Oxidative damage to mitochondrial DNA in maternal zebrafish (Danio rerio) exposed to dibutyl phthalate at environmentally relevant level.

Dibutyl phthalate (DBP) is a widely-used plasticizer that is dispersed in various environments, causing significant pollution and health risks. The toxic mechanism of DBP has been discussed in recent years, while the susceptibility of mitochondrial DNA (mtDNA) to DBP exposure and the resulting damage remain unclear. In this study, maternal zebrafish were exposed to environmentally relevant concentration of DBP for 0, 2, 4, and 6 weeks. Results showed that DBP exposure impaired health status, leading to the reduced body length and weight, condition factor, hepatosomatic index, and gonadosomatic index. Furthermore, DBP exposure induced oxidative stress and ATP deficiency in the gill and liver in a time-dependent manner. The oxidized mtDNA (ox-mtDNA) levels in the D-loop and ND1 regions were assessed in different tissues, showing distinct response patterns. The high energy-consuming tissues such as heart, brain, gill, and liver exhibited elevated susceptibility to mitochondrial damage, with a rapid increase in ox-mtDNA levels in the short term. Conversely, in muscle, ovary, eggs, and offspring, ox-mtDNA gradually accumulated over the exposure period. Notably, the ox-mtDNA levels in the D-loop region of blood showed a prompt response to DBP exposure, making it convenient for evaluation. Additionally, decreased hatching rates, increased mortality, lipoperoxidation, and depressed swimming performance were observed in offspring following maternal DBP exposure, suggesting the inherited impairments of maternal mtDNA. These findings highlight the potential for ox-mtDNA to serve as a convenient biomarker for environmental contamination, aiding in ecological risk assessment and forewarning systems in aquatic environment.

Mitochondrial DNA Stress-Mediated Health Risk to Dibutyl Phthalate Contamination on Zebrafish (Danio rerio) at Early Life Stage.

Plastics contaminations are found globally and fit the exposure profile of the planetary boundary threat. The plasticizer of dibutyl phthalate (DBP) leaching has occurred and poses a great threat to human health and the ecosystem for decades, and its toxic mechanism needs further comprehensive elucidation. In this study, environmentally relevant levels of DBP were used for exposure, and the developmental process, oxidative stress, mitochondrial ultrastructure and function, mitochondrial DNA (mtDNA) instability and release, and mtDNA-cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling pathway with inflammatory responses were measured in zebrafish at early life stage. Results showed that DBP exposure caused developmental impairments of heart rate, hatching rate, body length, and mortality in zebrafish embryo. Additionally, the elevated oxidative stress damaged mitochondrial ultrastructure and function and induced oxidative damage to the mtDNA with mutations and instability of replication, transcription, and DNA methylation. The stressed mtDNA leaked into the cytosol and activated the cGAS-STING signaling pathway and inflammation, which were ameliorated by co-treatment with DBP and mitochondrial reactive oxygen species (ROS) scavenger, inhibitors of cGAS or STING. Furthermore, the larval results suggest that DBP-induced mitochondrial toxicity of energy disorder and inflammation were involved in the developmental defects of impaired swimming capability. These results enhance the interpretation of mtDNA stress-mediated health risk to environmental contaminants and contribute to the scrutiny of mitochondrial toxicants.

Dibutyl phthalate exposure induced mitochondria-dependent ferroptosis by enhancing VDAC2 in zebrafish ZF4 cells.

Dibutyl phthalate (DBP) contamination has raised global concern for decades, while its health risk with toxic mechanisms requires further elaboration. This study used zebrafish ZF4 cells to investigate the toxicity of ferroptosis with underlying mechanisms in response to DBP exposure. Results showed that DBP induced ferroptosis, characterized by accumulation of ferrous iron, lipid peroxidation, and decrease of glutathione peroxidase 4 levels in a time-dependent manner, subsequently reduced cell viability. Transcriptome analysis revealed that voltage-dependent anion-selective channel (VDAC) in mitochondrial outer membrane was upregulated in ferroptosis signaling pathways. Protecting mitochondria with a VDAC2 inhibitor or siRNAs attenuated the accumulation of mitochondrial superoxide and lipid peroxides, the opening of mitochondrial permeability transition pore (mPTP), and the overload of iron levels, suggesting VDAC2 oligomerization mediated the influx of iron into mitochondria that is predominant and responsible for mitochondria-dependent ferroptosis under DBP exposure. Furthermore, the pivotal role of activating transcription factor 4 (ATF4) was identified in the transcriptional regulation of vdac2 by ChIP assay. And the intervention of atf4b inhibited DBP-induced VDAC2 upregulation and oligomerization. Taken together, this study reveals that ATF4-VDAC2 signaling pathway is involved in the DBP-induced ferroptosis in zebrafish ZF4 cells, contributing to the in-depth understanding of biotoxicity and the ecological risk assessment of phthalates.

Therapeutic outcomes of mycophenolate mofetil and glucocorticoid in thyroid-associated ophthalmopathy patients.

Objective: To analyze the efficacy of mycophenolate mofetil (MMF) and glucocorticoid administration in patients with thyroid-associated ophthalmopathy (TAO). Methods: Sixty patients with moderate to severe TAO treated in Jingzhou Central Hospital from January 2022 to June 2022 were selected and enrtolled in this study. The subjects were divided into experimental group (n=30) and control group (n=30) based on the random number table method. Glucocorticoid pulse therapy was provided in the control group, while MMF was given in the experimental group on the basis of Control group. Clinical activity score (CAS), quality of life (QOL), visual acuity, eyelid fissure width, intraocular pressure, and degree of exophthalmos were observed at the time of admission and at the 12th week and 24th post-treatment weeks. We compared the immune function (TRAb, IL-6, and CD4+/CD8+) of the two groups pre-treatment and 24 weeks post-treatment, and evaluated the clinical therapeutic effect. Results: The clinical effective rates at 12 and 24 weeks in the experimental group were higher (73.3% and 83.3%) than those in the control group (46.7% and 60.0%) (P <0.05). After 12 weeks of treatment, patients' CAS scores, and bilateral lid fissure width decreased and right eye visual acuity increased in the control group compared with those before treatment (P < 0.05); further, after 24 weeks of treatment, patients' QOL scores and bilateral visual acuity increased and CAS scores, bilateral lid fissure width and proptosis decreased compared with those before treatment, and patients' QOL scores, CAS scores and bilateral proptosis improved more than those at 12 weeks of treatment (P <0.05). Additionally, greater improvements were observed in the patients' QOL and CAS scores, and proptosis after 24-week treatment than after 12-week treatment (P<0.05). In the experimental group, the QOL score and binocular visual acuity increased, whereas the CAS score, intraocular pressure, lid width, and proptosis decreased after 12 weeks of treatment as compared to the values of these parameters in the pre-treatment period (P < 0.05); after 24 weeks of treatment, greater improvements were established in the ocular-related indexes improved compared to the pre-treatment period and after 12 weeks of treatment (P < 0.05). After 12 weeks of treatment, the patients in the experimental group had more considerable improvements in the right visual acuity, right intraocular pressure, and left lid fissure width than the control group (P < 0.05); at 24 weeks of treatment, patients in the experimental group had greater improvements in the QOL score, bilateral visual acuity, intraocular pressure, bilateral lid fissure width, and bilateral proptosis than the control group (P < 0.05). No significant differences were found in the values of TRAb, IL-6, and CD4+/CD8+ between the two groups before treatment (P>0.05); the values of TRAb, IL-6, and CD4+/CD8+ in the experimental group was significantly lower than those before treatment and in the control group after 24weeks of treatment. (P>0.05). No statistically significant difference was observed in the incidence of liver damage and menstrual disorders between the two groups during the 24 weeks of treatment (P>0.05). Conclusion: The combination of oral MMF and glucocorticoid shock therapy is an effective drug for the treatment of patients with moderately active TAO.

Hierarchical CoNiO2 Microflowers Assembled by Mesoporous Nanosheets as Efficient Electrocatalysts for Hydrogen Evolution Reaction.

In order to alleviate the energy crisis and propel a low-carbon economy, hydrogen (H2) plays an important role as a renewable cleaning resource. To break the hydrogen evolution reaction (HER) bottleneck, we need high-efficiency electrocatalysts. Based on the synergistic effect between bimetallic oxides, hierarchical mesoporous CoNiO2 nanosheets can be fabricated. Combining physical representations with electrochemical measurements, the resultant CoNiO2 catalysts present the hierarchical microflowers morphology assembled by mesoporous nanosheets. The ultrathin two-dimensional nanosheets and porous surface characteristics provide the vast channels for electrolyte injection, thus endowing CoNiO2 the outstanding HER performance. The excellent performance with a fewer onset potential of 94 mV, a smaller overpotential at 10 mA cm-2, a lower Tafel slope of 109 mV dec-1 and better stability after 1000 cycles makes CoNiO2 better than that of metallic Co and metallic Ni.

Insight into the health risk implicated in mitochondrial toxicity of dibutyl phthalate exposure on zebrafish (Danio rerio) cells.

Dibutyl phthalate (DBP) is commonly applied plasticizer in plastic products such as face masks, easily leaches or migrates into environment and its widespread contamination posed profound health risks. Further concerns rise regarding to the toxicity of DBP at subcellular level, while little is known about the ranging effects on mitochondrial susceptibility. Present study investigated the mitochondrial impairments with implicated cell death upon DBP exposure on zebrafish cells. Elevated mitochondrial oxidative stress reduced its membrane potential and count, enhanced fragmentation, and impaired ultrastructure that showed smaller size and cristae rupture. Afterwards, the critical function of ATP synthesis was damaged and the stabilized binding capacity between DBP with mitochondrial respiratory complexes was simulated by the molecular docking. And the top pathways enrichment of mitochondrion and metabolism by transcriptome analyses verified the mitochondrial dysfunction that indicated the human diseases risks. The mitochondrial DNA (mtDNA) replication and transcription with DNA methylation modifications were also disrupted, reflecting the genotoxicity on mtDNA. Moreover, the activated autophagy and apoptosis underlying mitochondrial susceptibility integrated into cellular homeostasis changes. These findings provide the first systemic evidence broadening and illustrating the mitochondrial toxicity of DBP exposure on zebrafish model that raise concern on phthalates contamination and ecotoxicological evaluation.