Systematic evaluation of CdSe/ZnS quantum dots toxicity on the reproduction and offspring health in male BALB/c mice.

Increased applications of quantum dots (QDs) in the biomedical field have aroused attention for their potential toxicological effects. Although numerous studies have been carried out on the toxicity of QDs, their effects on reproductive and development are still unclear. In this study, we systematically evaluated the male reproductive toxicity and developmental toxicity of CdSe/ZnS QDs in BALB/c mice. The male mice were injected intravenously with CdSe/ZnS QDs at the dosage of 2.5 mg/kg BW or 25 mg/kg BW, respectively, and the survival status, biodistribution of QDs in testes, serum sex hormone levels, histopathology, sperm motility and acrosome integrity was measured on Day 1, 7, 14, 28 and 42 after injection. On Day 35 after treatment, male mice were housed with non-exposed female mice, and then offspring number, body weight, organ index and histopathology of major organs, blood routine and biochemical tests of offspring were measured to evaluate the fertility and offspring health. The results showed that CdSe/ZnS QDs could rapidly distribute in the testis, and the fluorescence of QDs could still be detected on Day 42 post-injection. QDs had no adverse effect on the structure of testis and epididymis, but high-dose QDs could induce apoptosis of Leydig cells in testis at an early stage. No significant differences in survival of state, body weight organ index of testis and epididymis, sex hormones levels, sperm quality, sperm acrosome integrity and fertility of male mice were observed in QDs exposed groups. However, the development of offspring was obviously influenced, which was mainly manifested in the slow growth of offspring, changes in organ index of main organs, and the abnormality of liver and kidney function parameters. Our findings revealed that CdSe/ZnS QDs were able to cross the blood-testis barrier (BTB), produce no discernible toxic effects on the male reproductive system, but could affect the healthy growth of future generations to some extent. In view of the broad application prospect of QDs in biomedical fields, our findings might provide insight into the biological safety evaluation of the reproductive health of QDs.

PEGylated CuInS2/ZnS quantum dots inhibit neurite outgrowth by downregulating the NGF/p75NTR/MAPK pathway.

The widespread application of cadmium-free CuInS2/ZnS QDs has raised great concern regarding their potential toxicity to humans. To date, toxicological data related to CuInS2/ZnS QDs are scarce. Neurons play extraordinary roles in regulating the activities of organs and systems, and serious consequences occur when neurons are damaged. Currently, the potential toxicity of CuInS2/ZnS QDs on neurons has not been fully elucidated. Here, we investigate the neurotoxicity of PEGylated CuInS2/ZnS (CuInS2/ZnS-PEG) QDs on neuron-like PC12 cells. We found that CuInS2/ZnS-PEG QDs were taken up by PC12 cells, but at a concentration range from 0 to 100 µg/mL, they did not affect the survival rate of the PC12 cells. In addition, we found that CuInS2/ZnS-PEG QDs significantly inhibited neurite outgrowth from and the differentiation of PC12 cells in the presence of NGF, while COOH-modified CuInS2/ZnS QDs or free PEG did not have a similar effect. Further studies showed that CuInS2/ZnS-PEG QDs obviously downregulated the expression of low-affinity NGF receptor (p75NTR) and subsequently negatively regulated the downstream MAPK cascade by dephosphorylating ERK1/2 and AKT. Taken together, these results suggest that CuInS2/ZnS-PEG QDs disturb NGF signal transduction from external stimuli to relevant internal signals, thus affecting normal biological processes such as neurite outgrowth and cell differentiation.

Nephrotoxicity Evaluation of Indium Phosphide Quantum Dots with Different Surface Modifications in BALB/c Mice.

InP QDs have shown a great potential as cadmium-free QDs alternatives in biomedical applications. It is essential to understand the biological fate and toxicity of InP QDs. In this study, we investigated the in vivo renal toxicity of InP/ZnS QDs terminated with different functional groups-hydroxyl (hQDs), amino (aQDs) and carboxyl (cQDs). After a single intravenous injection into BALB/c mice, blood biochemistry, QDs distribution, histopathology, inflammatory response, oxidative stress and apoptosis genes were evaluated at different predetermined times. The results showed fluorescent signals from QDs could be detected in kidneys during the observation period. No obvious changes were observed in histopathological detection or biochemistry parameters. Inflammatory response and oxidative stress were found in the renal tissues of mice exposed to the three kinds of QDs. A significant increase of KIM-1 expression was observed in hQDs and aQDs groups, suggesting hQDs and aQDs could cause renal involvement. Apoptosis-related genes (Bax, Caspase 3, 7 and 9) were up-regulated in hQDs and aQDs groups. The above results suggested InP/ZnS QDs with different surface chemical properties would cause different biological behaviors and molecular actions in vivo. The surface chemical properties of QDs should be fully considered in the design of InP/ZnS QDs for biomedical applications.

BDE-47 induces metabolic dysfunction-associated steatotic liver disease (MASLD) through CD36-mediated increased fatty acid uptake and PPARα-induced abnormal fatty acid oxidation in BALB/c mice.

The widespread existence of 2,2',4,4'-tetra-bromodiphenyl ether (BDE-47) in the environment has aroused great concern. BDE-47 induces the occurrence of metabolic dysfunction-associated steatotic liver disease (MASLD), but the mechanism has not been fully elucidated. Here, we further investigate the underlying mechanism using BALB/c mice. After BDE-47 exposure, the livers of mice enlarged, the serum levels of ALT, ALP, TG and TC enhanced, and hepatic steatosis occurred. Transcriptome sequencing identifies 2250 differentially expressed genes (DEGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis reveals that down-regulated DEGs are mainly enriched in pathways associated with lipid metabolism, particularly in fatty acid (FA) degradation. And up-regulated DEGs are mainly enriched in pathways related to lipid and FA transport. The expression levels of AhR, Pparγ and Cd36 involved in FA uptake are up-regulated, and those of PPARα and target genes including Cpt1 and Cyp4a1 related to ß and ω-oxidation are inhibited. These results reveal BDE-47 could lead to metabolic dysfunction-associated steatotic liver disease (MASLD) by promoting FA uptake via upregulating Cd36 and hindering oxidative utilization by downregulating PPARα.

Cytotoxicity and transcriptome changes triggered by CuInS2/ZnS quantum dots in human glial cells.

As a newly developed cadmium-free quantum dot (QD), CuInS2/ZnS has great application potential in many fields, but its biological safety has not been fully understood. In this study, the in vitro toxicity of CuInS2/ZnS QDs on U87 human glioma cell line was explored. The cells were treated with different concentrations of QDs (12.5, 25, 50 and 100 µg/mL), and the uptake of QDs by the U87 cells was detected by fluorescence imaging and flow cytometry. The cell viability was observed by MTT assay, and the gene expression profile was analyzed by transcriptome sequencing. These results showed that QDs could enter the cells and mainly located in the cytoplasm. The uptake rate was over 90 % when the concentration of QDs reached 25 µg/mL. The cell viability (50 and 100 µg/mL) increased at 24 h (P < 0.05), but no significant difference after 48 h and 72 h treatment. The results of differential transcription showed that coding RNA accounted for the largest proportion (62.15 %), followed by long non-coding RNA (18.65 %). Total 220 genes were up-regulated and 1515 genes were down-regulated, and significantly altered gene functions included nucleosome, chromosome-DNA binding, and chromosome assembly. In conclusion, CuInS2/ZnS QDs could enter U87 cells, did not reduce the cell viability, but would obviously alter the gene expression profile. These findings provide valuable information for a proper understanding of the toxicity risk of CuInS2/ZnS QD and promote the rational utilization of QDs in the future.

BDE-47 induced PC-12 cell differentiation via TrkA downstream pathways and caused the loss of hippocampal neurons in BALB/c mice.

As the most abundant congener of polybrominated diphenyl ethers (PBDEs) detected in environment and human biotic samples, 2, 2', 4, 4'-tetrabromodiphenyl ether (BDE-47) has been found to accumulate in brain and induce neurotoxicity, however, the detailed mechanism has not been clearly elucidated. To investigate the neurotoxicity of BDE-47, undifferentiated PC-12 cells were exposed to different doses of BDE-47, and BDE-47 dissolved in corn oil was orally administered to mice for 8 consecutive weeks. Our data showed that BDE-47 obviously changed cell morphology, altered cell viability, promoted cell apoptosis, and induced reactive oxygen species (ROS) production. BDE-47 promoted the differentiation of PC-12 cells by enhancing the expression of TrkA receptor and the phosphorylation levels of ERK and Akt. Moreover, BDE-47-induced differentiation of PC-12 cells was suppressed by inhibitors of corresponding pathways (MAPK/ERK and PI3K/Akt). H&E staining of brain showed neurons in DG and CA1 areas of hippocampus decreased after BDE-47 exposure. Transcriptome sequencing of brain tissue suggested that multiple signaling pathways related to neuron death and nerve function were significantly regulated. In conclusion, these results provided new evidence for revealing the neurotoxicity of BDE-47, and offered important experimental basis for environmental controlling and post-exposure health risk assessment of BDE-47.

BDE-47 disturbs the immune response of lymphocytes to LPS by downregulating NF-κB pathway.

The health risks associated with 2,2',4,4'-tetra-bromodiphenyl ether (BDE-47) have become an increasing concern due to its widespread presence in the environment and biological samples. To date, the potential toxicity of BDE-47 to immune system remains unclear. In this study, we aimed to study the immunotoxicity of BDE-47 using spleen-derived lymphocytes in vitro and BALB/c mice in vivo. In vitro results showed that lymphocytes exposed to 12.5-100 µM BDE-47 exhibited unchanged cell viability but decreased release of IL-6 and TNF-α when responding to lipopolysaccharide (LPS). The expression levels of p-p65, p-IκBα, TrkA and p-Akt involved in NF-κB pathway were obviously decreased, and NF-κB activator PMA could recover the BDE-47-induced inhibitory effect on IL-6 and TNF-α release by lymphocytes in response to LPS. In vivo data showed that BDE-47 orally administered to mice (1 mg/kg, 10 mg/kg, 100 mg/kg per day, 30 days) did not significantly affect body weight, organ index and histomorphology of spleen. However, ELISA assay showed that serum IL-6 and TNF-α levels from BDE-47-treated mice after intraperitoneal injection of LPS were significantly reduced, and high-throughput mouse cytokines screening found 13 more cytokines down-regulated in the serum. Transcriptomic sequencing of spleens identified 488 differential expressed genes (DEGs). GO enrichment analysis of these DEGs suggested that the GO term of response to LPS (GO: 0032,496) was significantly involved. KEGG enrichment analysis showed that the down-regulated DEGs significantly enriched in multiple immune-related signaling pathways including the NF-κB signaling pathway (mmu04064). Overall, these data suggested that BDE-47 could negatively regulate NF-κB signaling pathways to inhibit the immune response of lymphocytes to LPS, suggesting that exposures to BDE-47 may disturb the immune balance and increase the body's susceptibility to infectious diseases.

Cytotoxicity and Immune Dysfunction of Dendritic Cells Caused by Graphene Oxide.

Graphene, known as "black gold", has important applications in various fields. In previous studies, it has been proved that graphene oxide (GO) which is a derivative of graphene has low toxicity. However, the immunotoxicity of GO has not been fully elucidated. In this work, we used DC2.4 cell line to investigate the in vitro immunotoxicity of two types of GO, mono-layer GO (mono-GO) and multi-layer GO (multi- GO). We found that mono-GO had less effect on cell viability than multi-GO, but both mono-GO and multi-GO significantly induced the generation of ROS in DC2.4 cells. Interestingly, mono-GO caused DC2.4 cells to aggregate, thus changed the cell morphology significantly. However, no similar influence occurred for multi-GO. In addition, the results showed that these two GOs obviously enhance the release of TNF-α by DC2.4 cells with and without LPS stimulation. GO did not affect the level of IL-6 released from DC2.4 cells, but multi-GO promoted the release of IL-6 while mono-GO inhibited the production of IL-6 when cells were in response to LPS stimulation. Whole-transcriptome sequencing analysis found some immune-related differentially expressed genes including H2-DMb1, Ncbp3, Oas2, Men1, Fas, Cd320, Cd244, and Tinagl1 which are engaged in the immune system process. These results suggested that both mono-GO and multi-GO are immunotoxic to DC2.4 cells, which provides important basis for subsequent biological and clinical medical applications.

Birth Order, Sibship Size, Childhood Environment and Immune-Related Disorders, and Risk of Lymphoma in Lymphoid Cancer Families.

BACKGROUND: Familial aggregation of lymphoid cancers and immune-related disorders suggests a role for genetic susceptibility; however, few studies examine environmental factors. According to the hygiene hypothesis, adult-onset immune-related diseases may be a consequence of reduced childhood infectious exposures and aberrant immune development. In a cohort of 196 multiple-case lymphoid cancer families, we analyzed environmental factors related to the hygiene hypothesis. METHODS: Family structure, childhood environment, and immune-related disorders were examined among 196 lymphoid cancer families, in relation to risk of lymphoid cancer. We report on 450 lymphoid cancer cases and 1,018 unaffected siblings using logistic regression models with generalized estimating equations to estimate ORs and 95% confidence intervals (CI) for association. RESULTS: The risk of lymphoma tended to decrease with later birth order (OR = 0.83; 95% CI, 0.78-0.89) and larger sibship size (OR = 0.82; 95% CI, 0.79-0.85). High maternal education, above average family income during childhood, allergies (OR = 2.25; 95% CI, 1.44-3.51), and tonsillectomy (OR = 1.78; 95% CI, 1.14-2.78) were independent risk factors for lymphoma. Familial lymphoid cancer cases were more likely to report environment (OR = 1.90; 95% CI, 1.21-2.98) and drug (OR = 2.30; 95% CI, 1.41-3.73) allergies. CONCLUSIONS: These associations underscore the complex etiology of familial lymphoma. To our knowledge, this is the largest multiple-case family-based study that supports the hygiene hypothesis contributing to lymphoid cancer risk. IMPACT: Understanding the mechanism by which environmental and lifestyle factors affect lymphoid cancer risk may advance cancer prevention, even in the familial context.

In vitro and in vivo immunotoxicity of PEGylated Cd-free CuInS2/ZnS quantum dots.

The annual increase in the production and the use of engineering quantum dots (QDs) have led to concern about exposure and safety of QDs. To resolve the risk of Cd release from QDs, a series of Cd-free QDs, represented by CuInS2/ZnS QDs, has been developed in recent years. However, the toxicological profile of CuInS2/ZnS QDs has not been fully elucidated, especially, their immunotoxicity. Here, we performed a detailed in vitro cytotoxicity study on PEGylated CuInS2/ZnS QDs using the DC2.4 cell line and investigated their in vivo immunotoxicity using BALB/c mice. In vitro experiments showed that CuInS2/ZnS QDs were taken up by cells, promoted cell viability, enhanced release of tumor necrosis factor-α, and decreased the level of interleukin (IL)-6 in response to lipopolysaccharide stimulation. More than 5000 genes at the transcriptome level were observed by high-throughput RNA sequencing after CuInS2/ZnS QD exposure. In vivo study showed that CuInS2/ZnS QDs increased the levels of IL-4 on day 1 and enhanced the levels of IL-10 and IL-13 on day 28 in mice. There was no obvious difference in the number of spleen-derived lymphocytes, organic index, hematology and immune organ histology on days 1 and 28 after treatment. These findings demonstrated that PEGylated CuInS2/ZnS QDs disturbed the function of DC2.4 immune cells in vitro, but caused no obvious toxicity to immune system in vivo, suggesting that PEGylated CuInS2/ZnS QDs are biocompatible and have potential for bioapplication in the future.

In vivo Comparison of the Biodistribution and Toxicity of InP/ZnS Quantum Dots with Different Surface Modifications.

INTRODUCTION: Indium phosphide (InP) quantum dots (QDs) have shown a broad application prospect in the fields of biophotonics and nanomedicine. However, the potential toxicity of InP QDs has not been systematically evaluated. In particular, the effects of different surface modifications on the biodistribution and toxicity of InP QDs are still unknown, which hinders their further developments. The present study aims to investigate the biodistribution and in vivo toxicity of InP/ZnS QDs. METHODS: Three kinds of InP/ZnS QDs with different surface modifications, hQDs (QDs-OH), aQDs (QDs-NH2), and cQDs (QDs-COOH) were intravenously injected into BALB/c mice at the dosage of 2.5 mg/kg BW or 25 mg/kg BW, respectively. Biodistribution of three QDs was determined through cryosection fluorescence microscopy and ICP-MS analysis. The subsequent effects of InP/ZnS QDs on histopathology, hematology and blood biochemistry were evaluated at 1, 3, 7, 14 and 28 days post-injection. RESULTS: These types of InP/ZnS QDs were rapidly distributed in the major organs of mice, mainly in the liver and spleen, and lasted for 28 days. No abnormal behavior, weight change or organ index were observed during the whole observation period, except that 2 mice died on Day 1 after 25 mg/kg BW hQDs treatment. The results of H&E staining showed that no obvious histopathological abnormalities were observed in the main organs (including heart, liver, spleen, lung, kidney, and brain) of all mice injected with different surface-functionalized QDs. Low concentration exposure of three QDs hardly caused obvious toxicity, while high concentration exposure of the three QDs could cause some changes in hematological parameters or biochemical parameters related to liver function or cardiac function. More attention needs to be paid on cQDs as high-dose exposure of cQDs induced death, acute inflammatory reaction and slight changes in liver function in mice. CONCLUSION: The surface modification and exposure dose can influence the biological behavior and in vivo toxicity of QDs. The surface chemistry should be fully considered in the design of InP-based QDs for their biomedical applications.

In Vivo Toxicity Evaluation of PEGylated CuInS2/ZnS Quantum Dots in BALB/c Mice.

In recent years, quantum dots (QDs) have emerged as a potential contrast agent for bioimaging due to their bright luminescence and excellent photostability. However, the wide use of QDs in vivo has been limited due to underlying toxicity caused by leakage of heavy metals. Although non-cadmium QDs have been developed to resolve this issue, a comprehensive understanding of the toxicity of these newly developed QDs remains elusive. In this study, we administered PEGylated copper indium sulfide/zinc sulfide (CuInS2/ZnS), which are typical non-cadmium QDs, and analyzed the long-term effects of these nanoparticles in BALB/c mice. Body weight, hematology, blood biochemistry, organ histology, and biodistribution were examined at different time points. We found no significant difference in body weight after injection of CuInS2/ZnS QDs. These CuInS2/ZnS QDs entered and were accumulated in major organs for 90 days post-injection. The majority of biochemical indicators were not significantly different between the QDs-treated group and the control group. In addition, no significant histopathological abnormalities were observed in the treated mice compared with the control mice. CuInS2/ZnS QDs did not lead to observable toxicity in vivo following either the administration of a high or low dose. Our research not only provides direct evidence of the bio-safety of CuInS2/ZnS QDs, but also a feasible method for evaluating nanoparticle toxicity.

Cardiotoxicity of Intravenously Administered CdSe/ZnS Quantum Dots in BALB/c Mice.

Since CdSe quantum dots (QDs) are increasingly used in electronics, medical, and pharmaceutical science due to their excellent optical properties, it is necessary to carry out thorough and systematic studies on their biosafety. Numerous studies have reported the toxicity of QDs on liver, kidney, immune system, and reproductive system. However, few studies have been done on the cardiotoxicity of QDs. In this study, we administered carboxylated CdSe/ZnS QDs in BALB/c mice via the tail vein and analyzed the in vivo cardiotoxicity of CdSe/ZnS QDs. The body weight, hematology, serum biochemistry, histology, heart elements concentration, echocardiography, and heart oxidative stress markers were carried out at different time. There were no significant differences in body weight and heart organ index between QDs group and the control group. Hematology results showed the platelet (PLT) counts on Day 1 and Day 42 in both high dose QDs group and low dose QDs group, and the PLT counts on Day1 in the high dose group were significantly higher than that in control group. Serum biochemistry results showed that lactate dehydrogenase (LDH), creatine kinase (CK), and creatine kinase isoenzyme (CK-MB) of mice exposed to CdSe/ZnS QDs were significantly higher than that of the control group on Day 1, and CK-MB levels still remained high on Day 7. A higher concentration of Cd was observed in the heart of CdSe/ZnS QDs exposed mice on Day 42, whereas no Cd was detected in the control group, which suggested that QDs can accumulate in heart. No significant histopathological changes and cardiac function were observed in all mice at different time after treatment. Increased level of glutathione peroxidase (GPx) and malondialdehyde (MDA) was observed in mice administered with high dose QDs on Day 1, and increased level of total antioxidant capacity (T-AOC) and MDA activities was observed on Day 42. These results indicated that CdSe/ZnS QDs could accumulate in heart, cause some biochemical indicators change, induce oxidative damage, and have cardiotoxicity. Our findings might provide valuable information on the biological safety evaluation of the cardiovascular system of QDs.

S100A12 Serum Levels and PMN Counts Are Elevated in Childhood Systemic Vasculitides Especially Involving Proteinase 3 Specific Anti-neutrophil Cytoplasmic Antibodies.

Objectives: Chronic primary systemic vasculitidies (CPV) are a collection of rare diseases involving inflammation in blood vessels, often in multiple organs. CPV can affect adults and children and may be life- or organ-threatening. Treatments for adult CPV, although effective, have known severe potential toxicities; safety and efficacy of these drugs in pediatric patients is not fully understood. There is an unmet need for biologic measures to assess the level of disease activity and, in turn, inform treatment choices for stopping, starting, or modifying therapy. This observational study determines if S100 calcium-binding protein A12 (S100A12) and common inflammatory indicators are sensitive markers of disease activity in children and adolescents with CPV that could be used to inform a minimal effective dose of therapy. Methods: Clinical data and sera were collected from 56 participants with CPV at study visits from diagnosis to remission. Serum concentrations of S100A12, C-reactive protein (CRP) and hemoglobin (Hb) as well as whole blood cell counts and erythrocyte sedimentation rate (ESR) were measured. Disease activity was inferred by physician's global assessment (PGA) and the pediatric vasculitis activity score (PVAS). Results: Serum concentrations of standard markers of inflammation (ESR, CRP, Hb, absolute blood neutrophil count), and S100A12 track with clinically assessed disease activity. These measures-particularly neutrophil counts and sera concentrations of S100A12-had the most significant correlation with clinical scores of disease activity in those children with vasculitis that is associated with anti-neutrophil cytoplasmic antibodies (ANCA) against proteinase 3. Conclusions: S100A12 and neutrophil counts should be considered in the assessment of disease activity in children with CPV particularly the most common forms of the disease that involve proteinase 3 ANCA. Key messages: - In children with chronic primary systemic vasculitis (CPV), classical measures of inflammation are not formally considered in scoring of disease activity. - Inflammatory markers-specifically S100A12 and neutrophil count-track preferentially with the most common forms of childhood CPV which affect small to medium sized vessels and involve anti neutrophil cytoplasmic antibodies (ANCA) against proteinase-3.