ABSTRACT
Background Exposure to arsenic can damage trophoblast cells and thus induce abortion, but the mechanism is not known. Objective To investigate the role of miR-145 and PTEN/AKT/mTOR pathway in arsenic-induced abortion and trophoblast cell damage in rats. Methods In the animal experiment, twenty SD pregnant rats were randomly divided into a normal control group (saline gavage) and an arsenic-induced abortion group (10.65 mg·kg−1 sodium arsenite solution was administered by gavage, and the gavage volume was 10 mL·kg−1), with 10 rats in each group. After the miscarriage occurred in the arsenic-induced abortion group (5-6 d after exposure), placental tissues were collected from the two groups. The mRNA expression levels of microRNA-145 (miR-145), phosphatase and tensin homologue (PTEN), kinase B (AKT), mammalian target of rapamycin (mTOR) were detected by real-time quantitative PCR (RT-PCR), and the protein expression levels of PTEN, AKT, mTOR, p-AKT, and p-mTOR were detected by Western blotting. For the in vitro study with immortalized human trophoblast cell line (HTR-8/SVneo cells), a control group, an arsenic exposure group, an miR-145 overexpression group, and an arsenic exposure+miR-145 overexpression group were prepared and cultured for 72 h with 37 °C and 5% CO2, at cell density of 5×105 cells per well, and the arsenic exposure concentration was 20 μmol·L−1. The MTT method was applied to detect cell viability, crystal violet staining to detect the number of monoclonal formation, flow cytometry to detect the level of apoptosis, Image J Angiogenesis Analyzer 1.8.0 plug-in to evaluate total blood vessel length and total blood vessel number; the detection indexes and methods of genes and proteins were the same as "animal experiment". Results (1) In the animal experiment, compared with the normal control group, the expression level of miR-145 mRNA in the placenta tissues of the arsenic-induced abortion group was increased (P<0.05), and the expression levels of PTEN, AKT, mTOR mRNA and proteins, and p-AKT and p-mTOR proteins were decreased (P<0.05). (2) For the in vitro study, compared with the control group, the cell viability rate, number of monoclonal formation, total vessel length, and total vessel number were decreased, and the apoptosis rate was increased in the arsenic exposure group, the miR-145 overexpression group, and the arsenic exposure+miR-145 overexpression group (P<0.05). Compared with the arsenic exposure group and the miR-145 overexpression group, the cell viability rate, number of monoclonal formation, total vessel length, and vessel number were decreased, and the apoptosis rate was increased in the arsenic exposure+miR-145 overexpression group (P<0.05). Compared with the control group, the levels of miR-145 mRNA in the arsenic exposure group, the miR-145 overexpression group, and the arsenic exposure+miR-145 overexpression group increased (P<0.05), the expression levels of PTEN, AKT, mTOR mRNA and protein and the expression levels of p-AKT and p-mTOR protein were decreased (P<0.05); compared with the arsenic exposure group and the miR-145 overexpression group, the level of miR-145 mRNA in the arsenic exposure+miR-145 overexpression group was increased (P<0.05), and the levels of PTEN, AKT, mTOR mRNA and protein as well as p-AKT and p-mTOR protein were decreased (P<0.05). Conclusion miR-145 might be related to abortion due to arsenic exposure. miR-145 could inhibit the proliferation and angiogenesis of trophoblast HTR-8/SVNEO cells, and promotes their apoptosis; the mechanism may be related to the inhibition of PTEN/AKT/mTOR pathway.
ABSTRACT
For the minimized phase transtorming risk, the most stable polymorph is generally considered as the desirable solid form for pharmaceutical applications. However, occasionally, the stable form may have some shortcomings such as low solubility, dissolution rate and bioavailability, etc. In that case, the metastable form which is kinetically stable at room or lower temperature could be selected. Using metastable form may result in polymorph transformation in pharmaceutical manufacture and storage. Hence, the knowledge of the transformation between solid forms is essential to the development of the drug materials. In this paper, we will review the recent studies in the area of crystal conversion of polymorphs and hydrates, to illustrate some cases to introduce the types, conditions and mechanisms of the crystalline solid transformation.
ABSTRACT
Objective To explore the mechanism of Niaochangshu capsule in the treatment of postmenopausal overactive bladder, through observing its influence on bladder weight and the expression of eNOS and AQP1 of ovariectomized female rats. Methods Female SD rats were divided into blank group, model group, Nilestriol group and Niaochangshu group. Rats were removed ovaries except the blank group. The treatment groups were given corresponding drugs, blank group and model group were given normal saline by gavage. After 4 weeks, the bladders' weight and thickness were detected, the expressions of eNOS and AQP1 in serum and bladder tissue were determined by ELISA, and NO by spectrophotometry. Results Ovariectomy resulted in decreased bladder weight, bladder mucosal and muscular atrophy, and opposite changes showed after given Niaochangshu. The expressions of eNOS and NO in bladder and serum were decreased significantly after ovariectomy, while increased by given Niaochangshu capsule or nylestriol (P<0.05), and there was significant difference between Niaochangshu group and Nilestriol group (P<0.05). The expression of AQP1 was decreased in the model group, and increased after given nylestriol or Niaochangshu capsule. While the expression of AQP1 in bladder had no significant difference among the four groups. Conclusion Niaochangshu capsule can reverse bladder mucosal and muscular atrophy caused by estrogen deficiency, and increase the content of eNOS in serum and bladder, thus play the role in the treatment of postmenopausal overactive bladder.