Hydrogen inhibits endometrial cancer growth via a ROS/NLRP3/caspase-1/GSDMD-mediated pyroptotic pathway.

BACKGROUND: Pyroptosis belongs to a novel inflammatory programmed cell death pathway, with the possible prognosis of endometrial cancer related to the terminal protein GSDMD. Hydrogen exerts a biphasic effect on cancer by promoting tumor cell death and protecting normal cells, which might initiate GSDMD pathway-mediated pyroptosis. METHODS: We performed immunohistochemical staining and western immunoblotting analysis to observe expression of NLRP3, caspase-1, and GSDMD in human and xenograft mice endometrial cancer tissue and cell lines. We investigated treatment with hydrogen could boost ROS accumulation in endometrial cancer cells by intracellular and mitochondrial sources. GSDMD shRNA lentivirus was used to transfect endometrial cancer cells to investigate the function of GSDMD protein in pyroptosis. Propidium iodide (PI) staining, TUNEL assay, measurement of lactate dehydrogenase (LDH) release and IL-1ß ELISA were used to analysis pyroptosis between hydrogen-supplemented or normal culture medium. We conducted in vivo human endometrial tumor xenograft mice model to observe anti-tumor effect in hydrogen supplementation. RESULTS: We observed overexpression of NLRP3, caspase-1, and GSDMD in human endometrial cancer and cell lines by IHC and western immunoblotting. Hydrogen pretreatment upregulated ROS and the expression of pyroptosis-related proteins, and increased the number of PI- and TUNEL-positive cells, as well as the release of LDH and IL-1ß, however, GSDMD depletion reduced their release. We further demonstrated that hydrogen supplementation in mice was sufficient for the anti-tumor effect to inhibit xenograft volume and weight of endometrial tumors, as mice subjected to hydrogen-rich water displayed decreased radiance. Tumor tissue sections in the HRW groups presented moderate-to-strong positive expression of NLRP3, caspase-1 and GSDMD. Hydrogen attenuated tumor volume and weight in a xenograft mouse model though the pyroptotic pathway. CONCLUSIONS: This study extended our original analysis of the ability of hydrogen to stimulate NLRP3 inflammasome/GSDMD activation in pyroptosis and revealed possible mechanism (s) for improvement of anti-tumor effects in the clinical management of endometrial cancer.

An Observation of a Resident-as-Teacher Combined with Tutor Guided Hysteroscopy Teaching Program for Standardized Residency Training (SRT) in Obstetrics and Gynecology.

Objectives: The standardized residency training (SRT) program in China is an important link for continuing education and clinical work training for graduate students. The purpose of our study was to enable educators to maintain the effectiveness of hysteroscopy teaching techniques and make the standardized residency training students well experienced in surgery, thus demonstrating that higher efficiency of teaching can lead to better proficiency for surgery. Methods: We generated resident-as-teacher teaching round and tutor guided hysteroscopic surgery as well as a questionnaire based on the mastery degree of the basic theoretical knowledge and operational skills of hysteroscopy among seven junior residents and five senior residents of the Obstetrics and Gynecology Department, including four attending gynecologic surgeons of a hysteroscopy teaching program. Results: Senior residents felt confident to teach, while junior residents learned effectively through the teaching round. There were statistically significant differences in the whole operation time and the volume of distension fluid used between junior and senior residents (p < 0.05). Conclusions: This study acknowledges the need for new approaches to medical education for better characterization of the link between the use of teaching rounds through problem-based learning (PBL) discussion dominated by the residents themselves and overall surgical skills of teaching and learning.

Andrographolide suppresses melanin synthesis through Akt/GSK3ß/ß-catenin signal pathway.

BACKGROUND: Tyrosinase (TYR) is the key enzyme controlling the production of melanin. Very few papers have reported that andrographolide can inhibit melanin content. OBJECTIVE: To investigate the effects of andrographolide on melanin synthesis. METHODS: Cell viability, melanin content, TYR activity, transcriptional and protein expression levels of TYR family and other kinds of proteins involved in melanogenesis were measured after the treatments of andrographolide. RESULTS: It was found that andrographolide decreased melanin content, TYR activity and transcriptional and protein expression of TYR family and microphthalmia-associated transcription factor (MITF) in B16F10 melanoma cells. Data showed andrographolide also decreased melanin content and TYR content in ultraviolet B (UVB) irradiation induced brown guinea pigs. Moreover, we found that melanin content and TYR activity were effectively inhibited in Human Epidermis Melanocyte (HEM) treated with andrographolide at the medium concentrations without apparent effect on cell viability. Results in experiments treated with MG-132 or cycloheximide (CHX) showed that andrographolide lowered the content of ß-catenin in cell nucleus resulting from accelerating the degradation of ß-catenin. Phosphorylation of glycogen synthase kinase 3ß (GSK3ß) and Akt decreased simultaneously. 6-Bromoindirubin-3'-oxime (BIO, inhibitor of GSK3ß) and insulin-like growth factors-1 (IGF-1, activator of Akt) could reverse the decline of ß-catenin in B16F10 cells induced by andrographolide. CONCLUSION: These results demonstrate that andrographolide can effectively suppress melanin content and TYR activity in B16F10 cells, HEM cells and UVB-induced brown guinea pig skin by decreasing phosphorylation of GSK3ß dependent on Akt, promoting the degradation of ß-catenin, inhibiting ß-catenin into the nucleus and decreasing the expression of MITF and TYR family. Data indicate that andrographolide may be a potential whiting agent which can have great market in cosmetics and in clinical such as curing hyperpigmentation disorders.