited the expression of TBK1, p-TBK1, IRF3, and p-IRF3 and suppressed the secretion of the inflammatory cytokines IL-6 and IFN-α. Furthermore, the migration and invasion abilities of AM ESCs were significantly diminished after STING knockdown. These findings provide valuable insights into the role of mtDNA release and the cGAS-STING signaling pathway in the pathogenesis of AM.

Inspiring Tactics with the Improvement of Mitophagy and Redox Balance for the Development of Innovative Treatment against Polycystic Kidney Disease

Polycystic kidney disease (PKD) is the most common genetic form of chronic kidney disease (CKD), and it involves the development of multiple kidney cysts. Not enough medical breakthroughs have been made against PKD, a condition which features regional hypoxia and activation of the hypoxia-inducible factor (HIF) pathway. The following pathology of CKD can severely instigate kidney damage and/or renal failure. Significant evidence verifies an imperative role for mitophagy in normal kidney physiology and the pathology of CKD and/or PKD. Mitophagy serves as important component of mitochondrial quality control by removing impaired/dysfunctional mitochondria from the cell to warrant redox homeostasis and sustain cell viability. Interestingly, treatment with the peroxisome proliferator-activated receptor-α (PPAR-α) agonist could reduce the pathology of PDK and might improve the renal function of the disease via the modulation of mitophagy, as well as the condition of gut microbiome. Suitable modulation of mitophagy might be a favorable tactic for the prevention and/or treatment of kidney diseases such as PKD and CKD.