Selenium protects against cadmium-induced cardiac injury by attenuating programmed cell death via PI3K/AKT/PTEN signaling

Selenomethionine modulates the JAK2 / STAT3 / A20 pathway through oxidative stress to alleviate LPS-induced pyroptosis and inflammation in chicken hearts

Selenium (Se) is involved in many physiopathologic processes in humans and animals and is strongly associated with the development of heart disease. Lipopolysaccharides (LPS) are cell wall components of gram-negative bacteria that are present in large quantities during environmental pollution. To investigate the mechanism of LPS-induced cardiac injury and the efficacy of the therapeutic effect of SeMet on LPS, a chicken model supplemented with selenomethionine (SeMet) and/or LPS treatment, as well as a primary chicken embryo cardiomyocyte model with the combined effect of SeMet / JAK2 inhibitor (INCB018424) and/or LPS were established in this experiment. CCK8 kit, Trypan blue staining, DCFH-DA staining, oxidative stress kits, immunofluorescence staining, LDH kit, real-time fluorescence quantitative PCR, and western blot were used. The results proved that LPS exposure led to ROS explosion, hindered the antioxidant system, promoted the expression of the JAK2 pathway, and increased the expression of genes involved in the pyroptosis pathway, inflammatory factors, and heat shock proteins (HSPs). Upon co-treatment with SeMet and LPS, SeMet reduced LPS-induced pyroptosis and inflammation and restored the expression of HSPs by inhibiting the ROS burst and modulating the antioxidant capacity. Co-treatment with INCB018424 and LPS resulted in inhibited of the JAK2 pathway, attenuating pyroptosis, inflammation, and high expression of HSPs. Thus, LPS induced pyroptosis, inflammation, and changes in HSPs activity by activating of the JAK2 / STAT3 / A20 signaling axis in chicken hearts. Moreover, SeMet has a positive effect on LPS-induced injury. This work further provides a theoretical basis for treating cardiac injury by SeMet.

Role of long noncoding RNAs in pathological cardiac remodeling after myocardial infarction: An emerging insight into molecular mechanisms and therapeutic potential

Myocardial infarction (MI) is the leading cause of heart failure (HF), accounting for high mortality and morbidity worldwide. As a consequence of ischemia/reperfusion injury during MI, multiple cellular processes such as oxidative stress-induced damage, cardiomyocyte death, and inflammatory responses occur. In the next stage, the proliferation and activation of cardiac fibroblasts results in myocardial fibrosis and HF progression. Therefore, developing a novel therapeutic strategy is urgently warranted to restrict the progression of pathological cardiac remodeling. Recently, targeting long non-coding RNAs (lncRNAs) provided a novel insight into treating several disorders. In this regard, numerous investigations have indicated that several lncRNAs could participate in the pathogenesis of MI-induced cardiac remodeling, suggesting their potential therapeutic applications. In this review, we summarized lncRNAs displayed in the pathophysiology of cardiac remodeling after MI, emphasizing molecular mechanisms. Also, we highlighted the possible translational role of lncRNAs as therapeutic targets for this condition and discussed the potential role of exosomes in delivering the lncRNAs involved in post-MI cardiac remodeling.

Selenium attenuated food borne cadmium-induced intestinal inflammation in red swamp crayfish (Procambarus clarkii) via regulating PI3K/Akt/NF-κB pathway

Selenium (Se), an indispensable micronutrient for living organisms, has been extensively studied for its heavy metal-detoxifying properties in diverse biological systems and tissues. Nevertheless, it is not entirely certain whether Se can effectively protect against Cadmium (Cd)-induced gut inflammation, especially in aquatic animals. In this study, we employed various approaches, including transcriptome profiling, histological examinations, assessment of antioxidant enzyme activities, and analysis of gut microbiota composition to investigate the effects on crayfish growth and intestinal health after exposure to dietary Cd (15 mg kg-1 diet) and Se (15 mg kg-1 diet) individually or in combination for 8 weeks. The results revealed that dietary Cd exposure resulted in reduced body weight and survival rates, along with an increased occurrence of intestinal inflammation. Nevertheless, Se supplementation proved effective in mitigating the adverse effects of Cd on growth and gut health. Se exhibited a remarkable ability to counteract the disruption of gut antioxidant abilities induced by dietary Cd, as evidenced by the observed increases in ROS and MDA contents, decrease in GSH levels, and inhibition of antioxidative enzyme activities. At the concentration of 6 mg kg-1 in the diet, Se was found beneficial for maintaining gut microbiota richness and diversity. Among them, Flavobacterium, Thermomonas, and Chloronema displayed a weak negative correlation with the rate of gut inflammation. Meanwhile, the levels of short chain fatty acids (SCFAs), including acetic acid (AA) and butanoic acid (BA), showed a significant increase in the Se-Cd group compared to the Cd-only group. Furthermore, transcriptome analysis exhibited significant responses of the PI3K/Akt and NF-κB pathways following crayfish exposure to dietary Se and Cd, either separately or in combination. In short, this study provides a new evidence regarding the molecular mechanisms through which Se could regulate the PI3K/Akt and NF-κB pathways, either directly or indirectly via ROS and SCFAs, thereby alleviating Cd-induced gut inflammation in crayfish.

Enhancement of cardiac angiogenesis in a myocardial infarction rat model using selenium alone and in combination with PTXF: the role of Akt/HIF-1α signaling pathway

Ischemic heart diseases such as myocardial infarction (MI) are a global health problem and a leading cause of mortality worldwide. Angiogenesis is an important approach for myocardial healing following ischemia. Thus, this study aimed to explore the potential cardiac angiogenic effects of selenium (Se), alone and in combination with the tumor necrosis factor-alpha inhibitor, pentoxifylline (PTXF), via Akt/HIF-1α signaling. MI was induced in rats using two subcutaneous doses of isoprenaline (ISP) at a 24-h interval (150 mg/kg). One week later, rats were orally given Se (150 µg/kg/day), PTXF (50 mg/kg/day), or Se/PTXF combination. ISP-induced myocardial damage was evident by increased HW/TL ratios, ST segment elevation, and increased serum levels of CK-MB, LDH, and troponin-I. ISP increased the cardiac levels of the lipid peroxidation marker MDA; the pro-inflammatory cytokines IL-6, IL-1β, and TNF-α; and the pro-apoptotic protein Bax and caspase-3. In contrast, the cardiac levels of the antioxidant markers GSH and SOD and the anti-apoptotic marker Bcl-2 were reduced. Furthermore, ISP markedly increased the cardiac levels of p-Akt and HIF-1α proteins and the cardiac gene expression of ANGPT-1, VEGF, and FGF-2. Treatment with Se both alone and in combination with PTXF ameliorated the ISP-induced myocardial damage and further increased cardiac angiogenesis via Akt/HIF-1α signaling. Se/PTXF combined therapy was more beneficial than individual treatments. Our study revealed for the first time the cardiac angiogenic effects of Se both alone and in combination with PTXF in myocardial infarction, suggesting that both may be promising candidates for clinical studies.

The Role of Trace Elements in Cardiovascular Diseases

Essential trace elements play an important role in human physiology and are associated with various functions regulating cellular metabolism. Non-essential trace elements, on the other hand, often have well-documented toxicities that are dangerous for the initiation and development of diseases due to their widespread occurrence in the environment and their accumulation in living organisms. Non-essential trace elements are therefore regarded as serious environmental hazards that are harmful to health even in low concentrations. Many representatives of these elements are present as pollutants in our environment, and many people may be exposed to significant amounts of these substances over the course of their lives. Among the most common non-essential trace elements are heavy metals, which are also associated with acute poisoning in humans. When these elements accumulate in the body over years of chronic exposure, they often cause severe health damage in a variety of tissues and organs. In this review article, the role of selected essential and non-essential trace elements and their role in the development of exemplary pathophysiological processes in the cardiovascular system will be examined in more detail.

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.

Cadmium exposure disturbs myocardial lipid signature and induces inflammation in C57BL/6J mice

Cadmium is a highly ubiquitous environmental pollutant that poses a serious threat to human health. In this study, we assessed the cardiotoxicity of Cd exposure and explored the possible mechanisms by which Cd exerts its toxic effects. The results demonstrated that exposure to Cd via drinking water containing CdCl2 10 mg/dL for eight consecutive weeks induced cardiac injury in C57BL/6J mice. The histopathological changes of myocardial hemolysis, widening of myocardial space, and fracture of myocardial fiber were observed. Meanwhile, elevated levels of cardiac enzyme markers and up-regulation of pro-apoptotic genes also indicated cardiac injury after Cd exposure. Non-targeted lipidomic analysis demonstrated that Cd exposure altered cardiac lipid metabolism, resulted in an increase in pro-inflammatory lipids, and changed lipid distribution abundance. In addition, Cd exposure affected the secretion of inflammatory cytokines by activating the NF-κB signaling pathway, leading to cardiac inflammation in mice. Taken together, results of our present study expand our understanding of Cd cardiotoxicity at the lipidomic level and provide new experimental evidence for uncovering the association of Cd exposure with cardiovascular diseases.

Cadmium exposure caused cardiotoxicity in common carps (Cyprinus carpio L.): miR-9-5p, oxidative stress, energetic impairment, mitochondrial division/fusion imbalance, inflammation, and autophagy

Cadmium (Cd), a toxic heavy metal pollutant, is a threat to human and eatable fish health. Common carps are widely cultivated and eaten by humans. However, there are no reports about Cd-damaged common carp hearts. Our experiment attempted to investigate the cardiotoxicity of Cd to common carps by establishing a common carp Cd exposure model. Our results showed that Cd injured hearts. Moreover, Cd treatment induced autophagy via miR-9-5p/Sirt1/mTOR/ULK1 pathway. Cd exposure caused oxidant/antioxidant imbalance and oxidative stress; and led to energetic impairment. Energetic impairment partook in oxidative stress-mediated autophagy through AMPK/mTOR/ULK1 pathway. Furthermore, Cd caused mitochondrial division/fusion imbalance and resulted in inflammatory injury via NF-κB-COX-2-PTGEs and NF-κB-COX-2-TNF-α pathways. Oxidative stress mediated mitochondrial division/fusion imbalance, further induced inflammation and autophagy via OPA1/NF-κB-COX-2-TNF-α-Beclin1 and OPA1/NF-κB-COX-2-TNF-α/P62 pathways under Cd treatment. Taken together, miR-9-5p, oxidative stress, energetic impairment, mitochondrial division/fusion imbalance, inflammation, and autophagy participated in the mechanism of Cd-cardiotoxicity to common carps. Our study revealed harmful effect of Cd on hearts, and provided new information for researches of environmental pollutant toxicity.

Metal-Binding Proteins Cross-Linking with Endoplasmic Reticulum Stress in Cardiovascular Diseases

The endoplasmic reticulum (ER), an essential organelle in eukaryotic cells, is widely distributed in myocardial cells. The ER is where secreted protein synthesis, folding, post-translational modification, and transport are all carried out. It is also where calcium homeostasis, lipid synthesis, and other processes that are crucial for normal biological cell functioning are regulated. We are concerned that ER stress (ERS) is widespread in various damaged cells. To protect cells' function, ERS reduces the accumulation of misfolded proteins by activating the unfolded protein response (UPR) pathway in response to numerous stimulating factors, such as ischemia or hypoxia, metabolic disorders, and inflammation. If these stimulatory factors are not eliminated for a long time, resulting in the persistence of the UPR, it will aggravate cell damage through a series of mechanisms. In the cardiovascular system, it will cause related cardiovascular diseases and seriously endanger human health. Furthermore, there has been a growing number of studies on the antioxidative stress role of metal-binding proteins. We observed that a variety of metal-binding proteins can inhibit ERS and, hence, mitigate myocardial damage.

Pollutant-induced pyroptosis in humans and other animals

Pyroptosis is a form of lytic cell death with pro-inflammatory characteristics, induced upon the activation of certain inflammatory caspases by inflammasome complexes such as NLRP3 inflammasome. Gasdermin proteins as the mediators of pyroptosis form cell membrane pores upon activation, which release certain cellular contents into the extracellular space including inflammatory cytokines such as IL-1β and IL-18, and also damage the integrity of the cell membrane. Gasdermins have been implicated in autoimmune and inflammatory diseases, infectious diseases, deafness and cancer. Mostly in the last 2 years, diverse pollutant types including particulate matter, cadmium and polystyrene microplastics were reported to induce pyroptotic cell death in diverse tissues from mammals to birds. In the present study, we review our current understanding of pollutant-induced pyroptosis as well as current knowledge of upstream events leading to pyroptotic cell death upon exposure to pollutants.

Co-exposure to molybdenum and cadmium triggers pyroptosis and autophagy by PI3K/AKT axis in duck spleens

Excessive amounts of molybdenum (Mo) and cadmium (Cd) are toxicant, but their combined immunotoxicity are not clearly understood. To estimate united impacts of Mo and Cd on pyroptosis and autophagy by PI3K/AKT axis in duck spleens, Mo or/and Cd subchronic toxicity models of ducks were established by feeding diets with different dosages of Mo or/and Cd. Data show that Mo or/and Cd cause oxidative stress by increasing MDA concentration, and decreasing T-AOC, CAT, GSH-Px and T-SOD activities, restrain PI3K/AKT axis by decreasing PI3K, AKT, p-AKT expression levels, which evokes pyroptosis and autophagy by elevating IL-1β, IL-18 concentrations and NLRP3, Caspase-1, ASC, GSDME, GSDMA, NEK7, IL-1β, IL-18 expression levels, promoting autophagosomes, LC3 puncta, Atg5, LC3A, LC3B, LC3II/LC3I and Beclin-1 expression levels, and reducing expression levels of P62 and Dynein. Furthermore, the variations of abovementioned indexes are most pronounced in co-treated group. Overall, results reveal that Mo or/and Cd may evoke pyroptosis and autophagy by PI3K/AKT axis in duck spleens. The association of Mo and Cd exacerbates the changes.

Molybdenum and cadmium co-exposure promotes M1 macrophage polarization through oxidative stress-mediated inflammatory response and induces pulmonary fibrosis in Shaoxing ducks (Anas platyrhyncha)

High molybdenum (Mo) and cadmium (Cd) are harmful to the body, but pulmonary toxicity induced by Mo and Cd co-exposure is unknown. To assess the combined impacts of Mo and Cd on fibrosis through M1 polarization in the lung of ducks, 80 healthy 8-day-old Shaoxing ducks (Anas platyrhyncha) were randomly assigned to 4 groups and fed with containing unequal doses of Mo or/and Cd diet. Lung tissues were collected on the 16th week. Results indicated that Mo or/and Cd significantly increased their contents in the lungs, and led to trace elements disorder and histological abnormality, and oxidative stress accompanied by promoting contents of H₂ O₂ and MDA and decreasing activities of T-SOD, GSH-Px, and CAT, then activated the TLR4/NF-κB/NLRP3 pathway accompanied by upregulating Caspase-1, ASC, IL-18, IL-1β, TLR4, NF-κB, and NLRP3 expression levels, and disrupted M1/M2 balance to divert toward M1, which evoked the TGF-β/Smad2/3-mediated fibrosis by elevating TGF-β1, Smad2, Smad3, COL1A1, α-SMA, and MMP2 expression levels, and decreasing Smad7 and TIMP2 expression levels. The changes of the combined group were most obvious. To sum up, the research demonstrated that Mo or/and Cd may cause macrophages to polarize toward M1 by oxidative stress-mediated the TLR4/NF-κB/NLRP3 pathway, then result in fibrosis through the TGF-β1/Smad2/3 pathway in duck lungs. Mo and Cd may worsen lung damage.

Endoplasmic reticulum stress-controlled autophagic pathway promotes polystyrene microplastics-induced myocardial dysplasia in birds

In complex ecosystems, birds are generally long-lived and occupy high trophic positions, making them good bioindicators for monitoring environmental contaminants. The effects of microplastics (MPs) on myocardial development in bird is currently unknown. Chicks, as a high trophic level terrestrial bird, may be more affected by MPs exposure and. Therefore, we established an in vivo model of chicks exposed to different concentrations of polystyrene microplastics (PS-MPs) and selected 12-day-old chicken embryos in vitro to extract primary cardiomyocytes to further investigate the potential molecular mechanisms of the effect of PS-MPs on myocardial development in birds. Histopathological observations revealed that the PS-MPs treated exhibited loose and irregular myocardial arrangement, large cell gaps and broken myocardial fiber bundles. More mechanistically, TnnT2, Nkx2-5, Gata4, TBX5 and ACTN2 were down-regulated, endoplasmic reticulum (ER) stress markers GRP78, PERK, eIF2α, IRE1, ATF4, ATF6 and CHOP were overexpressed, autophagy-related genes LC3, ATG5, Beclin1 and P62 were down-expressed after PS-MPs exposure, and the addition of 4PBA effectively deregulated the above aberrant expression. Hence, our report indicated that PS-MPs induced myocardial dysplasia in birds is mainly attributed to the ER stress-mediated autophagic pathway. This provided data supporting the protection of birds from the health risks of MPs pollution. More critically, the study of cardiac developmental toxicity in birds may help to better explain or solve the problem of MPs pollution in complex ecosystems.