Sensing of H2O2-induced oxidative stress by the UPF factor complex is crucial for activation of catalase-3 expression in Neurospora

Genotoxicity of putrescine and its effects on gene expression in HepG2 cell line

Decomposing bodies release necro-leachate, a toxic fluid containing harmful compounds such as biogenic amines. This study investigated the genotoxic effects of the different concentrations (0.5, 1.4, 2.3, 3.2 mM) of bioamine putrescine on HepG2 cells using the comet assay, the micronucleus test, and gene expression analysis. The results were compared to negative control and indicated significant DNA damage in the comet assay highlighting tail DNA intensity that exhibited significant differences across all tested concentrations (0.5 = 192 %, 1.4 = 189 %, 2.3 = 208 %, 3.2 = 132 %). The micronucleus test revealed a significant increase in micronuclei for concentrations 0.5 (193 %), 1.4 (229 %), 2.3 (206 %); nuclear buds 3.2 (173 %); chromosomal bridges 3.2 (735 %). Furthermore, genes linked to oxidative stress and DNA damage exhibited statistically significant expression alterations. These findings suggest that putrescine has genotoxic potential in human-derived HepG2 cells, raising concerns about cemetery contaminants' occupational and environmental risks. This study is the first to assess putrescine's toxicity as an environmental pollutant, as previous research has mainly focused on its role in the food sector. These insights highlight the potential threats necro-leachate poses to environmental health, emphasizing the need for further research on cemetery pollution.

Lycopene Protects Corneal Endothelial Cells from Oxidative Stress by Regulating the P62-Autophagy-Keap1/Nrf2 Pathway

Oxidative stress is a key mechanism in corneal endothelial damage-related diseases, which is induced by environmental factors and genetic mutations. Lycopene (LYC), one of the most potent natural antioxidants, has been shown to offer significant protection against various diseases. However, its role and mechanisms in corneal endothelial damage remain unclear. In this study, an oxidative stress-induced injury model was created using the B4G12 cell line, and a disease model for Fuchs' endothelial corneal dystrophy (FECD) was established using genetically edited mice, both of which were treated with LYC. The results demonstrated that lycopene effectively protected corneal endothelial cells and slowed the progression of FECD. The protective mechanism involves upregulating P62 and activating autophagy, leading to Keap1 degradation, Nrf2 nuclear translocation, and activation of downstream antioxidant proteins. This study broadens the potential application of lycopene in protecting the corneal endothelium and provides a new non-surgical approach for treating corneal endothelial damage-related diseases.

Transcription factor VIB-1 activates catalase-3 expression by promoting PIC assembly in Neurospora crassa

The "p53-like" superfamily transcription factor, VIB-1, plays a crucial role in mediating heterokaryon incompatibility and regulating the transcription of specific genes involved in the secretion of extracellular hydrolases in Neurospora crassa. However, the precise mechanism underlying the transcriptional regulatory function of VIB-1 is still poorly understood. Here, we reveal that VIB-1 is involved in the H2O2-induced oxidative stress response, in which deletion of vib-1 leads to an H2O2-sensitive phenotype and inhibition of cat-3 expression. Conversely, VIB-1 overexpression confers an H2O2-resistant phenotype and robustly activates cat-3 in a dose-dependent manner. Importantly, we identified the DNA-binding domain of VIB-1 as the key component required for these regulatory processes. Furthermore, VIB-1 activates cat-3 transcription by interacting with and recruiting general transcription factors and RNA polymerase II to the cat-3 promoter, resulting in eviction of H2A.Z and a decrease in nucleosome density in these regions. Additionally, VIB-1 positively regulated the expression of other two target genes, NCU05841 and NCU02904, in the same manner. Together, our findings reveal a mechanism by which VIB-1 is involved in the transcriptional activation of cat-3 and other VIB-1-targeted genes by promoting PIC assembly on their promoters.

Non-dikarya fungi share the TORC1 pathway with animals, not with Saccharomyces cerevisiae

Target of rapamycin (TOR), discovered in Saccharomyces cerevisiae, is a highly conserved serine/threonine kinase acting as a regulatory hub between the cell and its environment. Like mammals, in fungi, the TOR complex 1 (TORC1) pathway is essential for coordinating cell growth in response to nutrient availability. The activation of TORC1 is similar in yeast and mammals, while its inhibition is more complex in mammals. This divergence of TORC1 regulation opens the question of how common are the yeast and mammalian variants in the fungal kingdom. In this work, we trace the evolutionary history of TORC1 components throughout the fungal kingdom. Our findings show that these fungi contain the mammalian-specific KICSTOR complex for TORC1 inhibition. They also possess orthologs of serine, arginine and methionine sensors of TORC1 pathway that orchestrate the response to nutrient starvation in mammals. The Rheb-TSC mediated activation of mammalian TORC1 that was lost in Saccharomycotina was also conserved in non-Dikarya. These findings indicate that the TORC1 pathway in non-Dikarya fungi resembles mammalian TORC1. Saccharomycotina lost many of the inhibitory components and evolved alternate regulatory mechanisms. Furthermore, our work highlights the limitations of using S. cerevisiae as a fungal model while putting forward other fungi as possible research models.

Catalase-associated immune responses in plant-microbe interactions: A review

Catalase, an enzyme central to maintaining redox balance and combating oxidative stress in plants, has emerged as a key player in plant defense mechanisms and interactions with microbes. This review article provides a comprehensive analysis of catalase-associated immune responses in plant-microbe interactions. It underscores the importance of catalase in plant defense mechanisms, highlights its influence on plant susceptibility to pathogens, and discusses its implications for understanding plant immunity and host-microbe dynamics. This review contributes to the growing body of knowledge on catalase-mediated immune responses and offers insights that can aid in the development of strategies for improved plant health and disease resistance.

The Effects of Resveratrol and Apigenin on Jejunal Oxidative Injury in Ducks and on Immortalized Duck Intestinal Epithelial Cells Exposed to H2O2

Oxidative stress increases the apoptosis of intestinal epithelial cells and impairs intestinal epithelial cell renewal, which further promotes intestinal barrier dysfunction and even death. Extensive evidence supports that resveratrol and apigenin have antioxidant, anti-inflammatory, and antiproliferative properties. Here, we investigated the ability of these two compounds to alleviate diquat-induced jejunal oxidative stress and morphological injury, using the duck as a model, as well as the effects of apigenin on oxidative stress induced by H2O2 in immortalized duck intestinal epithelial cells (IDECs). Ducks were randomly assigned to the following four groups, with five replicates: a control (CON) group, a diquat-challenged (DIQ) group, a resveratrol (500 mg/kg) + diquat (RES) group, and an apigenin (500 mg/kg) + diquat (API) group. We found that serum catalase (CAT) activity and total antioxidant capacity (T-AOC) markedly reduced in the RES and API groups as compared to the DIQ group (p < 0.05); moreover, serum S superoxide dismutase (SOD) levels increased significantly in the API group as compared to the DIQ group (p < 0.05). In jejunal mucosa, the malondialdehyde (MDA) content in the RES and API groups decreased more than that in the DIQ group (p < 0.05). In addition, the jejunal expression levels of the NRF2 and GCLM genes in the RES and API groups increased notably compared with those in the DIQ group (p < 0.05); meanwhile, CAT activity in the RES and API groups was markedly elevated compared with that in the CON group (p < 0.05). In IDECs, apigenin significantly restrained the H2O2-mediated increase in MDA content and decrease in CAT levels (p < 0.05). Furthermore, apigenin increased the protein expression of p-NRF2, NRF2, p-AKT, and p-P38; downregulated that of cleaved caspase-3 and cleaved caspase-9; and reduced the ratio of Bax/Bcl-2 in H2O2-treated IDECs (p < 0.05). In conclusion, resveratrol and apigenin can be used as natural feed additives to protect against jejunal oxidative stress in ducks.