Copper exposure induces hepatic G0/G1 cell-cycle arrest through suppressing the Ras/PI3K/Akt signaling pathway in mice

Titanium Dioxide Nanoparticles Induce Cell Cycle Arrest and Apoptosis through Inhibiting PI3K/AKT/mTOR Pathway in Spermatogonia

Titanium dioxide nanoparticles (TiO2 NPs) can result in the reduction of sperm numbers, but the mechanisms have not been well elucidated. The purpose of this study was to investigate the effects of TiO2 NPs on cell cycle and apoptosis in spermatogonia and to explore the role of PI3K/AKT/mTOR signaling pathway in this process. The mouse spermatogonia cell line (GC-1) was treated with TiO2 NPs at different concentrations (0, 25, 50, 75 and 100 μg/mL) for 24 h to detect cell viability, cell cycle, apoptosis, and key proteins related to cell cycle and PI3K/AKT/mTOR signaling pathway. The agonist (IGF-1) and inhibitor (LY294002) of PI3K were used to verify the role of PI3K/AKT/mTOR signaling pathway in cell cycle and apoptosis. TiO2 NPs significantly inhibited cell proliferation, induced cell cycle arrest at G0/G1 phase and resulted in apoptosis. TiO2 NPs downregulated the levels of cyclin-dependent kinases (CDKs) and cyclins, including CDK4, CDK2, Cyclin D1 and Cyclin E1, while upregulated the levels of p21 and p53 proteins. Furthermore, TiO2 NPs inhibited the PI3K/AKT/mTOR signaling pathway by decreasing the levels of p-PI3K, p-AKT and p-mTOR. IGF-1 reversed the G0/G1 phase arrest and apoptosis caused by TiO2 NPs. However, LY294002 aggravated the G0/G1 phase arrest and apoptosis resulting from TiO2 NPs. Collectively, TiO2 NPs induced cell cycle arrest at G0/G1 phase and apoptosis through inhibiting the activation of PI3K/AKT/mTOR pathway, which could be the main reason for the reduction in sperm numbers caused by TiO2 NPs.

The Effect of Cuproptosis-Related Proteins on Macrophage Polarization in Mesothelioma is Revealed by scRNA-seq

High invasiveness mesothelioma is a malignant tumor of the peritoneum or pleura. The effect of cuproptosis on mesothelioma (MESO) is still unknown, though. The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) datasets were used to identify differential genes linked to cuproptosis in mesothelioma. Multigene features were then created to assess the course of the disease. Use single-cell data and in vitro validation to uncover crucial gene regulation mechanisms. In MESO, we found nine differentially expressed genes linked to cuproptosis. Using univariate Cox and LASSO regression techniques, a 3-gene feature (P < 0.05) was created, showing a good predictive potential for survival time. According to the risk score, patients in the low-risk subset had a considerably greater survival rate than those in the high-risk subset (P = 0). The similar survival pattern and prediction performance are also seen in the validation queue. The findings of the drug sensitivity research indicate that in high-risk patients, vinblastine, paclitaxel, gefitinib, and erlotinib are sensitive medications (P < 0.05). Classical monocytes were identified as core cells connected to cuproptosis by the CellChat results. SLC31A1 is implicated in the positive regulation of M2 macrophage polarization, according to cell subtype analysis and in vitro confirmation. Genes linked to cuproptosis have a major influence on tumor immunity and can predict how MESO will progress.

Copper exposure induces mitochondrial dysfunction and hepatotoxicity via the induction of oxidative stress and PERK/ATF4 -mediated endoplasmic reticulum stress

Copper is an essential trace element, and excessive exposure could result in hepatoxicity, however, the underlying molecular mechanisms remain incompletely understood. The present study is aimed to investigate the molecular mechanisms of copper sulfate (CuSO4) exposure-induced hepatoxicity both in vivo and in vitro. In vitro, HepG2 and L02 cells were exposed to various doses of CuSO4 for 24 h. Cell viability, ROS production, oxidative stress biomarkers, mitochondrial functions, ultrastructure, intracellular calcium (Ca2+) concentration, and the expression of proteins related to mitochondrial apoptosis and endoplasmic reticulum (ER) stress were assessed. In vivo, C57BL/6 mice were treated with CuSO4 at doses of 10 and 30 mg/kg BW/day and co-treated with 4-PBA at 100 mg/kg BW/day for 35 days. Subsequently, liver function, histopathological features, and protein expression were evaluated. Results found that exposure to CuSO4 at concentrations of 100-400 μM for 24 h significantly decreased the viabilities of HepG2 and L02 cells and it was in a dose-dependent manner. Additionally, CuSO4 exposure induced significant oxidative stress and mitochondrial dysfunction in HepG2 cells, which were partially ameliorated by the antioxidant N-acetylcysteine (NAC). Furthermore, CuSO4 exposure prominently triggered ER stress, as evidenced by the upregulation of GRP94, GRP78, phosphorylated forms of PERK and eIF2α, and CHOP proteins in livers of mice and HepG2 cells. NAC treatment significantly inhibited CuSO4 exposure -induced ER stress in HepG2 cells. Pharmacological inhibition of ER stress through co-treatment with 4-PBA and the PERK inhibitor GSK2606414, as well as genetic knockdown of ATF4, partially mitigated CuSO4-induced cytotoxicity in HepG2 cells by reducing mitochondrial dysfunction and inhibiting the mitochondrial apoptotic pathway. Moreover, 4-PBA treatment significantly attenuated CuSO4-induced caspase activation and hepatoxicity in mice. In conclusion, these results reveal that CuSO4-induced hepatotoxicity involves mitochondrial dysfunction and ER stress by activating oxidative stress induction and PERK/ATF4 pathway.

Induction of Hepatocellular Carcinoma Cell Cycle Arrest and Apoptosis by Dendropanax morbifera Leveille Leaf Extract via the PI3K/AKT/mTOR Pathway

Liver cancer is prevalent worldwide and associated with a high mortality rate. Therefore, developing novel drugs derived from natural products to reduce the side effects of chemotherapy is urgently needed. In this study, the inhibitory effect of Dendropanax morbifera Leveille extract (DME) on growth of hepatocellular carcinoma (HCC) cells and its underlying mechanisms were investigated. DME suppressed the growth, migration, and invasion of SK-Hep1 human HCC cells. It also reduced the expression of the G0/G1 phase regulator proteins cyclin-dependent kinase (CDK) 4, cyclin D, CDK2, and cyclin E, thereby inducing G0/G1 arrest. Moreover, DME treatment reduced the expression of antiapoptotic proteins, including caspase-9, caspase-3, PARP, and Bcl-2 and increased the expression of the proapoptotic protein, Bax. DME also increased reactive oxygen species production and reduced the cellular uptake of rhodamine 123. DME treatment increased the levels of p-p38 and p-FOXO3a in a dose-dependent manner and decreased those of p-PI3K, p-AKT, p-mTOR, and p-p70 in SK-Hep1 cells. In addition, combined treatment with DME and LY294002, an AKT inhibitor, significantly reduced p-AKT levels. In summary, these results show that the PI3K/AKT/mTOR signaling pathway is involved in DME-mediated inhibition of proliferation, migration, and invasiveness, and induction of apoptosis of HCC cells.

CT2-3 induces cell cycle arrest and apoptosis in rheumatoid arthritis fibroblast-like synoviocytes through regulating PI3K/AKT pathway

Rheumatoid arthritis (RA) is a kind of chronic autoimmune disease. The existing therapies encountered several challenges. Therefore, continued novel anti-RA drug discovery remains necessary for RA therapy. Recently, our group reported a novel compound named CT2-3, which could be realized as a hybrid of the natural product magnolol and phthalimide and exhibited anti-lung cancer activity. However, the effect of CT2-3 on RA is unclear. Here, we aim to explore the effect and potential mechanism of CT2-3 on the abnormal functions of RA-fibroblast-like synoviocytes (RA-FLSs). In this study, we identified the important role of the dysregulated cell cycle and apoptosis of RA-FLSs in RA progression. Interestingly, we found that CT2-3 inhibited the proliferation and DNA replication of primary RA-FLSs and immortalized RA-FLSs namely MH7A. In addition, CT2-3 downregulated the mRNA and protein expression of cyclin-dependent kinase 2 (CDK2), cyclin A2, and cyclin B1, resulting in cell cycle arrest of primary RA-FLSs and MH7A cells. Also, CT2-3 downregulated the level of B-cell lymphoma-2 (Bcl-2), and increased the level of Bcl-2 associated X (Bax), contributing to apoptosis of primary RA-FLSs and MH7A cells. Furthermore, differential analyses of RNA-sequencing, Western blot, and network pharmacological analysis confirmed that CT2-3 inhibited phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway of primary RA-FLSs and MH7A cells. In conclusion, CT2-3 induces cell cycle arrest and apoptosis in RA-FLSs through modulating PI3K/AKT pathway, which may serve as a potential lead compound for further novel small molecule anti-RA drug development.

Influence of systemic copper toxicity on early development and metamorphosis in Xenopus laevis

The primary objective of the present study was to examine the influence of early systemic toxicity resulting from copper (Cu) exposure on metamorphic processes in Xenopus laevis. A 28-day exposure study with copper, initiated at developmental stage 10, was performed using test concentrations of 3.0, 9.0, 27.2, 82.5, and 250 μg Cu/L. The primary endpoints included mortality, developmental stage, embryo-larval malformation, behavioral effects, hindlimb length (HLL), growth (snout-vent length [SVL] and wet body weight), and histopathology. The 28-day LC50 value with 95% confidence intervals was 61.2 (51.4-72.9) μg Cu/L with 250 μg Cu/L resulting in complete lethality. Developmental arrest in the 82.5 and delay in the 27.2 μg Cu/L treatments was observed as early as study day 10 continuing throughout the remainder of exposure. SVL-normalized HLL, body weight, and SVL in the 27.2 and 82.5 μg Cu/L treatments were significantly decreased relative to control. At 82.5 μg Cu/L, and thyroid gland size was markedly reduced when compared with controls consistent with the stage of developmental and growth arrest. Concentration-dependent findings in the intestine, liver, gills, eyes, and pharyngeal mucosa were consistent with non-endocrine systemic toxicity. These were prevalent in the 9.0 and 27.2 μg Cu/L treatment groups but were minimally evident or absent in the 82.5 μg/L group, which was attributed to developmental arrest. In conclusion, developmental delay in larvae exposed to 27.2 and 82.5 μg Cu/L was the result of systemic toxicity occurring in early development prior hypothalomo-pituitary-thyroid axis (HPT)-driven metamorphosis and was not indicative of endocrine disruption.

Construction and systematic evaluation of a machine learning-based cuproptosis-related lncRNA score signature to predict the response to immunotherapy in hepatocellular carcinoma

Introduction

Hepatocellular carcinoma (HCC) is a common malignant cancer with a poor prognosis. Cuproptosis and associated lncRNAs are connected with cancer progression. However, the information on the prognostic value of cuproptosis-related lncRNAs is still limited in HCC.

Methods

We isolated the transcriptome and clinical information of HCC from TCGA and ICGC databases. Ten cuproptosis-related genes were obtained and related lncRNAs were correlated by Pearson's correlation. By performing lasso regression, we created a cuproptosis-related lncRNA prognostic model based on the cuproptosis-related lncRNA score (CLS). Comprehensive analyses were performed, including the fields of function, immunity, mutation and clinical application, by various R packages.

Results

Ten cuproptosis-related genes were selected, and 13 correlated prognostic lncRNAs were collected for model construction. CLS was positively or negatively correlated with cancer-related pathways. In addition, cell cycle and immune related pathways were enriched. By performing tumor microenvironment (TME) analysis, we determined that T-cells were activated. High CLS had more tumor characteristics and may lead to higher invasiveness and treatment resistance. Three genes (TP53, CSMD1 and RB1) were found in high CLS samples with more mutational frequency. More amplification and deletion were detected in high CLS samples. In clinical application, a CLS-based nomogram was constructed. 5-Fluorouracil, gemcitabine and doxorubicin had better sensitivity in patients with high CLS. However, patients with low CLS had better immunotherapeutic sensitivity.

Conclusion

We created a prognostic CLS signature by machine learning, and we comprehensively analyzed the signature in the fields of function, immunity, mutation and clinical application.

Copper-induced diurnal hepatic toxicity is associated with Cry2 and Per1 in mice

BACKGROUND

This study aimed to investigate diurnal variations in copper-induced hepatic toxicity and the molecular mechanisms underlying this chronotoxicity.

METHODS

Male C57BL/6J mice were intraperitoneally injected with copper chloride (CuCl2) at zeitgeber time 2 (ZT2) or 14 (ZT14), twice per week for 5 or 8 weeks. Seventy-two hours after the final CuCl2 injection, the mice were euthanized, and plasma samples were collected. The livers and kidneys were collected and weighed. In vitro experiments were performed to assess cell viability and fluctuations in clock gene expression levels in Hepa1-6 cells after CuCl2 treatment. We examined copper homeostasis- and apoptosis-related genes under clock genes overexpression.

RESULTS

Repeated CuCl2 administration for 8 weeks resulted in more severe toxicity at ZT14 compared to ZT2. CuCl2 administration at ZT14 elevated plasma aspartate aminotransferase, hepatic tumor necrosis factor-α, and interleukin-6 for 5 weeks, whereas the toxic effects of CuCl2 administration at ZT2 were weaker. Moreover, CuCl2 treatment inhibited Hepa1-6 cell viability in a dose-dependent manner. We observed increased expression of three clock genes (Ciart, Cry2, and Per1) after CuCl2 treatment. Among them, overexpression of Cry2 and Per1 accelerated CuCl2-induced inhibition of Hepa1-6 cell viability. Moreover, we found that the overexpression of Cry2 and Per1 regulates cleaved caspase-3 by modulating the copper transporter genes ATP7B and CTR1.

CONCLUSION

These results suggest that CuCl2-induced diurnal toxicity is associated with Cry2 and Per1 expression through the regulation of copper transporter genes in mice.

Carbohydrate Metabolism Parameters of Adult Glial Neoplasms According to Immunohistochemical Profile

This research aimed to investigate the interrelationship of carbohydrate metabolism parameters and immunohistochemical characteristics of glial tumors. Tumor tissue, peritumoral area, and adjacent noncancerous tissue fragments of 20 patients with gliomas of varying degrees of anaplasia were analyzed. The greatest differences in the carbohydrate metabolism compared to adjacent noncancerous tissues were identified in the tumor tissue: reduction in the levels of lactate and glycogen synthase kinase-3β. Significant differences with adjacent noncancerous tissues for the peritumoral zone were not found. The activity of the carbohydrate metabolism enzymes was different depending on the immunohistochemical glioma profile, especially from Ki 67 level. Bioinformatic analysis of the interactions of immunohistochemical markers of gliomas and carbohydrate metabolism enzymes using the databases of STRING, BioGrid, and Signor revealed the presence of biologically significant interactions with glycogen synthase kinase 3β, hexokinase, glucose-6-phosphate dehydrogenase, and transketolase. The established interconnection of glycolysis with methylation of the promoter of O-6-methylguanine-DNA-methyltransferase (MGMT) of gliomas can be used to increase chemotherapy efficiency.