NAC transcription factor SlNOR-like1 plays a dual regulatory role in tomato fruit cuticle formation.

The plant cuticle is an important protective barrier on the plant surface, constructed mainly by polymerized cutin matrix and a complex wax mixture. Although the pathway of plant cuticle biosynthesis has been clarified, knowledge of the transcriptional regulation network underlying fruit cuticle formation remains limited. In the present work, we discovered that tomato fruits of the NAC transcription factor SlNOR-like1 knockout mutants (nor-like1) produced by CRISPR/Cas9 [clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9] displayed reduced cutin deposition and cuticle thickness, with a microcracking phenotype, while wax accumulation was promoted. Further research revealed that SlNOR-like1 promotes cutin deposition by binding to the promoters of glycerol-3-phosphate acyltransferase6 (SlGPAT6; a key gene for cutin monomer formation) and CUTIN DEFICIENT2 (SlCD2; a positive regulator of cutin production) to activate their expression. Meanwhile, SlNOR-like1 inhibits wax accumulation, acting as a transcriptional repressor by targeting wax biosynthesis, and transport-related genes 3-ketoacyl-CoA synthase1 (SlKCS1), ECERIFERUM 1-2 (SlCER1-2), SlWAX2, and glycosylphosphatidylinositol-anchored lipid transfer protein 1-like (SlLTPG1-like). In conclusion, SlNOR-like1 executes a dual regulatory effect on tomato fruit cuticle development. Our results provide a new model for the transcriptional regulation of fruit cuticle formation.

Genome-wide identification of SINA gene family in Medicago truncatula and functional analysis of MtSINAL7.

Ubiquitination is an essential biological process that is vital for maintaining cellular activity and plays a critical role in precisely regulating protein levels within cells. The SINA (seven in absentia) protein belongs to the RING-type E3 ubiquitin ligase, which is one of the key enzymes involved in the process of ubiquitination. However, there have been few reports on the genome-wide identification of SINA gene family and the functional analysis of its specific genes, particularly in leguminous plants. In this study, a total of 20 MtSINA genes were identified from the genomes of Medicago truncatula, and classified into three subfamilies. These genes are distributed on 7 of 8 chromosomes with chromosome preference. The gene structures of most MtSINA genes are quite similar, and all MtSINA proteins contain conserved RING and SINA functional domains. Moreover, various cis-regulatory elements related to abiotic stress and hormone signals were found in the promoters of MtSINA genes. The expression profile indicates that a majority of MtSINA genes exhibit a significant response to abiotic stress. Furthermore, the study characterized the function of MtSINAL7 in plants and discovered its pivotal role in improving plant stress resistance. In summary, this study provides a new insight into the potential functions of MtSINA genes in Medicago truncatula.

Transcription factor SlBEL2 interferes with GOLDEN2-LIKE and influences green shoulder formation in tomato fruits.

Chloroplasts play a crucial role in plant growth and fruit quality. However, the molecular mechanisms of chloroplast development are still poorly understood in fruits. In this study, we investigated the role of the transcription factor SlBEL2 (BEL1-LIKE HOMEODOMAIN 2) in fruit of Solanum lycopersicum (tomato). Phenotypic analysis of SlBEL2 overexpression (OE-SlBEL2) and SlBEL2 knockout (KO-SlBEL2) plants revealed that SlBEL2 has the function of inhibiting green shoulder formation in tomato fruits by affecting the development of fruit chloroplasts. Transcriptome profiling revealed that the expression of chloroplast-related genes such as SlGLK2 and SlLHCB1 changed significantly in the fruit of OE-SlBEL2 and KO-SlBEL2 plants. Further analysis showed that SlBEL2 could not only bind to the promoter of SlGLK2 to inhibit its transcription, but also interacted with the SlGLK2 protein to inhibit the transcriptional activity of SlGLK2 and its downstream target genes. SlGLK2 knockout (KO-SlGLK2) plants exhibited a complete absence of the green shoulder, which was consistent with the fruit phenotype of OE-SlBEL2 plants. SlBEL2 showed an expression gradient in fruits, in contrast with that reported for SlGLK2. In conclusion, our study reveals that SlBEL2 affects the formation of green shoulder in tomato fruits by negatively regulating the gradient expression of SlGLK2, thus providing new insights into the molecular mechanism of fruit green shoulder formation.

Transplantation of endothelial progenitor cells improves myocardial hypertrophy in spontaneously hypertensive rats through HO-1/CREB3/AKT axis.

Hypertensive myocardial hypertrophy produces a hostile microenvironment characterized by cardiomyocyte hypertrophy, inflammation and oxidative stress, which also leads to endothelial progenitor cells (EPCs) dysfunction, preventing EPC migration, adhesion and angiogenesis. Heme oxygenase-1 (HO-1) is an intracellular protein that plays an important role in angiogenesis and cell survival. The upregulation of cAMP response element-binding protein 3 (CREB3) is closely related to the formation of endothelial cells. The purpose of this study was to evaluate the role of HO-1 and CREB3 in EPCs and their effects on hypertensive myocardial hypertrophy. EPCs were transfected with HO-1 adenoviral overexpression vector (Ad-HO-1) or together with CREB3 siRNA (si-CREB3), or transfected with CREB3 adenoviral overexpression vector (Ad-CREB3) or together with HO-1 siRNA, and then treated with 100 nM Ang Ⅱ for 12 h. Overexpressing HO-1 or CREB3 promoted adhesion to extracellular matrix, cell migration, and angiogenesis, inhibited the secretion of inflammatory factors TNF-α and IL-6, and reduced ROS level, ICAM-1 and MCP-1 mRNA expression levels in EPCs treated with Ang Ⅱ. Online prediction and Co-IP assay showed that HO-1 interacts with CREB3, and they promote expression of each other. EPC-conditioned medium supplemented with CREB3 recombinant protein decreased the levels of ANP and BNP mRNA in H9C2 cells treated with Ang Ⅱ and alleviated oxidative stress. Ad-CREB3 transfected EPCs promoted the phosphorylation of AKT in vivo and in vitro, thereby improving myocardial swelling and dysfunction in SHR rats. Taken together, transplantation of CREB3 overexpressing EPCs alleviates myocardial hypertrophy in spontaneously hypertensive rats by promoting HO-1 protein expression and AKT phosphorylation.

Association of selenium and cadmium with heart failure and mortality based on the National Health and Nutrition Examination Survey.

BACKGROUND: The association of selenium and cadmium with heart failure and mortality has not been thoroughly explored. METHODS: We analysed data from the National Health and Nutrition Examination Survey (NHANES) database over 12 years (1999-2000, 2003-2004 and 2011-2018), which includes blood selenium and cadmium. Multivariable logistic regression and Cox proportional hazards regression were used. RESULTS: In total, 15,689 participants were enrolled. The multivariate analysis showed that low blood selenium (odds ratio [OR] = 0.952, p < 0.001) and high blood cadmium (OR = 1.345, p < 0.001) were independent risk factors of heart failure. During 96802 person-year follow-up, 1697 deaths occurred. The multivariable adjusted hazard ratio (HR) for all-cause mortality was 0.82 (95% confidence interval [CI] = 0.71-0.95) for middle selenium levels and 0.76 (95% CI = 0.65-0.88) for high selenium levels compared to low selenium levels. Taking the low cadmium levels as reference, the multivariable adjusted HR for all-cause mortality among high cadmium levels was 1.68 (95% CI = 1.44-1.96). Furthermore, the association between selenium, cadmium and cardiovascular mortality was similar to that of all-cause mortality. A subgroup analysis of the study population showed that in individuals with heart failure, although selenium levels were not associated with risk of all-cause mortality, high selenium levels were associated with a lower risk of cardiovascular mortality (HR = 0.33, p = 0.0032). CONCLUSIONS: Low blood selenium and high blood cadmium were independent risk factors of heart failure. Blood selenium was inversely associated with all-cause mortality and cardiovascular mortality, whereas blood cadmium was positively associated with them. Furthermore, blood selenium was associated with a lower risk of cardiovascular mortality in individuals with heart failure.

Novel predictors of stent under-expansion regarding calcified coronary lesions assessed by optical coherence tomography.

A previous calcium scoring system using circumferential angle, thickness, and length of coronary calcium by OCT could assist in predicting stent under-expansion. However, this scoring system only reflects the calcification distribution within a single cross-section and fails to consider the lumen's original size. The current study aims to investigate whether novel parameters to quantify calcium lesions, including calcium burden, area, and volume assessed by optical coherence tomography (OCT), could predict stent under-expansion related to calcium lesions. Consecutive patients admitted between March 10th to October 19th 2021 with calcified coronary lesions undergoing percutaneous coronary intervention (PCI) with OCT guidance were screened for inclusion. The calcium burden, area, and volume of the target lesions were measured using OCT at pre-PCI. After successful stent implantation, stent expansion at the corresponding lesions was also measured by OCT. A total of 125 patients who underwent OCT-guided PCI were included in this study. While the calcium grades by angiography failed to show a significant correlation with stent expansion, maximum and average calcium burden, maximum calcium area, and calcium volume exhibited a moderate correlation with stent expansion. According to the receiver operating characteristic curves, the optimal cutoffs of calcium volume and area for predicting stent under-expansion were 4.37 mm3 and 2.48 mm2 , respectively. Calcium burden, area, and volume by OCT are more favorable predictors of stent under-expansion given its better performance than calcium grades by angiography. Using cutoffs of calcium area and volume could identify high-risk patients of under-expansion and might guide future clinical practice.

The functional development of the rumen is influenced by weaning and associated with ruminal microbiota in lambs.

Rumen development is critical for the development of early lambs. This work aims to evaluate the effects of abrupt weaning at day 21 on rumen fermentation, histomorphological traits and the ruminal microbiota compared with continuous suckling. Twelve pairs of artificially reared full-sib neonatal male Hu lambs were allocated to two groups, one of which was weaned at day 21 (EW group) and the other which was not weaned (CON group). At day 26 and day 49, six lambs from each group were randomly selected and sacrificed to collect ruminal contents and rumen tissue samples. Results showed that weaning influenced the fermentation parameters in the rumen, and altered the microbial community composition on day 49 (p < 0.05). Several genera were associated with rumen fermentation parameters (p < 0.05). Volatile fatty acid (VFA) concentration is the key parameter impacting microbiota composition. Weaning influenced the expression of genes associated with VFA metabolism and regulation of cell proliferation (p < 0.05). In conclusion, weaning significantly influenced the morphological and functional development of the rumen, and bacterial community composition. The microbial community composition was strongly associated with rumen weight and fermentation profiles, but not with morphological development.

The Roles of BLH Transcription Factors in Plant Development and Environmental Response.

Despite recent advancements in plant molecular biology and biotechnology, providing enough, and safe, food for an increasing world population remains a challenge. The research into plant development and environmental adaptability has attracted more and more attention from various countries. The transcription of some genes, regulated by transcript factors (TFs), and their response to biological and abiotic stresses, are activated or inhibited during plant development; examples include, rooting, flowering, fruit ripening, drought, flooding, high temperature, pathogen infection, etc. Therefore, the screening and characterization of transcription factors have increasingly become a hot topic in the field of plant research. BLH/BELL (BEL1-like homeodomain) transcription factors belong to a subfamily of the TALE (three-amino-acid-loop-extension) superfamily and its members are involved in the regulation of many vital biological processes, during plant development and environmental response. This review focuses on the advances in our understanding of the function of BLH/BELL TFs in different plants and their involvement in the development of meristems, flower, fruit, plant morphogenesis, plant cell wall structure, the response to the environment, including light and plant resistance to stress, biosynthesis and signaling of ABA (Abscisic acid), IAA (Indoleacetic acid), GA (Gibberellic Acid) and JA (Jasmonic Acid). We discuss the theoretical basis and potential regulatory models for BLH/BELL TFs' action and provide a comprehensive view of their multiple roles in modulating different aspects of plant development and response to environmental stress and phytohormones. We also present the value of BLHs in the molecular breeding of improved crop varieties and the future research direction of the BLH gene family.

Remediation of preservative ethylparaben in water using natural sphalerite: Kinetics and mechanisms.

As a typical class of emerging organic contaminants (EOCs), the environmental transformation and abatement of preservative parabens have raised certain environmental concerns. However, the remediation of parabens-contaminated water using natural matrixes (such as, naturally abundant minerals) is not reported extensively in literature. In this study, the transformation kinetics and the mechanism of ethylparaben using natural sphalerite (NS) were investigated. The results show that around 63% of ethylparaben could be absorbed onto NS within 38 hr, whereas the maximum adsorption capacity was 0.45 mg/g under room temperature. High temperature could improve the adsorption performance of ethylparaben using NS. In particular, for the temperature of 313 K, the adsorption turned spontaneous. The well-fitted adsorption kinetics indicated that both the surface adsorption and intra-particle diffusion contribute to the overall adsorption process. The monolayer adsorption on the surface of NS was primarily responsible for the elimination of ethylparaben. The adsorption mechanism showed that hydrophobic partitioning into organic matter could largely govern the adsorption process, rather than the ZnS that was the main component of NS. Furthermore, the ethylparaben adsorbed on the surface of NS was stable, as only less than 2% was desorbed and photochemically degraded under irradiation of simulated sunlight for 5 days. This study revealed that NS might serve as a potential natural remediation agent for some hydrophobic EOCs including parabens, and emphasized the significant role of naturally abundant minerals on the remediation of EOCs-contaminated water bodies.

Short Direct Repeats in the 3' Untranslated Region Are Involved in Subgenomic Flaviviral RNA Production.

Mosquito-borne flaviviruses consist of a positive-sense genome RNA flanked by the untranslated regions (UTRs). There is a panel of highly complex RNA structures in the UTRs with critical functions. For instance, Xrn1-resistant RNAs (xrRNAs) halt Xrn1 digestion, leading to the production of subgenomic flaviviral RNA (sfRNA). Conserved short direct repeats (DRs), also known as conserved sequences (CS) and repeated conserved sequences (RCS), have been identified as being among the RNA elements locating downstream of xrRNAs, but their biological function remains unknown. In this study, we revealed that the specific DRs are involved in the production of specific sfRNAs in both mammalian and mosquito cells. Biochemical assays and structural remodeling demonstrate that the base pairings in the stem of these DRs control sfRNA formation by maintaining the binding affinity of the corresponding xrRNAs to Xrn1. On the basis of these findings, we propose that DRs functions like a bracket holding the Xrn1-xrRNA complex for sfRNA formation.IMPORTANCE Flaviviruses include many important human pathogens. The production of subgenomic flaviviral RNAs (sfRNAs) is important for viral pathogenicity as a common feature of flaviviruses. sfRNAs are formed through the incomplete degradation of viral genomic RNA by the cytoplasmic 5'-3' exoribonuclease Xrn1 halted at the Xrn1-resistant RNA (xrRNA) structures within the 3'-UTR. The 3'-UTRs of the flavivirus genome also contain distinct short direct repeats (DRs), such as RCS3, CS3, RCS2, and CS2. However, the biological functions of these ancient primary DR sequences remain largely unknown. Here, we found that DR sequences are involved in sfRNA formation and viral virulence and provide novel targets for the rational design of live attenuated flavivirus vaccine.

Antiviral Resistance Protein Tm-22 Functions on the Plasma Membrane.

The tomato Tobacco mosaic virus resistance-22 (Tm-22 ) gene encodes a coiled-coil-nucleotide binding site-Leu-rich repeat protein lacking a conventional plasma membrane (PM) localization motif. Tm-22 confers plant extreme resistance against tobamoviruses including Tobacco mosaic virus (TMV) by recognizing the avirulence (Avr) viral movement protein (MP). However, the subcellular compartment where Tm-22 functions is unclear. Here, we demonstrate that Tm-22 interacts with TMV MP to form a protein complex at the PM We show that both inactive and active Tm-22 proteins are localized to the PM When restricted to PM by fusing Tm-22 to the S-acylated PM association motif, the Tm-22 fusion protein can still induce a hypersensitive response cell death, consistent with its activation at the PM Through analyses of viral MP mutants, we find that the plasmodesmata (PD) localization of the Avr protein MP is not required for Tm-22 function. These results suggest that Tm-22-mediated resistance takes place on PM without requirement of its Avr protein to be located to PD.

An intensive milk replacer feeding program benefits immune response and intestinal microbiota of lambs during weaning.

BACKGROUND: Pre-weaning milk replacer (MR) feeding program is a key factor affecting the health and welfare of lambs during their weaning. Weaning stress is well known as an inducement that negatively impacts the immune system of young ruminants, whose physiological and immune state is closely linked to the community of microbiota in their intestines. This study had two objectives: 1) To evaluate the innate immune response to weaning stress at both the physiological and molecular level; 2) To investigate changes to the jejunal chyme and mucosal adhesive microbiota between the control and high plane of MR groups. RESULTS: In this experiment, the plasma concentrations of cortisol, norepinephrine (NE) and tumor necrosis factor-α (TNFα) were higher in the C than the H group (P < 0.05), as was the expression of pro-inflammatory cytokines such as TNFα and CXCL8 (P < 0.05) in plasma. In jejunal tissue, the expression of TLR4 and TNFα were also higher in the C group (P < 0.01); histopathology showed the H group had lower lymphocyte infiltration. In the C group, however, major pathological changes were associated with extensive infiltration of lymphocytes, eosinophils, and neutrophils. Principal component analysis indicated the lamb immune response was influenced by weaning stress and modulated by the MR treatments. 16S-rRNA sequencing was used to evaluate jejunal mucosa and chyme bacterial diversity and composition. The C group's chyme had a greater alpha index (ACE: P = 0.095; Chao1: P = 0.085) than H group. In jejunal mucosa, the relative abundance of Plesiomonas was 4-fold higher (P = 0.017) in the C than the H group. CONCLUSIONS: This study's results revealed that weaning stress induced alterations to the lambs' immune system that lasted beyond the 21 d measured, and that a long-term inflammatory response effect was evidenced by changes in their hematological and expressed pro-inflammatory cytokines. Pre-weaning with a differing MR allowance resulted in complicated biological responses and compositional changes to the lambs' jejunal microbiota. Clearly, an intensive MR feeding program induced a milder immunity response and lower relative abundance of pathogenic bacteria when compared with the traditional feeding program.

[The establishment and identification of GPx-1(P198L) gene systemic expression transgenic mice].

OBJECTIVE: To generate systemic expression human cellular glutathione peroxidase-1 (GPx-1) (198Leu) transgenic mice model in order to investigate the functional variants in GPx-1 gene in oxidative stress-related diseases. METHODS: After linearization with BamnH I and Acc I, the transgenic construct GPx-1 (198Leu) was microinjected into the zygotes of C57BL/6J mice to generate transgenic mice, whose genotype was detected by PCR with specific primers. The GPx-1 gene expression profile was determined by Western blotting. RESULTS: 13 transgenic founder mice were successfully generated. Western blotting result showed that the protein expression level of 4 transgenic mice in hearts were higher than that of wild type mice. CONCLUSION: Human GPx-1PSL transgenic mice was successfully established. This kind of animal model is of significance for making further researches on oxidative stress-related diseases.

Effects of angiotensin-(1-7) on the proliferation and collagen synthesis of arginine vasopressin-stimulated rat cardiac fibroblasts: role of mas receptor-calcineurin-NF-κB signaling pathway.

: Interstitial fibrosis is a common pathological change in various heart diseases, especially cardiac hypertrophy. Arginine vasopressin (AVP), one of the hallmarks of heart failure, exhibits a profibrotic effect by promoting the proliferation and differentiation of cardiac fibroblasts (CFs). In contrast, angiotensin-(1-7) [Ang-(1-7)] was reported to be beneficial for cardiac remodeling by its antifibrotic effect. To evaluate the effect of Ang-(1-7) on AVP-stimulated CFs and the subsequent signaling molecules involved, CFs isolated from neonatal rat hearts were incubated with AVP and treated with or without Ang-(1-7). Cell proliferation, cell cycle, collagen production, and related cellular signaling molecules were then assessed. The results showed that Ang-(1-7) dose-dependently inhibited cell proliferation and collagen production in AVP-stimulated CFs. In addition, Ang-(1-7) also significantly suppressed calcineurin activity in a dose-dependent manner in AVP-stimulated CFs, which was associated with reduced collagen production. Accordingly, the nuclear translocation and transcriptional activity of nuclear factor-kappa B (NF-κB), downstream signal of calcineurin, were also notably restrained by Ang-(1-7) in AVP-stimulated CFs. Furthermore, the inhibitory effect of Ang-(1-7) on AVP-activated calcineurin-NF-κB signaling was completely reversed by the Mas receptor antagonist A-799. These findings suggest that Ang-(1-7) exerts an antifibrotic effect by inhibiting AVP-stimulated CF proliferation and collagen synthesis by inactivating Mas receptor-calcineurin-NF-κB signaling pathway.

Long-term prognostic value of major and minor ECG abnormalities in latent Keshan disease with suspect chronic Keshan disease.

OBJECTIVE: This study aims to determine whether baseline electrocardiography (ECG) abnormalities, the appearance of new ECG abnormalities, or other clinical characteristics are associated with increased rates of progression to chronic Keshan disease (KD) among patients with latent KD. METHODS: Four hundred and fourteen new latent KD patients from a monitored population in China were diagnosed and then followed for 10 years. Baseline and 10-year ECG abnormalities were classified according to the Minnesota Code as major and minor. Using Cox proportional hazards regression models, the addition of ECG abnormalities to traditional risk factors were examined to predict chronic KD events. RESULTS: In 414 latent KD patients with ECG abnormalities, 220 (53.1%) had minor and 194 (46.9%) had major ECG abnormalities. During the follow-up, 92 (22.2%) patients experienced chronic KD events; 32 (14.5%) and 60 (30.9%) of these chronic KD events occurred in the minor and major ECG abnormalities groups, respectively. After adjustment for baseline potential confounders, the hazard ratios and 95% confidence intervals (CIs) for progression to chronic KD in latent KD patients with major ECG abnormalities versus those with minor ECG abnormalities was 2.43 (95% CI 1.58-3.93). CONCLUSIONS: Major ECG abnormalities and new ventricular premature complex abnormalities that occurred during the follow-up were both associated with an increased risk of progression to chronic KD. Atrial fibrillation and right bundle branch block with left anterior hemiblock are the most strongly predictive components of major ECG abnormalities. Depending on the model, adding ECG abnormalities to traditional risk factors was associated with improved risk prediction in latent KD.

Decreased response of interneurons in the medial prefrontal cortex to 5-HT1A receptor activation in the rat 6-hydroxydopamine Parkinson model.

This study examined the response of interneurons in the medial prefrontal cortex (mPFC) to 5-HT1A receptor agonist 8-OH-DPAT and change in expression of 5-HT1A receptor on glutamate decarboxylase 67 (GAD67)-positive neurons in rats with 6-hydroxydopamine (6-OHDA) lesions of the substantia nigra pars compacta (SNc). Systemic administration of 5-HT1A receptor agonist 8-OH-DPAT dose-dependently inhibited the firing rate of the interneurons at all doses tested in sham-operated rats. In 6-OHDA-lesioned rats, 8-OH-DPAT, at the same doses, also inhibited the firing rate of the interneurons, whereas the inhibition was significant only at a high cumulative dose. Furthermore, injection of 8-OH-DPAT into the mPFC inhibited the interneurons in sham-operated rats, while having no effect on firing rate of the interneurons in 6-OHDA-lesioned rats. In contrast to sham-operated rats, SNc lesion reduced the expression of 5-HT1A receptor on GAD67-positive neurons in the prelimbic cortex, a sub-region of the mPFC. Our results indicate that degeneration of the nigrostriatal pathway leads to decreased response of mPFC interneurons to 5-HT1A receptor activation, which attributes to the down-regulation of 5-HT1A receptor expression in these interneurons.

An irregular approach of right atrial lead placement in a patient with persistent left superior vena cava and concomitant agenesis of the right-sided superior vena cava.

Persistent left superior vena cava (PLSVC) is the most common venous anomaly of the thorax. It could lead to catheter malplacement and even vascular injuries. We describe an unusual way to deliver a right atrial (RA) endocardial pacing lead in a 61-year-old female with a PLSVC concomitant agenesis of the right-sided SVC. After failed attempts with the standard procedure, we placed the RA lead tip in the PLSVC near the right auricle. The pacemaker worked well after one and 17 months of follow-up. We conclude that when placement of the RA lead fails, the PLSVC near the right auricle could be a next choice in the RA lead placement in patients with PLSVC concomitant agenesis of the right-sided SVC.

Estrogenic disruption effects and formation mechanisms of transformation products during photolysis of preservative parabens.

The ubiquitous presence of emerging contaminants (ECs) in the environment and their associated adverse effects has raised concerns about their potential risks. The increased toxicity observed during the environmental transformation of ECs is often linked to the formation of their transformation products (TPs). However, comprehension of their formation mechanisms and contribution to the increased toxicity remains an unresolved challenge. To address this gap, by combining quantum chemical and molecular simulations with photochemical experiments in water, this study investigated the formation of TPs and their molecular interactions related to estrogenic effect using the photochemical degradation of benzylparaben (BZP) preservative as a representative example. A non-targeted analysis was carried out and three previously unknown TPs were identified during the transformation of BZP. Noteworthy, two of these novel TPs, namely oligomers BZP-o-phenol and BZP-m-phenol, exhibited higher estrogenic activities compared to the parent BZP. Their IC50 values of 0.26 and 0.50 µM, respectively, were found to be lower than that of the parent BZP (6.42 µM). The binding free energies (ΔGbind) of BZP-o-phenol and BZP-m-phenol (-29.71 to -23.28 kcal·mol-1) were lower than that of the parent BZP (-20.86 kcal·mol-1), confirming their stronger binding affinities toward the estrogen receptor (ER) α-ligand binding domain. Subsequent analysis unveiled that these hydrophobic residues contributed most favorably to ER binding, with van der Waals interactions playing a significant role. In-depth examination of the formation mechanisms indicated that these toxic TPs primarily originated from the successive cleavage of ester bonds (OCH2C6H5 and COO group), followed by their combination with BZP*. This study provides valuable insight into the mechanisms underlying the formation of toxic TPs and their binding interactions causing the endocrine-disrupting effects. It offers a crucial framework for elucidating the toxicological patterns of ECs with similar structures.

Toxicity evolution of triclosan during environmental transformation and human metabolism: Misgivings in the post-pandemic era.

In the context of pandemic viruses and pathogenic bacteria, triclosan (TCS), as a typical antibacterial agent, is widely used around the world. However, the health risks from TCS increase with exposure, and it is widespread in environmental and human samples. Notably, environmental transformation and human metabolism could induce potentially undesirable risks to humans, rather than simple decontamination or detoxification. This review summarizes the environmental and human exposure to TCS covering from 2004 to 2023. Particularly, health impacts from the environmental and metabolic transformation of TCS are emphasized. Environmental transformations aimed at decontamination are recognized to form carcinogenic products such as dioxins, and ultraviolet light and excessive active chlorine can promote the formation of these dioxin congeners, potentially threatening environmental and human health. Although TCS can be rapidly metabolized for detoxification, these processes can induce the formation of lipophilic ether metabolic analogs via cytochrome P450 catalysis, causing possible adverse cross-talk reactions in human metabolic disorders. Accordingly, TCS may be more harmful in environmental transformation and human metabolism. In particular, TCS can stimulate the transmission of antibiotic resistance even at trace levels, threatening public health. Considering these accruing epidemiological and toxicological studies indicating the multiple adverse health outcomes of TCS, we call on environmental toxicologists to pay more attention to the toxicity evolution of TCS during environmental transformation and human metabolism.

Anti-hypertrophic and anti-oxidant effect of beta3-adrenergic stimulation in myocytes requires differential neuronal NOS phosphorylation.

RATIONALE: Stimulation of ß3-adrenoreceptors (ß3-AR) blunts contractility and improves chronic left ventricular function in hypertrophied and failing hearts in a neuronal nitric oxide synthase (nNOS) dependent manner. nNOS can be regulated by post-translational modification of stimulatory phosphorylation residue Ser1412 and inhibitory residue Ser847. However, the role of phosphorylation of these residues in cardiomyocytes and ß3-AR protective signaling has yet to be explored. OBJECTIVE: We tested the hypothesis that ß3-AR regulation of myocyte stress requires changes in nNOS activation mediated by differential nNOS phosphorylation. METHODS AND RESULTS: Endothelin (ET-1) or norepinephrine induced hypertrophy in rat neonatal ventricular cardiomyocytes (NRVMs) was accompanied by increased ß3-AR gene expression. Co-administration of the ß3-AR agonist BRL-37433 (BRL) reduced cell size and reactive oxygen species (ROS) generation, while augmenting NOS activity. BRL-dependent augmentation of NOS activity and ROS suppression due to NE were blocked by inhibiting nNOS (L-VNIO). BRL augmented nNOS phosphorylation at Ser1412 and dephosphorylation at Ser847. Cells expressing constitutively dephosphorylated Ser1412A or phosphorylated Ser847D nNOS mutants displayed reduced nNOS activity and a lack of BRL modulation. BRL also failed to depress ROS from NE in cells with nNOS-Ser847D. Inhibiting Akt decreased BRL-induced nNOS-Ser1412 phosphorylation and NOS activation, whereas Gi/o blockade blocked BRL-regulation of both post-translational modifications, preventing enhancement of NOS activity and ROS reduction. BRL resulted in near complete dephosphorylation of Ser847 and a moderate rise in Ser1412 phosphorylation in mouse myocardium exposed to chronic pressure-overload. CONCLUSION: ß3-AR regulates myocardial NOS activity and ROS via activation of nNOS involving reciprocal changes in phosphorylation at two regulatory sites. These data identify a novel and potent anti-oxidant and anti-hypertrophic pathway due to nNOS post-translational modification that is coupled to ß3-AR receptor stimulation.