[Effects of dexmedetomidine on hypoxia/reoxygenation injury-induced cell apoptosis and caspase-12 expression in A549 cells].

To investigate the effects of dexmedetomidine (DEX) on hypoxia/reoxygenation (H/R) injury-induced cell apoptosis and caspase-12 expression, A549 cells were randomly divided into 4 groups: control group, DEX group, H/R group and DEX+H/R group. Cells of control and DEX groups were cultured in the normoxic incubator for 30 h. Cells of H/R and DEX+ H/R groups were incubated in the anoxic cultivation for 6 h, followed by normoxic culture for 24 h, and DEX (1 nmol/L) was added into the culture medium in DEX and DEX+H/R groups. Morphological changes were observed under the inverted microscope. Cell viability was detected by CCK-8. The apoptosis index (AI) of A549 cells was detected by TUNEL method. The activity of caspase-3 enzyme in cells was detected by using caspase-3 kit. The expressions of GRP78, caspase-12 protein and mRNA were determined by Western blot and RT-PCR respectively. Compared with control group, the morphological changes of the cultured cells were observed: some of the cell fusion occurred and the shape of the cells was multilateral; the cell viability was decreased significantly (P < 0.01), the number of apoptotic cells and the AI value, caspase-3 activity, and the expressions of GRP78, caspase-12 protein/mRNA were significantly increased (P < 0.01) in H/R group. While the administration of DEX alleviated the H/R injury-induced cell damage, obviously increased the cell viability (P < 0.01), significantly decreased the increment of apoptotic cells and the AI value induced by H/R injury (P < 0.01), and also dramatically decreased the H/R injury-induced high level of caspase-3 activity (P < 0.01) as well as high expression of caspase-12 protein and mRNA (P < 0.01). Taken together, the results suggest that DEX can effectively protect A549 cells from the H/R injury, which may be mediated by down-regulating the expression of caspase-12 and inhibiting cell apoptosis.

[Effect of curcumin on caspase-12 and apoptosis in pulmonary ischemia/reperfusion injury mice].

OBJECTIVE: To explore the effect of curcumin (CUR) on cycteinyl aspirate specific protease-12 (Caspase-12) and pneumocyte apoptosis in pulmonary ischemia/reperfusion (I/R) injury mice. METHODS: The in vivo unilateral in situ pulmonary I/R injury mouse model was established in C57BL/6J mice. Sixty experimental mice were randomly divided into six groups by random digit table, i. e., the sham-operation group (Sham), the I/R group, the I/R + dimethyl sulfoxide group (I/R + DMSO), the I/R + low dose CUR pre-treated group (I/R + CUR-100), the I/R + middle dose CUR pre-treated group (I/R + CUR-150), the I/R + high dose CUR pre-treated group (I/R + CUR-200), 10 in each group. Mice were euthanized and their left lungs were excised. Wet lung weight to dry lung weight (W/D) and the total lung water content (TLW) were tested. The morphological changes of the lung tissue were observed and index of quantitative evaluation for alveolar damage (IQA) detected under light microscope. The ultra-microstructure of the lung tissue was observed under electron microscope. The mRNA and protein expression levels of Caspase-12 and glucose regulated protein (GRP78) were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Apoptosis index (AI) of the lung tissue was determined by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) method. RESULTS: Compared with the Sham group, expression levels of Caspase-12, GRP78 mRNA and protein all significantly increased in the I/R group (P < 0.05); W/D, TLW, IQA, and AI were all notably higher (P < 0.05, P < 0.01); the morphological and ultrastructural injury of the lung tissue were notably observed in I/R group. Compared with the I/R + DMSO group, expression levels of GRP78 mRNA and protein were increasingly higher in the I/R + CUR-100 group, the I/R + CUR-150 group, and the I/R +CUR-200 group (P < 0.05), expression levels of Caspase-12 mRNA and protein were lower (P < 0.05); W/D, TLW, IQA, and AI also decreased (P < 0.05, P < 0.01); the morphological and ultrastructural injury of the lung tissue were gradually alleviated in the I/R + CUR groups. CONCLUSION: CUR had better effect on the lung protection against I/R injury, which might be related to inhibition for pneumocyte apoptosis associated with Caspase-12 in excessive unfolded protein response (UPR).

[Role of autophagy in liver injury induced by lung ischemia/ reperfusion in rats].

Objective: To investigate the liver injury induced by lung ischemia / reperfusion(LI/R) and the role of autophagy in its prevention and treatment. Methods: The lung ischemia/reperfusion injury(LI/RI) model was prepared by anesthetizing the rats, cutting the trachea for mechanical ventilation, and using an arterial clamp to close the pulmonary hilum to simulate the ischemic process, and releasing the arterial clamp after 30 min to resume perfusion for 3 h. SD rats(n=24)were randomly divided into sham operation(sham)group,ischemia/reperfusion(I/R)group,solvent(DMSO)group and autophagy inhibitor (3-MA) group, 6 rats in each group. The rats were intraperitoneally injected with medicine before operation. After the rat LI/RI model was established,the rats were killed, and the lung wet/dry weight ratio was used to evaluate the success of modeling, the venous blood was collected to measure the contents of ALT and AST, and the liver tissues were collected. Light and electron microscopes were used to observed the liver tissues and cell shapes. The protein and mRNA expression levels of autophagy related proteins were determined by Western blot and RT-qPCR to suggest autophagy levels. Results: Compared with sham group, the lung wet/dry weight ratios in other groups were elevated, and the liver tissues of other groups were damaged significantly. Serum levels of AST and ALT were increased significantly and liver tissue damage was obvious, especially in I/R group. The light microscopy showed that the arrangement of hepatic cords was disordered or broken, hepatic sinuses were dilated, and edema of liver cells were observed; transmission electron microscopy showed varying degrees of mitochondria swelling up in liver cells in the other groups. At the same time, the expressions of AMPK, Beclin 1 and LC3 mRNA were increased, but the expressions of mTOR and p62 mRNA were decreased; the protein expressions of p-AMPK, Beclin 1, LC3-B were increased significantly, but those of p-mTOR and p62 were decreased (all P＜0.05). Compared with DMSO group, the injury of liver tissue in 3-MA group was alleviated, the damage degree of mitochondrial ultrastructure was lower, the levels of AST and ALT were decreased, the transcription and protein expression levels of autophagy related protein in liver tissue were decreased (P＜0.05). However, the injury degree of IR and DMSO groups were similar, and there was no significant differences in each index (P＞0.05). Conclusion: Lung ischemia/reperfusion can cause liver injury in rats. Autophagy can mediate liver injury induced by lung ischemia / reperfusion in rats and inhibiting autophagy can effectively reduce liver injury induced by LI/R in rats.

[The regulatory role of autophagy in rats lung ischemia/reperfusion injury].

Objective: To investigate the role of cell autophagy in lung ischemia/reperfusion injury in rats. Methods: Forty SD rats were randomly divided into 5 groups (n=8): ①Sham operated group (sham group):just open rat chest for 3.5 h; ②Ischemia/reperfusion group (I/R group):after open chest, clamp pulmonary hilus for 0.5h then reperfusion for 3 h; ③Solvent group (DMSO group): intraperitoneal injection of DMSO solution for 1h before operation; ④Autophagic inhibitor group (3-MA group); ⑤Autophagic agonist group (Rap group): intraperitoneal injection of autophagic agonist rapamycin before operation; the rest operations of DMSO, 3-MA and Rap groups are the same as that of I/R group. At the end of the experiment, the rats were killed by euthanasia-killing. The lung tissues were collected and the wet/dry weight ratio (W/D) and total lung water content (TLW) of the lung tissues were detected. The lung tissue structure and cell ultramicro morphology were observed by light microscopy and electron microscopy and the injuried alveolar rate(IAR) was calculated. The autophagy-related protein expressions were detected by Western blot. Results: Compared with sham group, the levels of W/D, TLW and IAR were increased, the expressions of autophagy related protein and p-AMPK, Beclin 1, LC3 II were also increased in other four groups, while the protein expressions of p-mTOR and p62 were decreased significantly (P＜ 0.05 or P＜0.01). Under the light microscope, the other groups of lung tissue had edema and exudation in varying degrees, the structure of alveoli was disordered, the ultrastructural damage of cells was aggravated under the electron microscope, and autophagosome could be observed. Compared with DMSO group, the expressions of autophagy related protein, the levels of W/D, TLW and IAR in 3-MA group were decreased (P＜0.05 or P＜0.01), the edema of lung interstitial was lighter, and less cells were found in alveolar cavity. Ultrastructural damage was also lighter and with less autophagosome. Besides, there was no significant difference among I/R, DMSO and Rap groups (P＞0.05). Conclusion: Autophagy can be activated during ischemia/reperfusion in rats to induce lung injury.

[Effects of excessive endoplasmic reticulum stress on lung ischemia/reperfusion induced myocardial injury in mice].

OBJECTIVE: To investigate the effects of excessive endoplasmic reticulum stress on lung ischemia/reperfusion (I/R) induced myocardial injury in mice. METHODS: Forty healthy SPF male C57BL/6J mice were divided into 4 groups randomly (n=10):sham operation group (Sham group), lung I/R group (I/R group), endoplasmic reticulum stress (ERS) pathway agonist Tunicamycin group (TM) and ERS inhibitor 4-phenyl butyric acid group (4-PBA). The model of lung I/R injury was established by clamping the left hilum of lung for 30 min followed by 180 min of reperfusion. In sham group, only sternotomy was performed, the hilum of lung was not clamped, and the mice were mechanically ventilated for 210 min. In TM and 4-PBA groups, TM 1mg/kg and 4-PBA 400 mg/kg were injected intraperitoneally, respectively, at 30 min before establishment of the model. At 180 min of reperfusion, blood samples were collected from the orbit for determination of myocardial enzyme. The animals were then sacrificed, and hearts were removed for determination of light microscope, TUNEL, Caspase 3 enzymatic activity, real-time polymerase chain reaction and Western blot. RESULTS: Compared with sham group, the cardiomyocytes had obvious damage under light microscope, and the serum creatine kinase-MB (CK-MB) and lactic dehydrogenase (LDH) activities, apoptosis index and Caspase 3 enzymatic activity were increased significantly, the expressions of p-Jun N-terminalkinase(p-JNK), Caspase 12, CCAAT/enhancer-binding protein homologous protein (CHOP) and glucose regulated protein 78(GRP78) protein and mRNA were up-regulated in I/R, TM and 4-PBA groups (P<0.01). Compared with I/R group, the cardiomyocytes damage was obvious under light microscope, and the serum CK-MB and LDH activities, apoptosis index and Caspase 3 enzymatic activity were increased significantly, the expressions of p-JNK, Caspase 12, CHOP and GRP78 protein and mRNA were up-regulated in group TM; while all above changes were relieved in group 4-PBA (P<0.01). Compared with TM group, the cardiomyocytes damage was relieved under light microscope, and the serum CK-MB and LDH activities, apoptosis index and Caspase 3 enzymatic activity were decreased significantly, the expressions of p-JNK, Caspase 12,CHOP and GRP78 protein and mRNA were down-regulated in group 4-PBA. CONCLUSIONS: The excessive endoplasmic reticulum stress participates in myocardial injury induced by lung ischemia/reperfusion (I/R) and inhibit excessive endoplasmic reticulum stress response can relieved myocardial injury.

[The effects of YHTJF on lung ischemia/reperfusion injury in mice].

OBJECTIVE: To explore whether yiqi huoxue tongluo jiedu fang (YHTJF, Traditional Chinese Medicine) alleviates the injury during lung ischemia/reperfusion (I/R) in mice through inhibiting oxidative stress or not. METHODS: C57BL/6J male mice (n=70) were randomly divided into 7 groups:control (C), carboxyl methyl cellulose-Na(CMC·Na) + normal control (CC), carboxyl methyl cellulose-Na + sham (CS), carboxyl methyl cellulose-Na + I/R (CIR), carboxyl methyl cellulose-Na + YHTJF-Low, CMC-Na + YHTJF-Middle, CMC-Na + YHTJF-High (CYL, CYM, CYH). The mice in CYL, CYM and CYH group were treated with YHTJF by intraperitoneal injection every day, while the carboxyl methyl cellulose-Na was administered with the same volume of CYL in CC, CS and CIR group. After 3 h-reperfusion, the left lung tissues were harvested to determine the lung wet/dry weight (W/D), the total lung water content (TLW), and the index of quantita-tive evaluation for alveolar damage (IQA). Morphological observation and terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) were applied to evaluate the structural changes and the apoptosis index (AI) of the lung tissues. The expressions superoxide of dis-mutase(SOD), malondialdehyde(MDA) and myeloperoxidase(MPO) in the lung tissues were detected by kits. RESULTS: Compared with group C, the W/D, TLW, IQA, AI, lung tissue structural changes, and the expressions of MDA and MPO in group I/R were increased obviously (P < 0.01), and the expression of SOD was decreased, while there was no significant difference between group CC and CS. Compared with group I/R, the parameters of these experiments in group CYL, CYM, CYH were all decreased, and the expression of SOD was increased, while the reduction in group CYM was the most remarkable among them (P < 0.01). CONCLUSIONS: YHTJF may attenuate the I/R injury of the lung by the inhibition of apoptosis via ROS pathway.

Therapeutic efficacy of chlorogenic acid on cadmium-induced oxidative neuropathy in a murine model.

The aim of the present study was to determine whether chlorogenic acid (CA) is able to modulate cadmium (Cd)-induced oxidative brain damage. Cd-treated rats displayed numerous pathological effects, including the inhibition of acetylcholinesterase, elevated lipid peroxidation, the depletion of enzymatic and non-enzymatic antioxidants, the reduction of membrane-bound ATPase activity, mitochondrial dysfunction and DNA fragmentation. Pretreatment of the rats with CA significantly attenuated these effects. These results lead to the hypothesis that the mechanisms by which CA attenuates the effects of Cd-induced oxidative brain damage include the maintenance of antioxidant homeostasis, inhibition of the membrane effects and the perpetuation of mitochondrial dysfunction. These data support the potential of CA as a beneficial intervention in the prevention of heavy metal poisoning due to Cd exposure.

[Effect of siRNA silencing the role of JNK gene in excessive endoplasmic reticulum stress on lung ischemia/reperfusion injury].

OBJECTIVE: To investigate the effect of siRNA silencing the role of C-Jun N-terminal Kinase (JNK) gene in excessive endoplasmic reticulum stress on lung ischemia/reperfusion injury. METHODS: Mouse model of pulmonary ischemia reperfusion injury (PIRI) in situ was established with unilateral lung in vivo. Seventy experimental mice were randomly allocated into seven groups (n = 10): Sham group (Sham group), ischemia reperfusion group (I/R), PBS+ Lipofectamine2000TM transfection reagent group (I/R + PBS+ Lipo group), negative control group (I/R+ SCR group), JNK-siRNA group (I/R + siRNA(JNK1), siRNA(JNK2), siRNA(JNK3)). Mice were euthanized after experimental time out, and left lung tissue was extracted. Wet/dry lung weight ratio (W/D) and total lung water content (TLW) were tested. Light microscope, alveolar damage quantitative evaluation index (IQA) and electron microscope were observed. The expression levels of JNK and glucose regulatex protein(GRP78) were detected by RT-PCR and Western blot. Apoptosis of lung tissue was determined by TUNEL. RESULTS: Compared with Sham group, all indicators above of I/R + PBS + Lipo group and I/R + SCR group were significantly increased (P < 0.01), and compared with I/R group, those indicators of the three groups all had no notable difference; those indicators were not statistically different between I/R + PBS + Lipo group and I/R + SCR group, and compared to the three groups, the above indicators in JNK-siRNA group were lower (P < 0.05, P < 0.01) except that the expression levels of GRP78 was not statistically different. CONCLUSION: I/R induces excessive ERS in lung tissue, in which JNK pathway participates in apoptosis, leading to lung tissue injury.

[Effects of curcumin on pneumocyte apoptosis and CHOP in pulmonary ischemia/reperfusion injury of mice].

OBJECTIVE: To investigate the effects of curcumin (CUR) on pneumocyte apoptosis and CCAAT/enhancer binding protein homologous protein (CHOP) in pulmonary ischemia/reperfusion injury (PIRI) in mice. METHODS: Sixty C57BL/6J mice were randomly allocated into six groups (n = 10): Sham operation group (Sham group), ischemia/reperfusion group (I/R group), ischemia/reperfusion + dimethyl sulfoxide group (DMSO group), ischemia/reperfusion + curcumin pre-treated with respectively 100 mg/kg, 150 mg/kg and 200 mg/kg groups (CUR-100 group, CUR-150 group and CUR-200 group). Left lung tissue of each group was excised after reperfusion for 3 h. Wet lung weight to dry lung weight (W/D) and total lung water content (TLW) were tested. The morphological and ultrastructural changes of lung tissue were observed under light microscope and electron microscope, and index of quantitative evaluation for alveolar damage (IQA) was calculated. The expression levels of CHOP and glucose regulated protein 78 (GRP78) were detected by RT-PCR and Western Blot. Apoptosis index (AI) of lung tissue was determined by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method. RESULTS: Compared with Sham group, the expression levels of CHOP, GRP78 mRNA and protein were all significantly increased (P < 0.05) in I/R group and DMSO group, W/D, TLW, IQA and AI were all notably higher (P < 0.01); morphological and ultrastructural injury in lung tissue were notably observed in I/R group. Compared with DMSO group, the expression levels of GRP78 mRNA and protein were increased higher (P < 0. 05) in CUR-100 group, CUR-150 group, and CUR-200 group, but the expression levels of CHOP mRNA and protein were decreased lower (P < 0.05), W/D, TLW, IQA and AI were also decreased (P < 0.05, P < 0.01); morphological and ultrastructural injury in lung tissue were gradually alleviated in CUR groups. CONCLUSION: I/R induces excessive unfolded protein response (UPR) in lung tissue, in which CHOP participates in pneumocyte apoptosis, leading to lung injury; CUR has notable effects on lung protection against I/R injury, which may be related to inhibition of apoptosis mediated by CHOP in excessive UPR.