Yan Yuan

Cadmium (Cd) is a toxic, non-essential metal that primarily enters animal bodies through the digestive and respiratory systems, leading to damage to multiple organs and tissues. Cd can accumulate in cartilage and induce damage to chondrocytes. Procyanidins (PAs), also known as concentrated tannic acid or oligomeric proanthocyanidins (OPCs), exhibit diverse biological and pharmacological activities. However, the mechanism of OPCs alleviates Cd-induced damage to chondrocytes in chickens remains to be further explored in vitro. Chondrocytes were isolated from both ends of the tibia of 17-day-old SPF chicken embryos, and then subsequently treated with various concentrations of Cd (0, 1, 2.5, 5, and 10 μmol/L) or OPCs (0, 5, 10, 20, and 40 μmol/L) to investigate the mechanism underlying extracellular matrix (ECM) degradation and damage. Cd reduced cell viability, glycosaminoglycan (GAG) secretion, and ECM degradation in chondrocytes by decreasing the expression of type II collagen alpha 1 (COL2A1) and aggrecan (ACAN) while increasing the release of cartilage oligomeric matrix protein (COMP), along with elevated levels of matrix-degrading enzymes, such as matrix metalloproteinases 1 (MMP1), MMP10, and MMP13, and a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS4) and ADAMTS5. Cd induced phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2) and the expression of matrix-degrading enzymes, impairing ECM synthesis, an effect that could be alleviated by ERK1/2 inhibitor U0126. Chondrocytes were treated with 5 μmol/L Cd and 10 μmol/L OPCs, and it was found that OPCs inhibited the activation of the ERK1/2 signaling pathway and the expression of matrix-degrading enzymes, while promoting ECM synthesis and alleviating Cd-induced ECM damage in chickens. This study provides a theoretical basis for clinical research on OPCs with respect to the prevention and treatment of Cd-induced chondrogenic diseases in poultry.

Zearalenone (ZEA), a mycotoxin widely present in crops and food, poses a major threat to animal and human health. The consumption of ZEA-contaminated food or feed causes intestinal damage. Therefore, exploring how to mitigate the intestinal damage caused by its ZEA is becoming increasingly important. Resveratrol (RSV), a polyphenol compound, mainly exists in Vitis vinifera, Polygonum cuspidatum, Arachis hypogaea, and other plants. It has potent anti-inflammatory and antioxidant activity. The primary objective of this study was to assess the defensive effects of RSV and its molecular mechanism on the intestinal mucosal injury induced by ZEA exposure in mice. The results showed that RSV pretreatment significantly reduced serum DAO and that D-lactate levels altered intestinal morphology and markedly restored TJ protein levels, intestinal goblet cell number, and MUC-2 gene expression after ZEA challenge. In addition, RSV significantly reversed serum pro-inflammatory factor levels and abnormal changes in intestinal MDA, CAT, and T-SOD. Additional research demonstrated that RSV decreased inflammation by blocking the translocation of nuclear factor-kappaB (NF-κB) p65 and decreased oxidative stress by activating the nuclear factor E2-related factor 2 (Nrf2) pathway and its associated antioxidant genes, including NQO1, γ-GCS, and GSH-PX. In summary, RSV supplementation attenuates intestinal oxidative stress, inflammation, and intestinal barrier dysfunction induced by ZEA exposure by mediating the NF-κB and Nrf2/HO-1 pathways.

The potential impact of the combination of a high‐fat diet (HFD) and polystyrene nanoplastics (PS‐NPs) on fertility cannot be ignored, especially when the fertility rate is declining. However, it has not attracted considerable attention. In this study, an obese mouse model was established using an HFD, and the reproductive function of male mice was evaluated after intragastric administration of 100 μL of a 10 mg/mL PS‐NP suspension for 4 weeks. By determining the morphology and vitality of sperm and related indicators of testosterone production, it was found that PS‐NPs aggravated the destruction of sperm mitochondrial structure, decrease sperm activity, and testosterone production in HFD‐fed mice. To comprehensively analyze the injury mechanism, the integrity of the blood testicular barrier (BTB) and the function of Leydig and Sertoli cells were further analyzed. It was found that PS‐NPs could destroy BTB, promote the degeneration of Leydig cells, reduce the number of Sertoli cells, and decrease lactate secretion in HFD‐fed mice. PS‐NPs further interfered with redox homeostasis in the testicular tissues of HFD‐fed mice. This study found that PS‐NPs could aggravate the damage to the reproductive system of obese male mice by further perturbing its redox homeostasis and revealed the potential health risk of PS‐NPs exposure under an HFD.

Vitamin D is a lipid soluble vitamin that is mostly used to treat bone metabolism-related diseases. In this study, the effect of Cd toxicity in vitro on osteogenic differentiation derived from BMSCs and the alleviating effect of lα, 25-(OH)₂D₃ were investigated. Cell index in real time was monitored using a Real-time cell analyzer (RTCA) system. The activity of alkaline phosphatase (ALP), and the calcified nodules and the distribution of Runx2 protein were detected using ALP staining, alizarin red staining, and immunofluorescence, respectively. Furthermore, the mitochondrial membrane potential and the apoptotic rate of BMSCs, the mRNA levels of RUNX2 and type Ⅰ collagen alpha2 (COL1A2) genes, and the protein expression of Col1 and Runx2 were detected using flow cytometry, qRT-PCR and western blot, respectively. The proliferation of BMSCs and osteogenic differentiation were enhanced after treatment with different concentrations of lα, 25-(OH)₂D₃ compared with the control group. However, 5 μmol/L Cd inhibited the proliferation of BMSCs. In addition, 10 nmol/L lα,25-(OH)₂D₃ attenuated the toxicity and the apoptosis of BMSCs treated by Cd, and also promoted the osteogenic differentiation including the activity of ALP, and the protein expression of Col1 and Runx2. lα, 25-(OH)₂D₃ can alleviate cadmium-induced osteogenic toxicity in White Leghorn chickens in vitro.

Zearalenone (ZEA) and deoxynivalenol (DON) are two common mycotoxins produced by the genus Fusarium and have potential immunotoxic effects that may lead to a weak immune response against bacterial infections. Listeria monocytogenes (L. monocytogenes), a food-borne pathogenic microorganism ubiquitous in the environment, actively multiplies in the liver, where hepatocytes are capable of resistance through mediated innate immune responses. At present, it is not clear if ZEA and DON affect hepatocyte immune responses to L. monocytogenes infection or the mechanisms involved. Therefore, in this study, in vivo and in vitro models were used to investigate the effects of ZEA and DON on the innate immune responses of hepatocytes and related molecules after L. monocytogenes infection. In vivo studies revealed that ZEA and DON inhibited the toll-like receptors 2 (TLR2)/nuclear factor kappa-B (NFκB) pathway in the liver tissue of L. monocytogenes-infected mice, downregulating the expression levels of Nitric oxide (NO), in the liver and repressing the immune response. In addition, ZEA and DON inhibited Lipoteichoic acid (LTA)-induced expression of TLR2 and myeloid differentiation factor 88 (MyD88) in Buffalo Rat Liver (BRL 3A) cells in vitro, downregulating the TLR2/NFκB signaling pathway and resulting in the decreased expression levels of NO, causing immunosuppressive effects. In summary, ZEA and DON can negatively regulate NO levels through TLR2/NFκB, inhibiting the innate immune responses of the liver, and aggravate L. monocytogenes infections in mouse livers.

Autophagic dysfunction is one of the main mechanisms of cadmium (Cd)-induced neurotoxicity. Puerarin (Pue) is a natural antioxidant extracted from the medicinal and edible homologous plant Pueraria lobata. Studies have shown that Pue has neuroprotective effects in a variety of brain injuries, including Cd-induced neuronal injury. However, the role of Pue in the regulation of autophagy to alleviate Cd-induced injury in rat cerebral cortical neurons remains unclear. This study aimed to elucidate the protective mechanism of Pue in alleviating Cd-induced injury in rat cerebral cortical neurons by targeting autophagy. Our results showed that Pue alleviated Cd-induced injury in rat cerebral cortical neurons in vitro and in vivo. Pue activates autophagy and alleviates Cd-induced autophagic blockade in rat cerebral cortical neurons. Further studies have shown that Pue alleviates the Cd-induced inhibition of autophagosome–lysosome fusion, as well as the inhibition of lysosomal degradation. The specific mechanism is related to Pue alleviating the inhibition of Cd on the expression levels of the key proteins Rab7, VPS41, and SNAP29, which regulate autophagosome–lysosome fusion, as well as the lysosome-related proteins LAMP2, CTSB, and CTSD. In summary, these results indicate that Pue alleviates Cd-induced autophagic dysfunction in rat cerebral cortical neurons by alleviating autophagosome–lysosome fusion dysfunction and lysosomal degradation dysfunction, thereby alleviating Cd-induced neuronal injury.