Deoxynivalenol exposure induces oxidative stress and apoptosis in human keratinocytes via PI3K/Akt and MAPK signaling pathway.

Deoxynivalenol (DON) is a mycotoxin frequently occurring in human and animal food worldwide, which raises increasing public health concerns. In the present study, we used human keratinocytes (HaCaT cells) as an in vitro model to explore the cytotoxic effect of DON. The results showed that the cells exhibited varying degrees of damage, including decreased cell number and viability, cell shrinkage and floating, when treated with 0.125, 0.25, and 0.5 µg/mL DON for 6, 12, and 24 h, respectively. Furthermore, exposure to DON for 24 h significantly increased the lactate dehydrogenase (LDH) release and intracellular reactive oxygen species (ROS), and prominently decreased the superoxide dismutase (SOD) and catalase (CAT) activity. Additionally, DON exposure induced mitochondrial damage and cell apoptosis through reducing mitochondrial membrane potential. Then, we performed RNA-sequencing to investigate the molecular changes in HaCaT cells after DON exposure. The RNA-sequencing results revealed that DON exposure altered the gene expression involved in apoptosis, MAPK signaling pathway, and PI3K/Akt signaling pathway. Moreover, DON exposure significantly decreased the mRNA and protein expression of Bcl-2, and increased the mRNA and protein expression of Bax, Caspase 3 and COX-2, the protein expression of PI3K, and the phosphorylation levels of Akt, ERK, p38, and JNK. Taken together, these findings suggest that DON exposure could induce cell damage, oxidative stress, and apoptosis in HaCaT cells through the activation of PI3K/Akt and MAPK pathways.

Untargeted metabolomics yields insight into extramammary Paget's disease mechanisms.

Background: Extramammary Paget's disease (EMPD) is a rare cutaneous malignancy, commonly affecting the external genitalia and perianal area of the elderly with unclear pathogenesis. Metabolomics provides a novel perspective for uncovering the metabolic mechanisms of a verity of cancers. Materials and methods: Here, we explored the metabolome of EMPD using an untargeted strategy. In order to further investigate the potential relationship between metabolites and gene expression, we re-analyzed the gene expression microarray data (GSE117285) using differential expression analysis and functional enrichment analyses. Results: Results showed that a total of 896 metabolites were identified and 87 metabolites including 37 upregulated and 50 downregulated significantly in EMPD were sought out. In the following feature selection analyses, four metabolites, namely, cyclopentyl fentanyl-d5, LPI 17:0, guanosine-3',5'-cyclic monophosphate, kynurenine (KYN, high in EMPD) were identified by both random forest and support vector machine analyses. We then identified 1,079 dysfunctional genes: 646 upregulated and 433 downregulated in EMPD. Specifically, the tryptophan-degrading enzyme including indoleamine-2,3-dioxygenase-1 (IDO1) and tryptophan 2,3-dioxygenase (TDO2) were also increased. Generally, cancers exhibit a high expression of IDO1 and TDO2 to catabolize tryptophan, generating abundant KYN. Moreover, we also noticed the abnormal activation of sustaining proliferative signaling in EMPD. Conclusion: In conclusion, this study was the first to reveal the metabolome profile of EMPD. Our results demonstrate that IDO1/TDO2-initialized KYN metabolic pathway may play a vital role in the development and progression of EMPD, which may serve as a potential therapeutic target for treating EMPD.

Chlorogenic acid attenuates deoxynivalenol-induced apoptosis and pyroptosis in human keratinocytes via activating Nrf2/HO-1 and inhibiting MAPK/NF-κB/NLRP3 pathways.

Deoxynivalenol (DON) is a common mycotoxic contaminant, frequently found in food and feed, causing a severe threat to human and animal health. Because of the widespread contamination of DON, humans involved in agricultural practices may be directly exposed to DON through the skin route. Chlorogenic acid (CGA) is a phenolic acid, which has anti-inflammatory and antioxidant properties. However, it is still unclear whether CGA can protect against DON-induced skin damage. Here, the effect of CGA on mitigating damage to human keratinocytes (HaCaT) triggered by DON, as well as its underlying mechanisms were investigated. Results demonstrated that DON exposure significantly decreased cell viability, and induced excessive mitochondrial reactive oxygen species (mtROS) generation, mitochondrial damage, oxidative stress, cell apoptosis and pyroptosis. However, CGA pretreatment for 2 h significantly increased cell viability and reversed DON-induced oxidative stress by improving antioxidant enzyme activities such as superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), reducing mtROS generation and enhancing mitochondrial function through activating Nrf2/HO-1 pathway. Moreover, CGA significantly increased the Bcl-2 protein expression, decreased the protein expressions of Bax and cleaved Caspase-3, and suppressed the phosphorylated of ERK, JNK, NF-κB. Further experiments revealed that CGA could also inhibit the pyroptosis-related protein expressions including NLRP3, cleaved Caspase-1, GSDMD-N, cleaved IL-1ß and IL-18. In conclusion, our results suggest that CGA could attenuate DON-induced oxidative stress, inflammation, and apoptosis by activating the Nrf2/HO-1 pathway and inhibiting MAPK/NF-κB/NLRP3 pathway. CGA might be a novel promising therapeutic agent for alleviating the dermal damage triggered by DON.

Triptolide Induces Apoptosis and Autophagy in Cutaneous Squamous Cell Carcinoma via Akt/mTOR Pathway.

BACKGROUND: Tripterygium wilfordii Hook F provided the source of the first diterpenoid triepoxide lactone, Triptolide, identified as the primary constituent causing the anticancer activity. So far, it has not been reported whether triptolide has a therapeutic effect on cutaneous squamous cell carcinoma (cSCC). OBJECTIVE: This study investigates the triptolide's therapeutic impact on cSCC both in vitro and in vivo and investigates the triptolide's potential involvement in signaling pathways. METHODS: The CCK-8 assays, wound healing assays, and colony formation assays were used to assess the effects of triptolide on the proliferation and migration of cSCC cells. The alteration in gene expression following triptolide treatment was shown by RNA sequencing. Flow cytometry was then applied to evaluate cell apoptosis. Western blot was used to find the associated proteins' expressions. The effectiveness of triptolide was then evaluated in vivo using a xenograft model, and histological staining was employed to determine the visceral toxicity. RESULTS: Triptolide greatly reduces the migratory and proliferative capacity of cSCC cells. Triptolide dramatically decreased cell viability and migration in the A431 and SCL-1 cells compared to the control group, according to the CCK8 assay, wound healing assay, and colony formation assay. Flow cytometry demonstrated that treatment with 10- 40 nM triptolide increased apoptosis in a concentration-dependent manner, with a statistically significant difference. Furthermore, mice given triptolide had smaller tumor sizes than those in the control group. Triptolide treatment drastically altered the expression of autophagic and apoptotic proteins. The considerable reduction in the proteins Akt and mTOR levels further illustrated the critical function of triptolide in cSCC. CONCLUSION: Triptolide caused cSCC cells to engage in autophagy and apoptosis by inhibiting the Akt/mTOR signaling pathways. Triptolide may be a possible antitumor agent for the treatment of cSCC.