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Aim: To investigate the DNA damage response (DDR) in a cyclophosphamide (CTX)‐induced mouse model of premature ovarian failure (POF). Methods: The POF model was established by injecting mice with CTX. The body, ovarian weights, the estrus cycle, and pathological changes of the ovaries were recorded. The serum levels of 17 β‐estradiol (E2) and follicle‐stimulating hormone (FSH) were measured. The expression of Ki67, β‐galactosidase (β‐gal), p21, p53, γH2AX, and pATM in ovarian tissues was detected by immunohistochemistry. The expression of β‐gal, γH2AX, and pATM was analyzed by immunofluorescence staining of primary cultured granulosa cells (GCs). Results: The body and ovarian weights decreased, the estrus cycles were erratic, and the FSH level increased, whereas the E2 level decreased in POF mice compared to controls. The pathological consequences of POF revealed an increase in atretic follicles, corpus luteum, and primordial follicles and a decrease in the number of primary, secondary, and tertiary follicles. Ki67 expression was reduced, β‐gal, p21, p53, γH2AX, and pATM expression were elevated in the ovaries of POF mice. The expression of β‐gal, γH2AX, and pATM increased in GCs with the concentration in a time‐dependent manner. Conclusion: In total, CTX induced POF in mice, which was mediated by the DDR pathway of ATM‐P53‐P21. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the effects of gossypol acetic acid (GAA) on the proliferation of human mucoepidermoid carcinoma cell line MEC-1 in vitro and its possible molecular mechanisms of DNA double-strand breaks (DSB). MTT assay was performed to test the inhibition of proliferation of MEC-1 cells by GAA. DSB and γH2AX foci formation induced by GAA were detected by neutral comet assay and immunostaining. GAA (5-40 μmol/L) inhibited the growth of MEC-1 cells in a dose- and time-dependent manner. One of the indexes of comet assay, percentage of head DNA was decreased, however other indexes, including tail length, percentage of tail DNA, tail moment (TM) and Olive tail moment (OTM) were increased when treated with 2.5- 40 μmol/L GAA for 24 h or 20 μmol/L GAA for 3-48 h, compared with those in control. The percentage of γH2AX-positive cells was also increased when MEC-1 was treated with 2.5-20 μmol/L GAA for 24 h or 20 μmol/L GAA for 3-48 h, compared with that in control. All these results show that GAA inhibits the proliferation of MEC-1, and DSB maybe one of the mechanisms of inhibitory effect of GAA on the growth of tumor cells.

Objective: To observe the influence of matrine on airway inflammation and early airway remodeling in asthmatic mice., Methods: Fifty BALB/c mice were randomly divided into 5 groups: a normal control group (A), an asthmatic group (B), a dexamethasone (DXM) group (C, 2 mg/kg), a high-dose matrine group (D, 50 mg/kg) and a low-dose matrine group (E, 25 mg/kg). The mice model of asthma in the B, C, D, and E groups was established by ovalbumin (OVA) intraperitoneal injections and aerosolization. Intra-gastric administration of different medications in C, D, E groups and 0.9% sodium chloride in B group were carried out 1 hour before provocation. 0.9% sodium chloride was used for intraperitoneal injection, aerosolization and intra-gastric administration in group A. The lung tissue slices were stained, and then the grade of inflammation around the wall of bronchi, mucous secretion, and the percentage of goblet-cells were counted. The areas of bronchial smooth muscle and of collagen deposition in airway wall were analyzed. The transcriptions and protein expressions of transforming growth factor-beta(1) (TGF-beta(1)) and connective tissue growth factor (CTGF) were measured respectively by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry., Results: In the A, B, C, D, E groups, the grades of inflammation were 1.5 (1, 2), 4 (4, 5), 2 (1, 3), 2 (2, 3), 3 (2, 3.3), respectively; the degrees of mucous secretions were 1.5 (1, 2), 5 (4, 6), 2 (1, 3), 2 (2.5, 4), 3 (3, 4), respectively. These airway inflammatory parameters in group B were significantly higher than in group A (chi(2) = 21.3, 22.6, P all < 0.01), while they were remarkably decreased in group C compared to group B (chi(2) = 13.3, 15.0, P all < 0.01). These parameters in group D and group E were also lower than those in group B (chi(2) = 9.1, 10.9; 9.8, 9.7; P all < 0.05). The percentage of goblet cells in airway epithelium was (1.7 +/- 0.5)%, (54.7 +/- 15.5)%, (20.4 +/- 5.9)%, (31.7 +/- 7.6)% and (36.2 +/- 10.8)%, respectively; it was significantly higher in group B than in group A (t = 12.0, P < 0.01), and remarkably lower in groups C and D than in group B (t = 7.7, 5.1, P all < 0.01), and lower in group E than in B group (t = 4.2, P < 0.05). In these 5 groups, the area of bronchial smooth muscle was (11.5 +/- 2.1) microm(2)/microm, (30.0 +/- 3.3) microm(2)/microm, (15.2 +/- 3.1) microm(2)/microm, (22.2 +/- 4.8) microm(2)/microm and (26.5 +/- 3.4) microm(2)/microm, respectively; it was significantly higher in group B than in group A (t = 11.4, P < 0.01), and remarkably lower in groups C, D and E than in group B (t = 9.1, 4.7, 2.2, P all < 0.01). The area of collagen deposition was (3.9 +/- 1.8) microm(2)/microm, (24.4 +/- 6.1) microm(2)/microm, (15.4 +/- 3.5) microm(2)/microm, (16.6 +/- 6.0) microm(2)/microm and (17.5 +/- 4.4) microm(2)/microm, respectively; it was also significantly higher in group B than in group A (t = 9.3, P < 0.01), and remarkably lower in groups C and D than in group B (t = 4.1, 3.5, P all < 0.01), and lower in group E than in B group (t = 3.2, P < 0.05). The mRNA levels of TGF-beta(1) were 160 +/- 25, 247 +/- 37, 174 +/- 23, 195 +/- 25 and 207 +/- 42, respectively, and those of CTGF were 86 +/- 8, 160 +/- 24, 94 +/- 10, 93 +/- 14 and 104 +/- 10, respectively in the 5 groups. The levels were remarkably increased in group B, as compared to group A (t = 6.1, 11.6, P all < 0.01), and the levels in groups C, D and E were remarkably decreased, as compared to group B, the difference being significant (t = 3.7, 2.7, 5.1; 10.6, 8.6, 10.3; P all < 0.01). The protein level of TGF-beta(1) in lung tissues was 21 +/- 5, 36 +/- 8, 26 +/- 5, 26 +/- 5 and 26 +/- 5, respectively, and that of CTGF was 15 +/- 4, 27 +/- 5, 21 +/- 4, 22 +/- 3 and 23 +/- 4, respectively in the 5 groups. The levels in B group were significantly increased, as compared to group A (t = 5.7, 6.4, P all < 0.01), and those in groups C and D were significantly decreased (t = 3.9, 3.9; 3.2, 2.8, P all < 0.01), and that in group E was also lower (t = 3.8, 2.5, P all < 0.05), as compared to group B. In all the groups, the protein levels of TGF-beta(1) and CTGF were positively correlated with the area of bronchial smooth muscle and with the area of collagen deposition (r = 0.435, 0.583, 0.522, 0.590, P all < 0.01)., Conclusions: Matrine inhibited airway inflammation and early airway remodeling in asthmatic mice. The signal transduction of TGF-beta(1) and CTGF maybe involved.