Surface water extracts impair gene profiles and differentiation in human mesenchymal stem cells

Evaluation of the iodoacetic acid effects on adipose-derived mesenchymal stem cells and alteration of their osteogenic differentiation potential by inducing oxidative stress

Drinking water disinfection byproducts (DBPs) can adversely affect human health. Iodoacetic acid (IAA) is a DBP associated with most cytotoxic, genotoxic, and mutagenic disorders. However, its effects on the osteogenic differentiation of adipose-derived mesenchymal stem cells, ADMSCs, remain unknown. In this study, the cytotoxicity, cytokine response, phenotype, and osteogenic differentiation potential of the ADMSCs were evaluated in the presence and absence of IAA. It was revealed that IAA induces a toxic response at a concentration of 2 µM. Flow cytometry confirmed no significant alterations in ADMSCs' phenotype after treatment with 10 nM and 1 µM IAA for 48 h. IAA led to a decreased secretion of IL-8, a dose-dependent secretion of IL-10, and no significant change in the secretion of IL-6 compared to the control group. The osteogenic differentiation ability of ADMSCs in the presence of different concentrations and exposure times to IAA was evaluated by measurement of alkaline phosphatase activity, calcium content, Alizarin Red S, real-time PCR, and immunocytochemistry assays. The findings show that the osteogenic differentiation of ADMSCs decreased at higher concentrations of IAA and extended exposure time, confirming the potential disruption of the osteogenic differentiation of ADMSCs.

Integrated respiratory toxicity of municipal wastewater to human bronchial epithelial cells and 3D bronchospheres

Respiratory symptoms have been reported in wastewater treatment workers and residents living close to sewage treatment plant. However, toxicological research about the respiratory hazards of municipal wastewater is scarce. The present study aims to gain insight into the comprehensive respiratory hazards induced by the contaminant mixtures in municipal wastewater. The integrated respiratory hazards of effluents from four secondary wastewater treatment plants (SWTPs), a tertiary wastewater treatment plant (TTP), and a constructed wetland (CW) were evaluated using normal human bronchial epithelial cells (NHBE) bioassay, and toxicity reduction efficiency of various treatment techniques was analyzed. Effluents caused cytotoxicity, oxidative damage, inflammation response with the increased levels of IL-6 and CXCL8, and impaired barrier integrity with decreased expressions of ZO-1 and occludin in NHBE. Further, the effluents inhibited the development of 3D bronchospheres, increased irregular surface and cell debris, and suppressed the formation of luminal structures. TTP E effluent significantly increased the expression of MUC5AC in bronchospheres. The integrated biomarker response (IBR) of the influent was removed by 40.2% at SWTPs, 18.2% at TTP, and 36.6% at CW, respectively. The IBR of the final effluents from SWTPs, TTP, and CW were 7.2, 7.7, and 7.7, respectively. Significant correlation with toxicity biomarkers was frequently observed for stearyl alcohol, o-cresol, phenanthrene, butylated hydroxytoluene, and dimethyl phthalate. The present study provided human relevant evidence concerning the adverse respiratory effects associated with discharge. The necessity for deep water treatment, performance optimization, and the potential means were suggested for improving water quality and protecting respiratory health.

The expression of RBPJ and its potential role in rheumatoid arthritis

BACKGROUND

Recombination signal-binding protein for immunoglobulin kappa J region (RBPJ) is a transcriptional regulator that plays an important role in maintaining immune homeostasis. This study aimed to estimate the expression of RBPJ in rheumatoid arthritis (RA) patients and investigate its relationship with RA.

METHODS

A total of 83 newly diagnosed RA patients and 70 healthy controls were included. mRNA was extracted from peripheral blood mononuclear cells (PBMCs), and the expression of RBPJ was detected using quantitative real-time PCR (qRT‒PCR). An RA dataset (GSE89408) was obtained from the Gene Expression Omnibus (GEO) database, and RA synovial tissues were divided into two groups. The differentially expressed genes (DEGs) were selected with the "DESeq2" R package.

RESULTS

RBPJ expression was lower in RA patients than in health controls and was negatively correlated with the DAS28 score, C-reactive protein (CRP) level and erythrocyte sedimentation rate (ESR). RA synovial tissues from GSE89408 were classified into RBPJ-low (≤ 25%) and RBPJ-high (≥ 75%) groups according to RBPJ expression, and 562 DEGs were identified. Gene Ontology (GO) enrichment analyses revealed that the DEGs significantly affected the regulation of T cell activation and lymphocyte/mononuclear cell differentiation. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that the most enriched pathways of DEGs were the T cell receptor signaling pathway, Th1/2 and Th17 cell differentiation, the PI3K - Akt signaling pathway and cytokine‒cytokine receptor interaction. CytoHubba Plugin revealed that most of the top 10 genes were involved in osteoclast differentiation, the T cell receptor signaling pathway and cytokine‒cytokine receptor interaction.

CONCLUSIONS

RBPJ expression was significantly lower in RA patients and negatively correlated with disease activity. GEO dataset analysis demonstrated that RBPJ may be involved in osteoclast differentiation, T cell activation and differentiation, and the T cell receptor signaling pathway. Our research may contribute to understanding the potential mechanisms by which RBPJ regulates T cell differentiation and cytokine‒cytokine receptor interaction in RA patients.

Integrated toxicity of secondary, tertiary, wetland effluents on human stem cells triggered by ERα and PPARγ agonists

Residual pollutants in discharged and reused water pose both direct and indirect human exposure. However, health effects caused by whole effluent remain largely unknown due to the lack of human relevant model for toxicity test. Effluents from four secondary wastewater treatment plants (SWTPs), a tertiary wastewater treatment plant (TWTP) and a constructed wetland (CW) were evaluated for the integrated toxicity of the organic extractions. Multiple-endpoint human mesenchymal stem cells (MSCs) assay was used as an in vitro model relevant to human health. The effluents caused cytotoxicity, oxidative stress and genotoxicity in MSCs. The osteogenic and neurogenic differentiation were inhibited and the adipogenic differentiation were stimulated by some of the effluent extractions. The SWTP, TWTP and CW treatments reduced integrated biomarker response (IBR) by 26.3 %, 17.5 % and 33.3 % respectively, where the IBR values of final CW (8.3) and TWTP (8.2) effluents were relatively lower than SWTPs (9.1). Among multiple biomarkers, the inhibition of osteogenesis was the least reduced by wastewater treatment. Besides, ozone disinfection in tertiary treatment increased cytotoxicity and differentiation effects suggesting the generation of toxic products. The mRNA expressions of estrogen receptor alpha (ERα) and peroxisome proliferator-activated receptor gamma (PPARγ) were significantly upregulated by effluents. The inhibitory effects of effluents on neural differentiation were mitigated after antagonizing ERα and PPARγ in the cells. It is suggested that ERα and PPARγ agonists in effluents were largely accountable for the impairment of stem cell differentiation. Besides, the concentrations of n-C29H60, o-cresol, fluorene and phenanthrene in the effluents were significantly correlated with the intergrated stem cell toxicity. The present study provided toxicological evidence for the relation between water contamination and human health, with an insight into the key toxicity drivers. The necessity for deep water treatment and the potential means were suggested for improving water quality.

Toxicity removal from contaminated water by constructed wetlands assessed using multiple biomarkers in human stem cell assays

Constructed wetlands (CWs) have been developed rapidly as a sustainable water treatment technique. However, the capability of CWs for remediating the contaminated water based on toxicity assessment remains largely unknown. Four surface flow CWs and two integrated surface-subsurface flow CWs, from five cities in central and eastern region of China were evaluated, concerning the adverse effects of effluents and the toxicity reduction efficiency. Human bone marrow mesenchymal stem cells (hBMSCs) were employed as a human relevant in vitro model. The influent extractions caused cytotoxicity in a dose-dependent manner. The non-cytotoxic dilutions of the influents enhanced the genotoxicity marker γ-H2AX and reactive oxygen species levels. In addition, the influent repressed the osteogenic and neurogenic differentiation, and stimulated the adipogenic differentiation. Cytotoxicity of the contaminated water was reduced by 54 %-86 % after treatment with CWs. CWs were effective to remove part of the sub-lethal effects, with lower reduction than cytotoxicity. The integrated biomarker response (IBR) value of the effluents from the six CWs is lower than that of four secondary and one tertiary wastewater treatment plants. The IBR of the six CWs influents were in the range of 8.6-10.6, with a reduction of 15-50 % after the pollution restoration in CWs. The two integrated surface-subsurface flow CWs achieved higher IBR removal than the four surface flow CWs, possibly due to improved treatment effects by the combined systems. Cytotoxic and genotoxic effects of polar fractions in the CW effluents were stronger than the medium-polar and the non-polar fractions. Besides, PPARγ agonists present in the effluents played crucial roles and ERα agonists may make modest contributions. The present study enhances understanding of the role of CWs in achieving safe wastewater reclamation and provides evidence for further improving toxicity reduction in CWs performance.

Effects of triclosan exposure on stem cells from human exfoliated deciduous teeth (SHED) fate

Triclosan (TCS), a widely used broad-spectrum antibacterial agent and preservative, is commonly found in products and environments. Widespread human exposure to TCS has drawn increasing attention from researchers concerning its toxicological effect. However, minimal studies have focused on the impact of TCS exposure on human stem cells. Therefore, the aim of the present study was to evaluate the effects of TCS exposure on stem cells from human exfoliated deciduous teeth (SHED) and its molecular mechanisms. A series of experimental methods were conducted to assess cell viability, morphology, proliferation, differentiation, senescence, apoptosis, mitochondrial function, and oxidative stress after SHED exposure to TCS. Furthermore, transcriptome analysis was applied to investigate the response of SHED to different concentrations of TCS exposure and to explore the molecular mechanisms. We demonstrated that TCS has a dose-dependent proliferation and differentiation inhibition of SHED, while promoting cellular senescence, mitochondrial dysfunction, endoplasmic reticulum (ER) stress, and oxidative stress, as well as significantly induces apoptosis and autophagy flux inhibition at high concentrations. Interestingly, no significant morphological changes in SHED were observed after TCS exposure. Transcriptome analysis of normal and TCS-induced SHED suggested that SHED may use different strategies to counteract stress from different concentrations of TCS and showed significant differences. We discovered that TCS mediates cellular injury of SHED by enhancing the expression of PTEN, thereby inhibiting the phosphorylation levels of PI3K and AKT as well as mTOR expression. Collectively, our findings provide a new understanding of the toxic effects of TCS on human stem cell fate, which is important for determining the risk posed by TCS to human health.