Poly(ADP-ribose) polymerase(PARP) is a protein-modifying and nucleotide-polymerizing enzyme. As a critical element in DNA repair, PARP can be activated by DNA strand breaks. Excessive activation of PARP, however, can deplete NAD + and ATP, leads to cell death. Cleavage of PARP by activated caspase-3 play an important role in cell apoptosis.

AIM and METHODS: to elucidater the effect of poly(ADP-ribose) polymerase(PARP) on tracheal hyperreactivity of guinea - pig induced by peroxynitrite, the responses of guinea pig tracheas to histamine af- ter incubation with peroxynitrite in the absence and presence of 3 - aminobenzamide(3 - AB), a highly selective inhibitor for PARP, were observed in vitro. RESULTS: The exposure of tracheal strips to peroxynitrite led to epithelial damage and hyperreacitivity to histamine, both of which were reversed by 3 - AB(l mmol/L or 5mmol/L), whereas incubation of tracheal strips with 3 - AB(5 mmol/L) had no effect on the reponses. CONCLUSION:PARP is involved in the epithelial damage and hyperreactivity of guinea - pig tracheas induced by peroxynitrite. The results suggested that inhibition of excessive activation of PARP may represent a novel strategy for the prevention and therapy of airway hyperreactivity in asthma.

AIM: To explore the effect of peroxynitrite (ONOO -) on pulmonary microvascular endothelial barrier and roles of ONOO - in the pathogenesis of acute lung injury in vivo. METHODS: SD rats in different groups were insufflated with various concentrations of ONOO -, decomposed ONOO - or vehicle (alkaline normal saline), respectively. Then permeability changes in pulmonary microvascular walls were detected and the pathological alterations of pulmonary tissue were examined under light microscope. Malondialdehyde(MDA) contents were measured in normal lung homogenate pretreated with various concentration of ONOO -. RESULTS: Intratracheal insufflation of ONOO - resulted in dose-dependent increase in lung coefficient, lung wet/dry ratio, lung water contents and Evans blue contents, together with significant pulmonary pathological changes such as diffuse alveolar collapse, capillary congestion, focal hemorrhage, and endothelial swollen. In addition, ONOO - can also elicit increase in MDA contents in normal lung homogenate. CONCLUSION: ONOO - may induce dysfunctions of pulmonary microvascular endothelial barriers, it is suggested that enhanced endogenous ONOO - generation may take part in the pathogenesis of acute lung injury.

AIM: To study the mechanism responsible for ONOO --induced the airway epithelial injury. METHODS: Effects of 3-aminobenzamide(3-AB), a poly-(ADP-ribose) polymerase(PARP) inhibitor, and Ac-DEVD-CHO, a caspase-3 inhibitor, on LDH release and apoptosis of cultured rat tracheal epithelial (RTE) cells induced by ONOO - were examined. The cleavage of PARP was analysed by Western blot. RESULTS: 3-AB inhibited the release of LDH induced by ONOO - partially, and had no effect on the apoptosis of RTE cells. Caspase-3 inhibitor Ac-DEVD-CHO obviously prevented the apoptosis of RTE cells induced by ONOO - in a dose-dependent manner. The cleavage of PARP was observed in the process of apoptosis of RTE cells induced by ONOO -. CONCLUSIONS: PARP activation represents one of the pathways of ONOO --mediated epithelial injury, and the excessive activation of PARP contributes to the necrosis in RTE cells induced by ONOO -. Cleavage of PARP by activated caspase-3 plays a crucial role in the apoptosis of RTE cells induced by ONOO -.

Objective To observe PDX-1 expression in the pancreas of type 2 diabetic rat model and effects of rosiglitazone (RGZ) on it. Methods Type 2 diabetic rat model was induced by long-term feeding with high-fat foods followed by a single intraperitoneal injection of low dose of streptozotocin (STZ). The morphological changes of pancreas were examined by microscopy and immunohistochemistry. The mRNA levels of PDX-1 and insulin were determined by RT-PCR. PDX-1 protein expression was detected with Western blot. Results The percentage of insulin-positive cells(12.75±2.18)，the average optical densities of PDX-1-positive area(0.240±0.051)，PDX-1 mRNA level (0.153±0.071)and PDX-1 protein level(0.253±0.028) were significantly lower in untreated diabetic rats than in the controls(42.61±2.68，0.648±0.087，0.49±0.032，0.720±0.036 respectively)(all P＜0.01)，and in RGZ-treated versus untreated group those parameters increased significantly (all P＜0.05~0.01). Conclusions Rosiglitazone could protect islet cell function，and improve PDX-1 expressions in both mRNA and protein levels.

AIM:To study the effect of ONOO- on the airway epithelial injury. METHODS: The mitochondrial respiration, the amount of lactate dedydrogenase (LDH) release into the cell culture medium, the levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), and the cellular apoptosis were examined after exposure of cultured rat tracheal epithelial (RTE) cells to ONOO-. RESULTS: Exposure of RTE cells to 0.25, 0.5 and 1 mmol/L ONOO- caused a dose-dependent suppression of the mitochondrial respiration . ONOO- also caused a dose-dependent increase in the percentage of LDH release. Exposure of RTE cells to ONOO- resulted in an increased generation of 8-OHdG in a dose-dependent manner. ONOO- caused an increase in apoptotic percentage in RTE cells in a time-dependent manner at different concentrations. CONCLUSION: ONOO- could cause necrosis and apoptosis in cultured RTE cells. Low concentration of ONOO- caused apoptosis in a time-dependent manner. Whereas exposure to high concentration of ONOO- resulted in cell necrosis, ONOO- caused a dose-dependent increase in the percentage of LDH release. Suppression of mitochondrial respiration and oxidative DNA damage by ONOO- may be the major cause of cellular injury induced by ONOO-.

Objective:To study the relationship between the expression of filamin A (FLNa) and clinical pathological features in invasive breast carcinoma. Methods:The expression of FLNa was measured by immunohistochemistry and flow cytometry in 46 cases of invasive breast carcinoma. Results:The expression level of FLNa was increased in poorly differentiated invasive breast carcinoma. There were significant differences between well-moderately differentiated and poorly differentiated groups (P<0.05). The expression level of FLNa in invasive breast carcinoma with lymph node metastasis was higher than that in non-metastasis group (P<0.05). Conclusion:The level of FLNa expression correlated with invasion and metastasis of invasive breast carcinoma. FLNa can be used as an assistant marker for prediction of breast carcinoma prognosis and has the potential to be a new target for cilinical therapy.

AIM and METHODS: To elucidate the mechanism of anti-endotoxic shock of cholecystokinin octapeptide(CCK-8), the effects of CCK-8 on changes in rabbit thoracic aortic reactivities induced by lipopolysaccharides(LPS) in vitro were studied, and the ultrastructure of the endothelial cells was observed under scanning electron microscope. RESULTS: Incubation of thoracic aortic rings(TARs) with LPS(100 mg/L) resulted in an time-dependent impairment of the endothelium-dependent relaxations to acetylcholine(incubation for 3, 7, 14 h), a reduction of contractive response to phenylphrine(incubation for 14 h) and ultrastructural injury in endothelial cells(incubation for 7 h), all of which were alleviated by concomitant incubation with CCK-8(1 mg/L). In contrast, neither the vascular contractions nor the relaxations were affected by CCK-8 (1 mg/L) alone. CONCLUSION: CCK-8 improved the vascular reactivities in the presence of LPS, which may be one of the anti-endotoxic shock mechanisms of CCK.

AIM: To investigate the effect of cholecystokinin octapeptide(CCK-8) on the L-arginine-nitric oxide(NO) pathway in rabbit thoracic aortae treated with lipopolysaccharide(LPS). METHODS: The isolated thoracic aortic rings(TARs) from rabbits were incubated with LPS, LPS+CCK or vehicle for 14 h. Then the contractility to phenylephrine(PE) by TARs and the response to L-arginine(L-Arg) by pre-contractile TARs were measured. In addition, we added NO synthase(NOS) inhibitors aminoguanidine(AG)and N ?-nitro-L-arginine(L-NNA) into organ baths to observe the changes of vascular contractility to PE. NOS activity in isolated TARs were also detected. RESULTS: Incubation of TARs with LPS for 14 h resulted in an increase of NOS activity and a reduction of contractility to PE. Treatment with CCK-8 significantly inhibited the increased NOS activity in thoracic aortae and improved the hypocontractility of TARs to the same degree as AG. CONCLUSION: CCK-8 may improve the hypocontractility of TARs induced by LPS by inhibiting the activity of NOS.

AIM：The mechanism of tumor necrosis factor-alpha (TNF-α) induced pulmonary artery hypertension(PAH) in endotoxic shock (ES) is not clear. Cholecystokinin-octapeptide (CCK-8) had anti-ES and anti-PAH effects. The impact of CCK-8 on changes in vascular reactivity and endothelial ultrastructure induced by TNF-α was studied. The role of nitric oxide (NO) was preliminarily studied. METHODS：Rabbit pulmonary artery rings were divided into four groups: TNF-α, TNF-α+CCK-8, CCK-8 and Vehicle. The rings were incubated for 2 h, 7 h or 14 h. Relaxative responses to ACh(10-8-10-5 mol/L)， SNP (10-9-10-6 mol/L) and contractile responses to PE(10-8-10-5 mol/L) were generated seperately. The NOS activity of rings was detected and the ultrastructure of endothelium was observed in the groups that incubated for 7 h.RESULTS:The relaxative responses to ACh were not affected by TNF-α and CCK-8 after incubation for 2 h. TNF-α(7 h,14 h) significantly reduced ACh-induced endothelium-dependent relaxation response of pulmonary artery. CCK-8 reversed the effect. CCK-8 itself had no effect on responses of normal pulmonary artery. Contraction to PE and relaxation to SNP were unaffected by TNF-α, CCK-8. The NOS activity increased in the TNF-α and the TNF-α+CCK-8 groups. While no significant difference was obseved between the Vehicle and the CCK-8 groups. Endothelial injury in TNF-α group and alleviated changes in TNF-α+CCK-8 group were observed. CONCLUSION:TNF-α significantly inhibits endothelium-dependent relaxation, which be one of the mechanisms of PAH induced by TNF-α during ES. It was found for the first time that CCK-8 reversed TNF-α induced impairment of endothelium-dependent relaxation and alleviated structural injury of endothelium, which might be one of the mechanisms of anti-PAH effect by CCK-8 during ES. The effects of TNF-α and CCK-8 might be related to NO.