Gene Silencing of Selenoprotein K Induces Inflammatory Response and Activates Heat Shock Proteins Expression in Chicken Myoblasts

Combination of Phycocyanin, Zinc, and Selenium Improves Survival Rate and Inflammation in the Lipopolysaccharide-Galactosamine Mouse Model

Sepsis is related to systemic inflammation and oxidative stress, the primary causes of death in intensive care units. Severe functional abnormalities in numerous organs can arise due to sepsis, with acute lung damage being the most common and significant morbidity. Spirulina, blue-green algae with high protein, vitamins, phycocyanin, and antioxidant content, shows anti-inflammatory properties by decreasing the release of cytokines. In addition, zinc (Zn) and selenium (Se) act as an antioxidant by inhibiting the oxidation of macromolecules, as well as the inhibition of the inflammatory response. The current study aimed to examine the combined properties of Zn, Se, and phycocyanin oligopeptides (ZnSePO) against lipopolysaccharide-D-galactosamine (LPS-GalN)-induced septic lung injury through survival rate, inflammatory, and histopathological changes in Balb/c mice. A total of 30 mice were allocated into three groups: normal control, LPS-GalN (100 ng of LPS plus 8 mg of D-galactosamine), LPS-GalN + ZnSePO (ZnPic, 52.5 µg/mL; SeMet, 0.02 µg/mL; and phycocyanin oligopeptide (PO), 2.00 mg/mL; at 1 h before the injection of LPS-GalN). Lung tissue from mice revealed noticeable inflammatory reactions and typical interstitial fibrosis after the LPS-GalN challenge. LPS-GalN-induced increased mortality rate and levels of IL-1, IL-6, IL-10, TGF-β, TNF-α, and NF-κB in lung tissue. Moreover, treatment of septic mice LPS-GalN + ZnSePO reduced mortality rates and inflammatory responses. ZnSePO considerably influenced tissue cytokine levels, contributing to its capacity to minimize acute lung injury (ALI) and pulmonary inflammation and prevent pulmonary edema formation in LPS-GalN-injected mice. In conclusion, ZnSePO treatment enhanced the survival rate of endotoxemia mice via improving inflammation and oxidative stress, indicating a possible therapeutic effect for patients with septic infections.

Selenium Deficiency Aggravates Heat Stress Pneumonia in Chickens by Disrupting the M1/M2 Balance

Selenium (Se) is an essential trace element found in the body. Se deficiency and M1/M2 imbalance are closely related to inflammation. Heat stress can decrease immune function and cause inflammation. In order to investigate whether Se deficiency can aggravate pneumonia caused by heat stress and the role of M1/M2 imbalance in the occurrence of pneumonia, 100 AA broilers were divided into two groups and fed the conventional diet (0.2 mg/kg Se) and the Se-deficient diet (0.03 mg/kg Se). After 40 days of feeding, the normal feeding group was randomly divided into a control group and a heat stress group. At the same time, the Se-deficient diet feeding group was randomly divided into a low Se group and a low Se heat stress group, with 25 chickens in each group. The model was established by exposure at 40℃. Six hours later, broilers were euthanized, and their lung tissues were collected. Hematoxylin and eosin staining, immunofluorescence, quantitative real-time PCR, and western blotting were used to detect lung histopathological changes and the expression of M1/M2 markers, nuclear receptor-κB (NF-κB) pathway genes, and heat shock proteins. Meanwhile, the activity and content of oxidative stress-related indices were also detected. We found that the expression of interleukin-1β, interleukin-6, interleukin-12, and tumor necrosis factor-α was upregulated and the expression of interleukin-2, interleukin-10, and interferon-γ was downregulated. Immunofluorescence showed that the expression of CD16 was increased, the expression of CD163 was weakened, and the M1/M2 imbalance was present. In addition, the NF-κB pathway was activated by the increased expressions of heat shock proteins and oxidative stress. There was an increase in malondialdehyde, nitric oxide, and inducible nitric oxide synthase content, while the activity of total antioxidant capacity, glutathione peroxidase, catalase, and superoxide dismutase decreased, and the expression of NF-κB and cyclooxygenase-2 increased. These results suggest that low Se induces M1/M2 imbalance through oxidative stress activation of the NF-κB pathway and aggravates lung tissue inflammation caused by heat stress. This study offers a theoretical basis for exploring the pathogenesis of various kinds of inflammation induced by Se deficiency from the perspective of M1/M2 and provides a reference for the prevention of such diseases.

Selenium-deficient diet induces inflammatory response in the pig adrenal glands by activating TLR4/NF-κB pathway via miR-30d-R_1

Selenium (Se) is an important trace element to maintain the body's dynamic balance. Lack of Se can cause inflammation. Studies have shown that inflammation often leads to disorders of the hypothalamic-pituitary-adrenal axis, but the mechanism by which Se deficiency causes inflammation of the porcine adrenal glands is still unclear. In order to study the effect of Se deficiency on the adrenal glands of pigs, we obtained Se-deficient pig adrenal glands through a low-Se diet. The results of mass spectrometry showed that the Se content in the Se-deficient group was only one-tenth of the control group. We detected the expression of the toll-like receptor 4 (TLR4) and downstream factors by qRT-PCR and Western blotting, and found that the lack of Se affected the TLR4/NF-κB pathway. It is known that miR-155-3p, miR-30d-R_1, and miR-146b have all been verified for targeting relationship with TLR4. We confirmed by qRT-PCR that miR-30d-R_1 decreased most significantly in the Se-deficient pig model. Then we tested 25 selenoproteins and some indicators of oxidative stress. It is confirmed that Se deficiency reduces the antioxidant capacity and induces oxidative stress in pig adrenal tissue. In short, a diet lacking Se induces oxidative stress in pig adrenal tissues and leads to inflammation through the miR-30d-R_1/TLR4 pathway. This study provides a reference for the prevention of adrenal inflammation in pigs from a nutritional point of view.

Effect of mitochondrial quality control on the lycopene antagonizing DEHP-induced mitophagy in spermatogenic cells

Di(2-ethylhexyl) phthalate (DEHP) is a widespread environmental contaminant, which is mainly used as a plasticizer to improve the flexibility of products; however, its extensive use causes male reproductive damage. Lycopene (LYC) has a protective effect on male reproductive toxicity. Nevertheless, the underlying role of LYC in DEHP-induced spermatogenic cell damage remains unclear. Our study aimed to investigate the role of LYC in DEHP-induced spermatogenic cell damage and its underlying mechanism. Male ICR mice were treated with LYC (5 mg kg-1) and/or DEHP (500 mg kg-1 or 1000 mg kg-1) for 28 days. The results showed that LYC alleviated the DEHP-induced decrease in mitochondria volume density and mitochondrial membrane potential (ΔΨm). Subsequently, LYC prevented the DEHP-induced PGC-1α-mediated reduction in mitochondrial biogenesis in spermatogenic cells. LYC exhibited a potential preventive effect against DEHP-induced mitophagy caused by mitochondrial dynamics disorder in the spermatogenic cells. Meanwhile, LYC relieved DEHP-induced mitochondrial stress in the spermatogenic cells by activating UPRmt. These results proved that mitochondrial quality control may be related to the beneficial role of LYC in preventing DEHP-induced mitophagy in spermatogenic cells. This study provides new evidence of mitochondrial quality control as a target for LYC treatment, which can prevent DEHP-induced toxicity.

LncRNA 0003250 accelerates heart autophagy and binds to miR-17-5p as a competitive endogenous RNA in chicken induced by selenium deficiency

Long noncoding RNAs (LncRNAs) have been demonstrated to be associated with a variety of myocardial diseases, but how LncRNAs regulate autophagy in selenium (Se)-deficient myocardial injury is infrequently reported. Here, we screened out a novel long noncoding RNA, microRNA, and ATG7 through transcriptomic results. We employed a Se-deficient chicken model in vivo, and primary cultured cardiomyocytes treated by correlation in vitro. The results showed that Se deficiency upregulated the expression of ATG7, and miR-17-5p inhibited cardiomyocyte autophagy by targeting ATG7. Furthermore, we found that LncRNA 0003250 regulated miR-17-5p, and thus affected the expression of ATG7 and autophagic cell death. Our present study proposed a novel model for the regulation of cardiomyocytes autophagy, which includes LncRNA 0003250, miR-17-5p and ATG7 in the chicken heart. Our conclusions may provide a feasible diagnostic tool for Se-deficient cardiomyocyte injury.

The Role of Selenium in Oxidative Stress and in Nonthyroidal Illness Syndrome (NTIS): An Overview

Selenium is a trace element, nutritionally classified as an essential micronutrient, involved in maintaining the correct function of several enzymes incorporating the selenocysteine residue, namely the selenoproteins. The human selenoproteome including 25 proteins is extensively described here. The most relevant selenoproteins, including glutathione peroxidases, thioredoxin reductases and iodothyronine deiodinases are required for the proper cellular redox homeostasis as well as for the correct thyroid function, thus preventing oxidative stress and related diseases. This review summarizes the main advances on oxidative stress with a focus on selenium metabolism and transport. Moreover, thyroid-related disorders are discussed, considering that the thyroid gland contains the highest selenium amount per gram of tissue, also for future possible therapeutic implication.

The role of necroptosis and apoptosis through the oxidative stress pathway in the liver of selenium-deficient swine

Necroptosis is regarded as a new paradigm of cell death that plays a key role in the liver damage observed with selenium (Se) deficiency.

Di-(2-ethylhexyl) phthalate (DEHP)-induced hepatotoxicity in quail (Coturnix japonica) via suppression of the heat shock response

Di-(2-ethylhexyl) phthalate (DEHP) is a widespread environmental toxicant that severely impacts agricultural production and animal and human health. Nevertheless, DEHP-induced hepatotoxicity at the molecular level in quail remains unexplored. The heat shock response (HSR), involving heat shock proteins (HSPs) and heat shock transcription factors (HSFs), is a highly conserved molecular response that is triggered by stressors, especially exposure to toxicants. To explore the DEHP-induced hepatotoxicity that occurs via regulation of HSR in birds, female quail were dosed with DEHP by oral gavage (0, 250, 500 and 1000 mg/kg) for 45 days. Based on histopathological analysis, the livers of the DEHP-treated groups exhibited structural alterations of hepatocytes, including mitochondrial swelling, derangement of hepatic plates, inflammatory cell infiltration and adipose degeneration. Ultrastructural evaluation of the livers of DEHP-treated quail revealed swollen mitochondria, partial disappearance of mitochondrial membranes and cristae, nuclear chromatin margination and nuclear condensation. The expression of HSF1 and HSF3 significantly decreased after DEHP exposure. The levels of HSPs (HSP10, HSP25, HSP27, HSP40, HSP47, HSP60, HSP70 and HSP90) were significantly downregulated in the livers of DEHP-treated quail. In this study, we concluded that DEHP exposure resulted in liver function damage and hepatotoxicity by reducing the expression of HSFs and HSPs in quail liver, which inhibited the protective effect of the HSR signaling pathway.

Di (2-ethyl hexyl) phthalate (DEHP)-induced kidney injury in quail (Coturnix japonica) via inhibiting HSF1/HSF3-dependent heat shock response

Di (2-ethyl hexyl) phthalate (DEHP) as a plasticizer can leach away from the plastic and hence entrances into the animal food chain which caused serious hazard in organs of animals, but there are few studies on DEHP kidney toxicity. The heat-shock response (HSR) consisting of the HSPs and HSFs plays an important role in various toxicity stress conditions. To investigate the influence on kidney toxicity and the modulation of HSR during DEHP exposure, female quail were fed the diet with 0, 250, 500 and 750 mg/kg DEHP by gavage administration for 45 days. The shrinkages of glomeruli and dilation of kidney tubule epithelia cells were observed in the kidney of DEHP-exposed quail. DEHP treatment could significantly decrease the expressions of HSP25, HSP27, HSP47, HSP60, while the expressions of HSP10, HSP40, HSP70, HSP90, HSP110 were upregulated in the kidney. In addition, the expression levels of HSF1 and HSF3 were significantly increased under DEHP. This is the first study to demonstrate quail exposure to DEHP is in fact detrimental to bird kidney. Besides, DEHP could attack HSR by affecting the synthesis of HSFs to mediate the transcription of the HSPs resulting in kidney damage.

The role of heat shock protein 70 in oxidant stress and inflammatory injury in quail spleen induced by cold stress

The aim of this study was to investigate the role of heat shock protein 70 (Hsp70) in oxidative stress and inflammatory damage in the spleen of quails which were induced by cold stress. One hundred ninety-two 15-day-old male quails were randomly divided into 12 groups and kept at 12 ± 1 °C to examine acute and chronic cold stress. We first detected the changes in activities of antioxidant enzymes in the spleen tissue under acute and chronic cold stress. The activities of glutathione peroxidase (GSH-Px) fluctuated in acute cold stress groups, while they were significantly decreased (p < 0.05) after chronic cold stress. The activities of superoxide dismutase (SOD), inducible nitric oxide synthase (iNOS), and nitric oxide (NO) content were decreased significantly (p < 0.05) in both of the acute and chronic cold stress groups. Malondialdehyde (MDA) content was significantly increased (p < 0.05) under cold stress except the 0.5 h group of acute cold stress. Besides, histopathological analysis showed that quail's spleen tissue was inflammatory injured seriously in both the acute and chronic cold stress groups. Additionally, the inflammatory factors (cyclooxygenase-2 (COX-2), prostaglandin E synthase (PTGES), iNOS, nuclear factor-kappa B (NF-κB), and tumor necrosis factor-a (TNF-α)) and Hsp70 mRNA levels were increased in both of the acute and chronic cold stress groups compared with the control groups. These results suggest that oxidative stress and inflammatory injury could be induced by cold stress in spleen tissues of quails. Furthermore, the increased expression of Hsp70 may play a role in protecting the spleen against oxidative stress and inflammatory damage caused by cold stress.

Copper or/and arsenic induce oxidative stress-cascaded, nuclear factor kappa B-dependent inflammation and immune imbalance, trigging heat shock response in the kidney of chicken

Excessive amount of copper (Cu) and inorganic arsenic (iAs) coexists in drinking water in many regions, this is associated with high risk of nephropathy, defined as chronic structural and functional disorders of the kidney. However, the underlying mechanisms are not well understood. In this study, a total of 72 day-old Hy-line chickens were exposed to 300 mg/kg copper sulphate or/and 30 mg/kg arsenic trioxide for 12 weeks. Indicators of oxidative stress, inflammation and heat shock proteins (HSPs) production were analyzed in kidney. The results showed that, when the toxicant was administrated alone, there is an antagonism between redox homeostasis during the first 4 weeks, which follows a collapse of antioxidant system manifested by damaged biomembrane structure. What's worse, oxidative damage-cascaded histopathological lesions were accompanied by increases of proinflammatory mediators and an imbalance of "Th1/Th2 drift" (Th, helper T cell) regulated by nuclear factor kappa B (NF-κB). Simultaneously, intense heat shock response went with the organism. The above-mentioned renal lesions and indicators changes were time-dependent, more complex and deteriorated effects were observed in Cu/iAs combined groups compared with the others. This study supports Cu and iAs have a synergistic type on the nephro-toxicological process additively. In conclusion, oxidative stress and inflammatory induced by Cu or/and iAs are potential mechanisms in their nephrotoxicity, increased heat shock response may play a renoprotection function in tissues damage.