Cadmium exposure induces inflammation and necroptosis in porcine adrenal gland via activating NF-κB/MAPK pathway

Molybdenum and cadmium co-induce necroptosis through Th1/Th2 imbalance-mediated endoplasmic reticulum stress in duck ovaries

Cadmium (Cd) and excess molybdenum (Mo) pose serious threats to animal health. Our previous study has determined that Cd and/or Mo exposure can cause ovarian damage of ducks, while the specific mechanism is still obscure. To further investigate the toxic mechanism of Cd and Mo co-exposure in the ovary, forty 8-day-old female ducks were randomly allocated into four groups for 16 weeks, and the doses of Cd and Mo in basic diet per kg were as follows: control group, Mo group (100 mg Mo), Cd group (4 mg Cd), and Mo + Cd group (100 mg Mo + 4 mg Cd). Cadmium sulfate 8/3-hydrate (CdSO4·8/3H2O) and hexaammonium molybdate ((NH4)6Mo7O24·4H2O) were the origins of Cd and Mo, respectively. At the 16th week of the experiment, all ovary tissues were collected for the detection of related indexes. The data indicated that Mo and/or Cd induced trace element disorders and Th1/Th2 balance to divert toward Th1 in the ovary, which activated endoplasmic reticulum (ER) stress and then provoked necroptosis through triggering RIPK1/RIPK3/MLKL signaling pathway, and eventually caused ovarian pathological injuries and necroptosis characteristics. The alterations of above indicators were most apparent in the joint group. Above all, this research illustrates that Mo and/or Cd exposure can initiate necroptosis through Th1/Th2 imbalance-modulated ER stress in duck ovaries, and Mo and Cd combined exposure aggravates ovarian injuries. This research explores the molecular mechanism of necroptosis caused by Mo and/or Cd, which reveals that ER stress attenuation may be a therapeutic target to alleviate necroptosis.

Adverse effects of cadmium on lymphoid organs, immune cells, and immunological responses

Humans and animals possess robust immune systems to safeguard against foreign pathogens. However, recent reports suggest a greater incidence of immunity breakdown due to exposure to environmental pollutants, with heavy metals emerging as potential candidates in such immuno-toxicological studies. While we have extensive data on the general toxicity resulting from exposure to heavy metals, comprehensive documentation of their role as immune disruptors remains scarce. Cd (Cadmium) exerts immunomodulation by interfering with immune organs and cells, leading to altered structure, physiology, and function, thereby inducing symptoms of immune deregulation, inflammation and/or autoimmunity. This review aims to summarize the link between Cd exposure and immune dysfunction, drawing from case studies on exposed human subjects, as well as research conducted on various model organisms and in-vitro culture systems.

Cadmium promoted LPS-induced inflammation through TLR4/IκBα/NFκ-B signaling by increasing ROS-mediated incomplete autophagy

Cadmium (Cd) exposure is considered as non-infectious stressor to human and animal health. Recent studies suggest that the immunotoxicity of low dose Cd is not directly apparent, but disrupts the immune responses when infected with some bacteria or virus. But how Cd alters the adaptive immunity organ and cells remains unclear. In this study, we applied lipopolysaccharide (LPS, infectious stressor) to induced inflammation in spleen tissues and T cells, and investigated the effects after Cd exposure and the underlying mechanism. Cd exposure promoted LPS-induced the expressions of the inflammatory factors, induced abnormal initiation of autophagy, but blocked autophagic flux. The effects Cd exposure under LPS activation were reversed by the autophagy promoter Rapamycin. Under LPS activation conditions, Cd also induced oxidative stress by increasing the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), and reducing total antioxidant capacity (T-AOC) activity. The increased superoxide dismutase (SOD) activity after Cd exposure might be a negative feedback or passive adaptive regulation of oxidative stress. Cd-increased autophagic flux inhibition and TNF-α expression were reversed by ROS scavenger α-tocopherol (TCP). Furthermore, under LPS activation condition, Cd promoted activation of toll-like receptor 4 (TLR4)/IκBα/NFκ-B signaling pathway and increased TLR4 protein stability, which were abolished by the pretreatment of Rapamycin. The present study confirmed that, by increasing ROS-mediated inhibiting autophagic degradation of TLR4, Cd promoted LPS-induced inflammation in spleen T cells. This study identified the mechanism of autophagy in Cd-aggravated immunotoxicity under infectious stress, which could arouse public attention to synergistic toxicity of Cd and bacterial or virus infection.

Environmental risk factors provoke new thinking for prevention and treatment of dementia with Lewy bodies

In recent years, environmental factors have received attention in the pathogenesis of neurodegenerative diseases. Other than genetic factors, the identification of environmental factors and modifiable risk factors may create opportunities to delay the onset or slow the progression of Lewy body disease. Researchers have made significant progress in understanding environmental and modifiable risk factors over the past 30 years. To date, despite the increasing number of articles assessing risk factors for Lewy body disease, few reviews have focused on their role in its onset. In this review, we reviewed the literature investigating the relationship between Lewy body disease and several environmental and other modifiable factors. We found that some air pollutants, exposure to some metals, and infection with some microorganisms may increase the risk of Lewy body disease. Coffee intake and the Mediterranean diet are protective factors. However, it is puzzling that low educational levels and smoking may have some protective effects. In addition, we proposed specific protocols for subsequent research directions on risk factors for neurodegenerative diseases and improved methods. By conducting additional case-control studies, we could explore the role of these factors in the etiopathogenesis of Lewy body disease, establishing a foundation for strategies aimed at preventing and reducing the onset and burden of the disease.

The mechanism of cadmium exposure-induced lymph node necroptosis and inflammation in piglets: Activation of CYP450 through VDR / CREB1 pathway

Cadmium (Cd) is toxic non-essential heavy metal that precipitates adverse health effects in humans and animals, but the effect of Cd on lymph node toxicity of piglets is still unclear. In order to explore the possible molecular mechanism of Cd toxicity to lymph nodes of piglets, ten 6-week-old male weaned piglets were randomly divided into two groups, C group and Cd group. Group C was fed with basal diet, while group Cd was fed with basal diet supplemented with CdCl2 (20 mg/kg) for 40 days, the pigs were euthanized and the mesenteric, inguinal and submandibular lymph nodes (MLN, ILN, SLN) were collected. The results indicated that Cd could induce the inflammatory cell infiltration, microvascular hemorrhage, microthrombosis and cell necrosis in MLN, ILN and SLN of piglets, induced Cytochrome P450 proteins (CYP1A1、CYP2E1、CYP2A1 and CYP3A2) mRNA levels and the protein levels of Vitamin D receptor (VDR) and cAMP response element binding protein 1 (CREB1). In addition, Cd exposure upregulated the mRNA and protein levels of dynamin-related protein 1 (DRP1), receptor-interacting protein kinase 3 (RIP3), mixed lineage kinase domain-like protein (MLKL), and increased tumor necrosis factor-α (TNFα), interferon-γ (IFNγ), interleukin-2 (IL-2), interleukin-4 (IL-4), cyclooxygenase 2 (COX-2) protein levels, and the damage degree of three kinds of lymph nodes was similar after Cd exposure. In general, these results manifest that Cd exposure regulates VDR/CREB1 pathway, activates CYP450s, induces necroptosis of lymph nodes, and leads to inflammation.

Cadmium (Cd) and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) co-exposure induces acute kidney injury through oxidative stress and RIPK3-dependent necroptosis

Environmental pollution is complex, and co-exposure can accurately reflect the true environmental conditions that are important for assessment of human health. Cadmium (Cd) is a widespread toxicant that can cause acute kidney injury (AKI), while its combined effect with 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) is not fully understood. Thus, we used an in vivo model where C57BL/6J mice were treated with low dietary intake of Cd (5 mg/kg/day) and/or BDE-47 (1 mg/kg/day) for 28 days to examine AKI, and in vitro experiments to investigate the possible mechanism. Results showed that Cd or BDE-47 caused pathological kidney damage, accompanied by elevated urea nitrogen (BUN) and urinary creatinine, as well as increased interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), and reduced IL-10 in kidney tissues. In vitro Cd or BDE-47 exposure decreased cell viability and induced cell swelling and blebbing of human embryonic kidney 293 (HEK-293) and renal tubular epithelial cell lines (HKCs), and changes in co-exposure was larger than that in Cd and BDE-47 treatment. Oxidative stress indicators of the reactive oxygen species (ROS) and malondialdehyde (MDA) were elevated, while the antioxidant superoxide dismutase (SOD) was decreased. Necrosis occurred with increased lactate dehydrogenase (LDH) release and propidium iodide (PI) staining, which was attenuated by the ROS scavenger N-acetyl-L-cysteine (NAC). Furthermore, necroptotic genes of receptor-interacting protein kinase-3 (RIPK3), classical mixed lineage kinase domain-like protein-dependent (MLKL), IL-1β and TNF-α were up-regulated, whereas RIPK1 was down-regulated, which was attenuated by the RIPK3 inhibitor GSK872. These findings demonstrate that Cd or BDE-47 alone produces kidney toxicities, and co-exposure poses an additive effect, resulting in AKI via inducing oxidative stress and regulating RIPK3-dependent necroptosis, which offers a further mechanistic understanding for kidney damage, and the combined effect of environmental pollutants should be noticed.

Cadmium exposure induces necroptosis of porcine spleen via ROS-mediated activation of STAT1/RIPK3 signaling pathway

Cadmium (Cd), a heavy metal, is used in a wide range of applications, such as plastics, electroplating process, electronics, and so forth. Due to its bioaccumulation ability, Cd can contaminate soil, water, air and food. To determine the effect of Cd exposure on the necroptosis in pig spleen and its mechanistic investigation, we constructed a model in pigs by feeding them food containing 20 mg/kg Cd. In this study, we analyzed the effects of Cd exposure on pig spleen through HE staining, Quantitative real-time PCR (qRT-PCR), Western blot (WB), and principal component analysis (PCA). Results show that Cd exposure can destroy the structure and function of pig spleen, which is closely related to necroptosis. Further results show that Cd exposure can induce necroptosis through ROS-mediated activation of Signal transducer and activator of transcription 1/Receptor-Interacting Serine/Threonine-Protein Kinase 3 (STAT1/RIPK3) signaling pathway in pig spleen. Additionally, Cd exposure also can affect the stability of mitochondrial-associated endoplasmic reticulum membrane (MAMs) structure, which also contributes to the process of necroptosis. Our study provides insights into the physiological toxicity caused by Cd exposure.

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.

Selenium alleviates cadmium-induced oxidative stress, endoplasmic reticulum stress and programmed necrosis in chicken testes

Cadmium (Cd) is a common heavy metal pollutant, and one of the important target organs of its toxicity is the testis. Selenium (Se) has the ability to antagonize the toxicity of Cd. However, the mechanism of the alleviating effects of Se on Cd in chicken testis injury through oxidative stress, endoplasmic reticulum stress (ERS), and programmed necrosis remained unclear. To explore this, 80 7-day-old chickens were divided into the Control group, the Se group (1.00 mg/kg Se), the Cd group (150.00 mg/kg Cd), and the CdSe group. On the 30th and 60th days, serum and chicken testis tissue samples were collected for testing. The results showed that Cd exposure resulted in swelling and deformation of seminiferous tubules, and thinning of the seminiferous epithelium. The ROS and MDA increased, and the SOD, CAT, GSH, GSH-Px decreased. The expression of GRP78, PERK, IRE1, ATF6, CHOP, and JNK in the Cd group increased. The expression of TNF-α, TNFR1, RIP1, RIP3, MLKL, and PARP1 increased, while the expression of Caspase-8 decreased. Histopathological changes, oxidative stress, ERS, and programmed necrosis were improved after CdSe treatment. In conclusion, Se antagonized the toxicity of Cd, and Se could alleviate Cd-induced oxidative stress, ERS, and programmed necrosis in chicken testis.

Ferroptosis Inhibitors Suppress Prostaglandin Synthesis in Lipopolysaccharide-Stimulated Macrophages

Necrostatin-1 blocks ferroptosis via an unknown mechanism and necroptosis through inhibition of receptor-interacting protein kinase-1 (RIP1). We report that necrostatin-1 suppresses cyclooxygenase-2-dependent prostaglandin biosynthesis in lipopolysaccharide-treated RAW264.7 macrophages (IC₅₀ ∼ 100 μM). This activity is shared by necrostatin-1i (IC₅₀ ∼ 50 μM), which lacks RIP1 inhibitory activity, but not the RIP1 inhibitors necrostatin-1s or deschloronecrostatin-1s. Furthermore, we show that the potent ferroptosis inhibitors and related compounds ferrostatin-1, phenoxazine, phenothiazine, and 10-methylphenothiazine strongly inhibit cellular prostaglandin biosynthesis with IC₅₀'s in the range of 30 nM to 3.5 μM. None of the compounds inhibit lipopolysaccharide-mediated cyclooxygenase-2 protein induction. In the presence of activating hydroperoxides, the necrostatins and ferroptosis inhibitors range from low potency inhibition to stimulation of in vitro cyclooxygenase-2 activity; however, inhibitory potency is increased under conditions of low peroxide tone. The ferroptosis inhibitors are highly effective reducing substrates for cyclooxygenase-2's peroxidase activity, suggesting that they act by suppressing hydroperoxide-mediated activation of the cyclooxygenase active site. In contrast, for the necrostatins, cellular prostaglandin synthesis inhibition does not correlate with peroxidase-reducing activity but rather with the presence of a thiohydantoin substituent, which conveys the ability to reduce the endoperoxide intermediate prostaglandin H₂ to prostaglandin F_2α in vitro. This finding suggests that necrostatin-1 blocks cellular prostaglandin synthesis and ferroptosis via a redox mechanism distinct from action as a one-electron donor. The results indicate that a wide range of compounds derived from redox-active chemical scaffolds can block cellular prostaglandin biosynthesis.