Search

Backgrounds: Nitric oxide (NO) plays a key role in the pathological chondrocyte apoptosis of osteoarthritis (OA). Cytoskeletal proteins form cytoskeleton network to maintain normal chondrocyte structure and function. JNK and ERK pathways are the signal pathways involved in the cell apoptosis. The role of cytoskeletal proteins in cytoskeleton perturbation and cell apoptosis was investigated in this study. Objectives: In vitro cell apoptosis was induced in rabbit articular chondrocytes by NO donor Sodium Nitroprusside (SNP). The JNK-specific inhibitor SP600125 and ERK-specific inhibitor PD98059 were employed to clarify the mechanism. The level of apoptosis was evaluated by TUNEL assay and Annexin V flow cytometry. Results: SNP induced concentration-dependent apoptosis, which was further enhanced by PD98059 but reduced by SP600125. Furthermore, PD98059 significantly increased caspase-3 expression and activity respectively, whereas SP600125 reduced caspase-3 expression and activity. SP600125 increased the cytoskeletal protein mRNA and protein expression, while PD98059 decreased them. Conclusion: Intracellular JNK/ERK pathways were involved in chondrocyte apoptosis induced by SNP through oppositely regulated effects on cytoskeletal proteins; ERK pathway protected cytoskeletal protein from dissolution via inhibition of caspase-3 activation, while JNK pathway promoted the dissolution via activation of caspase-3 activity. [ABSTRACT FROM AUTHOR]

Fluorosis often causes female reproductive dysfunction. A rapid turnover of DNA methylation is a pathological change in many human diseases, including female reproductive dysfunction. The role of DNA methylation in fluorosis was unknown and investigated in this experiment. Fifty fluorosis women patients were selected as High F group and forty-six healthy women were recruited as Control group were enrolled. In addition, ovarian granulosa cells were obtained from five women in High F group and five women in Control group. All ten women went through in vitro fertilization (IVF) process with DNA methylation sequencing. KGN cells (human granulosa cell line) were cultured with different concentrations of sodium fluoride (0–8 mM NaF) for 24 h for the in vitro study. The level of DNA methylation in blood samples was significantly higher in High F group than that in Control group. The level of serum estradiol (E2) was significantly lower in women from High F group, while the levels of serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in High F group were significantly higher than that in Control group. The methylation sequences of KGN cells relating to autophagy were significantly changed by NaF treatment dose-dependently. Based on these results, it is concluded that DNA methylation and autophagy may play a significant role in the pathophysiology of reproductive dysfunction caused by fluorosis. [ABSTRACT FROM AUTHOR]

Taking excessive sodium fluoride may cause female reproductive dysfunction, but underlying molecular mechanism is unclear. The ovarian granulosa cells are the key endocrine cells releasing reproductive hormones. The miRNAs in the granulosa cells play an important function in regulating reproduction. The aim of this study is to explore the role of miRNAs in granulosa cell apoptosis and autophagy, as well as estradiol (E2) release in response to excessive sodium fluoride. The ovarian granulosa cells (KGN cells) were treated in vitro by different concentrations of sodium fluoride (NaF) for 24 h. The level of estradiol (E2) in the incubation medium was measured by ELISA kits. The total RNA and protein were collected and purified from KGN cells. The expression of miRNAs was detected by the real-time PCR. The signal molecules involved in cell apoptosis and autophagy were detected by the real-time PCR and Western blotting. Six miRNAs in granulosa cells were significantly up- or downregulated by NaF and selected for real-time PCR analysis. The miR-378d was the most significantly upregulated one dose dependently by NaF. It was positively correlated to the extent of apoptosis but negatively correlated to the level of autophagy in KGN cells in response to NaF. In addition, miR-378d promoted E2 release in response to 1 and 2 mM NaF but reduced E2 release in response to 4 and 8 mM NaF treatments. It is concluded that expression of miR-378d in ovarian granulosa cells is negatively correlated to the autophagy and E2 release and positively correlated to cell apoptosis under the influence of NaF. [ABSTRACT FROM AUTHOR]

Background: Nitric oxide (NO) and reactive oxygen species (ROS) play an important role in the pathology of human osteoarthritis (OA). Ankylosing spondylitis (AS) and atypical OA have similar clinical manifestations and often require differential diagnosis. The mechanism is however not totally clear yet. This study aims to investigate the effects of excessive NO-ROS in OA patients and the effects of extracellular signal-regulated kinases (ERK) pathway in NO-induced apoptosis of chondrocytes during OA progress. Methods and results: Serum samples from OA or AS as pathological control patients and healthy controls were collected for NO and related chemical measurements. The rabbit articular chondrocytes were cultured in vitro, and NO was applied by Sodium Nitroprusside (SNP) in culture medium to mimic OA condition in patients. The level of SNP-evoked chondrocyte apoptosis with or without PD98059 (ERK-specific inhibitor) was evaluated by TUNEL assay, Annexin V flow cytometry and Western blotting. The activity and mRNA expression of caspase-3 in chondrocytes were measured by assay kits and RT-PCR. The levels of NO and malondialdehyde (MDA) in serum were significantly higher in OA patients, while only MDA was significantly higher in AS patients. However, the level of superoxide dismutase (SOD) was lower in both OA and AS patients. SNP induced chondrocyte apoptosis was enhanced by PD98059 with increased protein expression and functional activity of caspase-3. Conclusions: The increase in nitric oxide occurs specifically in OA patients. ERK pathway may play a protective role on the NO-induced chondrocyte apoptosis, and inhibition of ERK pathway enhances the NO-induced apoptosis. [ABSTRACT FROM AUTHOR]

Excessive intake of fluoride may cause female reproductive dysfunction but pathological mechanism is unclear. The miRNAs in follicular fluid are a class of small non-coding RNAs from granulosa cells. The aim of this study is to examine the differential expressions of miRNAs in ovarian granulosa cells from women suffering from fluorosis and infertility. Five fluorosis women suffering infertility and 5 non-fluorosis (normal ovarian secretory function control) women were included as two groups. These two groups were indexed by serum and urine fluoride (F) levels as high F group and control group. The concentrations of estradiol (E2), progesterone (P), human chorionic gonadotropin (HCG), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured by ELISA kits. The characteristics of menstruation from each woman were collected. The total RNA was isolated from granulosa cells for sequencing. The validation was completed by RT-qPCR. There was no significant difference between the two groups on age, the levels of E2, FSH, P, HCG, and LH in serum, and the characteristics of menstruation. A total of 37 miRNAs were upregulated and 40 miRNAs downregulated in follicular fluid from granulosa cells in the high F group compared with that in the control group. The expression of hsa-miR-29b increased in fluorosis patients identified by the miRNA sequence analysis. The distinct expression patterns of miRNAs in women requiring IVF from fluorosis area provide a new direction for molecular mechanism of fluorosis caused reproductive dysfunction. [ABSTRACT FROM AUTHOR]

Trans-oxanes are important liquid crystals. The commonly used techniques for the synthesis were to react 2-substituted propylene glycols with substituted formaldehydes. Such process produces toxic cis-oxanes, which are harmful to the environment. The cis to trans isomerization of wasted cis-oxanes was studied in the presence of p-toluenesulfonic acid as catalyst. The yield of cis to trans conversion was over 70%, which was much higher than 42–69% when traditional methods were employed. The total yield of the new method was increased to 90%. Further investigation of effects of catalysts, reaction times, temperatures on the cis-trans conversion was carried out. Proposed mechanism of this process for the conversion was discussed. [ABSTRACT FROM AUTHOR]