Yttrium chloride-induced cytotoxicity and DNA damage response via ROS generation and inhibition of Nrf2/PPARγ pathways in H9c2 cardiomyocytes

Adverse effects and underlying mechanism of rare earth elements

BACKGROUND

Rare earth elements (REEs) have found broad application in a range of industries, including electronics, automotive, agriculture, and healthcare. However, their widespread utilization and release into the environment pose potential risks of human exposure. Despite extensive research on REEs toxicity, the relationship between exposure and subsequent health concerns remains ambiguous. Given that the biological effects of REEs can vary based on their design and application, assessing their toxicity can be highly challenging.

OBJECTIVE

This review is to offer a thorough comprehension of REEs' application and toxicity, guiding future research and policy-making to safeguard public health and environmental integrity.

METHODS

A systematic search across PubMed, Web of Science, Cochrane Library, and Embase was conducted using the terms: ("rare earth" OR "lanthanoid") AND ("health hazard" OR "toxic" OR "adverse health effect"). From 5,924 initial records, 89 studies were selected through deduplication and two-stage screening to assess systemic toxicity of REEs. An additional 100 articles on REEs mechanisms and applications were incorporated via citation tracking. All selections followed PRISMA guidelines with dual-author verification to ensure rigor.

CONCLUSION

The review emphasizes REEs' applications in various domains and documents potential environmental pathways. Furthermore, it elaborates on current processes to assess REEs-related toxicity across different model organisms and cell lines, estimating health threats posed by REEs exposure. Finally, based on the findings of both in vivo and in vitro experiments, the potential toxic mechanisms of REEs are detailed. To guide future research and policy development to safeguard public health and environmental integrity.

Yttrium-90-doped metal-organic frameworks (MOFs) for low-dose rate internal radiation therapy of tumors

Brachytherapy, or internal radiation therapy, is a highly effective treatment option for localized tumors. Herein, injectable and biodegradable metal-organic frameworks (MOFs) were engineered to deliver the therapeutic radioisotope yttrium-90 (90Y). Particles of bimetallic MIL-100(Fe,Y) and Y-BTC, doped with 90Y and 88Y, were synthesized in a single step and retained radioyttrium in various buffer solutions. Tumor injectability and radioisotope retention were evaluated using tumor-bearing mice. In vivo analysis and calculations showed that radiolabeled MIL-100(Fe,Y) emitted more than 38% of its radioactivity, while Y-BTC emitted greater than 75% of its radioactivity, for 7 days at the tumor site upon intratumoral injection, without significant yttrium accumulation in off-target tissues. The anticancer effects of MIL-100(Fe,Y,90Y) and 90Y,Y-BTC particles were assessed using 3D multicellular tumor spheroids and a tumor-bearing mouse model, respectively. 90Y-doped MIL-100(Fe,Y) particles penetrated A549 tumor spheroids and caused superior cytotoxic effects compared to non-radioactive particles or 90YCl3, added at the same dose. Brachytherapy with 90Y-doped Y-BTC MOFs induced inhibition of B16F1 melanoma tumor growth and resulted in an increased median survival of 8.5 days compared to 4.5 days in untreated mice. This study shows the feasibility of preparing radioactive 90Y-containing biodegradable non-toxic MOF particles that are advantageous for low-dose rate internal radiotherapy.

Association between concentrations of rare earth elements in chorionic villus and risk for unexplained spontaneous abortion

Rare earth elements (REEs) exposure during pregnancy may increase the risk of unexplained spontaneous abortion. However, the association between REEs intrauterine exposure and unexplained spontaneous abortion had yet to be studied. In order to conduct this large case-control study, we thus collected chorionic villus from 641 unexplained spontaneous abortion and 299 control pregnant women and detected the concentrations of 15 REEs by inductively coupled plasma mass spectrometer (ICP-MS). Because the detection rates of 10 REEs were less than 80%, the remaining 5 REEs, which were lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd) and yttrium (Y), underwent to further analysis. The association between 5 REEs and unexplained spontaneous abortion was assessed by using the logistic regression, bayesian kernel regression (BKMR) and weighted quantile sum regression (WQS) models. In the adjusted logistic regression model, Pr, Nd and Y enhanced the incidence of unexplained spontaneous abortion in a dose-dependent way and Ce increased the risk only at high concentration group. The result of BKMR model demonstrated that the risk of unexplained spontaneous abortion increased as the percentile of five mixed REEs increased. Y and Nd were both significantly associated with an increased incidence of unexplained spontaneous abortion, but La was correlated with a decrease in the risk of unexplained spontaneous abortion. Pr was substantially associated with an increase in the risk of unexplained spontaneous abortion when other REEs concentrations were fixed at the 25th and 50th percentiles. According to WQS regression analysis, the WQS index was significantly associated with unexplained spontaneous abortion (OR = 3.75, 95% CI:2.40-5.86). Y had the highest weight, followed by Nd and Pr, which was consistent with the analysis results of our other two models. In short, intrauterine exposure to REEs was associated with an increased risk of unexplained spontaneous abortion, with Y, Nd and Pr perhaps playing an essential role.

Tl(I) and Tl(III)-induce genotoxicity, reticulum stress and autophagy in PC12 Adh cells

Thallium (Tl) and its two cationic species, Tl(I) and Tl(III), are toxic for most living beings. In this work, we investigated the effects of Tl (10-100 µM) on the viability and proliferation capacity of the adherent variant of PC12 cells (PC12 Adh cells). While both Tl(I) and Tl(III) halted cell proliferation from 24 h of incubation, their viability was ~ 90% even after 72 h of treatment. At 24 h, increased levels of γH2AX indicated the presence of DNA double-strand breaks. Simultaneously, increased expression of p53 and its phosphorylation at Ser15 were observed, which were associated with decreased levels of p-AKTSer473 and p-mTORSer2448. At 72 h, the presence of large cytoplasmic vacuoles together with increased autophagy predictor values suggested that Tl may induce autophagy in these cells. This hypothesis was corroborated by images obtained by transmission electron microscopy (TEM) and from the decreased expression at 72 h of incubation of SQSTM-1 and increased LC3β-II to LC3β-I ratio. TEM images also showed enlarged ER that, together with the increased expression of IRE1-α from 48 h of incubation, indicated that Tl-induced ER stress preceded autophagy. The inhibition of autophagy flux with chloroquine increased cell mortality, suggesting that autophagy played a cytoprotective role in Tl toxicity in these cells. Together, results indicate that Tl(I) or Tl(III) are genotoxic to PC12 Adh cells which respond to the cations inducing ER stress and cytoprotective autophagy.

Nrf2 prevents diabetic cardiomyopathy via antioxidant effect and normalization of glucose and lipid metabolism in the heart

Metabolic disorders and oxidative stress are the main causes of diabetic cardiomyopathy. Activation of nuclear factor erythroid 2-related factor 2 (Nrf2) exerts a powerful antioxidant effect and prevents the progression of diabetic cardiomyopathy. However, the mechanism of its cardiac protection and direct action on cardiomyocytes are not well understood. Here, we investigated in a cardiomyocyte-restricted Nrf2 transgenic mice (Nrf2-TG) the direct effect of Nrf2 on cardiomyocytes in DCM and its mechanism. In this study, cardiomyocyte-restricted Nrf2 transgenic mice (Nrf2-TG) were used to directly observe whether cardiomyocyte-specific overexpression of Nrf2 can prevent diabetic cardiomyopathy and correct glucose and lipid metabolism disorders in the heart. Compared to wild-type mice, Nrf2-TG mice showed resistance to diabetic cardiomyopathy in a streptozotocin-induced type 1 diabetes mouse model. This was primarily manifested as improved echocardiography results as well as reduced myocardial fibrosis, cardiac inflammation, and oxidative stress. These results showed that Nrf2 can directly act on cardiomyocytes to exert a cardioprotective role. Mechanistically, the cardioprotective effects of Nrf2 depend on its antioxidation activity, partially through improving glucose and lipid metabolism by directly targeting lipid metabolic pathway of AMPK/Sirt1/PGC-1α activation via upstream genes of sestrin2 and LKB1, and indirectly enabling AKT/GSK-3β/HK-Ⅱ activity via AMPK mediated p70S6K inhibition.

Yttrium Oxide nanoparticles induce cytotoxicity, genotoxicity, apoptosis, and ferroptosis in the human triple-negative breast cancer MDA-MB-231 cells

BACKGROUND

Triple-negative breast cancer (TNBC) is a lethal mammary carcinoma subtype that affects females and is associated with a worse prognosis. Chemotherapy is the only conventional therapy available for patients with TNBC due to the lack of therapeutic targets. Yttrium oxide (Y2O3) is a rare earth metal oxide, whose nanoparticle (NPs) formulations are used in various applications, including biological imaging, the material sciences, and the chemical synthesis of inorganic chemicals. However, the biological activity of Y2O3-NPs against TNBC cells has not been fully explored. The current study was conducted to assess Y2O3-NPs' anticancer activity against the human TNBC MDA-MB-231 cell line.

METHODS

Transmission electron microscopy (TEM), X-ray diffraction, Zeta potential, and dynamic light scattering (DLS) were used to characterize the Y2O3-NPs. SRB cell viability, reactive oxygen species (ROS) measurement, single-cell gel electrophoresis (comet assay), qPCR, flow cytometry, and Western blot were employed to assess the anticancer activity of the Y2O3-NPs.

RESULTS

Our results indicate favorable physiochemical properties of Y2O3-NPs (with approximately average size 14 nm, Zeta Potential about - 53.2 mV, and polydispersity index = 0.630). Y2O3-NPs showed a potent cytotoxic effect against MDA-MB-231 cells, with IC50 values of 74.4 µg/mL, without cytotoxic effect on the normal retina REP1 and human dermal fibroblast HDF cell lines. Further, treatment of MDA-MB-231 cells with IC50 Y2O3-NPs resulted in increased oxidative stress, accumulation of intracellular ROS levels, and induced DNA damage assessed by Comet assay. Upon Y2O3-NPs treatment, a significant increase in the early and late phases of apoptosis was revealed in MDA-MB-231 cells. qPCR results showed that Y2O3-NPs significantly upregulated the pro-apoptotic genes CASP3 and CASP8 as well as ferroptosis-related gene heme oxygenase-1 (HO-1), whereas the anti-apoptotic gene BCL2 was significantly downregulated.

CONCLUSION

This study suggests that Y2O3-NPs are safe on normal REP1 and HDF cells and exhibited a potent selective cytotoxic effect against the TNBC MDA-MB-231 cells through increasing levels of ROS generation with subsequent DNA damage, and induction of apoptosis and ferroptosis.

CPT2-mediated fatty acid oxidation inhibits tumorigenesis and enhances sorafenib sensitivity via the ROS/PPARγ/NF-κB pathway in clear cell renal cell carcinoma

Kidney cancer is a common kind of tumor with approximately 400,000 new diagnoses each year. Clear cell renal cell carcinoma (ccRCC) accounts for 70-80% of all renal cell carcinomas. Lipid metabolism disorder is a hallmark of ccRCC. With a better knowledge of the importance of fatty acid oxidation (FAO) in cancer, carnitine palmitoyltransferase 2 (CPT2) has gained prominence as a major mediator in the cancer metabolic pathway. However, the biological functions and mechanism of CPT2 in the progression of ccRCC are still unclear. Herein, we performed assays in vitro and in vivo to explore CPT2 functions in ccRCC. Moreover, we discovered that CPT2 induced FAO, which inhibited the generation of reactive oxygen species (ROS) by increasing nicotinamide adenine dinucleotide phosphate (NADPH) production. Additionally, we demonstrated that CPT2 suppresses tumor proliferation, invasion, and migration by inhibiting the ROS/ PPARγ /NF-κB pathway. Gene set enrichment analysis (GSEA) and drug sensitivity analysis showed that high expression of CPT2 in ccRCC was associated with higher sorafenib sensitivity, which was also validated in vitro and in vivo. In summary, our results suggest that CPT2 acts as a tumor suppressor in the development of ccRCC through the ROS/PPARγ/NF-κB pathway. Moreover, CPT2 is a potential therapeutic target for increasing sorafenib sensitivity in ccRCC.

The rare-earth yttrium induces cell apoptosis and autophagy in the male reproductive system through ROS-Ca2+-CamkII/Ampk axis

China has the world's largest reserves of rare earth elements (REEs), but widespread mining and application of REEs has led to an increased risk of potential pollution. Yttrium (Y), the first heavy REEs to be discovered, poses a substantial threat to human health. Unfortunately, little attention has been given to the impact of Y on human reproductive health. In this study, we investigated the toxic effects of YCl3 on mouse testes and four types of testicular cells, including Sertoli, Leydig, spermatogonial and spermatocyte cells. The results showed that YCl3 exposure causes substantial damage to mouse testes and induces apoptosis and autophagy, but not pyroptosis or necrosis, in testicular cells. Genome-wide gene expression analysis revealed that YCl3 induced significant changes in gene expression, with Ca2+ and mitochondria-related genes being the most significantly altered. Mechanistically, YCl3 exposure induced mitochondrial dysfunction in testicular cells, triggering the overproduction of reactive oxygen species (ROS) by impairing the Nrf2 pathway, regulating downstream Ho-1 target protein expression, and increasing Ca2+ levels to activate the CamkII/Ampk signaling pathway. Blocking ROS production or Ca2+ signaling significantly attenuates apoptosis and autophagy, while supplementation with Ca2+ reverses the suppression of apoptosis and autophagy by ROS blockade in testicular cells. Notably, apoptosis and autophagy induced by YCl3 treatment are independent of each other. Thus, our study suggests that YCl3 may impair the antioxidant stress signaling pathway and activate the calcium pathway through the ROS-Ca2+ axis, which promotes testicular cell apoptosis and autophagy independently, thus inducing testicular damage and impairing male reproductive function.

Yttrium chloride induces ferroptosis in cardiomyocytes via iron accumulation and triggers cardiac lipid peroxidation and inflammation that cause heart adverse events in mice

The growing presence of yttrium (Y) in the environment raises concern regarding its safety and toxicity. However, limited toxicological data are available to determine cardiotoxicity of Y and its underlying mechanisms. In the present study, yttrium chloride (YCl3) intervention with different doses was performed in male Kunming mice for the toxicological evaluation of Y in the heart. After 28 days of intragastric administration, 500 mg/kg·bw YCl3 induces iron accumulation in cardiomyocytes, and triggers ferroptosis through the glutathione peroxidase 4 (GPX4)/glutathione (GSH)/system Xc- axis via the inhibition of Nrf2 signaling pathway. This process led to cardiac lipid peroxidation and inflammatory response. Further RNA sequencing transcriptome analysis found that many genes involved in ferroptosis and lipid metabolism-related pathways were enriched. The ferroptosis induced by YCl3 in cardiomyocytes ultimately caused cardiac injury and dysfunction in mice. Our findings assist in the elucidation of the potential subacute cardiotoxicity of Y3+ and its underlying mechanisms.

Ferritin-Hijacking Nanoparticles Spatiotemporally Directing Endogenous Ferroptosis for Synergistic Anticancer Therapy

Existing ferroptosis as an iron-dependent form of regulated cell death primarily relies on importing exogenous iron. However, the excessive employment of toxic materials may cause potential adverse effects on human health. Herein, a ferritin-hijacking nanoparticle (Ce6-PEG-HKN₁₅ ) is fabricated, by conjugating the ferritin-homing peptide HKN₁₅ with the photosensitizer chlorin e6 (Ce6) for endogenous ferroptosis without introducing Fenton-reactive metals. Once internalized, the designed Ce6-PEG-HKN₁₅ NPs can specifically accumulate around ferritin. With laser irradiation, the activated Ce6 in nanoparticles potently generates reactive oxygen species (ROS) surrounding ferritin. Abundant ROS not only helps to destroy the iron storage protein and activate endogenous ferroptosis but also directly kill tumor cells. In turn, the released iron partially interacts with intracellular excess H₂ O₂ to produce O₂ , thereby enhancing photodynamic therapy and further amplifying oxidative stress. Overall, this work highlights the possibility of endogenous ferroptosis via spatiotemporally destroying ferritin, offering a paradigm for synergistic ferroptosis-photodynamic antitumor therapy.