Effect of gestational and lactational nonylphenol exposure on airway inflammation in ovalbumin-induced asthmatic rat pups

ERβ activation improves nonylphenol-induced depression and neurotransmitter secretion disruption via the TPH2/5-HT pathway

The aim of this study is to investigate the role of estrogen receptor β (ERβ) in nonylphenol (NP) - induced depression - like behavior in rats and its impact on the regulation of the TPH2/5-HT pathway. In the in vitro experiment, rat basophilic leukaemia cells (RBL-2H3) cells were divided into the four groups: blank group, NP group (20 μM), ERβ agonist group (0.01 μM), and NP＋ERβ agonist group (20 μM＋0.01 μM). For the in vivo experiment, 72 adult male Sprague-Dawley rats were randomly divided into following six groups: the Control, NP (40 mg/kg) group, ERβ agonist (2 mg/kg, Diarylpropionitrile (DPN)) group, ERβ inhibitor (0.1 mg/kg, 4-(2-phenyl-5,7-bis(trifluoromethyl)pyrazolo[1,5-a]pyrimidin-3-yl) phenol (PHTPP)) group, NP+ERβ agonist (40 mg/kg NP ＋ 2 mg/kg DPN) group, and NP+ERβ inhibitor (40 mg/kg NP + 0.1 mg/kg PHTPP) group, with 12 rats in each group. Each rat in drug group were given NP by gavage and/or received a single intraperitoneal injection of DPN 2 mg/kg or PHTPP 0.1 mg/kg. Both in vivo and in vitro, NP group showed a decrease in the expression levels of ERβ, tryptophan hydroxylase (TPH1), and tryptophan hydroxylase-2 (TPH2) genes and proteins, and reduced levels of DA, NE, and 5-hydroxytryptophan (5-HT) neurotransmitters. RBL-2H3 cells showed signs of cell shrinkage, with rounded cells, increased suspension and more loosely arranged cells. The effectiveness of the ERβ agonist stimulation exhibited an increase exceeding 60% in RBL-2H3 cells. The application of ERβ agonist resulted in an alleviation the aforementioned alterations. ERβ agonist activated the TPH2/5-HT signaling pathways. Compared to the control group, the NP content in the brain tissue of the NP group was significantly increased. The latency to eat for the rats was longer and the amount of food consumed was lower, and the rats had prolonged immobility time in the behavioral experiment of rats. The expression levels of ERβ, TPH1, TPH2, 5-HT and 5-HITT proteins were decreased in the NP group, suggesting NP-induced depression-like behaviours as well as disturbances in the secretion of serum hormones and monoamine neurotransmitters. In the NP group, the midline raphe nucleus showed an elongated nucleus with a dark purplish-blue colour, nuclear atrophy, displacement and pale cytoplasm. ERβ might ameliorate NP-induced depression-like behaviors, and secretion disorders of serum hormones and monoamine neurotransmitters via activating TPH2/5-HT signaling pathways.

Trichosanthin-derived peptide Tk-PQ attenuates immune rejection in mouse tracheal allotransplant model by suppressing PI3K-Akt and inducing type II immune polarization

Obliterative bronchiolitis (OB) is one of the main complications affecting long-term survival of post-lung transplantation patients. In this study, we evaluated the efficacy of Tk-PQ (a peptide derived from trichosanthin) in alleviating OB in a mouse ectopic tracheal transplant model. We found that post-transplantation treatment of Tk-PQ significant ameliorated OB symptoms including luminal occlusion, epithelial cells loss and fibrosis in the allograft. In addition, Tk-PQ promoted immune suppressive environment by inducing Th2 polarization and increasing Treg population which in turn led to elevated levels of anti-inflammatory cytokines IL-4, IL-10, IL-33 and decreased levels of pro-inflammatory IL-1β. Mechanistically, we used transcriptome analysis of splenic T cells from allografted mice to show that Tk-PQ treatment down-regulated the PI3K-Akt signaling pathway. Indeed, the immune suppression phenotypes of Tk-PQ was recapitulated by a PI3K inhibitor LY294002. Taken together, Tk-PQ regulates post-transplantation immuno-rejection by modulating the balance of T cell response via the PI3K-Akt pathway, making it a promising peptide based immune rejection suppressant for patients receiving allotransplant.

Effects and mechanism of perinatal nonylphenol exposure on cardiac function and myocardial mitochondria in neonatal rats

BACKGROUND

Nonylphenol (NP) is a common environmental endocrine disruptor that is associated with the development of cardiovascular disease. However, the toxic effect of NP on mitochondria in the heart of offspring to exposed individuals remains exclusive.

OBJECTIVE

To investigate whether perinatal NP exposure causes mitochondrial damage in the hearts of offspring of exposed individuals and determine its mechanism of action through both animal and cell experiments.

METHODS AND RESULTS

For the in vivo experiment, pregnant rats were randomly divided into four groups: the control group (corn oil, C), low dose group (2.5 mg/kg/day, L-NP group), medium dose group (50 mg/kg/day, M-NP group), and high dose group (100 mg/kg/day, H-NP group), with 12 rats in each group. The NP concentration in the hearts of offspring at PND21 and PND90 increased with the increase of the NP dose. Perinatal NP exposure induced a gradual increase in systolic blood pressure in offspring at PND90. In the H-NP group, there was a high degree of inflammatory cell infiltration, myofibril breaks, inconspicuous or absent nuclei, and pink collagen deposition. At PND90, the membrane integrity of mitochondria in the H-NP group was disrupted, the cristae disorder was aggravated, and there was internal lysis with vacuolation. Compared to the control group, the mitochondrial membrane potential of offspring at PND21 and PND90 was decreased in each of the NP exposure groups. NP exposure decreased the activity of mitochondrial respiratory enzyme complex I (CI) and increased the activity of mitochondrial respiratory enzyme complex IV (CIV) in the offspring. At PND21 and PND90, the mRNA and protein expression levels of cardiac mitochondrial PGC-1α, NRF-1, and TFAM decreased with increasing NP dose in a dose-dependent manner. In the in vitro experiment, H9C2 cells were divided into the following four groups: the blank group, RSV group (15 μg/ml), RSV + NP group (15 μg/ml RSV + 120 mmol/L NP), and NP group (120 mmol/L). With increasing NP concentration, the cell survival rate gradually decreased. Compared to the control, the membrane potential was significantly decreased in the NP group; the protein expression levels of SIRT1, PGC-1α, NRF-1, and TFAM in the NP group were significantly lower.

CONCLUSION

Perinatal NP exposure caused mitochondrial damage and dysfunction in the offspring of exposed individuals in a dose-dependent manner. This toxic effect may be related to NP-induced mitochondrial pathology in the offspring and the inhibition of both gene and protein expression involved in the PGC-1α/NRF-1/TFAM mitochondrial biogenesis signaling pathway following NP exposure.

Ameliorative Effect of a Neoteric Regimen of Catechin plus Cetirizine on Ovalbumin-Induced Allergic Rhinitis in Rats

Allergic rhinitis (AR) affects 20–50% of the global population. Available treatments are limited by their adverse effects. We investigated the anti-allergic effects of catechin alone and combined with cetirizine against ovalbumin-induced AR. Rats were sensitized with ovalbumin and received catechin (14 days) and then challenged with aerosolized ovalbumin (1%) to determine AR clinical scores. Histamine, histamine release, and histidine decarboxylase (HDC) activity were determined in blood, peritoneal mast cells, and stomachs, respectively. Vascular permeability and safety were assessed using Evans blue leakage and barbiturate-induced sleeping-time assays, respectively. Catechin and cetirizine binding with HDC was investigated by docking and binding energy analyses. The clinical scores of the combination regimen were superior to either drug alone. All treatments reduced vascular leakage, with no effect on barbiturate-induced sleeping time. Only the catechin-treated rats showed reduced histamine levels and HDC activity. Docking studies revealed that catechin has a 1.34-fold higher extra-precision docking score than L-histidine. The binding energy scores for catechin-HDC, L-histidine-HDC, and histamine-HDC were −50.86, −37.64, and −32.27 kcal/mol, respectively. The binding pattern of catechin was comparable to the standard HDC inhibitor, histidine methyl ester, but with higher binding free energy. Catechin binds the catalytic residue S354, unlike cetirizine. The anti-allergic effects of catechin can be explained by HDC inhibition and possible antihistaminic activity.

The inflammatory injury of heart caused by ammonia is realized by oxidative stress and abnormal energy metabolism activating inflammatory pathway

Inflammation is an essential biological process for maintaining homeostasis in the body. However, excessive inflammatory response is closely related to many chronic diseases. Ammonia is a known environmental pollutant and a main harmful gas in the environment of livestock house. It causes deterioration of air quality and poses a threat to human and animal health. Chickens are very sensitive to ammonia. In order to assess the toxicity of ammonia to the heart, the pathology, ATPase activities, markers of oxidative stress, inflammatory pathways and inflammation markers were investigated in the hearts of chickens exposed to ammonia. The results showed that the cardiac pathological structure, oxidative stress index, and ATPase activity changed significantly in ammonia-treated chickens. In addition, the inflammation pathways (JAK/STAT and MAPK) were activated in the ammonia group, and the inflammatory markers (COX-2, TNF-α, NF-κB and PPAR-γ) were significantly altered at both mRNA and protein levels. In conclusion, excess ammonia can activate inflammatory pathways through oxidative stress and abnormal energy metabolism, and induce cardiac inflammatory injury. Our findings will provide a new insight for better assessing the toxicity mechanism of ammonia on the heart.