Overexpression of NAT10 induced platinum drugs resistance in breast cancer cell / 中华肿瘤杂志

Objective: To observe the platinum drugs resistance effect of N-acetyltransferase 10 (NAT10) overexpression in breast cancer cell line and elucidate the underlining mechanisms. Methods: The experiment was divided into wild-type (MCF-7 wild-type cells without any treatment) group, NAT10 overexpression group (H-NAT10 plasmid transfected into MCF-7 cells) and NAT10 knockdown group (SH-NAT10 plasmid transfected into MCF-7 cells). The invasion was detected by Transwell array, the interaction between NAT10 and PARP1 was detected by co-immunoprecipitation. The impact of NAT10 overexpression or knockdown on the acetylation level of PARP1 and its half-life was also determined. Immunostaining and IP array were used to detect the recruitment of DNA damage repair protein by acetylated PARP1. Flow cytometry was used to detect the cell apoptosis. Results: Transwell invasion assay showed that the number of cell invasion was 483.00±46.90 in the NAT10 overexpression group, 469.00±40.50 in the NAT10 knockdown group, and 445.00±35.50 in the MCF-7 wild-type cells, and the differences were not statistically significant (P>0.05). In the presence of 10 μmol/L oxaliplatin, the number of cell invasion was 502.00±45.60 in the NAT10 overexpression group and 105.00±20.50 in the NAT10 knockdown group, both statistically significant (P<0.05) compared with 219.00±31.50 in wild-type cells. In the presence of 10 μmol/L oxaliplatin, NAT10 overexpression enhanced the binding of PARP1 to NAT10 compared with wild-type cells, whereas the use of the NAT10 inhibitor Remodelin inhibited the mutual binding of the two. Overexpression of NAT10 induced PARP1 acetylation followed by increased PARP1 binding to XRCC1, and knockdown of NAT10 expression reduced PARP1 binding to XRCC1. Overexpression of NAT10 enhanced PARP1 binding to LIG3, while knockdown of NAT10 expression decreased PARP1 binding to LIG3. In 10 μmol/L oxaliplatin-treated cells, the γH2AX expression level was 0.38±0.02 in NAT10 overexpressing cells and 1.36±0.15 in NAT10 knockdown cells, both statistically significant (P<0.05) compared with 1.00±0.00 in wild-type cells. In 10 μmol/L oxaliplatin treated cells, the apoptosis rate was (6.54±0.68)% in the NAT10 overexpression group and (12.98±2.54)% in the NAT10 knockdown group, both of which were statistically significant (P<0.05) compared with (9.67±0.37)% in wild-type cells. Conclusion: NAT10 overexpression enhances the binding of NAT10 to PARP1 and promotes the acetylation of PARP1, which in turn prolongs the half-life of PARP1, thus enhancing PARP1 recruitment of DNA damage repair related proteins to the damage sites, promoting DNA damage repair and ultimately the survival of breast cancer cells.

Morroniside improves the neurological function in intracerebral hemorrhage rats by inhibiting inflammatory response / 中国组织工程研究

BACKGROUND: Morroniside has been shown to play roles of anti-inflammation, antioxidant, anti-apoptosis, promoting vascular and neural regeneration, anti-platelet aggregation and neuroprotection in the rat model of ischemic brain injury, but whether it can inhibit the inflammatory reaction of cerebral hemorrhage is unclear. OBJECTIVE: To observe the changes of inflammatory factors (interleukin-1, tumor necrosis factor-α) and inflammatory-related proteins (nuclear factor-κB and SUMO2/3) as well as neurologic function in a rat model of cerebral hemorrhage treated with morroniside at different doses. METHODS: Healthy male Sprague-Dawley rats were randomly divided into sham operation, cerebral hemorrhage and low-, medium- and high-dose morroniside groups. The model of cerebral hemorrhage was established in the latter four groups by injecting autologous blood from the tail artery, followed by intragastric injection of 30, 90, 270 mg/kg morroniside in the three morronicide groups, respectively, three times daily for consecutive 7 days; the rats in the sham operation and model groups were given same volume of normal saline. Then, the neurological function was evaluated by Neurological Severity Scores; the brain tissue around the hematoma were removed to observe the morphological changes of neurocytes around the hematoma by hematoxylin-eosin staining; the expression levels of interleukin-1 and tumor necrosis factor α in the brain tissue were detected by ELISA; the expression levels of nuclear factor-κB and SUMO2/3 were detected by immunohistochemistry and western blot assay. RESULTS AND CONCLUSION: Compared with the icerebral hemorrhage group, the low-, medium- and high-dose morroniside groups showed a significnat neurological improvement, especially the high-dose group (P < 0.05). Compared with the sham operation group, the cerebral hemorrhage and morroniside groups exhibited a significant increase in the nerve function damage and expression levels of interleukin-1, tumor necrosis factor α, nuclear factor-κB and SUMO2/3 (P < 0.05). Compared with the cerebral hemorrhage group, in the low-, medium- and high-dose morroniside groups, the expression levels of interleukin-1 and tumor necrosis factor α were significantly reduced, and expression levels of nuclear factor-κB and SUMO2/3 were significantly increased (P < 0.05). In summary, high-dose morroniside can improve the neurological function in rats with cerebral hemorrhage by down-regulating the levels of inflammatory cytokines.

Improved development of somatic cell cloned bovine embryos by a mammary gland epithelia cells in vitro model

Previous studies have established a bovine mammary gland epithelia cells in vitro model by the adenovirus-mediated telomerase (hTERT-bMGEs). The present study was conducted to confirm whether hTERT-bMGEs were effective target cells to improve the efficiency of transgenic expression and somatic cell nuclear transfer (SCNT). To accomplish this, a mammary-specific vector encoding human lysozyme and green fluorescent protein was used to verify the transgenic efficiency of hTERT-bMGEs, and untreated bovine mammary gland epithelial cells (bMGEs) were used as a control group. The results showed that the hTERT-bMGEs group had much higher transgenic efficiency and protein expression than the bMGEs group. Furthermore, the nontransgenic and transgenic hTERT-bMGEs were used as donor cells to evaluate the efficiency of SCNT. There were no significant differences in rates of cleavage or blastocysts or hatched blastocysts of cloned embryos from nontransgenic hTERT-bMGEs at passage 18 and 28 groups (82.8% vs. 81.9%, 28.6% vs. 24.8%, 58.6% vs. 55.3%, respectively) and the transgenic group (80.8%, 26.5% and 53.4%); however, they were significantly higher than the bMGEs group (71.2%, 12.8% and 14.8%), (p < 0.05). We confirmed that hTERT-bMGEs could serve as effective target cells for improving development of somatic cell cloned cattle embryos.

Studies on dangerous factors causing child cerebral palsy / 中国康复理论与实践

@#ObjectiveTo understand dangerous factors causing child cerebral palsy and try to diagnose and treat cerebral palsy early, and decrease the ratio of cripple.MethodsTo analyze if the occurrence, style or complication of cerebral palsy having a relation to dangerous factors such as sexes, birth weight, premature delivery, twins, neonatal asphyxia, infection of newborn, nuclear icterus, mother's age, virus infection in the duration of pregnancy, threatened abortion and family history of cerebral palsy.ResultsThe ration of male and female is 1.47∶1 in 146 cases of child cerebral palsy. Factors causing cerebral palsy are low birth weight (79.45%), premature delivery (64.38%), neonatal asphyxia (41.78%), threatened abortion (32.89%), twins (31.53%), infection of newborn (12.33%), nuclear icterus (6.16%), parturient with advanced age (3.42%), having infection history in the duration of pregnancy (2.74%), and family history of cerebral palsy (0.68%). Both styles and complications of cerebral palsy have a relation to dangerous factors.ConclusionsThe low birth weight, premature delivery, neonatal asphyxia, twins and threatened abortion all are higher dangerous factors causing child cerebral palsy. In order to abstain the occurrence of these dangerous factors, it is important to educate people and doctors recognizing all dangerous factors. It is also helpful to lower the ratio of cripple that regularly examining child with dangerous factors, discovering symptoms and complications of cerebral palsy in time, and diagnosing and treating cerebral palsy as soon as possible.