In Utero Exposure to Fine Particles Decreases Early Birth Weight of Rat Offspring and TLR4/NF-κB Expression in Lungs

Bioinformatics analysis of ferroptosis in frozen shoulder

OBJECTIVES

Frozen shoulder is a common shoulder disease that significantly affects the patient's life and work. Ferroptosis is a new type of programmed cell death, which is involved in many diseases. However, there have been no studies reporting the relationship between frozen shoulders and ferroptosis. This study identified potential molecular markers of ferroptosis in frozen shoulders to provide more effective strategies for the treatment of frozen shoulders.

METHODS

GSE238053 was downloaded from the Gene Expression Omnibus (GEO) dataset and intersected with ferroptosis genes to obtain differentially expressed genes (DEGs). The signaling pathways and biological functions of DEGs were performed by WebGestalt and Metascape. The interactions related to these DEGs and the key genes between frozen shoulders and ferroptosis was performed by STRING and Cytoscape. A frozen shoulders rat model was used to validate our predicted genes, Western Blot and qRT-PCR was used to assess the expression levels of our genes of interest.

RESULTS

A total of 34 DEGs between GSE238053 and Ferroptosis Database were obtained, most of which were involved in the HIF-1 signaling pathway and inflammatory response. A protein-protein interaction network was obtained by Cytoscape and the key genes (IL-6, HMOX1 and TLR4) were screened by MCODE. Our results of Western Blot showed that the protein expression level of TLR4 and HMOX1 were elevated, and the protein level of IL-6 decreased in frozen shoulders rat model. The mRNA level after frozen shoulders showed that IL-6 was upregulated, whereas TLR4 and HMOX1were downregulated.

CONCLUSIONS

The results demonstrated that ferroptosis may affect the pathological process of frozen shoulders through these signaling pathways and genes. The identification of IL-6, HMOX1 and TLR4 genes can provide new therapeutic targets for frozen shoulders.

Maternal urban particulate matter (SRM 1648a) exposure disrupted the cellular immune homeostasis during early life: The potential attribution of altered placental transcriptome profile

Ambient fine particular matter (PM2.5) exposure has been associated with numerous adverse effects including triggering functional disorders of the placenta and inducing immune imbalance in offspring. However, how maternal PM2.5 exposure impacts immune development during early life is not fully understood. In the current study, we exposed mice with low-, middle-, and high-dose PM2.5 during pregnancy to investigate the potential link between the transcriptional changes in the placenta and immune imbalance in mice offspring induced by PM2.5 exposures. Using flow cytometry, we found that the proportions of B cells, CD3+CD4+ T cells, CD3+CD8+ T cells, and macrophage (Mφ) cells were altered in the blood of PM2.5-exposed mice pups but not dendritic cells (DCs) and natural killer cells (NKs). Using bulk RNA sequencing, we found that PM2.5 exposure altered the transcriptional profile which indicated an inhibition of the complement and coagulation cascades in the placenta. Weighted gene co-expression network analysis (WGCNA) revealed the potential crosstalk between the perturbation of placental gene expression and the changes of immune cell subsets in pups on postnatal day 10 (PND10). Specifically, WGCNA identified a cluster of genes including Defb15, Defb20, Defb25, Cst8, Cst12, and Adam7 that might regulate the core immune cell types in PND10 pups. Although the underlying mechanisms of how maternal PM2.5 exposure induces peripheral lymphocyte disturbance in offspring still remain much unknown, our findings here shed light on the potential role of placental dysfunction in these adverse effects.

Implication of ferroptosis in hepatic toxicity upon single or combined exposure to polystyrene microplastics and cadmium

Microplastics (MPs) are a newly emerging type of pollutants. To date, MPs have been found in the atmosphere, soil, water, and even in human samples, posing a non-negligible threat to humans. Furthermore, multiple heavy metals have been found to co-exist with MPs or be absorbed by MPs. This leads to a widespread concern about their combined toxicity, which is currently elusive. Herein, we investigated the single or combined toxic effects of polystyrene MPs (PS-MPs) and cadmium chloride (CdCl2) on the liver and hepatocytes. After co-incubation, cadmium (Cd) can be absorbed by PS-MPs, resulting in physiochemical alterations of PS-MPs. In vivo and in vitro experiments revealed that PS-MPs solely or together with CdCl2 induced ferroptosis in hepatocytes, a newly defined programmed cell death characterized by lipid oxidation and iron accumulation. PS-MPs exerted more ferroptotic effect on hepatocytes than CdCl2, and combined exposure to PS-MPs and CdCl2 enhanced their ferroptotic effect, mainly by stimulating reactive oxygen species (ROS) production and inhibiting antioxidant activity. Upon single or combined exposure to PS-MPs and CdCl2, the induction of ferroptosis in hepatocytes can be inhibited by N-acetyl-cysteine (NAC, an ROS scavenger), deferoxamine (DFO, an iron chelator), and particularly ferrostatin-1 (Fer-1, a specific ferroptosis inhibitor). Fer-1 efficiently rescued the cell viability of hepatocytes upon exposure to PS-MPs and CdCl2 through enhancing the antioxidant system via upregulating GPX4 and SLC7A11. These findings would contribute to an in-depth understanding of the single and combined toxicity of microplastics and cadmium.

Effects of maternal urban particulate matter SRM 1648a exposure on birth outcomes and offspring growth in mice

The association between exposure to particulate matter (PM) during pregnancy and abnormal birth outcomes is still inconclusive. This study aims to provide more evidence for this public health concern by investigating birth outcomes and the growth of offspring in mice exposed to PM during pregnancy. C57BL/6 J pregnant mice were exposed to PM via nasal drip at three doses or solvent control. The dam weight gain was recorded during pregnancy. The number of pups, pup weight, and placental weight were recorded at embryonic day 18.5 (E18.5) necropsy. For mice that gave birth naturally, we calculated the gestation length and measured the body weight of offspring once a week from the 1st to the 6th week after birth. The results showed that there were no significant differences in maternal body weight gain, conception rate, pregnancy duration, and litter size among different groups. There were no significant differences in fetal weight, placental weight, and fetal/placental weight ratio at E18.5. Weight gain in offspring was reduced after birth. The average body weight of offspring in the high-dose group was significantly lower than that in the control group at weeks 5 in female pups. There were no significant differences in the body weight of male offspring among groups from 1st to the 6th. Together, our study indicated that maternal exposure to PM did not significantly impact birth outcomes of C57BL/6 J mice but affected growth trajectories in offspring after birth in a dose- and fetal sex-dependent manner.

Distinct adverse outcomes and lipid profiles of erythrocytes upon single and combined exposure to cadmium and microplastics

The growing accumulation of environmental microplastics (MPs) has become a global concern. MPs are capable to interact with other environmental contaminants leading to altered toxicity. Red blood cells (RBCs), are the target with highest priority for most of toxic xenobiotics after entering blood stream. Whether co-existence of MPs changes the toxicity of cadmium, a typical hemolysis inducer, in RBCs is unknown. We investigated the adverse effects of CdCl₂ and Polystyrene-MPs (PS-MPs) on RBCs in mice. We found that CdCl₂ induced mild microcytic hypochromic anemia while PS-MPs induced polycythemia vera, indicating distinct outcomes between them. Moreover, co-treatment of PS-MPs with CdCl₂ did not change the phenotype of microcytic hypochromic anemia, indicating an antagonistic relationship between CdCl₂ and PS-MPs. However, the lipid profiles were also distinct between single exposure and combined exposure to CdCl₂ and PS-MPs. The significant changed lipids were mainly involved in altering the physiochemical or biological properties of RBCs, including decreased membrane components, disrupted bilayer thickness and intrinsic lipid curvature. These results indicated impaired membrane functions of RBCs. The altered lipid profiles observed in the current study may represent new and previously unrecognized harmful characteristics of cadmium and MPs on erythrocytes at low dose without apparent induction of anemia.