Co-exposure to Environmentally Relevant Levels of Molybdenum and Cadmium Induces Oxidative Stress and Ferroptosis in the Ovary of Ducks.

Excessive doses of molybdenum (Mo) and cadmium (Cd) have toxic effects on animals. Nevertheless, the reproductive toxicity elicited by Mo and Cd co-exposure remains obscure. To evaluate the co-induce toxic impacts of Mo and Cd on ovaries, 8-day-old 40 healthy ducks were stochastically distributed to four groups and were raised a basal diet supplemented with Cd (4 mg/kg Cd) and/or Mo (100 mg/kg Mo). In the 16th week, ovary tissues were gathered. The data revealed that Mo and/or Cd decreased GSH content, CAT, T-SOD, and GSH-Px activities and increased MDA and H2O2 levels. Moreover, there was a significant decrease in nuclear Nrf2 protein level and its related downstream factors, while cytoplasmic Nrf2 protein level showed a substantial increase. Additionally, a marked elevation was observed in ferrous ion content and TFRC, GCLC, SLC7A11, ACSL4, and PTGS2 expression levels, while FTH1, FTL1, FPN1, and GPX4 expression levels were conversely reduced. These indicators exhibited more marked changes in the joint exposure group. In brief, our results announced that Mo and/or Cd resulted in oxidative stress and ferroptosis in duck ovaries. Synchronously, the Cd and Mo mixture intensified the impacts.

Molybdenum and cadmium co-induce apoptosis and ferroptosis through inhibiting Nrf2 signaling pathway in duck (Anas platyrhyncha) testes.

Cadmium (Cd) and high molybdenum (Mo) are injurious to the body. Previous research has substantiated that Cd and Mo exposure caused testicular injury of ducks, but concrete mechanism is not fully clarified. To further survey the toxicity of co-exposure to Cd and Mo in testis, 40 healthy 8-day-old Shaoxing ducks (Anas platyrhyncha) were stochasticly distributed to 4 groups and raised with basic diet embracing Cd (4 mg/kg Cd) or Mo (100 mg/kg Mo) or both. At the 16th wk, testis tissues were gathered. The characteristic ultrastructural changes related to apoptosis and ferroptosis were observed in Mo or Cd or both groups. Besides, Mo or Cd or both repressed nuclear factor erythroid 2-related factor 2 (Nrf2) pathway via decreasing Nrf2, Heme oxygenase-1 (HO-1), NAD(P)H quinone oxidoreductase 1 (NQO1), Glutamate-cysteine ligase catalytic subunit (GCLC) and Glutamate-cysteine ligase modifier subunit (GCLM) mRNA expression of and Nrf2 protein expression, then stimulated apoptosis by elevating Bcl-2 antagonist/killer-1 (Bak-1), Bcl-2-associated X-protein (Bax), Cytochrome complex (Cyt-C), caspase-3 mRNA expression, cleaved-caspase-3 protein expression and apoptosis rate, as well as reducing B-cell lymphoma-2 (Bcl-2) mRNA expression and ratio of Bcl-2 to Bax, and triggered ferroptosis by upregulating Acyl-CoA Synthetase Long Chain Family Member 4 (ACSL4), transferrin receptor (TFR1) and Prostaglandin-Endoperoxide Synthase 2 (PTGS2) expression levels, and downregulating ferritin heavy chain 1 (FTH1), ferritin light chain 1 (FTL1), ferroportin 1 (FPN1), solute carrier family 7 member 11 (SCL7A11) and glutathione peroxidase 4 (GPX4) expression levels. The most obvious changes of these indexes were observed in co-treated group. Altogether, the results announced that Mo or Cd or both evoked apoptosis and ferroptosis by inhibiting Nrf2 pathway in the testis of ducks, and co-exposure to Mo and Cd exacerbated these variations.

HNRNPA2B1-mediated m6A modification of FOXM1 promotes drug resistance and inhibits ferroptosis in endometrial cancer via regulation of LCN2.

N6-methyladenosine (m6A) methylation is an extensive posttranscriptional RNA modification, and it is associated with various cellular responses, especially in tumor progression. An m6A "reader"-HNRNPA2B1 has been found oncogenic in multiple malignancies. As a key proliferation-related transcription factor, forkhead box protein M1 (FOXM1) is involved in tumorigenesis. Here, we elucidated the underlying mechanism by which HNRNPA2B1-mediated modification of FOXM1 promotes endometrial cancer (EC). The GSE115810 dataset was used to analyze the upregulated gene mRNA in late-stage EC tissues. The expression levels of HNRNPA2B1, FOXM1, and LCN2 in EC samples were shown by western blotting and qPCR. The interaction among HNRNPA2B1, FOXM1, and LCN2 in EC cells was detected using bioinformatics analysis, RNA immunoprecipitation (RIP), RNA pull-down, RNA decay analysis, and luciferase reporter experiments. Cisplatin (DDP)-resistant EC cells were constructed using HEC-1-A and HEC-1-B cells, named HEC-1-A/DDP and HEC-1-B/DDP, respectively. Proliferation, migration, and invasiveness in treated HEC-1-A/DDP and HEC-1-B/DDP cells were detected by EdU, wound healing, and transwell assays. Ferroptosis-resistant gene expression, MDA level, and ROS level were measured. The m6A modification level in EC tissues was elevated. HNRNPA2B1 and FOXM1 levels were upregulated in EC. HNRNPA2B1 expression was positively related to FOXM1 expression in EC samples, and HNRNPA2B1 bound to the 3'UTR of FOXM1 and stabilized FOXM1 mRNA via m6A modification. FOXM1 positively regulated LCN2 expression in EC cells by binding to the LCN2 promotor. Knockdown of FOXM1 downregulated ferroptosis-resistant gene expression and increased MDA and ROS levels in DDP-resistant EC cells. Rescue assays revealed that LCN2 overexpression eliminated the effects mediated by FOXM1 knockdown on the proliferation, migration, invasiveness, and ferroptosis in DDP-resistant EC cells. In conclusion, HNRNPA2B1-mediated mA modification of FOXM1 facilitates drug resistance and inhibits ferroptosis in EC cells by upregulating LCN2 expression.

Co-exposure to molybdenum and cadmium evokes necroptosis and decreases apoptosis in duck myocardium.

Superfluous molybdenum (Mo) and cadmium (Cd) in the environment are detrimental to organisms through their accumulation. The NF-κB/TNF-α axis plays a vital part in regulating necroptosis and apoptosis. However, the impacts of Mo and/or Cd on myocardium injury in ducks and the function of NF-κB/TNF-α axis are not clear in the process. In this research, ducks exposed to different dosages of Mo and/or Cd were applied as the study object. The findings substantiated that the accumulation of Mo and/or Cd caused elements imbalance and necroptosis in myocardial tissue. As p-NF-κB/TNF-α expression up-regulated, RIPK1/RIPK3/p-MLKL expression significantly increased in all treatment groups, while the expression of c-caspase-8/3 markedly decreased. Moreover, apoptosis rate obviously decreased in Cd treated groups and clearly elevated in Mo group. Mitochondria-mediated apoptosis was activated by excessive Mo and inhibited by Mo + Cd, but Cd exposure alone had little effect on it. Collectively, our research confirmed that Mo and/or Cd evoked necroptosis via NF-κB/TNF-α axis, and decreased death receptor-mediated apoptosis in duck myocardium, the impacts of Mo and/or Cd on mitochondrial-mediated apoptosis were different. These results are significant for studying toxicology of Mo and/or Cd and preserving the ecosystem.

MEN1 is a regulator of alternative splicing and prevents R-loop-induced genome instability through suppression of RNA polymerase II elongation.

The fidelity of alternative splicing (AS) patterns is essential for growth development and cell fate determination. However, the scope of the molecular switches that regulate AS remains largely unexplored. Here we show that MEN1 is a previously unknown splicing regulatory factor. MEN1 deletion resulted in reprogramming of AS patterns in mouse lung tissue and human lung cancer cells, suggesting that MEN1 has a general function in regulating alternative precursor mRNA splicing. MEN1 altered exon skipping and the abundance of mRNA splicing isoforms of certain genes with suboptimal splice sites. Chromatin immunoprecipitation and chromosome walking assays revealed that MEN1 favored the accumulation of RNA polymerase II (Pol II) in regions encoding variant exons. Our data suggest that MEN1 regulates AS by slowing the Pol II elongation rate and that defects in these processes trigger R-loop formation, DNA damage accumulation and genome instability. Furthermore, we identified 28 MEN1-regulated exon-skipping events in lung cancer cells that were closely correlated with survival in patients with lung adenocarcinoma, and MEN1 deficiency sensitized lung cancer cells to splicing inhibitors. Collectively, these findings led to the identification of a novel biological role for menin in maintaining AS homeostasis and link this role to the regulation of cancer cell behavior.

Loss of MEN1 leads to renal fibrosis and decreases HGF-Adamts5 pathway activity via an epigenetic mechanism.

BACKGROUND: Renal fibrosis is a serious condition that results in the development of chronic kidney diseases. The MEN1 gene is an epigenetic regulator that encodes the menin protein and its role in kidney tissue remains unclear. METHODS: Kidney histology was examined on paraffin sections stained with hematoxylin-eosin staining. Masson's trichrome staining and Sirius red staining were used to analyze renal fibrosis. Gene and protein expression were determined by quantitative real-time PCR (qPCR) and Western blot, respectively. Immunohistochemistry staining in the kidney tissues from mice or patients was used to evaluate protein levels. Flow cytometry was used to analyze the cell cycle distributions and apoptosis. RNA-sequencing was performed for differential expression genes in the kidney tissues of the Men1f/f and Men1∆/∆ mice. Chromatin immunoprecipitation sequencing (ChIP-seq) was carried out for identification of menin- and H3K4me3-enriched regions within the whole genome in the mouse kidney tissue. ChIP-qPCR assays were performed for occupancy of menin and H3K4me3 at the gene promoter regions. Luciferase reporter assay was used to detect the promoter activity. The exacerbated unilateral ureteral obstruction (UUO) models in the Men1f/f and Men1∆/∆ mice were used to assess the pharmacological effects of rh-HGF on renal fibrosis. RESULTS: The expression of MEN1 is reduce in kidney tissues of fibrotic mouse and human diabetic patients and treatment with fibrotic factor results in the downregulation of MEN1 expression in renal tubular epithelial cells (RTECs). Disruption of MEN1 in RTECs leads to high expression of α-SMA and Collagen 1, whereas MEN1 overexpression restrains epithelial-to-mesenchymal transition (EMT) induced by TGF-ß treatment. Conditional knockout of MEN1 resulted in chronic renal fibrosis and UUO-induced tubulointerstitial fibrosis (TIF), which is associated with an increased induction of EMT, G2/M arrest and JNK signaling. Mechanistically, menin recruits and increases H3K4me3 at the promoter regions of hepatocyte growth factor (HGF) and a disintegrin and metalloproteinase with thrombospondin motifs 5 (Adamts5) genes and enhances their transcriptional activation. In the UUO mice model, exogenous HGF restored the expression of Adamts5 and ameliorated renal fibrosis induced by Men1 deficiency. CONCLUSIONS: These findings demonstrate that MEN1 is an essential antifibrotic factor in renal fibrogenesis and could be a potential target for antifibrotic therapy.

DNA methylation is involved in acclimation to iron-deficiency in rice (Oryza sativa).

Iron (Fe) is an essential micronutrient in plants, and Fe limitation significantly affects plant growth, yield and food quality. While many studies have reported the transcriptomic profile and pursue molecular mechanism in response to Fe limitation, little is known if epigenetic factors play a role in response to Fe-deficiency. In this study, whole-genome bisulfite sequencing analysis, high-throughput RNA-Seq of mRNA, small RNA and transposable element (TE) expression with root and shoot organs of rice seedlings under Fe-sufficient and Fe-deficient conditions were performed. The results showed that widespread hypermethylation, especially for the CHH context, occurred after Fe-deficiency. Integrative analysis of methylation and transcriptome revealed that the transcript abundance of Fe-deficiency-induced genes was negatively correlated with nearby TEs and positively with the 24-nucleotide siRNAs. The ability of methylation to affect the physiology and molecular response to Fe-deficiency was tested using an exogenous DNA methyltransferase inhibitor (5-azacytidine), and genetically using a mutant for domains rearranged methyltransferase 2 (DRM2), that lacks CHH methylation. Both approaches resulted in decreased growth and Fe content in rice plants. Thus, alterations in specific methylation patterns, directed by siRNAs, play an important role in acclimation of rice to Fe-deficient conditions. Furthermore, comparison with other reports suggests this may be a universal mechanism to acclimate to limited nutrient availability.