Long Non-coding RNA Expression Profile in Broiler Liver with Cadmium-Induced Oxidative Damage

Luteolin Alleviates Cadmium-Induced Kidney Injury by Inhibiting Oxidative DNA Damage and Repairing Autophagic Flux Blockade in Chickens

Chickens are a major source of meat and eggs in human food and have significant economic value. Cadmium (Cd) is a common environmental pollutant that can contaminate feed and drinking water, leading to kidney injury in livestock and poultry, primarily by inducing the generation of free radicals. It is necessary to develop potential medicines to prevent and treat Cd-induced nephrotoxicity in poultry. Luteolin (Lut) is a natural flavonoid compound mainly extracted from peanut shells and has a variety of biological functions to defend against oxidative damage. In this study, we aimed to demonstrate whether Lut can alleviate kidney injury under Cd exposure and elucidate the underlying molecular mechanisms. Renal histopathology and cell morphology were observed. The indicators of renal function, oxidative stress, DNA damage and repair, NAD+ content, SIRT1 activity, and autophagy were analyzed. In vitro data showed that Cd exposure increased ROS levels and induced oxidative DNA damage and repair, as indicated by increased 8-OHdG content, increased γ-H2AX protein expression, and the over-activation of the DNA repair enzyme PARP-1. Cd exposure decreased NAD+ content and SIRT1 activity and increased LC3 II, ATG5, and particularly p62 protein expression. In addition, Cd-induced oxidative DNA damage resulted in PARP-1 over-activation, reduced SIRT1 activity, and autophagic flux blockade, as evidenced by reactive oxygen species scavenger NAC application. The inhibition of PARP-1 activation with the pharmacological inhibitor PJ34 restored NAD+ content and SIRT1 activity. The activation of SIRT1 with the pharmacological activator RSV reversed Cd-induced autophagic flux blockade and cell injury. In vivo data demonstrated that Cd treatment caused the microstructural disruption of renal tissues, reduced creatinine, and urea nitrogen clearance, raised MDA content, and decreased the activities or contents of antioxidants (GSH, T-SOD, CAT, and T-AOC). Cd treatment caused oxidative DNA damage and PARP-1 activation, decreased NAD+ content, decreased SIRT1 activity, and impaired autophagic flux. Notably, the dietary Lut supplement observably alleviated these alterations in chicken kidney tissues induced by Cd. In conclusion, the dietary Lut supplement alleviated Cd-induced chicken kidney injury through its potent antioxidant properties by relieving the oxidative DNA damage-activated PARP-1-mediated reduction in SIRT1 activity and repairing autophagic flux blockade.

Antibody-platinum (IV) prodrugs conjugates for targeted treatment of cutaneous squamous cell carcinoma

Antibody-drug conjugates (ADCs) are a new type of targeting antibodies that conjugate with highly toxic anticancer drugs via chemical linkers to exert high specificity and efficient killing of tumor cells, thereby attracting considerable attention in precise oncology therapy. Cetuximab (Cet) is a typical antibody that offers the benefits of good targeting and safety for individuals with advanced and inoperable cutaneous squamous cell carcinoma (cSCC); however, its anti-tumor activity is limited to a single use. Cisplatin (CisPt) shows good curative effects; however, its adverse effects and non-tumor-targeting ability are major drawbacks. In this study, we designed and developed a new ADC based on a new cytotoxic platinum (IV) prodrug (C8Pt(IV)) and Cet. The so-called antibody-platinum (IV) prodrugs conjugates, named Cet-C8Pt(IV), showed excellent tumor targeting in cSCC. Specifically, it accurately delivered C8Pt(IV) into tumor cells to exert the combined anti-tumor effect of Cet and CisPt. Herein, metabolomic analysis showed that Cet-C8Pt(IV) promoted cellular apoptosis and increased DNA damage in cSCC cells by affecting the vitamin B6 metabolic pathway in tumor cells, thereby further enhancing the tumor-killing ability and providing a new strategy for clinical cancer treatment using antibody-platinum (IV) prodrugs conjugates.

Long non-coding RNAs regulate heavy metal-induced apoptosis in embryo-derived cells

Heavy metal pollution has been a worldwide prevalent problem, and particularly a threat to ecosystem integrity and animals' health. Previous studies on the mechanisms of heavy metal toxicity have focused on protein-coding genes, whereas most genomic transcripts are long non-coding RNAs (lncRNAs). Although lncRNAs are known to play important regulatory roles in biological processes, their role in heavy metal stress regulation is still not fully understood. We here developed an insect embryo cell model for studying metal toxicity and the underlying regulatory mechanisms. We performed genome-wide screening and functional characterization of lncRNAs induced by two essential and two non-essential heavy metals in Drosophila embryo-derived S2 cells. We identified 4894 lncRNAs, of which 1410 were novel. Forty-one lncRNAs, together with 328 mRNAs, were induced by all the four heavy metals. LncRNA-mRNA co-expression network and pathway enrichment analysis showed that detoxification metabolism, circadian rhythm, and apoptosis regulation pathways were activated in response to heavy metal stress. LncRNA CR44138 was remarkably upregulated in cells exposed to the four heavy metals and was associated with the apoptosis pathway. Expression interference confirmed that CR44138 aggravated cytotoxicity-induced apoptosis in cells under heavy metals stress. This study highlights the important role of lncRNAs in regulating the cellular response to heavy metals. This study also lays the foundation for discovering the novel regulatory mechanisms and developing diagnostic biomarkers of the toxic effects of heavy metal pollutants on organisms.

miR-210/NF-κB axis: A new direction for regulating cadmium-induced pig artery inflammatory injury

Cadmium (Cd) is a toxic metal pollutant that still exists in the environment. The microRNA (miRNA) is a type of noncoding RNA that plays an important role in gene posttranscriptional regulation and disease development. Although the toxic effects of Cd have been extensively studied, studies on the mechanism of Cd from the perspective of miRNA are still limited. So, we established a Cd-exposure pig model, which confirmed that Cd exposure would cause pig artery damage. The miR-210 with the most reduced expression and the nuclear factor kappa B (NF-κB) that had a targeting relationship with miR-210 were screened. The effect of miR-210/NF-κB on the artery damage induced by Cd exposure was investigated by acridine orange/ethidium bromide staining, reactive oxygen species (ROS) staining, quantitative PCR, and western blotting. The results showed that miR-210 inhibitor, pcDNA-NF-κB could induce ROS overproduction in pig hip artery endothelial cells, thus inducing Th1/Th2 imbalance and necroptosis, leading to increased inflammation, while small interfering RNA-NF-κB played a mitigating role. In conclusion, Cd can induce artery necroptosis and Th1/Th2 imbalance by regulating the miR-210/NF-κB axis, so as to lead to artery inflammatory damage. In this study, we explored the way in which Cd exposure causes artery damage in pig, providing a new perspective on the regulatory damage of miR-210/NF-κB axis.

Multifactorial Screening Reveals New Insight into Early Cadmium Exposure and Garlic Interactions in Dicentrarchus labrax

Environmental pollutants and especially metal trace elements remain an unmitigated threat to the overall life support system. Their chemical stability and accumulation pattern in the ecosystem make them a persistent hazard. This study aims to characterize the early cadmium (Cd) histological and hematological alterations and their corresponding plasma indicators in the Mediterranean sea bass (Dicentrarchus labrax). We also assessed garlic potential to prevent cadmium toxicity. For this purpose, 200 fish of 55 g mean weight were separated into 3 cylindroconical fiberglass tanks of 500-L capacity, each with a stocking density of 4 kg m^-3. The fish were regularly hand-fed 0% (control group), 2%, and 6% garlic-supplemented diets to apparent satiation twice a day for 1 month. At the end of the experiment, we injected 22.2 mM cadmium (CdCl2) intraperitoneally to the experimental groups and a placebo solution (9% NaCl) to the control groups; liver, kidney, heart, and blood tissue alterations were monitored with a full screening of their plasmatic indicators, 24 h before and 48 h after Cd injection. Subsequently, whole blood count and blood smears were performed to follow up on Cd-induced vascular damages. Our data showed that Cd induced thrombotic thrombocytopenic purpura, leading to widespread bleeding and cellular alterations in the targeted tissues. These alterations were associated with an obvious normochromic normocytic anemia in favor of microangiopathic hemolytic anemia. Cd injection has also seriously inhibited the overall enzymatic activities triggering a metabolic shift. Although garlic supplementation had little effect on cadmium-induced alterations, it significantly reduced biomass dispersion. Our data is the first evidence of the cadmium versatile toxicity involving vascular alterations as a central and a leading cause of the overall parenchymal lesions. Cd toxicity was associated with a specific enzymatic signature, which must be considered during the interpretation.

Transcriptome sequencing reveals genes involved in cadmium-triggered oxidative stress in the chicken heart

As a ubiquitous heavy metal, cadmium (Cd) is highly toxic to various organs. However, the effects and molecular mechanism of Cd toxicity in the chicken heart remain largely unknown. The goal of our study was to investigate the cardiac injury in chickens' exposure to Cd. We detected the levels of oxidative stress-related molecules in the Cd-induced chicken heart, and assessed the histopathological changes by hematoxylin and eosin staining. RNA sequencing was performed to identify differentially expressed mRNAs between the Cd-induced group and control group. The expression of candidate genes involved in oxidative stress was certified by quantitative reverse transcription PCR. Our results showed that the expression of glutathione, peroxidase, and superoxide dismutase was significantly decreased and malondialdehyde was increased in the heart of chickens by Cd induction. The disorderly arranged cardiomyocytes, swelled and enlarged cells, partial cardiomyocyte necrosis, blurred morphological structure, and notable inflammatory cell infiltration were observed in the Cd-induced chicken heart. RNA sequencing identified 23 upregulated and 11 downregulated mRNAs in the heart tissues of the chicken in the Cd-induced group, and functional pathways indicated that they were associated with oxidative stress. Moreover, CREM, DUSP8, and ITGA11 expressions were significantly reduced, whereas LAMA1 expression was induced in heart tissue of chickens by Cd treatment. Overall, our findings revealed that oxidative stress and pathological changes in the chicken heart could be triggered by Cd. The mRNA transcriptional profiles identified differentially expressed genes in the chicken heart by Cd induction, revealing oxidative stress-related key genes and enhancing our understanding of Cd toxicity in the chicken heart.