Effects of excessive endoplasmic reticulum stress on lung ischemia/reperfusion induced myocardial injury in mice / 中国应用生理学杂志

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 (=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 (<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 (<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.

Effects of dexmedetomidine on hypoxia/reoxygenation injury-induced cell apoptosis and caspase-12 expression in A549 cells / 生理学报

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 / 中国中西医结合杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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).</p>

Effect of siRNA silencing the role of JNK gene in excessive endoplasmic reticulum stress on lung ischemia/reperfusion injury / 中国应用生理学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>I/R induces excessive ERS in lung tissue, in which JNK pathway participates in apoptosis, leading to lung tissue injury.</p>

Effects of curcumin on pneumocyte apoptosis and CHOP in pulmonary ischemia/reperfusion injury of mice / 中国应用生理学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Effect of notoginsenoside Rg1 on p38MAPK expression of pulmonary arterial smooth muscle cells exposed to hypoxia hypercapnia / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To study the effect of Notoginsenoside Rgl on p38 mitogen activated protein kinase (p38MAPK) expression in pulmonary artery smooth muscle cells (PASMCs) cultured in hypoxia hypercapnia.</p><p><b>METHODS</b>SD rat PASMCs was primary cultured, the cells of passage 2- 5 were divided into six groups: normoxic group (N group), hypoxia hypercapnia group (H group), dimethyl sulfoxide (DMSO) control group (HD group), Rg1 treated group (Rg low dose, Rg middle dose and Rg high dose group). Western blot was used to detect the expression of p-p38MAPK protein, and RT-PCR to determine the expression of p38MAPK mRNA.</p><p><b>RESULTS</b>Western blot and RT-PCR analysis indicated that the expression of p-p38MAPK protein and p-p38MAPK mRNA were significantly higher in HD group than those in N group (P < 0.01). Whereas, in Rg1 treated groups, the level of p-p38MAPK markedly decreased (P < 0.01) in dose-dependent manner.</p><p><b>CONCLUSION</b>Notoginsenoside Rg1 has protective effects on PASMCs under hypoxia hypercapnia condition, which may be related to inhibiting expression of p38MAPK.</p>

The role of JNK in apoptosis of renal tubular epithelial cells in diabetic rats with fluctuant high blood glucose / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the signal transduction mechanisms of apoptosis in renal tubular epithelial cells in diabetic rats with fluctuant high blood glucose.</p><p><b>METHODS</b>Healthy SD rats were randomly divided into 3 groups: normal control group (A), stable high blood glucose group (B) and fluctuant high blood glucose group (C). Diabetic rats were induced by intraperitoneal injection of streptozotocin (STZ, 65 mg/kg), and the fluctuant high blood glucose animal model was induced by intraperitoneal injection of ordinary insulin and glucose at different time point every day. The superoxide dismutase (SOD) activity and the content of malonaldehyde (MDA) in renal tissue homogenate were detected with colorimetry. The protein expression of Nox4 and JNK were examined by immunohistochemistry and Western blot. Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL).</p><p><b>RESULTS</b>After 12 experimental weeks, significantly increased cell apoptosis, up-regulation of Nox4 and P-JNK expression in renal tubular epithelial cells were observed in B and C groups compared with those in A group. The MDA content increased and SOD activity decreased in renal tissue in B and C groups. Above effects were more obviously shown in C group.</p><p><b>CONCLUSION</b>Fluctuant high blood glucose induced more apoptosis of renal tubular epithelial cell than stable high blood glucose in diabetic kidney, which might be related to the activation of JNK signal transduction pathway.</p>

Effects of cyclosporine A on pneumocyte apoptosis with lung ischemia/reperfusion injury in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effects of cyclosporine A (CsA), a powerful inhibitor of mitochondrial permeability transition pore (MPTP), on pneumocyte apoptosis, the release of cytochrome C and the activity of caspase-3 after lung ischemia/reperfusion, and explore the mechanisms.</p><p><b>METHODS</b>Single lung in situ ischemia/reperfusion animal model was used. 30 SD rats were randomly divided into three groups (n = 10): sham (S) group, ischemia/reperfusion (I/R) group and cyclosporine A (CsA) group. Apoptosis of pneumocyte was assessed by TUNEL method, cytochrome C (CytC) in cytoplasm was detected by immunohistochemistry techniques, and the activity of caspase-3 was measured with spectrophotometer.</p><p><b>RESULTS</b>The content of CytC in cytoplasm, the activity of caspase-3, and the value of apoptosis index (AI) in ischemia/reperfusion group were evidently higher than that in S group (P < 0.01). CsA suppressed apoptosis as well as CytC release and caspase-3 activity (P < 0.01).</p><p><b>CONCLUSION</b>CsA can prevent the release of cytochrome C, block the apoptosis of pneumocyte accordingly maybe by closing the MPTP.</p>

Effects of safflower injection on cycloxygenase in rabbits lung ischemia/reperfusion injury / 中国应用生理学杂志

<p><b>AIM</b>To observe protective effects of safflower injection (SI) on lung ischemia/reperfusion injury (LIRI) and investigate its potential mechanism.</p><p><b>METHODS</b>Rabbit lung model of ischemia/reperfusion injury was constituted in vivo. The rabbits were randomly divided into three groups: sham-operation group (S group), ischemia/reperfusion group (I/R group) and ischemia/reperfusion plus safflower injection group (SI group). Malondialdehyde (MDA) content, superoxide dismutase (SOD) and xanthine oxidase (XO) activities in serum were measured. The lung tissue sampled at the end of the experiment was assayed for wet/dry weight ratio (W/D), injured alveoli rate (IAR) and ultrastructural changes were observed under electron microscope. The expression of COX-1 and COX-2 were measured by immunohistochemistry (IHC). The expressions of COX-1mRNA and COX-2mRNA were observed by in situ hybridization (ISH).</p><p><b>RESULTS</b>In I/R group, XO and MDA increased and SOD decreased in serum, while the same changes happened in SI group but less severely(P<0.01). The value of W/D and IAR was much higher in I/R group than S group, but decreased in SI group. Electron microscope showed obvious ultrastructural injury brought by LIRI in I/R group, which was greatly attenuated in SI group. The IHC and ISH demonstrated that COX-2 and COX-2mRNA in pulmonary tissue of I/R group were significantly higher than those of SI group (P < 0.01). The difference of COX-1 and COX-1mRNA in pulmonary tissue among the three groups was not significant.</p><p><b>CONCLUSION</b>The ischemia/reperfusion lung injury insults induced the regulation of COX-2 in lung. Safflower injection may attenuate lung ischemia/reperfusion injury through inhibiting cyclooxygenase-2 expression.</p>

Effect of ligustrazine and L-arginine on function of mitochondria in myocardium after ischemia/reperfusion injury of myocardium in rabbits / 中国应用生理学杂志

<p><b>AIM</b>To study the effect of ligustrazine (LGT) and L-arginine(L-Arg)on function of mitochondria in myocardium after myocardial ischemia/reperfusion injury (MI/RI).</p><p><b>METHODS</b>50 rabbits were randomly divided into five groups (n=10): Control group(A), MI/R group(B), MI/R + LGT group (C), MI/R+ L-Arg group (D), MI/R+ LGT + L-Arg group (E). The mitochondrial respiratory function, Ca2+ concentration ([Ca2+]m), malondialdehyde (MDA) content and superoxide dismutase (SOD) activity were deter mined. Meanwhile, the contents of ATP and EC in the myocardial tissue were measured, respectively.</p><p><b>RESULTS</b>It was found that mitochondrial respiratory control rate (RCR), state 3 (ST3), SOD in C, D, E group were higher than those of B group, state 4 (ST4), [Ca2+]m, MDA were lower than those of B group, ATP and EC levels of myocardial tissue were higher than those in B group; and there were not significant differences between E and A group of above.</p><p><b>CONCLUSION</b>LGT and IL-Arg can improve function of mitochondria in myocardium after ischemia/reperfusion injury of myocardium in rabbits by decreasing oxygen free radical level and Ca" overload in the mitochondria.</p>

Effect of ligustrazine on expression of Fas/FasL in pulmonary injury induced by ischemia/reperfusion in rabbits / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effect of ligustrazine (LGT) on expression of Fas/FasL mRNA during pulmonary ischemia/reperfusion injury (PI/RI) in the rabbits.</p><p><b>METHODS</b>Single lung ischemia/reperfusion animal model was used in this study. The rabbits were randomly divided into three groups (n = 30, in each): sham operated group (Sham), I/R group (I/R) and I/R + LGT group (I/R + LGT). Changes of several parameters which included apoptotic index (AI), wet to dry ratio of lung tissue weight (W/D) and index of quantitative assessment of histologic lung injury (IQA) were measured at 1h, 3h, 5h after reperfusion in lung tissue. Meanwhile the location and expression of Fas/FasL mRNA were observed. Lung tissue was prepared for light microscopic and electron microscopic ob servation at 1 h, 3 h, 5 h after reperfusion.</p><p><b>RESULTS</b>As compared with group I/R, Fas/FasL mRNA slightly expressed in intima and extima of small pulmonary artery, alveoli, and bronchiole epithelia in group LGT. The values of AI, W/D and IQA showed significantly lower in group I/R + LGT than that in group I/R at 1 h, 3 h, 5 h after reperfusion in lung tissue (P < 0.01 and P < 0.05). Meanwhile, abnormal changes of the lung tissue in morphologically were lessen markedly in group I/R + LGT.</p><p><b>CONCLUSION</b>Ligustrazine has notable protective effects on PI/RI in rabbits by inhibiting Fas/FasL mRNA express in lung tissue and decreasing apoptosis.</p>