Procyanidin B2 alleviates uterine toxicity induced by cadmium exposure in rats: The effect of oxidative stress, inflammation, and gut microbiota.

Environmental exposure to hazardous materials causes enormous socioeconomic problems due to its deleterious impacts on human beings, agriculture and animal husbandry. As an important hazardous material, cadmium can promote uterine oxidative stress and inflammation, leading to reproductive toxicity. Antioxidants have been reported to attenuate the reproductive toxicity associated with cadmium exposure. In this study, we investigated the potential protective effect of procyanidin oligosaccharide B2 (PC-B2) and gut microbiota on uterine toxicity induced by cadmium exposure in rats. The results showed that the expression levels of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were reduced in utero. Proinflammatory cytokines (including tumor necrosis factor-α, interleukin-1ß and interleukin-6), the NLRP3 inflammasome, Caspase-1 and pro-IL-1ß were all involved in inflammatory-mediated uterine injury. PC-B2 prevented CdCl2-induced oxidative stress and inflammation in uterine tissue by increasing antioxidant enzymes and reducing proinflammatory cytokines. Additionally, PC-B2 significantly reduced cadmium deposition in the uterus, possibly through its significant increase in MT1, MT2, and MT3 mRNA expression. Interestingly, PC-B2 protected the uterus from CdCl2 damage by increasing the abundance of intestinal microbiota, promoting beneficial microbiota, and inhibiting harmful microbiota. This study provides novel mechanistic insights into the toxicity of environmental cadmium exposure and indicates that PC-B2 could be used in the prevention of cadmium exposure-induced uterine toxicity.

Corrigendum: Combined intestinal metabolomics and microbiota analysis for acute endometritis induced by lipopolysaccharide in mice.

[This corrects the article DOI: 10.3389/fcimb.2021.791373.].

The costs of "blue sky": environmental regulation and employee income in China.

Strict environmental regulations may change the behavioral decisions of firms. Based on the exogenous impact of the Chinese Central Government's inclusion of environmental performance in the assessment targets of municipal officials in 2007, this study uses the difference-in-difference method to explore the impact of environmental regulations on employee income. We find that (1) environmental regulations will significantly reduce the average wage level of employees in polluting industries and have no significant impact in nonpolluting industries. (2) This effect is more pronounced in eastern China, where environmental regulations are more stringent, and in areas where political promotion incentives are stronger. (3) Mechanistic analysis finds that environmental regulations will affect employee income by increasing costs and constraining financing. (4) More importantly, we find that the decline in the average wage level of firms is mainly due to the decline in the average wage level of ordinary employees, and the average wage level of management has not decreased significantly, which means that environmental regulations have expanded the functional income distribution. Our findings contribute to a comprehensive understanding of the effectiveness of environmental regulatory policy implementation and associated economic cost issues.

Combined Intestinal Metabolomics and Microbiota Analysis for Acute Endometritis Induced by Lipopolysaccharide in Mice.

Endometritis is generally caused by bacterial infections, including both acute and chronic infections. In the past few decades, accumulated evidence showed that the occurrence of diseases might be related to gut microbiota. The progression of diseases is previously known to change the composition and diversity of intestinal microbiota. Additionally, it also causes corresponding changes in metabolites, primarily by affecting the physiological processes of microbiota. However, the effects of acute endometritis on intestinal microbiota and its metabolism remain unknown. Thus, the present study aimed to assess the effects of acute endometritis on intestinal microbes and their metabolites. Briefly, endometritis was induced in 30 specific pathogen-free (SPF) BALB/c female mice via intrauterine administration of lipopolysaccharide (LPS) after anesthesia. Following this, 16S rRNA gene sequencing and liquid chromatogram-mass spectrometry (LC-MS) were performed. At the genus level, the relative abundance of Klebsiella, Lachnoclostridium_5, and Citrobacter was found to be greater in the LPS group than in the control group. Importantly, the control group exhibited a higher ratio of Christensenellaceae_R-7_group and Parasutterella. Furthermore, intestinal metabolomics analysis in mice showed that acute endometritis altered the concentration of intestinal metabolites and affected biological oxidation, energy metabolism, and biosynthesis of primary bile acids. The correlation analysis between microbial diversity and metabolome provided a basis for a comprehensive understanding of the composition and function of the microbial community. Altogether, the findings of this study would be helpful in the prevention and treatment of acute endometritis in the future.

Effect of Inonotus obliquus polysaccharide on composition of the intestinal flora in mice with acute endometritis.

Inonotus obliquus Polysaccharide (IOP) is a large molecule extracted from Inonotus obliqus, a medicinal fungus, which has a wide range of biological activities and has been shown to be associated with inflammation. The purpose of this study is to investigate whether IOP can help to reduce acute endometritis by regulating intestinal flora. We observed pathological changes in mice with endometritis following treatment with IOP and evaluated changes in the levels of interleukin-6 (IL-6), interleukin-1ß (IL-1ß) and tumor necrosis factor α (TNF-α), and further studied the effects of IOP on the intestinal flora of endometritis mice using 16S rRNA high-throughput sequencing. The results showed that IOP improved the condition of uterine tissues and reduced the release of pro-inflammatory cytokines. Meanwhile, the 16S rRNA sequencing results showed that IOP could regulate the changes in intestinal microflora at the level of genera, possibly by changing the relative abundance of some genera.