Decreased thioredoxin reductase 3 expression promotes nickel-induced damage to cardiac tissue via activating oxidative stress-induced apoptosis and inflammation

Streptococcus mitis enhances metal-induced apoptosis in reconstructed human gingiva but not skin

BACKGROUND

Commensal bacteria colonizing oral mucosa and skin play an essential role in maintaining host-microbiome homeostasis. It is unknown whether cytotoxicity resulting from metal ions leaching from medical devices may be influenced by commensal microbes.

OBJECTIVE

Determine whether the extent of apoptosis triggered by nickel or titanium ions is influenced by Streptococcus mitis and whether apoptosis occurs via the intrinsic or extrinsic apoptosis pathway.

METHODS

Reconstructed Human Gingiva (RHG) and Skin (RHS) were topically exposed to titanium or nickel salts in the presence or absence of S. mitis. Cytotoxicity and apoptosis were assessed by histology, immunohistochemistry, TUNEL assay, and Western Blot.

RESULTS

S. mitis alone resulted in negligible cytotoxicity. After metal exposure, localized apoptosis was observed in the epithelium and fibroblasts within the lamina propria hydrogel of both RHG and RHS. S. mitis enhanced metal-mediated apoptosis in gingiva but not in skin. Apoptosis was mediated via the extrinsic pathway caspase 8. Activation of the execution phase of apoptosis occurred via caspases 3 and 7, and PARP-1.

CONCLUSION

Our study supports the finding that metals have irritant, cytotoxic properties resulting in apoptosis when leaching into skin or gingiva. Particularly for gingiva, commensal microbes exaggerate this detrimental effect.

Reveal the mechanism of hepatic oxidative stress in mice induced by photo-oxidation milk using multi-omics analysis techniques

INTRODUCTION

Photo-oxidation is recognized as a contributor to the deterioration of milk quality, posing potential safety hazards to human health. However, there has been limited investigation into the impact of consuming photo-oxidized milk on health.

OBJECTIVES

This study employs multi-omics analysis techniques to elucidate the mechanisms by which photo-oxidized milk induces oxidative stress in the liver.

METHODS

Mouse model was used to determine the effect of the gavage administration of milk with varying degrees of photo-oxidation on the mouse liver. The damage degree was established by measuring serum markers indicative of oxidative stress, and with a subsequent histopathological examination of liver tissues. In addition, comprehensive metabolome, lipidome, and transcriptome analyses were conducted to elucidate the underlying molecular mechanisms of hepatic damage caused by photo-oxidized milk.

RESULTS

A significant elevation in the oxidative stress levels and the presence of hepatocellular swelling and inflammation subsequent to the gavage administration of photo-oxidized milk to mice. Significant alterations in the levels of metabolites such as lumichrome, all-trans-retinal, L-valine, phosphatidylglycerol, and phosphatidylcholine within the hepatic tissue of mice. Moreover, photo-oxidized milk exerted a pronounced detrimental impact on the glycerophospholipid metabolism of mice liver. The peroxisome proliferator-activated receptors (PPAR) signaling pathway enrichment appreciated in the animals that consumed photo-oxidized milk further supports the substantial negative influence of photo-oxidized milk on hepatic lipid metabolism. Gene set enrichment and interaction analyses revealed that photo-oxidized milk inhibited the cytochrome P450 pathway in mice, while also affecting other pathways associated with cellular stress response and lipid biosynthesis.

CONCLUSION

This comprehensive study provides significant evidence regarding the potential health risks associated with photo-oxidized milk, particularly in terms of hepatic oxidative damage. It establishes a scientific foundation for assessing the safety of such milk and ensuring the quality of dairy products.

LncRNA Miat knockdown protects against pirarubicin-induced cardiotoxicity by targeting miRNA-129-1-3p

Pirarubicin (THP) is a widely used antitumor drug in clinical practice, but its cardiotoxicity limits its use. The aim of this study was to investigate the protective effect and mechanism of knockdown of lncRNA Miat in THP-induced cardiotoxicity. The extent of damage to immortalized cardiomyocytes in mice was assessed by CCK8, TUNEL, ROS, Ca2+ , RT-qPCR, and Western blot. The relative levels of Miat in THP-treated cardiomyocytes (HL-1) were measured. The protective effect of Miat on THP-treated HL-1 was assessed. The binding relationship between lncRNA Miat and mmu-miRNA-129-1-3p was verified by a dual luciferase reporter gene assay. The protective role of Miat/miRNA-129-1-3p in THP-induced HL-1 was explored by performing a rescue assay. THP reduced cell viability, induced apoptosis, triggered oxidative stress and calcium overload. Expression of Miat in HL-1 was significantly elevated after THP treatment. Miat knockdown significantly alleviated the cardiotoxicity of THP. MiR-129-1-3p is a direct target of Miat. Knockdown of miR-129-1-3p reversed the protective effect of Miat knockdown on HL-1. Miat knockdown can alleviate THP-induced cardiomyocyte injury by regulating miR-129-1-3p.

Role of Txnrd3 in NiCl2-induced kidney cell apoptosis in mice: Potential therapeutic effect of melatonin

Nickel (Ni) exposure is a significant risk factor for kidney dysfunction and oxidative stress injury in humans. Thioredoxin reductase 3 (Txnrd3), an important enzyme in animals, plays a role in maintaining cellular homeostasis and regulating oxidative stress. However, its protective effect against kidney injury has been determined. Melatonin (Mel) has antioxidant and anti-apoptotic effects and therefore may be a preventive and therapeutic agent for kidney injury. Our study aimed to investigate the roles of Mel and Txnrd3 in the treatment of nickel-induced renal injury. We divided 80 wild-type mice and 80 Txnrd3 -/- mice (C57BL/6 N) into a control group treated with saline, Ni group treated with 10 mg/kg NiCl2, Mel group treated with 2 mg/kg Mel, and Ni + Mel group given NiCl2 and Mel for 21 days. Histopathological and ultrastructural observation of the kidney showed that nuclei were wrinkled and mitochondrial cristae were broken in the Ni group, and these changes were significantly attenuated by Mel treatment. Mitochondrial and nuclear damage improved significantly in the Ni + Mel and Txnrd3-/- Ni + Mel groups. Furthermore, NiCl2 exposure decreased T-AOC, SOD, and GSH activities in the kidney. The decreases in antioxidant enzyme activity were attenuated by Mel, and these improvements were abolished by Txnrd3 knockout. NiCl2-induced increases in the mRNA and protein levels of apoptosis factors (Bax, Cyt-c, caspase-3, and caspase-9) were attenuated by Mel treatment, and Txnrd3 knockout abolished the repressive effect of Mel on apoptosis genes. Overall, we concluded that Mel improves oxidative stress and apoptosis induced by NiCl2 by regulating Txnrd3 expression in the kidney. Our results provide evidence for the role of Mel in NiCl2-induced kidney injury and identify Txnrd3 as a potential therapeutic target for renal injury.

Catalpol ameliorates inflammation and oxidative stress via regulating Sirt1 and activating Nrf2/HO-1 signaling against acute kidney injury

BACKGROUND

Septic acute kidney injury (SAKI) is usually caused by sepsis. It has been shown that catalpol (Cat) impairs sepsis-evoked organ dysfunction to a certain degree. The current work aims to evaluate the protective effects of Cat on SAKI and potential mechanisms in vivo and in vitro.

METHODS

SAKI cellular and murine model were set up using lipopolysaccharide (LPS) in vitro and in vivo. Cell apoptosis in cells was determined by TUNEL assay. Levels of inflammatory cytokines were detected by enzyme-linked immunosorbent assay (ELISA). The levels of the markers of oxidative injury were evaluated by corresponding commercial kits. Protein levels were assayed via western blotting and immunohistochemistry (IHC) staining.

RESULTS

The results demonstrated that LPS upregulated TNF-α, IL-6, and malondialdehyde levels, and downregulated superoxide dismutase, whereas Cat treated cells have the opposite results. Functional assays displayed that Cat remarkably reversed the LPS-challenged damage as the impairment of TNF-α and IL-6 levels, oxidative stress, and the apoptosis in HK-2 cells. Moreover, knockdown of Sirtuin 1 (Sirt1) counteracted the suppressive impact of Cat on LPS-triggered inflammatory response, oxidative stress, and renal damage. Further, Cat elevated Sirt1 expression and activated the Nrf2/HO-1 signaling in LPS-engendered SAKI in vivo and in vitro.

CONCLUSION

Our study clearly proved that Cat protected against LPS-induced SAKI via synergic antioxidant and anti-inflammatory actions by regulating Sirt1 and Nrf2/HO-1 signaling pathways.

Molecular Mechanisms of Selenium Mitigating Lead Toxicity in Chickens via Mitochondrial Pathway: Selenoproteins, Oxidative Stress, HSPs, and Apoptosis

Lead (Pb), a hazardous heavy metal, can damage the health of organisms. However, it is not clear whether Pb can damage chicken cerebellums and thalami. Selenium (Se), an essential nutrient for organisms, has a palliative effect on Pb poisoning in chickens. In our experiment, a model of chickens treated with Pb and Se alone and in combination was established to investigate the molecular mechanism of Se alleviating Pb-caused damage in both chicken cerebellums and thalami. Our morphological results indicated that Pb caused apoptotic lesions, such as mitochondrial and nuclear damage. Further, the anti-apoptotic gene Bcl-2 decreased; on the contrary, four pro-apoptotic genes (p53, Bax, Cyt c, and Caspase-3) increased under Pb treatment, meaning that Pb caused apoptosis via the p53-Cyt c-Caspase-3 pathway. Furthermore, we further demonstrated that Pb elevated four HSPs (HSP27, HSP40, HSP70, and HSP90), as well as HSP70 took part in the molecular mechanism of Pb-caused apoptosis. In addition, we found that Pb exposure led to oxidative stress via up-regulating the oxidant H2O2 and down-regulating four antioxidants (CAT, SOD, GST, and GPx). Moreover, Pb decreased three Se-containing factors (Txnrd1, Txnrd2, and Txnrd3), further confirming that Pb caused oxidative stress. Interestingly, Se supplementation reversed the above changes caused by Pb and alleviated Pb-induced oxidative stress and apoptosis. A time dependency was demonstrated for Bcl-2, Bax, and Cyt c in the cerebellums, as well as CAT, GPx, and p53 in the thalami of Pb-exposed chickens. HSP70 in cerebellums and HSP27 in thalami were more sensitive than those in thalami and cerebellums, respectively, under Pb exposure. Pb-induced apoptosis of thalami was more severe than cerebellums. In conclusion, after Pb treatment, Txnrds mediated oxidative stress, oxidative stress up-regulated HSPs, and finally, HSP70 triggered apoptosis. Se supplementation antagonized Pb-induced oxidative stress and apoptosis via the mitochondrial pathway and selenoproteins in chicken cerebellums and thalami. This study provides new information for the mechanism of environmental pollutant poisoning and the detoxification of Se on abiotic stress.

Nickel induces hepatotoxicity by mitochondrial biogenesis, mitochondrial dynamics, and mitophagy dysfunction

Nickel (Ni) is an important and widely hazardous chemical industrial waste. Excessive Ni exposure could cause multi-organs toxicity in human and animals. Liver is the major target organ of Ni accumulation and toxicity, however, the precise mechanism is still unclear. In this study, nickel chloride (NiCl₂ )-treatment induced hepatic histopathological changes in the mice, and, transmission electron microscopy results showed mitochondrial swollen and deformed of hepatocyte. Next, the mitochondrial damages including mitochondrial biogenesis, mitochondrial dynamics, and mitophagy were measured after NiCl₂ administration. The results showed that NiCl₂ suppressed mitochondrial biogenesis by decreasing PGC-1α, TFAM, and NRF1 protein and mRNA expression levels. Meanwhile, the proteins involved in mitochondrial fusion were reduced by NiCl₂ , such as Mfn1 and Mfn2, however, mitochondrial fission proteins Drip1 and Fis1 were significantly increased. The up-regulation of mitochondrial p62 and LC3II expression indicated that NiCl₂ increased mitophagy in the liver. Moreover, the receptor-mediated mitophagy and ubiquitin (Ub)-dependent mitophagy were detected. NiCl₂ promoted PINK1 accumulation and Parkin recruitment on mitochondria. And, the receptor proteins of mitophagy Bnip3 and FUNDC1 were increased in the NiCl₂ -treated mice liver. Overall, these results show that NiCl₂ could induce mitochondria damage in the liver of mice, and, dysfunction of mitochondrial biogenesis, mitochondrial dynamics and mitophagy involved in the molecular mechanism of NiCl₂ -induced hepatotoxicity.

N-acetyl-L-cysteine alleviated the oxidative stress-induced inflammation and necroptosis caused by excessive NiCl2 in primary spleen lymphocytes

Introduction

Nickel (Ni) is widely used in industrial manufacturing and daily life due to its excellent physical and chemical properties. However, Ni has the potential to harm animals' immune system, and spleen is a typical immune organ. Therefore, it is crucial to understand the mechanism of NiCl2 damage to the spleen. The purpose of this study is to investigate the effects of different concentrations of NiCl2 exposure and intervening with strong antioxidants on spleen lymphocytes to better understand the damage mechanism of Ni on spleen lymphocytes.

Methods

In this experiment, mice spleen lymphocytes were used as the research object. We first measured the degree of oxidative stress, inflammation, and necroptosis caused by different NiCl2 concentrations. Subsequently, we added the powerful antioxidant N-acetyl-L-cysteine (NAC) and used hydrogen peroxide (H2O2) as the positive control in subsequent experiments.

Results

Our findings demonstrated that NiCl2 could cause spleen lymphocytes to produce a large number of reactive oxygen species (ROS), which reduced the mRNA level of antioxidant enzyme-related genes, the changes in GSH-PX, SOD, T-AOC, and MDA, the same to the mitochondrial membrane potential. ROS caused the body to produce an inflammatory response, which was manifested by tumor necrosis factor (TNF-α) in an immunofluorescence experiment, and the mRNA level of related inflammatory genes significantly increased. In the case of caspase 8 inhibition, TNF-α could cause the occurrence of necroptosis mediated by RIP1, RIP3, and MLKL. AO/EB revealed that spleen lymphocytes exposed to NiCl2 had significant necroptosis, and the mRNA and protein levels of RIP1, RIP3, and MLKL increased significantly. Moreover, the findings demonstrated that NAC acted as an antioxidant to reduce oxidative stress, inflammation, and necroptosis caused by NiCl2 exposure.

Discussion

Our findings showed that NiCl2 could cause oxidative stress, inflammation, and necroptosis in mice spleen lymphocytes, which could be mitigated in part by NAC. The study provides a point of reference for understanding the toxicological effect of NiCl2. The study suggests that NAC may be useful in reducing the toxicological effect of NiCl2 on the immune system. The research may contribute to the development of effective measures to prevent and mitigate the toxicological effects of NiCl2 on the immune system.