Novel RNA polymerase I inhibitor CX-5461 suppresses imiquimod-induced experimental psoriasis.

Clinical treatment of psoriasis remains challenging because of possible long-term drug toxicities and loss of therapeutic effects over time. CX-5461 is a novel selective inhibitor of RNA polymerase I. Our previous studies have shown that CX-5461 has potent anti-inflammatory effects. Here we investigated whether CX-5461 could inhibit the development of imiquimod-induced experimental psoriasis in mice. Adult male C57BL/6 mice were used, and psoriasis-like lesions were induced by topical imiquimod treatment. In vivo, we demonstrated that topical application of CX-5461 prevented the development of imiquimod-induced psoriasis, with decreases in keratinocyte proliferation, T-cell infiltration and pathological angiogenesis. CX-5461 also reversed existing skin inflammation induced imiquimod and retarded the development of 12-O-tetradecanoylphorbol-13-acetate-induced epidermal hyperplasia and inflammation. In vitro, CX-5461 induced cell cycle arrest in keratinocytes, inhibited expressions of interleukin-17, interleukin-23 receptor and retinoic acid receptor-related orphan receptor-γt in activated T cells, and reduced angiogenic functions of endothelial cells. In conclusion, CX-5461 exhibits therapeutic effects on experimental psoriasis in mice, likely via multiple mechanisms including anti-proliferative, anti-inflammatory and anti-angiogenic activities.

Association of ß-arrestin1 and p53-Mdm2 signaling in the development of missed abortion.

BACKGROUND: Missed abortion is a peculiar form of spontaneous abortion before 20 weeks' gestation. The definite etiology and pathogenesis are not fully understood. Recent studies have demonstrated that p53/Mdm2-mediated ubiquitination of the IGF-1R may be closely related to G-protein-coupled receptor kinases (GRK)/ß-arrestin1 system. Our previous studies have confirmed that the elevated expression of p53 and Mdm2 may be responsible for apoptosis during missed abortion. However, there was no information surrounding ß-arrestin1 in missed abortion. METHODS: The mRNA levels of ß-arrestin1 in villous samples of 30 missed abortion patients and 31 healthy controls were determined by real-time quantitative polymerase chain reaction (PCR). Immunohistochemistry was used to explore the expression and location of ß-arrestin1, p53, Mdm2, VEGF and HIF-lα in trophoblasts. Transwell assays were performed to examine the influences of ß-arrestin1 expression on cell invasion. Furthermore, we tested the effect of ß-arrestin1 on the expression of p53, Mdm2, ERK, AKT and NF-κB. RESULTS: The expression of ß-arrestin1 in the villous samples of missed abortion group was dramatically lower than control group by quantitative real-time-PCR and immunohistochemistry. Furthermore, the patients with missed abortion showed significantly higher levels of p53, Mdm2, HIF-lα and lower level of VEGF than healthy controls by immunohistochemistry. Functional studies showed that suppression of ß-arrestin1 in HTR-8 cells inhibited cell invasion. The protein expressions of ERK and AKT in HTR-8 cells were significantly downregulated by reducing the expression of ß-arrestin1, while the expressions of p53, Mdm2, NF-κB were enhanced. Overexpression of ß-arrestin1 exhibited the adverse effect. CONCLUSION: Our data indicated that ß-arrestin1 play an important role in maintaining the maternal-fetal tolerance, the decreased expression of ß-arrestin1 in the villous samples may be related with the development of missed abortion.

Therapeutic efficacy of the novel selective RNA polymerase I inhibitor CX-5461 on pulmonary arterial hypertension and associated vascular remodelling.

BACKGROUND AND PURPOSE: CX-5461 is a novel selective RNA polymerase I (Pol I) inhibitor. Previously, we found that CX-5461 could inhibit pathological arterial remodelling caused by angioplasty and transplantation. In the present study, we explored the pharmacological effects of CX-5461 on experimental pulmonary arterial hypertension (PAH) and PAH-associated vascular remodelling. EXPERIMENTAL APPROACH: PAH was induced in Sprague-Dawley rats by monocrotaline or Sugen/hypoxia. KEY RESULTS: We demonstrated that CX-5461 was well tolerated for in vivo treatments. CX-5461 prevented the development of pulmonary arterial remodelling, perivascular inflammation, pulmonary hypertension, and improved survival. More importantly, CX-5461 partly reversed established pulmonary hypertension. In vitro, CX-5461 induced cell cycle arrest in human pulmonary arterial smooth muscle cells. The beneficial effects of CX-5461 in vivo and in vitro were associated with increased activation (phosphorylation) of p53. CONCLUSION AND IMPLICATIONS: Our results suggest that pharmacological inhibition of Pol I may be a novel therapeutic strategy to treat otherwise drug-resistant PAH.

Fertility-sparing management of low-grade endometrial stromal sarcoma: analysis of an institutional series, a population-based analysis and review of the literature.

BACKGROUND: Low-grade endometrial stromal sarcoma (LGESS) is the second most common malignant mesenchymal tumor of the uterus which usually affects young women. However, the researches on the safety and feasibility of the fertility-sparing management of it are limited. METHODS: A retrospective analysis was performed including 5 women diagnosed with LGESS treated with fertility-sparing management at Qilu Hospital of Shandong University from 2010 to 2019. Besides that, 1,070 patients diagnosed with LGESS in SEER database from 1973 to 2016 were examined. By using the Kaplan-Meier method, survival curves were estimated, and comparisons of statistical significance were performed with the stratified log-rank test within each group. RESULTS: Five patients with LGESS were enrolled in this study. All patients were submitted to fertility-sparing surgeries, after surgery, they all continued hormonal therapy for one year. Four out of the 5 patients recurred, to be more exact, 3 of them recurred in uterus and the other one in the uterus and iliac vascular region. They all suffered further surgery and all 5 patients were alive at the time of last contact. Besides, among these patients, two conceived naturally and delivered a healthy baby by cesarean section. Among 1,070 patients in SEER database, only 28 (2.6%) patients underwent local tumor excision, including excisional biopsy (39%), myomectomy (25%), laser ablation or excision (4%) and polypectomy (4%). There was no statistical significance was observed among TH±BSO, radical hysterectomy, subtotal hysterectomy and local tumor excision (P=0.29). CONCLUSIONS: Our analysis indicated that for those young LGESS patients who wish to preserve their fertility, the feasibility and safety of fertility-sparing management should be considered after gynecological oncologist and gynecological pathologist making professional decisions.

Pharmacological preconditioning with the cellular stress inducer thapsigargin protects against experimental sepsis.

Previous studies have shown that pretreatment with thapsigargin (TG), a cellular stress inducer, produced potent protective actions against various pathologic injuries. So far there is no information on the effects of TG on the development of bacterial sepsis. Using lipopolysaccharides- and cecal ligation/puncture-induced sepsis models in mice, we demonstrated that preconditioning with a single bolus administration of TG conferred significant improvements in survival. The beneficial effects of TG were not mediated by ER stress induction or changes in Toll-like receptor 4 signaling. In vivo and in cultured macrophages, we identified that TG reduced the protein production of pro-inflammatory cytokines, but exhibited no significant effects on steady state levels of their transcriptions. Direct measurement on the fraction of polysome-bound mRNAs revealed that TG reduced the translational efficiency of pro-inflammatory cytokines in macrophages. Moreover, we provided evidence suggesting that repression of the mTOR (the mammalian target of rapamycin) signaling pathway, but not activation of the PERK (protein kinase R-like endoplasmic reticulum kinase)-eIF2α (eukaryotic initiation factor 2α) pathway, might be involved in mediating the TG effects on cytokine production. In summary, our results support that pharmacological preconditioning with TG may represent a novel strategy to prevent sepsis-induced mortality and organ injuries.

Macrophage-stimulated microRNA expression in mural cells promotes transplantation-induced neointima formation.

In this study, we tested the possibility that macrophages might contribute to neointima formation by stimulating microRNA expressions in mural cells. Thoracic aortas from F344 rats were transplanted into recipient Lewis rats. Clodronate liposome was used for in vivo macrophage depletion. Using miR-21 as a prototypic example of vascular enriched microRNA, we showed that macrophage depletion reduced the expression level of miR-21, which was upregulated in the allograft. This effect of macrophage depletion was accompanied by attenuations in neointimal hyperplasia and transplantation-induced vascular inflammation. Using in vitro assays, we identified that macrophages might stimulate miR-21 expression in smooth muscle cells and adventitial fibroblasts via the release of tumor necrosis factor-α. We also showed that silencing of miR-21 suppressed tumor necrosis factor-induced proliferation, migration, and inflammatory responses in mural cells. Our results suggest that macrophage may promote transplantation-induced neointima formation by stimulating miR-21 expression in vascular mural cells, which promotes mural cell proliferation, migration and/or inflammation. Moreover, we have established that tumor necrosis factor-α has a major role in mediating this paracrine process.

Simultaneous determination of ascaridole, p-cymene and α-terpinene in rat plasma after oral administration of Chenopodium ambrosioides L. by GC-MS.

A sensitive and reliable GC-MS method was developed and validated for the simultaneous determination of ascaridole, p-cymene and α-terpinene in rat plasma using naphthalene as internal standard. The plasma samples were extracted with ethyl acetate. Chromatographic separation was carried out on a HP-5MS capillary analytical column (30 m × 0.25 mm, 0.25 µm) and detection was performed on a quadrupole mass spectrometer detector operated under selected ion monitoring mode. The method showed excellent linearity over the investigated concentration range (r > 0.99) with the limit of quantitation down to 50, 10 and 5 ng/mL for ascaridole, p-cymene and α-terpinene, respectively. The intra-day and inter-day precisions (RSD) were <11.3%, and the accuracy was between 90.7 and 113.8%. The method was successfully applied to investigate the pharmacokinetics of Chenopodium ambrosioides L. following oral administration to rats.

Simultaneous determination of creatine phosphate, creatine and 12 nucleotides in rat heart by LC-MS/MS.

A simple, rapid and sensitive LC-MS/MS method was developed and validated for simultaneous determination of creatine phosphate (CP), creatine (Cr) and 12 nucleotides in rat heart. The analytes, ATP, ADP, AMP, GTP, GDP, GMP, CTP, CDP, CMP, UTP, UDP, UMP, CP, Cr, were extracted from heart tissue with pre-cooled (0°C) methanol/water (1:1, v/v) and separated on a Hypersil Gold AQ C18 column (150mm×4.6mm, 3µm) using an isocratic elution with a mobile phase consisting of 2mmol/L ammonium acetate in water (pH 10.0, adjusted with ammonia). The detection was performed by negative ion electrospray ionization in selective reaction monitoring mode (SRM). In the assay, all the analytes showed good linearity over the investigated concentration range (r>0.99). The accuracy was between 80.7% and 120.6% and the precision expressed in RSD was less than 15.6%. This method was successfully applied to measure the concentrations of the 12 nucleotides, creatine phosphate and creatine in rat heart for the first time.