高压氧对大鼠肠缺血-再灌注损伤致细胞凋亡的影响

目的 观察大鼠在小肠缺血-再灌注(I/R)不同时期应用高压氧(HBO)治疗对小肠黏膜细胞凋亡的影响,并探讨其作用机制.方法 采取大鼠肠系膜上动脉(SMA)钳夹缺血60 min,松钳夹再灌注60 min,建立S-D大鼠小肠I/R损伤模型,并随机(随机数字法)分成4组:I/R组、缺血前HBO治疗组或HBO预处理组(HBO-P)、缺血期HBO治疗组(HBO-I)和再灌注期HBO治疗组(HBO-R).再灌注60 min后,取回肠末端小肠标本.采用酶连免疫吸附试验法(Elisa)检测肠道组织TNF-α,用比色法检测肠道组织匀浆含量ATP,用免疫组化法检测小肠组织中半胱氨酸天门冬氨酸特异蛋白酶(Caspase-3)的表达.数据以均数±标准差(-x±s)表示,采用单因素方差分析检验,独立样本间比较采用SNK-q检验.结果 肠道组织TNF-α含量在HBO-I组最低,其次为HBO-P组(每两组比较P＜0.05),但前两组明显低于HBO-R组和I/R组(P＜0.05),HBO-R组略低于I/R组,但差异无统计学意义(P＞0.05);Caspase-3表达在HBO-I组最低,HBO-P组次之(两组比较P＜0.05);HBO-R和I/R组最高(与前两组比较P＜0.05),尽管HBO-R组略低于I/R组,但差异无统计学意义(P＞0.05);ATP含量在HBO-I组最低,HBO-P组次之(两组比较P＜0.05),HBO-R和I/R组最高(与前两组比较P＜0.05),尽管HBO-R组略低于I/R组,但差异无统计学意义(P＞0.05).结论 HBO、小肠I/R损伤和小肠黏膜上皮凋亡之间存在联系;HBO治疗可以维持黏膜上皮细胞能量代谢,减少ATP耗竭,降低肠道组织TNF-α含量,减轻I/R损伤小肠黏膜上皮凋亡;在缺血期和缺血前应用HBO治疗显示有益结果,特别是在缺血期应用HBO效果最好,再灌注期应用HBO无效.     

Post-conditioning with gradually increased reperfusion provides better cardioprotection in rats

BACKGROUND:

Rapid and complete reperfusion has been widely adopted in the treatment of patients with acute myocardial infarction (AMI), but this process sometimes can cause severe reperfusion injury. This study aimed to investigate different patterns of post-conditioning in acute myocardial ischemia-reperfusion injury, and to detect the role of mitogen activated protein kinase (MAPK) during the injury.

METHODS:

Rats were randomly divided into five groups: sham group, reperfusion injury (R/ I) group, gradually decreased reperfusion group (GDR group, 30/10-25/15-15/25-10/30 seconds of reperfusion/ischemia), equal reperfusion group (ER group, 20/20 seconds reperfusion/ischemia, 4 cycles), and gradually increased reperfusion group (GIR group, 10/30-15/25-25/15-30/10 seconds of reperfusion/ischemia). Acute myocardial infarction and ischemic post-conditioning models were established in the rats. Six hours after reperfusion, 3 rats from each group were sacrificed and myocardial tissues were taken to measure the expressions of phosphorylation of extracellular signal-regulated protein kinase (P-ERK), phosphorylated c-Jun N-terminal kinase (P-JNK), mitogen-activated protein kinase p38 (p38 MAPK), tumor necrosis factor-α (TNF-α), caspases-8 in the myocardial tissue, and cytochrome c in the cytosol using Western blot. Hemodynamics was measured at 24 hours after reperfusion, the blood was drawn for the determination of cardiac enzymes, and the heart tissue was collected for the measurement of apoptosis using TUNEL. One-way analysis of variance and the Q test were employed to determine differences in individual variables between the 5 groups.

RESULTS:

Three post-conditioning patterns were found to provide cardioprotection (P<0.05) compared with R/I without postconditioning. GIR provided the best cardioprotection effect, followed by ER and then GDR. Apoptotic index and serum marker levels were reduced more significantly in GIR than in ER (P<0.05). The enhanced cardioprotection provided by GIR was accompanied with significantly increased levels of P-ERK 1/2 (1.82±0.22 vs. 1.54±0.32, P<0.05), and lower levels of p-JNK, p38 MAPK, TNF-α, caspase-8, caspase-9 and cytochrome in the cytoplasm (P<0.05), compared with ER. The infarct size was smaller in the GIR group than in the ER group, but this difference was not significant (16.30%±5.22% vs. 20.57%±6.32%, P<0.05). All the measured variables were improved more significantly in the GIR group than in the GDR group (P<0.05).

CONCLUSION:

Gradually increased reperfusion in post-conditioning could attenuate reperfusion injury more significantly than routine method, thereby the MAPK pathway plays an important role in this process.KEY WORDS: Ischemia-reperfusion injury, Postconditioning, Apoptosis     

Erythropoietin Ameliorates Oxidative Stress and Tissue Injury following Renal Ischemia/Reperfusion in Rat Kidney and Lung

Objective

To study the effect of erythropoietin (EPO) treatment on renal and lung injury following renal ischemia/reperfusion (I/R).

Materials and Methods

Thirty male Wistar rats were assigned to three groups of 10 rats each. The first group was sham-operated, the second was subjected to renal I/R (30 min of ischemia followed by 24 h of reperfusion). The third group was subjected to renal I/R and treated with EPO in two doses: the first dose 1 h prior to ischemia (1,000 U/kg) and the second dose 6 h after ischemia (1,000 U/kg).

Results

The renal and lung tissue injury index, tissue serum blood urea nitrogen and creatinine (Cr) were higher in the renal I/R group compared to the renal I/R + EPO group; the difference was statistically significant (p < 0.05). Kidney and lung tissue glutathione peroxidase and superoxide dismutase levels were higher in the renal I/R + EPO group than the renal I/R group; the difference was also statistically significant (p < 0.05).

Conclusion

The data showed that EPO pretreatment could be effective in reducing renal and lung injury following renal I/R and could improve the cellular antioxidant defense system. Hence EPO pretreatment may be effective for attenuating renal and lung injury after renal I/R-induced injury during surgical procedures, hypotension, renal transplantation and other conditions inducing renal I/R.Key Words: Erythropoietin, Ischemia/reperfusion, Kidney, Lung     

PKCα signaling pathway involves in TNF-α-induced IP3R1 expression in human mesangial cells

BACKGROUND:

This study aimed to explore the effects of TNF-α on the expression of IP₃R1 mRNA and protein in human mesangial cells (HMCs), and to elucidate the mechanism of TNF-α relating to IP₃R1 expression in the occurrence of hepatorenal syndrome (HRS).

METHODS:

HMCs were stimulated by tumor (TNF-α) with 100 ng/mL for different hours (2, 4, 8, and 24 hours). The expression changes of IP₃R1 mRNA and protein were detected by quantitative real-time polymerase chain reaction and immunoblotting. Several inhibitors including D609, {"type":"entrez-nucleotide","attrs":{"text":"U73122","term_id":"4098075","term_text":"U73122"}}U73122, PP1, safingol, rottlerin and non-radioactive protein kinase C (PKC) were used to examine the mechanism of signal transduction of TNF-α-regulated IP₃R1 in HMCs.

RESULTS:

The levels of IP₃R1 mRNA at 2 hours after TNF-α exposure were significantly enhanced and peaked at 8 hours in HMCs (P<0.01), then descended at 24 hours (P<0.01). The levels of IP₃R1 protein at 4 hours after TNF-α exposure were obviously increased and peaked at 24 hours after TNF-α exposure (P<0.01). Compared to the control group, safingol (PKCα inhibitor) and D609 (phosphatidylcholine-specific phospholipase C inhibitor) significantly blocked the TNF-αinduced expression of IP₃R1 mRNA (3.30±0.81 vs. 1.95±0.13, P<0.05; 2.10±0.49, P<0.01) and IP₃R1 protein (3.09±0.13 vs. 1.86+0.39, P<0.01; 1.98±0.02, P<0.01). TNF-α promoted PKCα activation with maximal PKCα phosphorylation that occurred 8 hours after stimulation measured by non-radioactive PKC assay, and the effect was markedly attenuated by pretreatment with D609 or safingol.

CONCLUSION:

TNF-α increased the expression of IP₃R1 and this was mediated, at least in part, through the PC-PLC/PKCα signaling pathways in HMCs.KEY WORDS: TNF-α, Hepatorenal syndrome, Human mesangial cells, Protein kinase C, Phosphatidylcholine-specific phospholipase C     

320排CT灌注成像评价兔下肢缺血再灌注损伤

目的 观察兔下肢急性缺血再灌注损伤CT灌注成像（CTPI）参数的演变规律及与血清酶学检测指标（CK、LDH、MDA、SOD）的相关性。方法 将30只新西兰大白兔随机分为缺血再灌注（I/R）组与假手术组。将I/R组分为再灌注即刻、6、12、24 h亚组,每组6只,分别在右下肢缺血3 h后再灌注即刻、6 h、12 h、24 h时间点行双下肢CTPI并采血,得到CT灌注值血流量（AF）、血容量（BV）、对比剂清除率（C）,计算右下肢与左下肢各参数的比值,即rAF、rBV、rC,并测定血清CK、LDH、MDA、SOD;最后分别对rAF、rBV、rC与生化指标进行相关性分析。 结果 与假手术组比较,I/R组再灌注即刻、6、12、24 h亚组的rAF均值分别为0.92±0.14、0.89±0.12、0.88±0.20、0.75±0.11,随再灌注时间延长逐渐降低（P<0.05）;I/R各亚组血清CK、LDH及MDA显著高于假手术组（P均<0.05）,而SOD随再灌注时间延长而逐渐降低（P<0.05）。rAF与LDH、CK、MDA、SOD的相关系数分别为-0.64、-0.47、-0.68、0.59（P均<0.05）,仅rBV与LDH存在相关性（r=-0.45,P<0.05）。结论 320排CTPI可无创、半定量、较准确地监测兔下肢骨骼肌随再灌注时间推移的微循环改变;rAF较rBV、rC能更好地反映肌肉组织再灌注后损伤情况。     

Effects of pulmonary stretch reflex on lung injury in rabbits with acute respiratory distress syndrome

BACKGROUND:

Pulmonary stretch reflex plays an important role in regulation of respiratory movement. This study aimed to evaluate the effect of pulmonary stretch reflex on lung injury in rabbits with acute respiratory distress syndrome (ARDS).

METHODS:

ARDS rabbits were given intratracheal infusion of hydrochloric acid and ventilated with neurally adjusted ventilatory assistance (NAVA) with a tidal volume (V_T) of 6 mL/kg and the electrical activity of diaphragm (EAdi)-determined positive end expiratory pressure. After isolation of the bilateral vagus nerve trunk, the rabbits were randomized into two groups: sham operation (SHAM) group (n=5) and bilateral vagotomy (VAG) group (n=5). Gas exchange and respiratory mechanics were detected at baseline, after lung injury and 1, 2, and 3 hours after ventilation respectively. Pulmonary permeability index, pathological changes and inflammatory response were also measured.

RESULTS:

Compared with the SHAM group, PaO₂/FiO₂ in the VAG group decreased significantly 2 and 3 hours after ventilation (P<0.05). There was no significant difference in PaCO₂ between the SHAM and VAG groups (P>0.05), and the VAG group had a high V_T, peak pressure (Ppeak), and mean pressure (Pm) compared with the SHAM group 1, 2, 3 hours after ventilation (P<0.05). Compared to the SHAM group, dead space fraction (V_D/V_T) and respiratory system elastance (Ers) in the VAG group increased (P<0.05) and static pulmonary compliance (Cst) decreased markedly (P<0.05) after ventilation for 3 hours. Lung wet/dry weight ratio (W/D) (8.4±1.2 vs. 6.6±1.0), lung injury score (6.3±1.8 vs. 3.8±1.3), tumor necrosis factor-α (TNF-α) (779±372 pg/mL vs. 355±130 pg/mL) and interleukin-8 (IL-8) (169±21 pg/mL vs. 118±17 pg/mL) increased significantly in the VAG group compared with the SHAM group (P<0.05).

CONCLUSION:

Lung injury is aggravated after bilateral vagotomy, demonstrating that pulmonary stretch reflex may have protective effect on the lung.KEY WORDS: Pulmonary stretch reflex, Vagus nerve, Lung injury, Acute respiratory distress syndrome, Electrical activity of diaphragm, Mechanical ventilation     

Upregulated expression of S100A8 in mice brain after focal cerebral ischemia reperfusion

BACKGROUND:

Recent studies have showed that S100A8 has been implicated in the pathobiology of inflammatory disorders, and that cerebral ischemia reperfusion (I/R) rapidly activates inflammation responses via Toll-like receptor 4 (TLR4). This study aimed to explore the expression of S100A8 and the relationship between S100A8 and TLR4 in focal cerebral ischemia reperfusion injury.

METHODS:

C3H/HeJ mice (n=30) and C3H/HeN mice (n=30) were divided randomly into a C3H/HeJ model group (n=18), a C3H/HeJ control group (n=12), a C3H/HeN model group (n=18), and a C3H/HeN control group (n=12). Middle cerebral artery I/R model in mice was produced using a thread embolism method. The brains of the mice were collected after ischemia for 1 hour and reperfusion for 12 hours. Stroke outcome was evaluated by determination of infarct volume and assessment of neurological impairment scores. Brain injury after cerebral I/R was observed by an optical microscope after TTC and HE dyeing. The immunofluorescence technique and real time PCR were used to test the expression level of S100A8 in brain damage.

RESULTS:

Compared with C3H/HeN mice, TLR4-deficient mice (C3H/HeJ) had lower infarct volumes and better outcomes in neurological tests. The levels of S100A8 increased sharply in the brains of mice after I/R injury. In addition, mice that lacked TLR4 (C3H/HeJ) had lower expression of I/R-induced S100A8 than C3H/HeN mice in the model group, indicating that a close relationship might exist between the levels of S100A8 and TLR4.

CONCLUSION:

S100A8 interaction with TLR4 might be involved in brain damage and in inflammation triggered by I/R injury.KEY WORDS: S100A8, Toll-like receptor 4, Cerebral ischemia reperfusion, Inflammation     

Protective effect of glutamine in critical patients with acute liver injury

BACKGROUND:

Glutamine (Gln) supplementation is known to decrease oxidative stress and inflammatory response, enhance resistance to infectious pathogens, shorten hospital stay, and decrease medical costs of patients. This study was undertaken to evaluate the relationship between the effect of early parenteral glutamine (Gln) supplement on acute liver injury (ALI) and heat shock protein 70 (HSP-70) expression in critical patients.

METHODS:

Forty-four patients who had been admitted to the emergency intensive care unit (EICU) of Nanjing First Hospital Affiliated to Nanjing Medical University were randomly divided into a control group (n=22) and a Gln group (n=22). The patients of the two groups received enteral and parenteral nutrition. In addition, parenteral Gln 0.4 g/kg per day was given for 7 days in the Gln group. Serum HSP-70 and Gln were measured at admission and at 7 days after admission. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBiL), serum levels of HSP-70 and Gln, mechanical ventilation (MV) time, ICU stay, peripheral blood of TNF-α, IL-6, CD3, CD4 and CD4/CD8 levels were also measured in the two groups.

RESULTS:

In the Gln group, the levels of serum HSP-70 and Gln were significantly higher after Gln treatment than those before the treatment (P<0.01). HSP-70 level was positively correlated with the Gln level in the Gln group after administration of parenteral Gln (P<0.01). The levels of serum ALT, AST, TBiL and TNF-α, IL-6 were lower in the Gln group than in the non-Gln group (P<0.01). MV time and ICU stay were significantly different between the two groups (P<0.05). The levels of CD3, CD4 and CD4/CD8 were significantly higher in the Gln group than in the control group after treatment (P<0.05).

CONCLUSION:

Parenteral Gln significantly increases the level of serum HSP70 in critically ill patients. The enhanced expression of HSP70 is correlated with improved outcomes of Gln-treated patients with acute liver injury.KEY WORDS: Glutamine, Heat shock protein, Critically ill patients, Acute liver injury     

Effect of SP-A/B in lipoic acid on acute paraquat poisoning

BACKGROUND:

This study was undertaken to observe the concentration of SP-A/B and the pulmonary surfactant in the lung tissue of rats with acute lung injury/acute respiratory distress syndrome caused by paraquat poisoning after the treatment of metabolic antioxidant-lipoic acid and whether its influence was related to TNF-α.

METHODS:

Sixty-six male Sprage-Dawley rats were randomly divided into three groups: normal control group (NS group), 6 rats; paraquat poisoning group (PQ group), 30 rats; and paraquat+lipoic acid treatment group (LA group), 30 rats. The rats in the PQ and LA groups were subdivided into 3-, 6-, 12-, 24-, 48-hour subgroups, with 6 rats in each group. After the rats were sacrificed, lung tissue from the same part was taken from the rats. After HE staining, histological changes were observed in the tissue under a light microscope. Lung tissue was also taken to test the levels of superoxide dismutase (SOD) and malondialdehyde (MDA). Whole blood (0.8 mL) without anticoagulant was drawn from the tail vein of rats for the determination of the TNF-α level. The total RNA of the lung tissue was collected, and the Rt-PCR method was used to measure the levels of SP-A and SP-B mRNA.

RESULTS:

HE staining showed that histopathological changes were milder in the LA group than in the PQ group. There were significant differences in MDA and SOD levels between different intervals both in intergroups and intragroups except the 3-hour subgroup (P<0.01). Likewise, the significant differences in the levels of TNF-α were also present between the three groups and between different intervals (P<0.01). The significant differences in SP-A mRNA and SP-B mRNA amplification ratio were seen between the three groups at the same intervals (P<0.01), but the differences between different intervals in the PQ group were statistically significant (P<0.05). The differences between different intervals in the LA group were statistically significant (P<0.01).

CONCLUSION:

Lipoic acid in acute paraquat poisoning could diminish lung tissue damage by regulating directly tumor necrosis factor and indirectly the content of pulmonary surfactant so as to reduce pulmonary edema, improve lung compliance, and finally protect lung tissues.KEYWORDS: Lipoic acid, Paraquat, Acute lung injury, Surfactant protein, Tumor necrosis factor-α, Oxygen free radical, Superoxide dimutase, Malonaldehyde     

Effects of bone marrow-derived mesenchymal stem cells engraftment on vascular endothelial cell growth factor in lung tissue and plasma at early stage of smoke inhalation injury

BACKGROUND:

This study was undertaken to determine the effect of mesenchymal stem cells (MSCs) engraftment on vascular endothelial cell growth factor (VEGF) in lung tissue, plasma and extravascular lung water at early stage of smoke inhalation injury.

METHODS:

A rabbit smoke inhalation injury model was established using a home-made smoke inhalation injury generator, and rabbits were divided into two groups randomly: a control group (S group, n=32) and a MSCs treatment group (M group, n=32). 10 ml PBS was injected via the ear marginal vein immediately at injury into the S group. Third generation MSCs with a concentration of 1×10⁷/10 ml PBS were injected via the ear marginal vein immediately at injury into the M group. VEGF in peripheral blood and lung tissue were measured at 0 (baseline), 2, 4 and 6 hours after injection respectively and analyzed. The right lungs of rabbits were taken to measure lung water mass fraction.

RESULTS:

In the lung tissue, VEGF decreased gradually in the S group (P<0.05) and significantly decreased in the M group (P<0.05), but it increased more significantly than the values at the corresponding time points (P<0.05). In peripheral blood, VEGF increased gradually in the S group (P<0.05) and markedly increased in the M group (P<0.05), but it decreased more significantly than the values at corresponding time points (P<0.05).

CONCLUSION:

MSCs engraftment to smoke inhalation injury could increase VEGF in lung tissue, decrease VEGF in plasma and reduce extravascular lung water, indicating its protective effect on smoke inhalation injury.KEY WORDS: Mesenchymal stem cells, Smoke inhalation injury, Vascular endothelial cell growth factor, Extravascular lung water, Rabbit     

Potential role of a disintegrin and metalloproteinase-17 (ADAM17) in age-associated ventricular remodeling of rats

Excessive tumor necrosis factor-α (TNF-α) could enhance cell death and aggravate left ventricular remodeling and myocardial dysfunction. A disintegrin and metalloproteinase-17 (ADAM17), an important maturation regulator of TNF-α, might be involved in the aging-associated ventricular remodeling. The present study observed myocardial ADAM17 expression in young and aged rats and explored the association between cardiac structure/function and expression of ADAM17 in 6 month-old (n = 10, young group) and 24 month-old SD rats (n = 10, old group). The body, heart weight and heart weight/body weight ratio of rats in the old group were all significantly increased compared to that in the young group (P < 0.05). The left ventricular systolic end-diameter and end-diastolic diameters were significantly enlarged in the old group compared to the young group (P < 0.05), while the systolic function index including the left ventricular ejection fraction and left ventricular fractional shortening were similar between the two groups. The peak mitral flow velocity (E)/peak mitral annulus velocity (E′) ratio was significantly higher in the old group than in the young group (P < 0.05). Histological examination showed more damage of cardiomyocytes, interstitial collagen deposition and inflammatory cell infiltration in the old group. Immunohistochemistry examination showed that myocardial TNF-α expression was mainly located in cardiomyocytes and was significantly higher in the old group than in the young group (P < 0.05). The protein expression of myocardial ADAM17 detected by western blot was significantly higher in the old group than in the young group (P < 0.05), while TIMP-3 expression was similar between the two groups. The present study suggested that ADAM17 and inflammation might play an important role in aging-related myocardial remodeling through regulating TNF-α.

Excessive tumor necrosis factor-α (TNF-α) could enhance cell death and aggravate left ventricular remodeling and myocardial dysfunction.     

Cyclic arginine-glycine-aspartate attenuates acute lung injury in mice after intestinal ischemia/reperfusion

Introduction

Intestinal ischemia is a critical problem resulting in multiple organ failure and high mortality of 60 to 80%. Acute lung injury (ALI) is a common complication after intestinal ischemia/reperfusion (I/R) injuries and contributes to the high mortality rate. Moreover, activated neutrophil infiltration into the lungs is known to play a significant role in the progression of ALI. Integrin-mediated interaction is involved in neutrophil transmigration. Synthetic peptides containing an arginine-glycine-aspartate sequence compete with adhesive proteins and inhibit integrin-mediated interaction and signaling. Thus, we hypothesized that the administration of a cyclic arginine-glycine-aspartate peptide (cRGD) inhibited neutrophil infiltration and provided protection against ALI induced by intestinal I/R.

Methods

Ischemia in adult male C57BL/6 mice was induced by fastening the superior mesenteric artery with 4-0 suture. Forty-five minutes later, the vascular suture was released to allow reperfusion. cRGD (5 mg/kg body weight) or normal saline (vehicle) was administered by intraperitoneal injection 1 hour prior to ischemia. Blood, gut, and lung tissues were collected 4 hours after reperfusion for various measurements.

Results

Intestinal I/R caused severe widespread injury to the gut and lungs. Treatment with cRGD improved the integrity of microscopic structures in the gut and lungs, as judged by histological examination. Intestinal I/R induced the expression of β₁, β₂ and β₃ integrins, intercellular adhesion molecule-1, and fibronectin. cRGD significantly inhibited myeloperoxidase activity in the gut and lungs, as well as neutrophils and macrophages infiltrating the lungs. cRGD reduced the levels of TNF-α and IL-6 in serum, in addition to IL-6 and macrophage inflammatory protein-2 in the gut and lungs. Furthermore, the number of TUNEL-staining cells and levels of cleaved caspase-3 in the lungs were significantly lowered in the cRGD-treated mice in comparison with the vehicle mice.

Conclusions

Treatment with cRGD effectively protected ALI and gut injury, lowered neutrophil infiltration, suppressed inflammation, and inhibited lung apoptosis after intestinal I/R. Thus, there is potential for developing cRGD as a treatment for patients suffering from ALI caused by intestinal I/R.     

Endothelial cell injury with inflammatory cytokine and coagulation in patients with sepsis

BACKGROUND:

Current studies on CD62P have focused mainly on cardiovascular diseases, while only few studies have evaluated the effects of CD62P on the development of sepsis and the association between endothelial cell injury with inflammation and coagulation. This study attended to explore the association between endothelial cell injury with inflammation and coagulation by evaluating the expression of soluble CD62P (s-CD62P) in plasma and its mechanism in patients with sepsis, thus to provide the evidence of effective treatment of sepsis with anti-adhesion therapy targeted CD62P.

METHODS:

A total of 70 critically ill patients with systemic inflammatory response syndrome (SIRS) admitted to intensive care unit (ICU) between September 2009 and February 2010 were enrolled for a prospective and control study. According to the diagnostic criteria of sepsis/SIRS, the patients were divided into two groups: a sepsis group (n=38) and a SIRS group (n=32). Another 20 healthy volunteers served as a control group. Patients in the sepsis group and SIRS group were matched by clinical signs of high blood pressure, diabetes and its complications. The demographics of the patients including age, sex, body mass index (BMI), smoking and alcohol addict were compared among the groups. Six mL peripheral blood samples were collected within 24-hour admission in ICU for enzymelinked immunosorbent assay (ELISA) to detect the plasma levels of s-CD62P, TNF-α, and hs-CRP. And variables of coagulation function such as platelet (PLT), prothrombin (PT), activated partial thromboplastin time (APTT), D-dimer and antithrombin-III (AT-III) were analyzed during 24 hours after admission to ICU. Meanwhile sequential organ failure assessment (SOFA) score of critically ill patients was evaluated. Data were expressed as mean±standard deviation and were statistically analyzed by using SPSS 17.0 statistical software. The differences in plasma levels of s-CD62P of patients in each group were analyzed by ANOVA and the Kruskal-Wallis test. The relations between s-CD62P and inflammatory cytokines as well as with coagulation were determined by Pearson’s product moment correlation coefficient analysis. Changes were considered as statistically significant if P value was less than 0.05.

RESULTS:

Compared with the control group and SIRS group, the sepsis group demonstrated significantly higher levels of s-CD62P, TNF-α and highly sensitive C-reactive protein (hs-CRP) (P<0.05). The plasma levels of D-dimer, PT, and APTT in the sepsis and SIRS groups were significantly higher than those in the control group, while the platelet count and the activity of AT-III were obviously lower (P<0.05). In the sepsis group, the plasma levels of hs-CRP and TNF-α were positively correlated with PT, APTT, and D-dimer, and negatively correlated with AT-III and PLT (P<0.05). The plasma levels of s-CD62P were significantly correlated with the plasma levels of TNF-α, hs-CRP, D-dimer, PT, and APTT, whereas they were correlated negatively well with PLT and AT-III (P<0.05).

CONCLUSIONS:

The concentration of plasma s-CD62P is elevated as a early biomarker in patients with sepsis, and it serves as one of the pathogenic factors responsible for endothelial cell damage. Coagulation and mediators of inflammation promote each other, aggravating the severity of sepsis. Plasma s-CD62P may be an important factor for the development of coagulation and inflammatory reaction.KEY WORDS: Sepsis, Endothelial cell injury, Plasma soluble CD62P, Inflammatory cytokine, Coagulation     

Retracted Article: Elevation of USP4 antagonizes oxygen glucose deprivation/reoxygenation-evoked microglia activation and neuroinflammation-mediated neurotoxicity via the TRAF6-NF-κB signaling

An ischemic stroke is a devastating neurological disease with the typical occurrence of brain ischemia/reperfusion (I/R) injury, and it has high mortality and disability globally. Microglia activation after a stroke results in the release of pro-inflammatory cytokines that can further aggravate brain damage. A recent study confirmed the potential role of ubiquitin-specific peptidase 4 (USP4) in the injury process. Nevertheless, the role and mechanism of USP4 during an ischemic stroke remain elusive. In this research, we simulated an I/R injury by oxygen glucose deprivation/reoxygenation (OGD/R) in vitro and confirmed the obvious down-regulation of USP4 in microglia under OGD/R conditions. Moreover, USP4 elevation antagonized the OGD/R-induced microglia proliferation and activation by suppressing the NO levels and the expression of the microglial marker IBA-1. Additionally, the overexpression of USP4 suppressed the release of microglia activation-induced pro-inflammatory cytokines, including IL-1β, IL-6, and TNF-α. Intriguingly, incubation with the conditioned medium from the microglia under OGD/R conditions induced neurotoxicity by inhibiting cell viability and increasing the LDH release, apoptosis, and caspase-3 activity, which were reversed following USP4 overexpression. Mechanism analysis corroborated that USP4 up-regulation repressed the OGD/R-induced activation of TRAF6-NF-κB signaling. Notably, restoring the TRAF6 signaling ameliorated the suppressive effects of USP4 elevation on microglia activation, inflammation, and the subsequent neuron injury. These findings suggest that USP4 may alleviate ischemic stroke by restraining microglia-mediated neuro-inflammation and neurotoxicity via the TRAF6-NF-κB pathway, due to which it is a promising therapeutic agent against strokes.

An ischemic stroke is a devastating neurological disease with the typical occurrence of brain ischemia/reperfusion (I/R) injury, and it has high mortality and disability globally.     

碱性成纤维细胞生长因子对大鼠肾脏缺血/再灌注金属硫蛋白含量的影响

目的在大鼠离体肾脏缺血／再灌注（I／R）损伤模型上，观察碱性成纤维细胞生长因子（bFGF）对肾脏金属硫蛋白（MT）的影响，探讨bFGF肾脏保护作用的可能机制。方法复制离体肾脏I／R损伤模型。预先24h应用bFGF，以[Cd^109]-血红素饱和法测定肾脏MT含量，同时测定血清丙二醛（MDA）、超氧化物歧化酶（SOD）含量。结果肾缺血组、缺血／再灌注组及bFGF治疗组血浆SOD均非常显著低于对照组，而MT、MDA非常显著高于对照组（P〈0．01）；bFGF＋缺血组血浆SOD较缺血组略高，MT、MDA较缺血组略低，两者差异无显著性（P〉0．05）；bFGF＋缺血／再灌注组SOD较缺血／再灌注组非常显著升高，MT、MDA较缺血／再灌注组非常显著降低（P〈0．01）。结论MT参与了bFGF对大鼠离体肾脏缺血／再灌注损伤肾脏保护作用。     

Effects of α-methylnorepinephrine on cardiac function and myocardium at early stage of resuscitation in rabbits

BACKGROUND:

Recent studies have shown that α2-adrenergic agonists can reduce postresuscitation myocardial injury. This study was undertaken to observe changes of hemodynamics, myocardial injury markers cTnT and cardiac morphology by establishing a cardiopulmonary resuscitation model with rabbits, and to detect whether α-methyl norepinephrine (α-MNE) can reduce the myocardial injury after CPR and improve cardiac function.

METHODS:

Eighteen health rabbits, weighing 2.5-3.5 kg, both male and female, were provided by the Lanzhou Institute of Veterinary Medicine. After setting up a rabbit model of cardiopulmonary resuscitation, 18 rabbits were randomly divided into three groups. The rabbits in group A as an operation-control group were subjected to anesthesia, endotracheal intubation, and surgery without induction of ventricular fibrillation. The rabbits in group B as an epinephrine group were administered with 30 μg/kg epinephrineduring CPR. The rabbits in group C as a MNE group were administered with 100 μg/kg a-MNE during CPR. The left ventricular end-diastolic pressure (LVEDP), left ventricular pressure rise and fall rate (±dp/dt) and serum concentrations of BNP were measured. Statistical package of SPSS 10.0 was used for data analysis and significant differences between means were evaluated by ANOVA.

RESULTS:

Compared to group A, the LVEDP of other two groups increased respectively (P<0.01 all), and peak±dp/dt decreased in the other two groups (P<0.01). The increase of LVEDP was lower in group C than in group B (P<0.05), whereas peak±dp/dt was higher in group C than in group B (P<0.05) at the same stage. Compared to group A, the cTnT of the remaining two groups increased, respectively (P<0.01), and peaked at 30 minutes. cTnT was less elevated in group C than in group B (P<0.05) during the same period. In groups B and C, myocardial injury was seen under a light microscope, but the injury in group C was lighter than that in group B.

CONCLUSION:

Methylnorepinephrine can lessen myocardial dysfunction after CPR.KEY WORDS: Cardiopulmonary resuscitation;, α2-adrenergic agonist;, Post-resuscitation myocardial dysfunction     

Effect of exogenous phosphocreatine on cardiomycytic apoptosis and expression of Bcl-2 and Bax after cardiopulmonary resuscitation in rats

BACKGROUND:

Ischemia-reperfusion injury in the myocardium after cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) is an important pathologic basis of post-cardiac arrest of syndrome (PCAS), and apoptosis is one of the major mechanisms in myocardial ischemia-reperfusion injury. To lessen myocardial ischemia-reperfusion injury after cardiac arrest and CPR, it is important to reduce energy consumption and to increase energy supply in the myocardium. This study aimed to observe changes of cell apoptosis and expression of Bcl-2 and Bax protein on the myocardium after CPR in rats, and the protective effects of different doses of exogenous phosphocreatine (creatine phosphate, CP) on them.

METHODS:

A total of 32 male adult Sprague-Dawley rats were randomly divided into 4 groups: control group (group A), CPR group (group B), low-dose CP group (group C, CP 0.5 g/kg at beginning of CPR and 1.0 g/kg at 2 hours after CPR) and high-dose CP group (group D, CP 1.0 g/kg at beginning of CPR and 2.0 g/kg at 2 hours after CPR). Cardiac arrest was induced by asphyxiation and CPR started at 7 minutes after asphyxiation in groups B, C and D. Myocardium samples were taken at 24 hours after CPR. Cardiomycytic apoptosis was detected by the TdT-mediated dUTP-biotin nick end labeling (TUNEL) method. The expression of Bcl-2 and Bax protein was measured by immunohistochemistry.

RESULTS:

Cardiomyocytic apoptosis index (AI) and expression of Bcl-2 and Bax protein increased more significantly in groups B, C and D than in group A (P<0.01), but Bcl-2/Bax ratio significantly decreased (P<0.01). Cardiomyocytic AI and expression of Bcl-2 and Bax protein decreased more significantly in groups C and D than in group B (P<0.01), but Bcl-2/Bax ratio increased more significantly (P<0.01). Cardiomyocytic AI and expression of Bcl-2 and Bax protein decreased more significantly in group D than in group C (P<0.05), but Bcl-2/Bax ratio increased more significantly (P<0.05).

CONCLUSION:

Exogenous phosphocreatine, especially at a large dose, could inhibit cardiomyocytic apoptosis and alleviate myocardial injury after CPR in rats.KEY WORDS: Cardiopulmonary resuscitation, Phosphocreatine, Apoptosis, Bcl-2, Bax, TUNEL     

Effect of transforming growth factor-β1 on monocyte Toll-like receptor 4 expression in septic rats

BACKGROUND:

Sepsis is a tough problem in critical ill patients. This study aimed to investigate the dynamic changes of monocyte Toll-like receptor (TLR) 4 expression in peripheral blood of septic rats and to determine the effects of transforming growth factor (TGF)-β₁ on TLR4 expression.

METHODS:

Altogether 132 clean level SD rats were randomly divided into a control group (n=12), a sepsis model group (n=60), and a TGF-β₁ intervention group (n=60). In the sepsis model group and TGF-β₁ intervention group, the rats were subdivided into five groups (2-hour group, 6-hour group, 12-hour group, 24-hour group, and 48-hour group), with 12 rats in each group. Cecal ligation puncture (CLP) was performed in the sepsis model group and TGF-β₁ intervention group to establish models of sepsis. The rats in the sepsis model group were injected with 1 mL normal saline at the caudal vein 0.5 hour after the model establishment; the rats in the TGF-β₁ intervention group were injected with 20 ng/mL or 250 g TGF-β₁ 0.5 hour after the model establishment. Flow cytometry was used to detect the change of monocyte TLR4 in peripheral blood, and enzyme-linked immunosorbent assay (ELISA) was used to detect the change of TNF-α level in peripheral blood.

RESULTS:

At 6-12 hours after CLP, the monocyte TLR4 in peripheral blood started to decrease, and reached the lowest level at 12 hours. Compared to the control group, the monocyte TLR4 expression at 6 and 12 hours was lowered significantly (P<0.05). Compared to the sepsis model group at 2, 24 and 48 hours after CLP, the monocyte TLR4 expression in the TGF-β₁ intervention group decreased dramatically (P<0.05), but there were no differences between the two groups at 6 and 12 hours respectively. Compared to the control group, the concentration of NF-κ in liver tissue increased significantly 6 hours after CLP (P<0.05). After use of TGF-β₁, the concentration of NF-κ was decreased significantly but still higher than that of the control group. Compared to the control group, the concentration of TNF-α in peripheral blood was increased significantly at 2-48 hours after CLP (P<0.05). After use of TGF-β₁, TNF-α was further increased.

CONCLUSION:

During sepsis, TGF-β₁ can decrease the monocyte TLR4 expression and NF-κ in liver tissue, but facilitate the formation of proinflammatory mediator TNF-α. This finding indicates that TGF-β₁ may play a role in promoting inflammatory response during sepsis, but this regulation is not via direct regulation of monocyte TLR4 in peripheral blood.KEY WORDS: Sepsis, TGF-β₁, TLR4, Monocyte, TNF-α