SIRT6 reduces the symptoms of premature ovarian failure and alleviates oxidative stress and apoptosis in granulosa cells by degrading p66SHC via H3K9AC.

CONTEXT: Substantial evidence suggests that ovarian oxidative stress can result in severe ovarian dysfunction. OBJECTIVE: The purpose of this article is to investigate the potential of SIRT6 in alleviating premature ovarian failure (POF) by inhibiting oxidative stress. METHODS: To mimic POF, mice were administered daily subcutaneous injections of d-galactose. The levels of E2, FSH, LH, AMH, and progesterone in serum were measured, along with changes in follicles and SIRT6 levels. Mice were treated with the SIRT6 agonist MDL-800, SIRT6 levels, follicles, and aforementioned hormones were reassessed. The effects of MDL-800 on oxidative stress and apoptosis were subsequently identified. Primary granulosa cells were isolated from mice, and the effects of H2O2 and MDL-800 on cell viability, oxidative stress, SIRT6 level, and apoptosis were evaluated. In addition, the regulation of SIRT6 on H3K9AC/p66SHC was verified by examining changes in protein levels, promoter activity, and the reversal effects of p66SHC overexpression. RESULTS: MDL-800 mitigated hormone fluctuations, reduced follicle depletion in ovarian tissue, and attenuated oxidative stress and apoptosis in mice. In vitro experiments demonstrated that MDL-800 enhanced the resilience of primary granulosa cells against H2O2, as evidenced by increased cell viability and reduced oxidative stress and apoptosis. Furthermore, SIRT6 was found to decrease H3K9AC and p66SHC levels, as well as attenuate p66SHC promoter activity. The protective effects of MDL-800 on cells were reversed upon p66SHC overexpression. CONCLUSION: In summary, this study highlights that activation of SIRT6 can alleviate POF and reduce oxidative stress by degrading H3K9AC and suppressing p66Shc levels in granulosa cells.

Purinergic receptor P2X7 activates NOX2/JNK signaling to participate in granulosa cell inflammation and apoptosis in polycystic ovary syndrome.

Increasing evidence shows that polycystic ovary syndrome (PCOS) is often accompanied by an inflammatory response, hence, appropriately managing granulosa cell inflammation is critical to regaining ovarian function in PCOS. In this study, the differential levels of purinergic receptor P2X7 between the control and PCOS samples in the dataset GSE34526 were assessed, then PCOS mouse models were established. Following evaluating the fluctuations in hormone levels, inflammatory cytokines, and P2X7, mice received treatment with the P2X7 antagonist A740003. Its effects on hormones, inflammation, apoptosis, and NOX2 signaling in mice were examined. Afterward, primary mouse granulosa cells were isolated, and the mediating role of NOX2 signaling in the P2X7 regulatory pathway was confirmed by transfection of NOX2 overexpression plasmids. The results demonstrated that P2X7 was significantly elevated in the PCOS samples in the dataset. Compared with the control group, PCOS mice had significant differences in the follicle-stimulating hormone, luteinizing hormone, testosterone, anti-Müllerian hormone, inflammatory factors, and P2X7. Treatment with A740003 partially restored these parameter levels, including NOX2 signaling. Based on in vitro experiments on primary mouse granulosa cells, the above findings were re-verified, and the overexpression of NOX2 could reverse the regulatory function of P2X7. The present study highlights that P2X7 level increases in PCOS, and inhibition of P2X7 can reduce disease symptoms. It is involved in inflammation and apoptosis in granulosa cells through NOX2/JNK signaling.

[Infectivity of Human Adenovirus Type 55 to Human Intestinal Cells].

OBJECTIVE: To examine the infectivity of human adenovirus type 55 (HAdV-55) in human intestinal cells. METHODS: Caco-2 cells were cultured in vitro, and infected with HAdV-3, 7, 14 and 55. The expression of viral proteins in infected cells was detected with immunofluorescence method. The intracellular and supernatant viral DNA levels were determined with fluorescent quantitative PCR at different points of time. The level of infectious virus particles in the supernatant of Caco-2 cells was determined with adenovirus sensitive HEp-2 infection assay. RESULTS: Immunofluorescence assay showed positive result for the expression of HAdV-55 virus protein in Caco-2 cells 48 h post infection. HAdV-3, 7, 14, and 55 showed sustained replication and proliferation in Caco-2 cells. The level of viral DNA in infected cells and the supernatant increased with the infection time, and the viral DNA level of HAdV-55 was significantly higher than those of HAdV-3, 7 and 14. The infectious virus particles of HAdV-55 in Caco-2 supernatant were more than those of HAdV-3, 7 and 14, showing statistically significant difference ( P<0.05). Caco-2 cells were infected with low doses of virus (1×TCID 50), and the cytopathic effect (CPE) of HAdV-55 infection wells was more significant than that of HAdV-3, 7 and 14 infection wells. CONCLUSION: This study found that human intestinal cells were susceptible to HAdV-55, and the infection level was higher than that of other common respiratory infections caused by adenovirus types 3, 7 and 14.

[Correlation between TXB2, 6-Keto-PGF1alpha and liver metastasis in rats model with blood stasis].

OBJECTIVE: To observe the correlation between serum level of TXB2, 6-Keto-PGF1alpha and liver metastasis. METHODS: The metastatic model was made by injection of W256 carcinosarcoma. Rats were randomly divided into two groups: rats with blood stasis group and control group. Rats in control group were given normal saline via abdominal cavity once a day. Rats in blood stasis group were injected adrenalin in the fourteenth day. Tumor size and liver metastasis were observed. Serum TXB2 and 6-Keto-PGF1alpha were tested by radioimmunoassay. RESULTS: Tumor size in rats with blood stasis was significantly smaller than that of the control group (P<0.01). Occurrence of liver metastasis in rats with blood stasis was significantly lower than that of the control group (P<0.01). The values of 6-Keto-PGF1alpha, TXB2, and TXB2/6-Keto-PGF1alpha were higher in the group with blood stasis. CONCLUSION: In the status of blood stasis, W256 carcinosarcoma grows slowly, and liver metastasis increases insignificantly, with the elevations of 6-Keto-PGF1alpha, TXB2 and TXB2/6-Keto-PGF1alpha.