Cadmium Toxicity on Chondrocytes and the Palliative Effects of 1α, 25-Dihydroxy Vitamin D3 in White Leghorns Chicken's Embryo

Angelica sinensis polysaccharides mitigate cadmium-induced apoptosis in layer chicken chondrocytes by inhibiting the JNK signaling pathway

Cadmium (Cd), a toxic heavy metal pollutant, inflicts widespread damage on various organs and tissues, including cartilage, where it induces chondrocyte apoptosis. Angelica sinensis polysaccharides (ASP), a key active component of the traditional Chinese medicine Angelica sinensis, have been shown to possess anti-apoptotic effects on chondrocytes. This study investigates the in vitro effects of ASP on alleviating Cd-induced apoptosis in layer chicken chondrocytes, focusing on the mitochondrial apoptosis pathway mediated by the c-Jun N-terminal kinase (JNK) signaling pathway. Chondrocytes were isolated from layer chicken embryos and confirmed to express collagen type II alpha 1 (Col2a1). We found that Cd triggered apoptosis in the chondrocytes; however, the use of the JNK inhibitor SP 600125 mitigated mitochondrial structural damage casused by Cd, indicating the involvement of JNK signaling in this process. Furthermore, ASP effectively alleviated Cd-induced apoptosis in layer chicken chondrocytes by inhibiting JNK signaling in vitro. Our findings provide a theoretical foundation for the clinical application of ASP in preventing Cd-induced cartilage diseases in poultry.

Heavy metal contamination in eggs on poultry farms and ecological risk assessment around a gold mine area in northern Thailand

The aim of this study was to analyze and compare the Hg, Pb, Cd, and Mn levels in egg feed, soil, and water among laying hens, laying ducks, and free-grazing duck farms in contaminated and uncontaminated areas. This study revealed that the Hg concentration in the eggs of free-grazing ducks was significantly greater than that in the eggs of laying hens and ducks in both contaminated and uncontaminated areas. However, the Pb and Mn levels in the eggs of laying ducks and free-grazing ducks were significantly greater than those in the eggs of laying hens in the contaminated area. Unfortunately, the Hg, Pb, Cd, and Mn concentrations in the feed, soil, and water from these three farms in both areas were not significantly different (P > 0.05). Hg and Cd were confirmed to be enriched in the egg albumin fraction, while Pb and Mn were found mainly in the egg yolk. However, egg consumption from free-grazing duck farms was the riskiest to Hg, Pb, and Mn contamination in the contaminated area. Additionally, the ecological risk factor (ER) in the soil revealed that all the farms were at considerable to high environmental risk for Cd except for Hg and Pb. Although the potential ecological risk index (RI) indicated a moderate risk for all farms in both contaminated and uncontaminated areas, these results were not consistent with our hypothesis. Therefore, the information gained in this study could be useful for setting up mitigation strategies and making decisions about public health concerns related to health hazards, especially for ecological risk assessments of heavy metal contamination.

Molecular mechanisms of environmental pollutant-induced cartilage damage: from developmental disorders to osteoarthritis

The objective of the present study was to review the molecular mechanisms of the adverse effects of environmental pollutants on chondrocytes and extracellular matrix (ECM). Existing data demonstrate that both heavy metals, including cadmium (Cd), lead (Pb), and arsenic (As), as well as organic pollutants, including polychlorinated dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCB), bisphenol A, phthalates, polycyclic aromatic hydrocarbons (PAH), pesticides, and certain other organic pollutants that target cartilage ontogeny and functioning. Overall, environmental pollutants reduce chondrocyte viability through the induction apoptosis, senescence, and inflammatory response, resulting in cell death and impaired ECM production. The effects of organic pollutants on chondrocyte development and viability were shown to be mediated by binding to the aryl hydrocarbon receptor (AhR) signaling and modulation of non-coding RNA expression. Adverse effects of pollutant exposures were observed in articular and growth plate chondrocytes. These mechanisms also damage chondrocyte precursors and subsequently hinder cartilage development. In addition, pollutant exposure was shown to impair chondrogenesis by inhibiting the expression of Sox9 and other regulators. Along with altered Runx2 signaling, these effects also contribute to impaired chondrocyte hypertrophy and chondrocyte-to-osteoblast trans-differentiation, resulting in altered endochondral ossification. Several organic pollutants including PCDD/Fs, PCBs and PAHs, were shown to induce transgenerational adverse effects on cartilage development and the resulting skeletal deformities. Despite of epidemiological evidence linking human environmental pollutant exposure to osteoarthritis or other cartilage pathologies, the data on the molecular mechanisms of adverse effects of environmental pollutant exposure on cartilage tissue were obtained from studies in laboratory rodents, fish, or cell cultures and should be carefully extrapolated to humans, although they clearly demonstrate that cartilage should be considered a putative target for environmental pollutant toxicity.

Associations of Blood Cadmium Levels With Osteoarthritis Among US Adults in NHANES 2013-2018

BACKGROUND

Osteoarthritis (OA) is a global public health problem, and limited information is available on the effects of Cd on OA. The purpose of this study is to explore the relationship between Cd and OA.

METHOD

Weighted multivariable logistic regression model, trend test, restricted cubic spline, and stratified analysis were used to study the association between BCd and OA.

RESULTS

In the two regression models of weighted multivariable logistic regression analysis, the correlation between BCd and OA was positive. Compared with the lowest quartile of BCd exposure, the highest quartile had a 2.03-fold (95% confidence interval, 1.67 to 2.47), displaying a dose-response relationship (P for trend <0.00001). The restrictive cubic spline shows a positive linear relationship between BCd and OA.

CONCLUSION

There was a positive linear relationship between BCd and OA and a dose-response relationship.

The Effects of Seleno-Methionine in Cadmium-Challenged Human Primary Chondrocytes

Cadmium (Cd) is a potentially toxic element able to interfere with cellular functions and lead to disease or even death. Cd accumulation has been demonstrated in cartilage, where it can induce damage in joints. The aim of this study was to evaluate the effect of CdCl2 on primary cultures of human chondrocytes and the possible protective effect of seleno-methionine (Se-Met). Human primary articular chondrocytes were cultured and treated as follows: control groups, cells challenged with 7.5 μM and 10 μM CdCl2 alone, and cells pretreated with 10 and 20 μM Se-Met and then challenged with 7.5 μM and 10 μM CdCl2. Twenty-four hours after incubation, cell viability, histological evaluation with hematoxylin-eosin stain, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay were performed. Furthermore, reverse transcription-PCR was carried out to evaluate mRNA levels of BAX, BAK1, CASP-3, and CASP-9. After CdCl2 challenge at both doses, a reduced cell viability and an overexpression of BAX, BAK1, CASP-3, and CASP-9 genes, as well as a high number of TUNEL-positive cells, were demonstrated, all parameters becoming higher as the dose of CdCl2 was increased. The pretreatment with Se-Met lowered the expression of all considered genes, improved cell viability and morphological changes, and reduced the number of TUNEL-positive cells. It was concluded that Se-Met plays a protective role against CdCl2-induced structural and functional changes in chondrocytes in vitro, as it improved cell viability and showed a positive role in the context of the apoptotic pathways. It is therefore suggested that a translational, multifaceted approach, with plant-based diets, bioactive functional foods, nutraceuticals, micronutrients, and drugs, is possibly advisable in situations of environmental pollution caused by potentially toxic elements.

Vitamin D Alleviates Cadmium-Induced Inhibition of Chicken Bone Marrow Stromal Cells' Osteogenic Differentiation In Vitro

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.

Molecular cloning, expression analysis and functional characterization of chicken cytochrome P450 27A1: A novel mitochondrial vitamin D3 25-hydroxylase

Vitamin D₃ is hydroxylated by cytochrome P450 (CYP) before exerting biological effects. The chicken CYP involved in vitamin D₃ 25-hydroxylation has yet to be cloned, and little is known about its functional characteristics, tissue distribution, and cellular expression. We identified a novel, full-length CYP27A1 gene cloned from chicken hepatocyte cDNA that encodes a putative protein of 518 amino acids. Swiss modeling revealed that chicken CYP27A1 has a classic open-fold form. Multisequence homology alignment determined that CYP27A1 contains conserved motifs for substrate recognition and binding. Quantitative real-time PCR analysis in 2-mo-old Partridge Shank broilers demonstrated that CYP27A1 mRNA levels were highest in the liver, followed by the thigh muscles, the breast muscles, and kidneys. The transcripts of CYP27A1 in breast muscles were significantly higher in males than in females. A subcellular localization analysis demonstrated that CYP27A1 was mainly expressed in the mitochondria. In vitro enzyme assays suggested that recombinant CYP27A1 hydroxylates vitamin D₃ at the C-25 position to form 25-hydroxyvitamin D₃ (25(OH)D₃). The K_m and V_max values for CYP27A1-dependent vitamin D₃ 25-hydroxylation were estimated to be 4.929 μM and 0.389 mol min^-1 mg^-1 protein, respectively. In summary, these results suggest that CYP27A1 encodes a mitochondrial CYP that plays an important physiologic role in the 25-hydroxylation of vitamin D₃ in chickens, providing novel insights into vitamin D₃ metabolism in this species.

Maternal blood metal concentrations are associated with matrix metalloproteinases (MMPs) among pregnant women in Puerto Rico

BACKGROUND/AIM

Matrix metalloproteinases (MMPs) are important regulators of uterine remodeling, a critical process for healthy pregnancies, and studies have revealed a link between an imbalance in MMPs and adverse birth outcomes. Toxicological studies have indicated that exposure to heavy metals can alter the levels of inflammatory cytokines, including MMPs. Despite growing evidence, the clear association between heavy metal exposure and MMPs has yet to be explored extensively in human populations. To have a better understanding of the association, in this study, we assessed associations between maternal blood metal levels with MMPs among 617 pregnant women in the Puerto Rico PROTECT birth cohort.

METHODS

We measured blood concentrations for 11 metals in the first and/or second trimester of pregnancy using ICP-MS. MMPs (MMP1, MMP2, and MMP9) were quantified using a customized Luminex assay. Linear mixed effects models (LMEs) were used to regress MMPs on metals and included random intercepts for study participants to account for correlated repeated outcome measures. Fetal sex effects were estimated using interaction terms between metal exposure variables and fetal sex indicators.

RESULTS

We observed significant associations between cesium, manganese, and zinc with all the MMPs that were measured. We also observed differences in metal-MMPs associations by fetal sex. Cobalt was positively associated with MMP1 only in women with male fetuses, and cesium was negatively associated with MMP1 only in women with female fetuses. MMP2 had significant associations with maternal blood metal concentrations only in women with female fetuses.

CONCLUSION

Certain metals were significantly associated with MMPs that are responsible for uterine remodeling and healthy pregnancies. Most of these associations differed by fetal sex. This study highlighted significant metal-MMPs associations that may inform research on new avenues for understanding heavy metal-induced adverse birth outcomes and the development of diagnostic tools.

The Impact of Trace Elements on Osteoarthritis

Osteoarthritis (OA) is a progressive degenerative disease characterized by cartilage degradation, synovial inflammation, subchondral sclerosis and osteophyte formation. It has a multifactorial etiology with potential contributions from heredity, endocrine function, abnormal mechanical load and nutrition. Of particular considerations are trace element status. Several trace elements, such as boron and magnesium are essential for normal development of the bone and joint in human. While cadmium correlates with the severity of OA. The present review focuses on the roles of trace elements (boron, cadmium, copper, iron, magnesium, manganese, selenium, zinc) in OA and explores the mechanisms by which they act.

The Role of Galectin-3 in 1α,25(OH)2D3-Regulated Osteoclast Formation from White Leghorn Chickens In Vitro

Bones play an important role in maintaining the level of calcium in blood. They provide support for soft tissues and hematopoiesis and undergo continuous renewal throughout life. In addition, vitamin D is involved in regulating bone and calcium homeostasis. Galectin-3 (Gal-3) is a β-galactoside-binding protein that can regulate bone cell differentiation and function. Here, we aimed to study the regulatory effects of Gal-3 on vitamin-D-regulated osteoclastogenesis and bone resorption in chicken. Gal-3 expression in bone marrow stromal cells (BMSCs) from 18-day-old chicken embryos was inhibited or overexpressed. BMSCs were then co-cultured with bone marrow monocytes/macrophages (BMMs) with or without addition of 1α,25(OH)₂D₃. The results showed that 1α,25(OH)₂D₃ upregulated the expression of Gal-3 mRNA and receptor activator of nuclear-factor κB ligand (RANKL) expression in BMSCs and promoted osteoclastogenesis, as shown by the upregulated expression of osteoclast (OC) markers (CtsK, CAII, MMP-9, and TRAP) and increased bone resorption, a method for measuring the bone resorption area in vitro. Knockdown of Gal-3 by small-interfering RNA (siRNA) in BMSCs downregulated the expression of RANKL mRNA and attenuated the effects of 1α,25(OH)₂D₃ on osteoclastogenesis and bone resorption. Conversely, overexpression of Gal-3 in BMSCs enhanced the effects of osteoclastogenesis and bone resorption by increasing the expression of RANKL mRNA. These results demonstrated that Gal-3 mediates the differentiation and bone resorption of osteoclasts regulated by 1α,25(OH)₂D₃.