FUNDC1 induces apoptosis and autophagy under oxidative stress via PI3K/Akt/mTOR pathway in cataract lens cells

Insights into the role of FoxL2 in tebuconazole-induced male- biased sex differentiation of zebrafish

Tebuconazole (TEB) is a commonly used fungicide that inhibits the aromatase Cyp19A and downregulates the transcription factor forkhead box L2 (FoxL2), leading to male-biased sex differentiation in zebrafish larvae. However, the specific mechanism by which FoxL2 functions following TEB exposure remains unclear. In this study, the phosphorylation sites and kinase-specific residues in zebrafish FoxL2 protein (zFoxL2) were predicted. Subsequently, recombinant zFoxL2 was prepared via prokaryotic expression, and a polyclonal rabbit-anti-zFoxL2 antibody was generated. Zebrafish fibroblast (ZF4) cells were exposed to 100-μM TEB alone for 8 h, after which changes in the expression of genes involved in the foxl2 regulatory pathway (akt1, pi3k, cyp19a1b, c/ebpb and sox9a) were detected. When co-exposed to 1-μM estradiol and 100-μM TEB, the expression of these key genes tended to be restored. Interestingly, TEB did not affect the expression of the foxl2 gene or protein but it significantly suppressed the phosphorylation of FoxL2 (pFoxL2) at serine 238 (decreased by 43.64 %, p = 0.009). Co-immunoprecipitation assays showed that, following exposure to 100-μM TEB, the total precipitated proteins in ZF4 cells decreased by 17.02 % (p = 0.029) and 31.39 % (p = 0.027) in the anti-zFoxL2 antibody group and anti-pFoxL2 (ser238) antibody group, respectively, indicating that TEB suppressed the capacity of the FoxL2 protein to bind to other proteins via repression of its own phosphorylation. The pull-down assay confirmed this conclusion. This study preliminarily elucidated that the foxl2 gene functions via post-translational regulation through hypophosphorylation of its encoded protein during TEB-induced male-biased sex differentiation.

Isorhamnetin: what is the in vitro evidence for its antitumor potential and beyond?

Isorhamnetin (ISO) is a phenolic compound belonging to flavonoid family, showcasing important in vitro pharmacological activities such as antitumor, anti-inflammation, and organ protection. ISO is predominantly extracted from Hippophae rhamnoides L. This plant is well-known in China and abroad because of its "medicinal and food homologous" characteristics. As a noteworthy natural drug candidate, ISO has received considerable attention in recent years owing to its low cost, wide availability, high efficacy, low toxicity, and minimal side effects. To comprehensively elucidate the multiple biological functions of ISO, particularly its antitumor activities and other pharmacological potentials, a literature search was conducted using electronic databases including Web of Science, PubMed, Google Scholar, and Scopus. This review primarily focuses on ISO's ethnopharmacology. By synthesizing the advancements made in existing research, it is found that the general effects of ISO involve a series of in vitro potentials, such as antitumor, protection of cardiovascular and cerebrovascular, anti-inflammation, antioxidant, and more. This review illustrates ISO's antitumor and other pharmacological potentials, providing a theoretical basis for further research and new drug development of ISO.

Molecular mechanism of lycorine in the treatment of glioblastoma based on network pharmacology and molecular docking

Lycorine is a naturally active alkaloid that has been shown to have inhibitory effects on a variety of cancers. However, the underlying mechanism of lycorine in the treatment of glioblastoma (GBM) is unclear. In this study, we investigated the mechanism of lycorine in the treatment of GBM based on network pharmacology and molecular docking. Lycorine-related targets overlapped with GBM-related targets to obtain intersections that represent potential anti-GBM targets for lycorine. The protein-protein interaction (PPI) network was constructed using the STRING online database and analyzed by Cytoscape software, and 10 key target genes (AKT1, SRC, HSP90AA1, HRAS, MMP9, BCL2L1, IGF1, MAPK14, STAT1, and KDR) were obtained, which played an important role in the therapeutic effect of lycorine on GBM. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that lycorine acts on GBM by multiple pathways, including inducing apoptosis and reactive oxygen species production. The molecular docking results showed that lycorine had strong binding efficiency with the 10 key genes. In addition, we found that the use of lycorine-induced apoptosis in U-87 MG glioblastoma cells. Here, the mechanism of action of lycorine against GBM was elucidated and verified by experiments, which provided evidence support for its clinical application.

A bibliometric and visualized analysis of the pathogenesis of cataracts from 1999 to 2023

Research on the pathogenesis of cataracts is ongoing and the number of publications on this topic is increasing annually. This study offers an overview of the research status, popular topics, and scholarly tendencies in the field of cataract pathogenesis over recent decades，which helps to guide future research directions, and optimize resource allocation. In the present study, we performed a bibliometric analysis of cataract pathogenesis. Publications from January 1, 1999, to December 20, 2023, were collected from the Web of Science Core Collection (WoSCC), and the extracted data were quantified and analyzed. We analyzed and presented the data using Microsoft Excel, VOSviewer, CiteSpace, and Python. In all, 4006 articles were evaluated based on various characteristics, including publication year, authors, countries, institutions, journals, citations, and keywords. This study utilized VOSviewer to conduct visualized analysis, including co-authorship, co-citation, co-occurrence, and network visualization. The CiteSpace software was used to identify keywords with significant bursts of activity. The number of annual global publications climbed from 76 to 277 between 1999 and 2023, a 264.47% rise. Experimental Eye Research published the most manuscripts (178 publications), whereas Investigative Ophthalmology & Visual Science received the most citations (6675 citations). The most influential and productive country, institution, and author were the United States (1244 publications, 54,456 citations), University of California system (136 publications, 5401 citations), and Yao Ke (49 publications, 838 citations), respectively. The top 100 ranked keywords are divided into four clusters through co-occurrence analysis: (1) secondary cataracts, (2) oxidative stress, (3) gene mutations and protein abnormalities, and (4) alteration of biological processes in lens epithelial cells. Further discussions on the four subtopics outline the research topics and trends. In conclusion, the specific mechanism of cataract formation remains a popular topic for future research and should be explored in greater depth.

Ferroptosis in viral infection: a potential therapeutic target

Ferroptosis, known as a type of programmed cell death that is iron dependent, is characterized by intracellular iron accumulation, glutathione depletion, glutathione peroxidase inactivation and lipid peroxidation. More and more research in recent years has demonstrated the tight connection between viral infections and ferroptosis. This article reviews the potential role and mechanism of ferroptosis in viral infection, and these findings will help in the prevention and treatment of the virus.

Investigation of Mitochondrial Homeostasis Changes in Lens Epithelium of High-Myopic Cataract

PURPOSE

High myopia is demonstrated as a pathogenic factor for nuclear cataract. The main mechanism of high-myopia cataracts (HMC) is oxidative damage, which causes mitochondrial homeostasis imbalance. This study aimed to explore the mitochondrial homeostasis alterations in lens epithelial cells (LECs) of HMC.

METHODS

The lens epithelium tissues of 20 patients with HMC and 20 control subjects with age-related cataracts (ARC) were collected. The real-time quantitative PCR and western blot assays were performed for gene expressions. Immunofluorescence (IF) assays were performed for mitochondrial marker TOM20, DNA damage marker 15A3, and autophagosome marker LC3. Transmission electron microscopy (TEM) was used to observe the changes in mitochondria morphology. Mitochondrial ROS, and mitochondrial membrane potential were detected by MitoSOX fluorescence, and JC-1 MitoMP staining, respectively. Rat lenses cultured in vitro were pretreated with CCCP and H2O2 (10 and 400 µM) for 24 h.

RESULTS

The copy number of mtDNA was decreased in HMC patients compared to the ARC patients. Increased mitochondrial-oriented oxidative stress response was detected in LECs of HMC compared to that of ARC. Altered expressions of mitochondrial homeostasis and mitophagy markers, including TFAM, PGC1α, MFN1, MFN2, Drp1, PINK1, Parkin and LC3, were found in HMC patients. Reciprocally, no significant differences in the expression of BNIP3 and FUNDC1 were found between HMC and ARC patients. Importantly, TEM revealed that the obvious mitochondrial fission and mitophagy phenomena occur in the LECs of HMC patients compared to the ARC patients. Moreover, CCCP aggreated the mitoROS production and depolarized mitochondrial membrane potential in the H2O2-treated human lens epithelial cells line (SRA01/04); Most important, rat lens organ culture experiments indicated a significant increase in H2O2-induced lens opacity following mitochondrial uncoupling CCCP treatment.

CONCLUSION

This study has identified for the first time the abnormal mitochondrial homeostasis in HMC, and provide a new perspective on the potential mechanisms of HMC, which occurs earlier and at a higher incidence rate than ARC.

Astaxanthin Inhibits H2O2-Induced Excessive Mitophagy and Apoptosis in SH-SY5Y Cells by Regulation of Akt/mTOR Activation

Oxidative stress, which damages cellular components and causes mitochondrial dysfunction, occurs in a variety of human diseases, including neurological disorders. The clearance of damaged mitochondria via mitophagy maintains the normal function of mitochondria and facilitates cell survival. Astaxanthin is an antioxidant known to have neuroprotective effects, but the underlying mechanisms remain unclear. This study demonstrated that astaxanthin inhibited H2O2-induced apoptosis in SH-SY5Y cells by ameliorating mitochondrial damage and enhancing cell survival. H2O2 treatment significantly reduced the levels of activated Akt and mTOR and induced mitophagy, while pretreatment with astaxanthin prevented H2O2-induced inhibition of Akt and mTOR and attenuated H2O2-induced mitophagy. Moreover, the inhibition of Akt attenuated the protective effect of astaxanthin against H2O2-induced cytotoxicity. Taken together, astaxanthin might inhibit H2O2-induced apoptosis by protecting mitochondrial function and reducing mitophagy. The results also indicate that the Akt/mTOR signaling pathway was critical for the protection of astaxanthin against H2O2-induced cytotoxicity. The results from the present study suggest that astaxanthin can reduce neuronal oxidative injury and may have the potential to be used for preventing neurotoxicity associated with neurodegenerative diseases.

Sestrin 2 protects human lens epithelial cells from oxidative stress and apoptosis induced by hydrogen peroxide by regulating the mTOR/Nrf2 pathway

OBJECTIVE

We aimed to explore the effect and potential mechanism of Sestrin 2 (SESN2) in human lens epithelial cells (HLECs).

METHODS

To mimic the oxidative stress environment, SAR01/04 cells were treated with 200 μM hydrogen peroxide (H2O2) for 24 h. Cell viability and apoptosis were checked by cell counting kit-8 and flow cytometry. Western blot was taken to check the protein changes of SESN2, B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X (Bax), mechanistic target of rapamycin (mTOR), phosphorylated (p)-mTOR, ribosomal protein S6 kinase B1 (p70S6K), p-p70S6K, and nuclear factor erythroid 2-related factor 2 (Nrf2). Superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and reactive oxygen species (ROS) were detected via the corresponding reagent kit. The levels of interleukin (IL)-1β, IL-18, and tumor necrosis factor (TNF)-α were measured using enzyme-linked immunosorbent assay.

RESULTS

SESN2 was down-regulated in cataract lens tissue and up-regulated in SAR01/04 cells treated with H2O2. Under treatment of H2O2, up-regulation of SESN2 improved cell viability, enhanced the activity of SOD and CAT, inhibited cell apoptosis, and reduced the levels of MDA, ROS, IL-1β, IL-18, and TNF-α, while down-regulation of SESN2 caused the contrary effects. Further bioinformatics analysis suggested that SESN2 regulated the mTOR signaling pathway. Treatment of H2O2 inhibited p-mTOR and p-p70S6K protein expression, while overexpression of SESN2 increased p-mTOR and p-p70S6K protein expression in the H2O2 group and down-regulation of SESN2 further decreased p-mTOR and p-p70S6K protein expression in the H2O2 group. Additionally, H2O2 increased Nrf2 protein expression, and overexpression of SESN2 further increased Nrf2 protein expression in the H2O2 group. Importantly, rapamycin (an inhibitor of mTOR signaling pathway) and knockdown of Nrf2 reversed the promotive effects of SESN2 on cell viability and the inhibitive effects of SESN2 on cell apoptosis, oxidative stress, and inflammatory reaction.

CONCLUSION

SESN2 protected HLECs damage induced by H2O2, which was related to the activation of mTOR/Nrf2 pathway.

Mitochonic acid 5 rescues cardiomyocytes from doxorubicin-induced toxicity via repressing the TNF-α/NF-κB/NLRP3-mediated pyroptosis

AIMS

Doxorubicin (DOX) is an effective anti-tumor drug, but the cardiotoxicity severely limits its clinical use. Interestingly, a hypothesis has emerged suggesting an association between DOX-induced cardiotoxicity and mitochondrial disorders and oxidative stress. The mitochonic acid 5 (MA5) shows promise in alleviating mitochondrial dysfunction by promoting mitochondrial ATP synthesis and reducing reactive oxygen species (ROS) accumulation, though its potential in ameliorating DOX-induced cardiotoxicity remains elusive.

METHODS

Network pharmacology approach, molecular docking techniques, and molecular dynamics simulation (MDS) were used to reveal the specific drug targets and pharmaceutical mechanisms involved in the treatment of DOX-induced cardiotoxicity using MA5. For experimental verification, cardiomyocytes (H9c2) and mice were exposed to DOX in the presence or absence of MA5. Our investigation involved the assessment of echocardiographic parameters, cardiac enzymes, inflammatory factors, mitochondrial function, myocardial structure, and cardiomyocyte pyroptosis.

RESULTS

Among the 100 core targets identified in network pharmacology, MA5 was pharmacologically active against DOX-induced cardiotoxicity via pathways implicated in cancer, prostate cancer, lipids and atherosclerosis. Molecular docking analysis confirmed that MA5 docked well with TNF-α, interleukin-6 (IL-6), and caspase-3. Furthermore, MA5 exhibited a stronger affinity toward TNF-α than IL-6 and caspase-3. Subsequent MDS revealed the stability of binding between MA5 and TNF-α. The DOX-challenged mice also displayed abnormal myocardial enzymogram, disrupted systolic and diastolic function, and elevated inflammation and cardiomyocyte pyroptosis, which could be mitigated by the administration of MA5. Similarly, H9c2 cells exposed to DOX showed increased intracellular ROS production and impaired mitochondrial function, which were relieved by MA5 treatment.

CONCLUSION

Our findings suggest that MA5 attenuates DOX-induced cardiac anomalies through the TNF-α-mediated regulation of inflammation and pyroptosis. These insights offer a potential therapeutic strategy for managing DOX-induced cardiac complications, thereby improving the safety and efficacy of cancer treatments.

Natural Acetogenins, Chatenaytrienins-1, -2, -3 and -4, Mitochondrial Potential Uncouplers and Autophagy Inducers-Promising Anticancer Agents

The present paper details the complete stereoselective synthesis of four natural acetogenins, chatenaytrienins-1, -2, -3 and -4, previously isolated from the roots of fruit trees of the family Annonaceae (A. nutans and A. muricata), as an inseparable mixture. The novel organometallic reactions, developed by the authors, of Ti-catalyzed cross-cyclomagnesiation of O-containing and aliphatic allenes using available Grignard reagents were applied at the key stage of synthesis. We have studied the biological activity of the synthesized individual chatenaytrienins-1, -2, -3 and -4 in vitro, including their cytotoxicity in a panel of tumor lines and their ability to induce apoptosis, affect the cell cycle and mitochondria, and activate the main apoptotic signaling pathways in the cell, applying modern approaches of flow cytometry and multiplex analysis with Luminex xMAP technology. It has been shown that chatenaytrienins affect mitochondria by uncoupling the processes of mitochondrial respiration, causing the accumulation of ROS ions, followed by the initiation of apoptosis. The most likely mechanism for the death of cortical neurons from the consumption of tea from the seeds of Annona fruit is long-term chronic hypoxia, which leads to the development of an atypical form of Parkinson's disease that is characteristic of the indigenous inhabitants of Guam and New Caledonia.

Alleviating effect of lycorine on CFA‑induced arthritic pain via inhibition of spinal inflammation and oxidative stress

Chronic pain is the primary symptom of osteoarthritis affecting a patient's quality of life. Neuroinflammation and oxidative stress in the spinal cord contribute to arthritic pain and represent ideal targets for pain management. In the present study, a model of arthritis was established by intra-articular injection of complete Freund's adjuvant (CFA) into the left knee joint in mice. After CFA inducement, knee width and pain hypersensitivity in the mice were increased, motor disability was impaired, spinal inflammatory reaction was induced, spinal astrocytes were activated, antioxidant responses were decreased, and glycogen synthase kinase 3β (GSK-3β) activity was inhibited. To explore the potential therapeutic options for arthritic pain, lycorine was intraperitoneally injected for 3 days in the CFA mice. Lycorine treatment significantly reduced mechanical pain sensitivity, suppressed spontaneous pain, and recovered motor coordination in the CFA-induced mice. Additionally, in the spinal cord, lycorine treatment decreased the inflammatory score, reduced NOD-like receptor protein 3 inflammasome (NLRP3) activity and IL-1β expression, suppressed astrocytic activation, downregulated NF-κB levels, increased nuclear factor erythroid 2-related factor 2 expression and superoxide dismutase activity. Furthermore, lycorine was shown to bind to GSK-3β through three electrovalent bonds, to inhibit GSK-3β activity. In summary, lycorine treatment inhibited GSK-3β activity, suppressed NLRP3 inflammasome activation, increased the antioxidant response, reduced spinal inflammation, and relieved arthritic pain.

Cardiac-specific overexpression of catalase attenuates lipopolysaccharide-induced cardiac anomalies through reconciliation of autophagy and ferroptosis

Lipopolysaccharide (LPS) from Gram-negative bacteria is a major contributor to cardiovascular failure, but the signaling mechanisms underlying its stress response are not fully understood. This study aimed to investigate the effect of the antioxidant enzyme catalase on LPS-induced cardiac abnormalities and the mechanisms involved, with particular focus on the interplay between autophagy, ferroptosis, and apoptosis. Cardiac-specific catalase (CAT) overexpression and wild-type (WT) mice were stimulated with LPS (6 mg/kg, intravenous injection), and cardiac morphology and function were evaluated. Oxidative stress, ferroptosis, apoptosis, and mitochondrial status were monitored, and survival curves were plotted based on the results of LPS stimulation. The results showed that, compared with WT mice, mice overexpressing catalase had a higher survival rate under LPS stimulation. Ultrasound echocardiography, cardiomyocyte characteristics, and Masson's trichrome staining showed that LPS inhibited cardiac function and caused cardiac fibrosis, while catalase alleviated these adverse effects. LPS increased apoptosis (TUNEL, caspase-3 activation, cleaved caspase-3), increased O₂^·- production, induced inflammation (TNF-α), autophagy, iron toxicity, and carbonyl damage, and significantly damaged mitochondria (mitochondrial membrane potential, mitochondrial proteins, and ultrastructure). These effects were significantly alleviated by catalase. Interestingly, the antioxidant N-acetylcysteine, autophagy inhibitor 3-methyladenine, and ferroptosis inhibitor lipostatin-1 all eliminated the LPS-induced contraction dysfunction and ferroptosis (using lipid peroxidation). Induction of ferroptosis could eliminate the cardioprotective effect of NAC. In conclusion, catalase rescues LPS-induced cardiac dysfunction by regulating oxidative stress, autophagy, ferroptosis, apoptosis, and mitochondrial damage in cardiomyocytes.

A simple and accurate method to quantify real-time contraction of vascular smooth muscle cell in vitro

Vascular smooth muscle cells (VSMCs) constitute the medial layer of the blood vessel wall. Their contractile state regulates blood flow in physiological and pathological conditions. Current methods for assessing the contractility of VSMCs are not amenable to the high-throughput screening of pharmaceutical compounds. This study aimed to develop a method to address this shortcoming in the field. Real-time contraction was visualized in living VSMCs using the exogenous expression of green fluorescent protein (GFP). Image-Pro Plus software (IPPS) was used to measure various morphological cell indices. In phenylephrine-treated VSMCs, GFP fluorescence imaging was more accurate than brightfield imaging or phalloidin staining in representing VSMC morphology, as measured using IPPS. Among the multiple indices of VSMC shape, area and mean-diameter were more sensitive than length in reflecting the morphological changes in VSMC. We developed a new index, compound length, by combining the mean-diameter and length to differentiate contracted and uncontracted VSMCs. Based on the compound length, we further generated a contraction index to define a single-VSMC contractile status as single-VSMC contraction-index (SVCI). Finally, compound length and SVCI were validated to effectively assess cell contraction in VSMCs challenged with U46619 and KCl. In conclusion, GFP-based indices of compound length and SVCI can accurately quantify the real-time contraction of VSMCs. In future, the new method will be applied to high-throughput drug screening or basic cardiovascular research.

Relationship between ferroptosis and mitophagy in cardiac ischemia reperfusion injury: a mini-review

Cardiovascular diseases (CVD), with high morbidity and mortality, seriously affect people's life and social development. Clinically, reperfusion therapy is typically used to treat ischemic cardiomyopathy, such as severe coronary heart disease and acute myocardial infarction. However, reperfusion therapy can lead to myocardial ischemia reperfusion injury (MIRI), which can affect the prognosis of patients. Studying the mechanisms of MIRI can help us improve the treatment of MIRI. The pathological process of MIRI involves many mechanisms such as ferroptosis and mitophagy. Ferroptosis can exacerbate MIRI, and regulation of mitophagy can alleviate MIRI. Both ferroptosis and mitophagy are closely related to ROS, but there is no clear understanding of the relationship between ferroptosis and mitophagy. In this review, we analyzed the relationship between ferroptosis and mitophagy according to the role of mTOR, NLPR3 and HIF. In addition, simultaneous regulation of mitophagy and ferroptosis may be superior to single therapy for MIRI. We summarized potential drugs that can regulate mitophagy and/or ferroptosis, hoping to provide reference for the development of drugs and methods for MIRI treatment.