Cadmium exposure promotes thyroid pyroptosis and endocrine dysfunction by inhibiting Nrf2/Keap1 signaling

Environmental mineral density and thyroid malignancy: A multicenter cross-sectional study

BACKGROUND

Several trace minerals have been shown to be associated with thyroid cancer. Democratic Republic of Congo (DRC) is deemed the most mineral-rich country globally. Data on the characteristics of thyroid nodules in various mineral-rich regions of the DRC is scarce.

AIM

To analyze the differential spectrum of thyroid nodules based on locoregional variance in mineral density.

METHODS

We conducted a cross-sectional study on 529 patients with thyroid nodules residing in Katanga, South Kivu and Kinshasa between 2005 and 2019. Of these three provinces, Katanga and South Kivu have the highest mineral density with the DRC.

RESULTS

Mean patient age was 44.2 years ± 14.6 years with a female predominance, with a female to male ratio of 5.4. The 66.5% of patients had a family history of thyroid disease. Total 74 patients had simple nodules, and the remaining 455 patients had multiple nodules. The 87.7% of patients were euthyroid. The nodules exhibited varying characteristics namely hypoechogenicity (84.5%), solid echostructure (72.2%), macronodular appearance (59.8%), calcifications (14.4%) and associated lymphadenopathy (15.5%). The 22.3% of the nodules were malignant. Factors independently associated with malignancy were older age (≥ 60 years) [adjusted odds ratio (aOR) = 2.81], Katanga province (aOR = 8.19), solid echostructure (aOR = 7.69), hypoechogenicity (aOR = 14.19), macronodular appearance (aOR = 9.13), calcifications (aOR = 2.6) and presence of lymphadenopathy (aOR = 6.94).

CONCLUSION

Thyroid nodules emanating from the mineral-laden province of Katanga were more likely to be malignant. Early and accurate risk-stratification of patients with thyroid nodules residing in high-risk areas could be instrumental in optimizing survival in these patients.

The role of pyroptosis in environmental pollutants-induced multisystem toxicities

The global ecosystem is adversely affected by environmental pollutants, which have numerous deleterious consequences on both the environment and human health. A multitude of human organs and systems, including the neurological, digestive, cardiovascular, reproductive, and respiratory systems, can be adversely affected by these pollutants. Pyroptosis is a form of programmed cell death, primarily involving the Caspase-1/Gasdermin D (GSDMD) classical inflammasome pathway, Caspase-4/5/11/GSDMD non-classical inflammasome pathway, Caspase-3/8 pathway, and other signaling pathways, which induce cell death and regulate the occurrence of inflammatory responses. Pyroptosis plays an important role in a range of diseases, including cancer, neurodegenerative diseases and cardiovascular disease. Evidence has emerged in recent years indicating that environmental pollutants exert various toxic effects by modulating pyroptosis. In this review, we examine hepatotoxicity, cardiovascular toxicity, nephrotoxicity, neurotoxicity, pulmonary toxicity, reproductive toxicity and the related mechanisms caused by environmental pollutants through the regulation of pyroptosis. We aim to provide theoretical references for future toxicity research on environmental pollutants.

Systemic Lupus Erythematosus Exacerbates Hip Arthritis by Promoting Chondrocyte Pyroptosis in the Femoral Head via Activating the NF-κB Pathway

Systemic lupus erythematosus (SLE) is an autoimmune disease characterised by chronic inflammation and immune dysregulation, significantly impacting multiple organ systems, including the joints. While SLE is known to contribute to musculoskeletal complications, its role in hip arthritis development and the underlying mechanisms remain poorly understood. This study aims to investigate the relationship between SLE and hip arthritis progression using MRL/lpr mice, which exhibit early-onset SLE, compared with MRL/MpJ control mice at 14 weeks of age. Through comprehensive histological, immunohistochemical and molecular analyses, we evaluated articular cartilage (AC) degeneration, extracellular matrix (ECM) metabolism, inflammatory responses, and chondrocyte pyroptosis. Our results demonstrated that MRL/lpr mice developed an accelerated hip arthritis-like phenotype, manifesting as enhanced AC degeneration, impaired chondrocyte proliferation, heightened apoptosis and promoted inflammatory cytokine production. Notably, SLE markedly stimulated chondrocyte pyroptosis by increasing pyroptosis-related proteins, including NLRP3, ASC, CASPASE-1 and GSDMD, via activating the NF-κB pathway. These findings establish a novel mechanistic link between SLE and hip arthritis progression, demonstrating that SLE promotes chondrocyte pyroptosis to exacerbate AC degeneration via NF-κB activation, highlighting chondrocyte pyroptosis as a key driver of SLE-associated hip arthritis and a potential therapeutic target for mitigating SLE-induced joint manifestations.

Association between toxic heavy metals and noncancerous thyroid disease: a scoping review

Background

Toxic heavy metals such as chromium (Cr), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) are known to be priority pollutants due to their high degrees of toxicity and widespread presence in the environment. This review aimed to explore the association between heavy metals and noncancerous thyroid diseases by synthesizing findings from observational and experimental studies. This review addressed a critical intersection of environmental health, endocrinology, and public health. The findings would be of interest to a wide range of disciplines given the ubiquitous presence of toxic heavy metals in the environment and their potential to disrupt endocrine systems. The evidence-based information from diverse fields generated from this review will provide insights into the health implications of heavy metal exposure on thyroid function and guide the necessary interdisciplinary research and collaborative interventions.

Method

Three databases were searched, namely PubMed, Web of Science, and Scopus. The Arksey and O'Malley (2005) framework was used as a guide in conducting this scoping review. The reporting was carried out based on the Preferred Reporting Items for Systematic Reviews and the Meta-Analyses Extension for Scoping Reviews (PRISMA). The literature search retrieved 552 articles and 29 articles were included in the final review.

Results

As high as 83% of the 29 included studies followed an observational study design while the rest were experimental animal studies. Among the observational studies, two-thirds (66%) were cross-sectional studies while the rest were case-control studies (31%) and cohort studies (n = 1, 3%). Few number of studies in this review reported a significant association between Cr, As, Cd, Hg, and Pb with noncancerous thyroid diseases (2, 3, 16, 8, and 12) while another few (5, 8, 9, 5, and 11) did not show any significant association.

Conclusion

A heterogeneous and diverse sample population in the included studies could have potentially led to mixed findings about the association between toxic heavy metals and thyroid diseases in this review. Therefore, future research should prioritize longitudinal studies and controlled clinical trials to better elucidate the causative mechanisms and long-term impact of heavy metal exposure on thyroid health.

Effects of Trace Elements on Endocrine Function and Pathogenesis of Thyroid Diseases-A Literature Review

The thyroid gland is an endocrine organ whose hormones enable the proper functioning of the organism. The normal function of this organ is influenced by internal and external factors. One of the external factors is trace elements. Trace elements in appropriate concentrations are necessary for the proper functioning of the thyroid. Fe, Cu, Mn, I, Zn, and Se are part of the enzymes involved in oxidative stress reduction, while Cd, Hg, and Pb can increase ROS production. Cu and Fe are necessary for the correct TPO synthesis. An imbalance in the concentration of trace elements such as Fe, Cu, Co, I, Mn, Zn, Ag, Cd, Hg, Pb, and Se in thyroid cells can lead to thyroid diseases such as Graves' disease, Hashimoto's thyroiditis, hypothyroidism, autoimmune thyroiditis, thyroid nodules, thyroid cancer, and postpartum thyroiditis. Lack of adequate Fe levels may lead to hypothyroidism and cancer development. The thyroid gland's ability to absorb I is reversibly reduced by Co. Adequate levels of I are required for correct thyroid function; both deficiency and excess can predispose to the development of thyroid disorders. High concentrations of Mn may lead to hypothyroidism. Furthermore, Mn may cause cancer development and progression. Insufficient Zn supplementation causes hypothyroidism and thyroid nodule development. Cd affecting molecular mechanisms may also lead to thyroid disorders. Hg accumulating in the thyroid may interfere with hormone secretion and stimulate cancer cell proliferation. A higher risk of thyroid nodules, cancer, autoimmune thyroiditis, and hypothyroidism were linked to elevated Pb levels. Se deficiency disrupts thyroid cell function and may lead to several thyroid disorders. On the other hand, some of the trace elements may be useful in the treatment of thyroid diseases. Therefore, the effects of trace elements on the thyroid require further research.

Cadmium Exposure was Associated with Sex-Specific Thyroid Dysfunction: Consistent Evidence from Two Independent Cross-Sectional Studies Based on Urinary and Blood Cadmium Measurements

Population-based studies on the association between cadmium (Cd) exposure and thyroid function are limited and have shown conflicting results. Two independent cross-sectional studies using different Cd biomarkers were carried out in six rural areas with different soil Cd levels in China. Thyroid dysfunction was defined based on levels of thyroid stimulating hormone (TSH) and free thyroxine (FT4). Multivariable linear regression, multiple logistic regression, and restrictive cubic splines models were used to estimate the association between Cd and thyroid dysfunction. For both of the two independent studies, higher Cd levels were observed to be associated with lower TSH levels and higher risk of thyroid dysfunction. The negative relationship between urinary Cd and TSH was found in both total participants (β =  - 0.072, p = 0.008) and males (β =  - 0.119, p = 0.020) but not in females; however, the negative relationship between blood Cd and TSH was only found in females (β =  - 0.104, p = 0.024). Higher urinary Cd was associated with higher risk of thyroid dysfunction (OR = 1.77, p = 0.031), while higher blood Cd was associated with higher risk of thyroid dysfunction (OR = 1.95, p = 0.011). Results from the two independent cross-sectional studies consistently suggested that higher Cd levels were associated with sex-specific thyroid dysfunction.

Associations Between Heavy Metal Exposure from Milk and Steroid Hormones in Mothers

Environmental exposure to heavy metals is ubiquitous. However, its relationship with steroid hormone levels is not well understood, particularly in pregnant women. This study investigated the association between prenatal heavy metal exposure and steroid hormone levels in an e-waste disposal area in China. We analyzed the Cd, Cr, Mn, Pb, Cu, and As concentrations in 102 human milk samples collected 4 weeks after delivery. Multiple regression analysis was used to assess the associations and interactions between heavy metals and steroidal hormones. We found positive associations between Mn and estrone and estriol (estrone: β = 0.713, 95%CI = 0.046, 1.381 and estriol: β = 1.290, 95%CI = 0.494, 2.085) and between Cd and progesterone (β = 0.280; 95%CI = 0.053, 0.506). We observed negative associations between Cr and estrone and estriol (estrone: β = - 0.757, 95%CI = - 1.473, - 0.041 and estriol: β = - 1.354, 95%CI = - 2.209, - 0.499). At last, we found that Pb was negatively associated with estrone (estrone: β = - 0.537, 95%CI = - 1.053, - 0.020). Our results suggest that exposure to heavy metals may affect steroid hormone levels in mothers living in an e-waste recycling area in China.

Golgi apparatus regulated pyroptosis through the miR-32-5p/Golga7/NLRP3 axis in chicken splenic lymphocytes exposure to ammonia

Ammonia, a common toxic gas, posed a hazard to both human and chickens. The Golgi apparatus, an essential organelle, helped maintain the internal environment of the organism and supported the protein foundation for the endoplasmic reticulum to be involved in pyroptosis. Thus, the Golgi apparatus has garnered significant attention. The purpose of our research was to explore the mechanisms of Golgin A7 (Golga7) involved in pyroptosis after chicken exposure to ammonia. To reach our goal, we first created an in vitro ammonia model to study the effect of ammonia on chicken splenic lymphocyte pyroptosis. Then, leveraging this model, we established Golga7 and miR-32-5p knockdown and overexpression models to investigate their roles in ammonia-induced pyroptosis. We found the ultrastructural changes in the nucleus, Golgi apparatus, and mitochondria of chicken splenic lymphocytes exposure to ammonia. The damage of mitochondria increased the level of Reactive Oxygen Species (ROS), which caused the down-regulation of miR-32-5p. The miR-32-5p inhibitor increased the expression of Golga7 and pyroptosis-related genes (NOD-like receptor protein 3 (NLRP3), Cysteine aspartase-1 (Caspase-1), Golgin A3 (Golga3), Nuclear Factor-kappa B (NF-κB), and Tumor Necrosis Factor-alpha (TNF-α)), which induced the pyroptosis, but when miR-32-5p mimic/si-Golga7 (Golga7 inhibitor) was utilized, these effects were reduced. Our research demonstrated that miR-32-5p/Golga7 regulated NLRP3 involving in the pyroptosis of chicken splenic cells exposed to ammonia. Our study provided a valuable foundation for the prevention and treatment chickens ammonia poisoning in the livestock production.

Cadmium exposure triggers alveolar epithelial cell pyroptosis by inducing mitochondrial oxidative stress and activating the cGAS-STING pathway

BACKGROUND

Cadmium is a ubiquitous toxic metal and environmental pollutant. More and more studies have shown that cadmium exposure can damage lung function. Alveolar epithelial cells (AECs) are structural cells that maintain the stability of lung function. The injury of AECs is an essential determinant of many lung diseases. In the lung, cadmium accumulation can cause damage to AECs. However, the specific mechanism is still unclear. This study aimed to explore the key mechanism underlying the injury of AECs caused by cadmium exposure.

METHODS

The main modes of death of AECs induced by cadmium exposure were evaluated in vivo and in vitro. Transcriptomic changes of AECs induced by cadmium exposure were analyzed using RNA-sequence. Mitochondrial ROS scavengers (mitoQ), voltage-dependent anion channel 1 (VDAC1) oligomer inhibitor (VBIT4), and cyclic GMP-AMP synthase (cGAS) inhibitor (RU.521) were used to assess whether cadmium exposure triggered pyroptosis of AECs by inducing mitochondrial stress to activate the cGAS-STING-NLRP3 axis.

RESULTS

In this study, the expression of pyroptosis-related proteins was significantly up-regulated in the cadmium-exposed AECs, while the expression of apoptosis, necroptosis, and ferroptosis-related proteins had no significant up-regulated. The pan-caspase inhibitor ZVAD-FMK significantly reduced cell death. Thus, our research indicates that pyroptosis is the primary type of AEC death exported to cadmium. Mechanistically, RNA-seq and Western Blot results showed that cadmium exposure activated the cGAS-STING pathway in AECs and promoted pyroptosis by activating the NLRP3 inflammasome. Further investigation of the mechanism found that cadmium exposure caused mitochondrial oxidative stress, which led to mtDNA leakage into the cytoplasm and activated the cGAS-STING pathway. In addition, inhibition of the cGAS-STING pathway significantly alleviated lung injury induced by cadmium exposure in mice.

CONCLUSION

Our study confirmed that pyroptosis of AECs was a vital mechanism of lung injury after cadmium exposure in a cGAS-STING-dependent manner, which may provide a new target for the treatment of lung diseases induced by cadmium exposure.

Mitochondrial disruption resulting from Cepharanthine-mediated TOM inhibition triggers ferroptosis in colorectal cancer cells

BACKGROUND

Chemotherapy for colorectal cancer (CRC) urgently needs low-toxicity and highly effective phytomedicine. Cepharanthine (Cep) shown to have multiple anti-tumor effects, including colorectal cancer, whose pivotal mechanisms are not fully understood. Herein, the present work aims to reveal the impact of Cep on the mitochondrial and anti-injury functions of CRC cells.

METHODS

The TOM70/20 expression was screened by bioinformatic databases. SW480 cells were utilized as the colorectal cancer cell model. The expression of TOM70/20 and the downstream molecules were measured by western blots (WB). The ferroptosis was analyzed using Transmission electron microscopy (TEM), C11-BODIPY, PGSK, and DCFH-DA probes, wherein the detection was performed by flow cytometry and laser confocal microscopy. The anti-cancer efficacy was conducted by CCK-8 and Annexin-V/PI assay. The rescue experiments were carried out using Fer-1 and TOM70 plasmid transfection.

RESULTS

Bioinformatic data identified TOM20 and TOM70 were highly expressed in colorectal cancer, which could be down-regulated by Cep. Further findings disclosed that Cep treatment destroyed the mitochondria and inactivated the NRF2 signaling pathway, an essential pathway for resistance to ferroptosis, thereby promoting reactive oxygen species (ROS) generation in CRC cells. As a result, prominent ferroptosis could be observed in CRC cells in response to Cep, which thereby led to the reduced cell viability of cancer cells. On the contrary, recovery of TOM70 dampened the Cep-elicited mitochondria damage, ferroptosis, and anti-cancer efficacy.

CONCLUSION

In summary, Cep-mediated TOM inhibition inactivates the NRF2 signaling pathway, thereby triggering ferroptosis and achieving an anti-colorectal cancer effect. The current study provides an innovative chemotherapeutic approach for colorectal cancer with phytomedicine.

Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling in heavy metals-induced oxidative stress

Organisms encounter reactive oxidants through intrinsic metabolism and environmental exposure to toxicants. Reactive oxygen and nitrogen species (ROS, RNS) are generally considered detrimental because they induce oxidative stress. In order to combat oxidative stress, a potential modulator of cellular defense nuclear factor erythroid 2-related factor 2 (Nrf2) and its endogenous inhibitor Kelch-like ECH-associated protein 1 (Keap1) operate as a common, genetically preserved intrinsic defense system. There has been a significant increase in the amount of harmful metalloids and metals that individuals are exposed to through their food, water, and air, primarily due to human activities. Many studies have looked at the connection between the emergence of different ailments in humans and ecological exposure to metalloids, i.e., arsenic (As) and metals viz., chromium (Cr), mercury (Hg), cadmium (Cd), cobalt (Co), and lead (Pb). It is known that they can produce ROS in several organs by both direct and indirect means. Studies suggest that Nrf2 signaling is a crucial mechanism in maintaining antioxidant balance and can have two roles, depending on the particular biological setting. From one perspective, Nrf2 is an essential defense mechanism against metal-induced toxicity. Still, it may also operate as a catalyst for metal-induced carcinogenesis in situations involving protracted exposure and persistent activation. Therefore, this review aims to provide an overview of the antioxidant defense mechanism of Nrf2-Keap1 signaling and the interrelation between Nrf2 signaling and the toxic elements.

Nrf2, gp91phox and IL-17 are associated with severity and clinical outcomes of patients with subclinical hypothyroidism: a comparative study

The mechanisms underlying subclinical hypothyroidism (SCH) remain unclear, making timely and accurate differentiation between hypothyroidism and SCH, as well as severity assessment, challenging. This study aimed to investigate the role of NFE2 like bZIP transcription factor 2 (Nrf2), gp91phox, and interleukin-17 (IL-17) in the pathogenesis of SCH. In this prospective comparative study, 105 SCH patients, 105 hypothyroidism patients, and 105 healthy individuals were enrolled from January 2022 to August 2023. SCH patients were categorized into mild-moderate and severe groups based on thyroid-stimulating hormone (TSH) levels. Levels of TSH, free T4 (FT4), free T3 (FT3), thyroglobulin antibodies (TG-Ab), thyroid peroxidase antibodies (TPO-Ab), cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol (HDL-ch), and low-density lipoprotein-cholesterol (LDL-ch) were measured. Nrf2, IL-1β, IL-6, IL-17, and gp91phox levels were tested using ELISA. Nrf2, IL-17 and gp91phox were significantly higher in SCH and hypothyroidism patients compared to the healthy controls, with hypothyroidism patients showing the highest levels. Nrf2 levels were negatively correlated with TSH, TG-Ab and IL-17, but not gp91phox. Nrf2, IL-17 and gp91phox could be used for diagnosis of SCH and severe SCH. Only TG-Ab, IL-17 and gp91phox were independent risk factors for severe SCH. This study demonstrates a negative correlation between serum Nrf2 levels and SCH severity. TG-Ab, IL-17, and gp91phox are independent risk factors, and their associations with SCH pathology suggest their potential roles in the disease mechanism. These findings provide insights into SCH pathogenesis and highlight the need for further research to elucidate their diagnostic or prognostic significance.

Augmented Cornus officinalis Levels in Liuwei Dihuang Decoction Inhibits Nucleus Pulposus Cell Pyroptosis to Enhance Therapeutic Efficacy Against Intervertebral Disc Degeneration

Background

Intervertebral disc (IVD) degeneration (IVDD) is highly prevalent among the elderly population and stands as a leading cause of low back pain. Our prior studies have highlighted the therapeutic potential of Liuwei Dihuang decoction (LWDHD) and its component Cornus officinalis (CO)-derived compounds in alleviating IVDD and osteoarthritis, suggesting beneficial effects of CO in treating degenerative osteoarthropathies. However, uncertainty remains regarding the optimal CO dosage within LWDHD and its potential mechanism for effectively treating IVDD.

Objective

To ascertain the optimal dosage of CO within LWDHD for enhancing its therapeutic efficacy in treating IVDD, through a comparison of its effects across varied dosages using a mouse IVDD model.

Methods

Eight-week-old male C57BL/6J mice were subjected to a lumbar spine instability surgery to induce an IVDD model and received a modified LWDHD formulation containing varied dosages of CO (original dose of CO, or 5- or 10-time dose of CO (referred to as 1 × CO, 5 × CO, and 10 × CO)) for 8 weeks. The therapeutic efficacy on IVDD was evaluated through changes in lumbar spine function, histopathological morphology, extracellular matrix metabolism, nucleus pulposus cell viability, sensory nerve ingrowth, and nucleus pulposus (NP) cell pyroptosis.

Results

Augmenting CO levels in LWDHD led to a dose-dependent increase in the levels of CO-sourced active compounds in the plasma of mice. The modified LWDHD formulations, particularly the 5 × CO, exhibited a favorable pharmacological effect on lumbar function, structural integrity, ECM composition, NP cell viability, and sensory nerve ingrowth. Importantly, all 3 formulations notably mitigated NP cell pyroptosis by activating NRF2/KEAP1 pathway, with the 5 × CO formulation exhibiting superior efficacy. Additionally, a comprehensive score analysis indicated that 5 × CO formulation achieved the highest score.

Conclusion

These data underscore that elevating the dosage of CO to a specific threshold can enhance the effectiveness of LWDHD in treating IVDD.

Nickel Induces Pyroptosis via the Nrf2/NLRP3 Pathway in Kidney of Mice

Nickel (Ni) is considered a toxic metal, and excessive exposure can cause kidney damage. This study was designed to explore whether nickel chloride (NiCl2) can induce cell pyroptosis and its possible mechanism. Here, we found that NiCl2 treatment could reduce the kidney index and result in kidney damage. Meanwhile, NiCl2 could obviously induce renal pyroptosis, which was characterized by an increase in IL-18, IL-1β, NLRP3, and GSDMD expression. Furthermore, NiCl2 induced pyroptosis through the Nrf2/NLRP3 pathway which featured down-regulated protein and mRNA expression levels of Nrf2 and up-regulated protein and mRNA expression levels of Caspase-1, NLRP3, and GSDMD. In summary, excessive Ni exposure can induce renal cell pyroptosis, ultimately leading to kidney tissue damage and hindering normal development, and its possible mechanism may be due to the inhibition of the Nrf2 pathway.

NLRP3 inflammasome and its role in autoimmune diseases: A promising therapeutic target

The NOD-like receptor protein 3 (NLRP3) inflammasome is a protein complex that regulates innate immune responses by activating caspase-1 and the inflammatory cytokines IL-1β and IL-18. Numerous studies have highlighted its crucial role in the pathogenesis and development of inflammatory bowel disease, rheumatoid arthritis, systemic lupus erythematosus, autoimmune thyroid diseases, and other autoimmune diseases. Therefore, investigating the underlying mechanisms of NLRP3 in disease and targeted drug therapies holds clinical significance. This review summarizes the structure, assembly, and activation mechanisms of the NLRP3 inflammasome, focusing on its role and involvement in various autoimmune diseases. This review also identifies studies where the involvement of the NLRP3 inflammasome in the disease mechanism within the same disease appears contradictory, as well as differences in NLRP3-related gene polymorphisms among different ethnic groups. Additionally, the latest therapeutic advances in targeting the NLRP3 inflammasome for autoimmune diseases are outlined, and novel clinical perspectives are discussed. Conclusively, this review provides a consolidated source of information on the NLRP3 inflammasome and may guide future research efforts that have the potential to positively impact patient outcomes.

A critical review on the ecotoxicity of heavy metal on multispecies in global context: A bibliometric analysis

Heavy metals (HMs) have become a significant concern in the current era, with deleterious effects on diverse living organisms when exposed beyond threshold concentrations. Both nature and human beings have been constantly casting out HMs into environmental matrices through various activities. Innumerable cases of threatened diseases such as cancer, respiratory ailments, reproductive defects, skin diseases, and several others have been a cause of significant concern for humans as the number of instances has been increasing with each decade. HMs migrates via several pathways to infiltrate biological organisms and amass within them. Even though numerous treatment approaches are available for remediating HM pollution, however, they are expensive, along with other setbacks. Due to such constraints, combating HM contamination requires environmentally conscious strategies like bioremediation, which employs an array of biological systems to remove HMs from the environment. Nonetheless, to address the current global HM pollution situation, it is critical to comprehend not only how these hazardous HMs cause toxicity in various living organisms but also the knowledge gaps that currently exist concerning the subject of HM ecotoxicity. In the present investigation, data was extracted from Google Scholar using software program called Harzing's Publish or Perish. The collected information has been subsequently displayed as a network file using the VOSViewer software tool. Thus, the current review presents a significant insight with the inclusion of a readily accessible bibliometric analysis to comprehend the present status of HMs research, global research trends, existing knowledge discrepancies, and research challenges. Further, it also provides an in-depth review of HMs ecotoxicity, with a focus on arsenic (As), cadmium (Cd), and lead (Pb). Thus, as indicated by the bibliometric study, the present review will assist future investigators studying HMs ecotoxicity by providing baseline data concerning a wide range of living organisms and by addressing research gaps.

Environmental cadmium exposure perturbs systemic iron homeostasis via hemolysis and inflammation, leading to hepatic ferroptosis in common carp (Cyprinus carpio L.)

Cadmium (Cd) pollution is considered a pressing challenge to eco-environment and public health worldwide. Although it has been well-documented that Cd exhibits various adverse effects on aquatic animals, it is still largely unknown whether and how Cd at environmentally relevant concentrations affects iron metabolism. Here, we studied the effects of environmental Cd exposure (5 and 50 μg/L) on iron homeostasis and possible mechanisms in common carp. The data revealed that Cd elevated serum iron, transferrin saturation and iron deposition in livers and spleens, leading to the disruption of systemic iron homeostasis. Mechanistic investigations substantiated that Cd drove hemolysis by compromising the osmotic fragility and inducing defective morphology of erythrocytes. Cd concurrently exacerbated hepatic inflammatory responses, resulting in the activation of IL6-Stat3 signaling and subsequent hepcidin transcription. Notably, Cd elicited ferroptosis through increased iron burden and oxidative stress in livers. Taken together, our findings provide evidence and mechanistic insight that environmental Cd exposure could undermine iron homeostasis via erythrotoxicity and hepatotoxicity. Further investigation and ecological risk assessment of Cd and other pollutants on metabolism-related effects is warranted, especially under the realistic exposure scenarios.

Atrazine exposure promotes cardiomyocyte pyroptosis to exacerbate cardiotoxicity by activating NF-κB pathway

Atrazine is a ubiquitous herbicide with persistent environmental presence and accumulation in the food chain, posing potential health hazards to organisms. Increasing evidence suggests that atrazine may have detrimental effects on various organ systems, including the nervous, digestive, and immune systems. However, the specific toxicity and underlying mechanism of atrazine-induced cardiac injury remain obscure. In this study, 4-week-old male C57BL/6 mice were administered atrazine via intragastric administration at doses of 50 and 200 mg/kg for 4 and 8 weeks, respectively. Our findings showed that atrazine exposure led to cardiac fibrosis, as evidenced by elevated heart index and histopathological scores, extensive myofiber damage, and interstitial collagen deposition. Moreover, atrazine induced cardiomyocyte apoptosis, macrophage infiltration, and excessive production of inflammatory factors. Importantly, atrazine upregulated the expressions of crucial pyroptosis proteins, including NLRP3, ASC, CASPASE1, and GSDMD, via the activation of NF-κB pathway, thus promoting cardiomyocyte pyroptosis. Collectively, our findings provide novel evidence demonstrating that atrazine may exacerbate myocardial fibrosis by inducing cardiomyocyte pyroptosis, highlighting its potential role in the development of cardiac fibrosis.

Elucidating the role of Pyroptosis in papillary thyroid cancer: prognostic, immunological, and therapeutic perspectives

BACKGROUND

Pyroptosis, an inflammatory form of programmed cell death, has been implicated in the pathogenesis and progression of several cancers. However, the significance of pyroptosis-related genes (PRGs) in papillary thyroid cancer (PTC) remains unclear.

METHODS

Transcriptome and clinical data of PTC patients were obtained from The Cancer Genome Atlas. The expression patterns of PRGs were identified by consensus clustering. A prognostic model for predicting the thyroid cancer-free interval (TCFi) employed five machine learning methods. Enrichment and immune-related analyses were performed to elucidate the role of pyroptosis. The responses to radioactive iodine (RAI), immune checkpoint inhibitors (ICIs), molecular targeted therapy (MTT), and chemotherapy (CTx) were predicted based on pyroptosis-derived features. Additionally, the expression of prognostic PRGs was validated via six external datasets, 16 cell lines, and 20 pairs of clinical samples.

RESULTS

PTC patients were classified into three PyroClusters, C1 exhibited BRFA-like tumors with the highest invasiveness and the worst prognosis, C2 presented RAS-like tumors, and C3 was characterized by gene fusion. Nine PRGs (CXCL8, GJA1, H2BC8, IFI27, PRDM1, PYCARD, SEZ6L2, SIGLEC15, TRAF6) were filtered out to construct a PyroScore prognostic model. A derived nomogram demonstrated superior predictive performance than four clinical staging systems. A strong correlation between pyroptosis and tumor immune microenvironment (TIME) remodeling was observed in mechanistic analyses. Patients with a high PyroScore exhibited "hot" tumor immunophenotypes and had a poorer prognosis but could benefit more from ICIs and CTx (such as paclitaxel). Patients with a low PyroScore were more sensitive to RAI and MTT (such as pazopanib and sorafenib).

CONCLUSIONS

PyroScore model can effectively predict TCFi in patients with PTC. Dysregulated expression of PRGs is associated with the TIME modeling. Pyroptosis features have potential significance for developing novel therapeutic strategies for PTC patients.

Synergistic effect of PS-MPs and Cd on male reproductive toxicity: Ferroptosis via Keap1-Nrf2 pathway

It has been wildly reported that microplastics (MPs) can adsorb heavy metals and act as carriers for their transport into organisms. However, the combined toxicity of MPs and heavy metals remains poorly studied. In this study, we established single or co-exposure (i.e. complex/combined exposure) mice models to investigate the combined toxicity of MPs and cadmium (Cd) on male reproduction. The complexation of MPs and Cd enhanced the bioavailability of Cd, while the combination of MPs and Cd exerted synergistic effect. Ultimately, the co-exposure was reported to enhance the reproduction toxicity by single exposure, which reflected in testicular structure, spermatogenesis and sex hormone synthesis. More in-depth mechanistic investigation suggested that MPs and Cd synergistically inhibited the Keap1-Nrf2 pathway and its downstream genes, induced lipid peroxidation and ferroptosis, ultimately caused damage to reproductive structures and functions. Our results highlighted the synergistic effect of MPs and Cd on the reproductive toxicity in male mammals for the first time, which also provided valuable insights into the combined toxicity mechanisms of MPs and other pollutants.

AR/PCC herb pair inhibits osteoblast pyroptosis to alleviate diabetes-related osteoporosis by activating Nrf2/Keap1 pathway

Osteoporosis is a prevalent complication of diabetes, characterized by systemic metabolic impairment of bone mass and microarchitecture, particularly in the spine. Anemarrhenae Rhizoma/Phellodendri Chinensis Cortex (AR/PCC) herb pair has been extensively employed in Traditional Chinese Medicine to manage diabetes; however, its potential to ameliorate diabetic osteoporosis (DOP) has remained obscure. Herein, we explored the protective efficacy of AR/PCC herb pair against DOP using a streptozotocin (STZ)-induced rat diabetic model. Our data showed that AR/PCC could effectively reduce the elevated fasting blood glucose and reverse the osteoporotic phenotype of diabetic rats, resulting in significant improvements in vertebral trabecular area percentage, trabecular thickness and trabecular number, while reducing trabecular separation. Specifically, AR/PCC herb pair improved impaired osteogenesis, nerve ingrowth and angiogenesis. More importantly, it could mitigate the aberrant activation of osteoblast pyroptosis in the vertebral bodies of diabetic rats by reducing increased expressions of Nlrp3, Asc, Caspase1, Gsdmd and IL-1β. Mechanistically, AR/PCC activated antioxidant pathway through the upregulation of the antioxidant response protein Nrf2, while concurrently decreasing its negative feedback regulator Keap1. Collectively, our in vivo findings demonstrate that AR/PCC can inhibit osteoblast pyroptosis and alleviate STZ-induced rat DOP, suggesting its potential as a therapeutic agent for mitigating DOP.

Deciphering the Role of Selenoprotein M

Selenocysteine (Sec), the 21st amino acid, is structurally similar to cysteine but with a sulfur to selenium replacement. This single change retains many of the chemical properties of cysteine but often with enhanced catalytic and redox activity. Incorporation of Sec into proteins is unique, requiring additional translation factors and multiple steps to insert Sec at stop (UGA) codons. These Sec-containing proteins (selenoproteins) are found in all three domains of life where they often are involved in cellular homeostasis (e.g., reducing reactive oxygen species). The essential role of selenoproteins in humans requires us to maintain appropriate levels of selenium, the precursor for Sec, in our diet. Too much selenium is also problematic due to its toxic effects. Deciphering the role of Sec in selenoproteins is challenging for many reasons, one of which is due to their complicated biosynthesis pathway. However, clever strategies are surfacing to overcome this and facilitate production of selenoproteins. Here, we focus on one of the 25 human selenoproteins, selenoprotein M (SELENOM), which has wide-spread expression throughout our tissues. Its thioredoxin motif suggests oxidoreductase function; however, its mechanism and functional role(s) are still being uncovered. Furthermore, the connection of both high and low expression levels of SELENOM to separate diseases emphasizes the medical application for studying the role of Sec in this protein. In this review, we aim to decipher the role of SELENOM through detailing and connecting current evidence. With multiple proposed functions in diverse tissues, continued research is still necessary to fully unveil the role of SELENOM.

Higher cadmium exposure was associated with sex-specific thyroid dysfunction: Consistent evidence from two independent cross-sectional studies based on urinary and blood cadmium measurements

Population-based studies on the association between cadmium (Cd) exposure and thyroid function are limited and have shown conflicting results. Two independent cross-sectional studies using different Cd biomarkers were carried out in six rural areas with different soil Cd levels in China. Thyroid dysfunction was defined based on levels of thyroid stimulating hormone (TSH) and free thyroxine (FT4). Both multivariable linear regression, multiple logistic regression and restrictive cubic splines models were used to estimate the association between Cd and thyroid dysfunction. For both of the two independent studies, higher Cd levels were observed to be associated with lower TSH levels and higher risk of thyroid dysfunction. The negative relationship between urinary Cd and TSH was found in both total participants (β = -0.072, p = 0.008) and males (β = -0.119, p = 0.020) but not in females, however, the negative relationship between blood Cd and TSH was only found in females (β = -0.104, p = 0.024). Higher urinary Cd (> 2.52 μg/g creatinine) was associated with higher risk of thyroid dysfunction, while higher blood Cd was associated with higher risk of hyperthyroidism status. The adjusted Odds Ratio (OR) for the risk of hyperthyroidism status was 3.48 (95%CI:1.36-8.92) and 6.94 (95%CI:1.23-39.31) times higher with every natural log unit higher in blood Cd in total participants and males, respectively. Results from the two independent cross-sectional studies consistently suggested that higher Cd levels were associated with sex-specific thyroid dysfunction.

Sestrin2/Keap1/Nrf2 pathway regulates mucus hypersecretion in pulmonary epithelium induced by traffic-related PM2.5 and water-soluble extracts

The involvement of fine particulate matter (PM2.5) exposure in the progression of asthma has been extensively discussed in epidemiological and experimental evidence, which aroused widespread attention. Asthma is characterized by mucus hypersecretion. This study investigates the underlying toxic mechanism of traffic-related PM2.5 (TRPM2.5) and water-soluble extracts (WSE) on mucus hypersecretion in the lungs of rats with asthma and 16HBE cells. The ovalbumin-induced rats were administrated by instillation of TRPM2.5 and WSE in the trachea once three days for eight times. The results showed that TRPM2.5 and WSE had an adverse impact on mucus secretion. Specifically, conspicuous mucus stains and increased goblet cells in the bronchial epithelium by PAS staining were found in lung tissues of rats with asthma; MUC5AC gene and protein expression levels in lung tissues of rats with asthma and 16HBE cells were elevated. In addition, TRPM2.5 and WSE triggered oxidative damage via upregulation of malondialdehyde and myeloperoxidase as well as activation of the Sestrin2/Keap1/Nrf2 signaling pathway. Conversely, the knockdown of Sestrin2 effectively inhibited TRPM2.5 and WSE-induced mucus hypersecretion, oxidative stress, and Keap1/Nrf2 signaling pathway and its downstream target gene NQO1. Collectively, it was demonstrated that TRPM2.5 and WSE induced mucus hypersecretion mediated by the Sestrin2/Keap1/Nrf2 pathway.

Effects of Endocrine-Disrupting Heavy Metals on Human Health

Heavy metals play an important endocrine-disrupting role in the health consequences. However, the endocrine-disrupting mechanism of heavy metals is unclear. There are long-term and low-level metal/element exposure scenes for the human body in real life. Therefore, animal models exposed to high doses of heavy metals may not provide key information to elucidate the underlying pathogeny of human diseases. This review collects current knowledge regarding the endocrine-disrupting roles of heavy metals such as lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), nickel (Ni), copper (Cu), zinc (Zn), and manganese (Mn), summarizes the possible molecular mechanisms of these endocrine-disrupting chemicals (EDCs), and briefly evaluates their endocrine toxicity on animals and humans.