The Effect of Endotoxin on the Intestinal Mucus Layer in Non- and Post-pregnancy Mice.

The intestine is the most extensive storage organ of bacteria and endotoxins, and the mucosal immune system is the first barrier of the intestine. Mucin-2 (MUC2) is the major component of the mucus layers. In this study, we explored whether MUC2 plays a role in how lipopolysaccharide (LPS) invades the fetus from the gut to the uterus in pregnant mice. The results showed that the LPS levels of the ileum, colon, and uterus were significantly increased, and the content of secretory IgA (sIgA) in the ileum, colon, and uterus tissues was significantly decreased in the LPS(+) group on the 35th day after LPS treatment. On the 16th day of pregnancy, compared with the LPS(-) group, the level of ileum LPS was significantly decreased, and the content of LPS in the fetus was significantly increased in the LPS(+) group. The sIgA content in the fetus was significantly decreased in the uterus and placenta. The expression of MUC2 in the uterus, ileum, and colon was increased significantly in the LPS(+) group, especially in the uterus. It is suggested that endotoxins accumulate in the uterus during non-pregnancy. The high expression of MUC2 in the uterus can prevent LPS from translocating into uterine tissue. After pregnancy, MUC2 still protects uterine tissue, allowing a large amount of LPS to enter the fetal body through blood circulation. Therefore, the level of sIgA significantly decreased, resulting in a decline in fetal innate immune function.

Alteration of the PI3K/Akt signaling pathway by swainsonine affects 17ß-Estradiol secretion in ovary cells.

BACKGROUND: The ingestion of locoweed that contains the toxic indolizidine alkaloid swainsonine (SW) disrupts ovarian function, accompanied by delayed estrus, increased estrous cycle length, delayed conception, and abortion. GOALS: The direct effects of SW on ovary cell steroidogenesis remain unclear. MATERIALS AND METHODS: In this study, Chinese hamster ovary (CHO) cells were used to investigate the effects of SW on estradiol (E2) secretion and cell viability and the mechanisms involved in these processes. RESULTS: CHO cells were treated with SW. 17 ß-Estradiol mRNA expression was decreased in the SW group compared to that in the control group. Various concentrations of E2 and SW were added to cultured cells for 12 h and 36 h. Compared to the control group cells, CYP19A1 expression was decreased in the SW and SW + E2 treatment groups at 12 h and 36 h (P < 0.05). This showed that SW mainly inhibits the last step of estrogen synthesis. When CHO cells were treated with SW, the p-Akt protein levels were significantly decreased compared to that in the control group cells at 12 h and 36 h (P < 0.05). However, the p-Akt expression in the SW + E2 group was not significantly different compared to that in the control group cells (P > 0.05). When CHO cells were treated with SW and SW + E2, the PI3K protein levels were significantly down-regulated compared to that in the control group cells at 12 h and 36 h. CONCLUSION: Taken together, these studies demonstrate that SW is an inhibitor of PI3K/Akt signaling pathway. However, SW blocked PI3K activation in estrogen induction without blocking p-Akt activation in CHO cells. Therefore, SW + E2 blocked upstream but did not affect the downstream of the PI3K/Akt signaling pathway.

Reproductive Toxicities Caused by Swainsonine from Locoweed in Mice.

Swainsonine is the primary toxin in locoweeds. It causes intention tremors, reproductive dysfunction, emaciation, and death. The objective of the present study was to evaluate the potential reproductive and developmental toxicities caused by swainsonine in mice. The treatment groups consisting of three generations of mice were given a range of concentrations of swainsonine by intraperitoneal injection (2.50 mg/kg body weight (BW), 1.20 mg/kg BW, 0.60 mg/kg BW, and 0 mg/kg BW). The 0 mg/kg BW group exhibited significantly fewer estrous cycles and an increased number of estrous ones compared to the 2.50 mg/kg BW, 1.20 mg/kg BW, and 0.60 mg/kg BW groups (P < 0.05). All three generations of mice treated with swainsonine had significantly higher spleen, liver, and kidney indices and significantly lower body weights compared to the 0 mg/kg BW group (P < 0.05). For the first and second generations of treatment group, the copulation indices and the numbers of live pups on postnatal days (PND) 0, 4, and 15 were significantly decreased compared to those of the 0 mg/kg BW group (P < 0.05). The fertility and gestation indices of the treatment group of the first generation were significantly increased compared to the 2.50 mg/kg BW, 1.20 mg/kg BW, and 0.60 mg/kg BW groups of the second generation (P < 0.05). Cumulatively, these results indicate that swainsonine may cause reproductive and developmental toxicities in mice in both parents and offspring.

[Distribution of endophytic fungi in Oxytropis glabra DC].

OBJECTIVE: Endophytic fungi were detected and isolated from the stems, leaves, petioles and seeds of Oxytropis glabra DC sampled from Alashan of Inner Mongolia to investigate the infection rate and species distribution in different tissues. METHODS: The endophytic fungi infection rate and distribution of species in different tissues were investigated by making temporary slides, staining, isolation and identification. RESULTS: Endophytic fungi were detected and observed from all parts (stems, leaves, petioles and seeds) of the plant by temporary slides staining. A total of 79 isolates were cultivated from 4 different tissues by common separation methods, which belonged to 10 genera after identification. The infection rate and separation rate were seeds > leaves > stems > petioles. Undifilum oxytropis, Embellisia sp. L12 and Fusarium equiseti were the dominant species in this plant with the relative isolate frequency 77.32%, 64.00% and 50.00%, respectively. CONCLUSION: Endophytic fungi were commonly found in the all parts of Oxytropis glabra DC. There was an obviously difference in quantity, species and distribution of the endophytic fungi between different parts of plant. Seeds and leaves were the most vulnerable to infection and colonization by the endophytic fungi.