抑制mTOR信号通路对幼鼠肺损伤时p-AKT1分子的影响及意义

目的:探讨抑制哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)信号通路在高体积分数氧(高氧)致SD幼鼠肺损伤时对磷酸化AKT1(p-AKT1)分子的影响和意义。方法:72只SD幼鼠(3周龄)随机分为空气+生理盐水组、高氧+生理盐水组、高氧+OSI-027组及高氧+雷帕霉素组(n=18),分别构建动物模型。高氧选择90%氧气持续干预,生理盐水、OSI-027和雷帕霉素干预分别在观察期第1、3、6、8、10和13天时经腹腔注射给药。在造模第3、7和14天时取各组幼鼠进行体重测量、肺湿干重比(wet/drg weight ratio,W/D)计算、肺组织病理学检查、肺泡间隔宽度测定和肺损伤评分,肺组织免疫组化和Western blot检测磷酸化S6K1(p-S6K1)和p-AKT1的分布与水平。结果:与空气组比较,高氧组幼鼠体重明显下降(P0.05),肺损伤急性期肺W/D增高(P0.05),肺泡间隔宽度及肺损伤评分明显增加(P0.05),肺组织p-S6K1阳性细胞增多(P0.05),肺组织p-AKT1阳性细胞减少(P0.05),p-S6K1蛋白显著升高(P0.01),p-AKT1蛋白明显减低(P0.01);与高氧组比较,高氧+OSI-027组的肺组织损伤减轻,肺组织p-S6K1阳性细胞减少(P0.05),p-AKT1阳性细胞增多(P0.05),p-S6K1蛋白水平显著降低(P0.05),p-AKT1蛋白水平增加(P0.05);高氧+雷帕霉素组的肺损伤进一步加重(P0.05),p-S6K1阳性细胞减少(P0.05),p-AKT1阳性细胞增加(P0.05),p-S6K1蛋白水平显著降低(P0.05),p-AKT1蛋白水平显著增加(P0.05)。与高氧+雷帕霉素组比较,高氧+OSI-027组的肺组织损伤减轻(P0.05),肺组织p-AKT1阳性细胞减少(P0.05),p-AKT1蛋白水平降低(P0.05)。结论:p-AKT1参与了高氧肺损伤的发生发展,其调控机制可能与抑制mTOR信号通路的活化有关。高氧肺损伤时,p-AKT1蛋白水平下降,mTOR抑制剂能增加p-AKT1蛋白水平,但只有mTORC1/2双重抑制剂OSI-027能减轻高氧所致SD幼鼠的肺损伤及纤维化。     

Intratracheal administration of endotoxin attenuates hyperoxia-induced lung injury in neonatal rats

PURPOSE: This study was undertaken to determine the effects of intratracheal administration of endotoxin on hyperoxia-induced lung injury in neonatal rats. MATERIALS AND METHODS: Newborn Sprague Dawley rat pups were divided into four experimental groups: normoxia control (NC), normoxia with endotoxin treatment (NE), hyperoxia control (HC), and hyperoxia with endotoxin treatment (HE) groups. In HC and HE, rat pups were subjected to 14 days of hyperoxia (> 95% oxygen) within 12 hours after birth. In endotoxin treated group (NE and HE), Escherichia coli endotoxin (0.5microg in 0.03mL of saline) was given intratracheally at the 1st, 3rd and 5th postnatal day. Radial alveolar count (RAC), mean linear intercept (MLI), RAC/MLI ratios, and degree of fibrosis were measured to assess the changes in lung morphology. RESULTS: During the research period, survival rates in both HC and HE were notably reduced 7 days after endotoxin was administered, but body weight gain was considerably reduced only in HC. On day 14, significant arrest in alveolarization, as evidenced by the decrease of RAC and RAC/MLI ratio and increase of MLI as well as increased fibrosis, were noted in HC. Although slight but significant arrest in alveolarization and increased fibrosis score were observed in NE compared to NC, the hyperoxia-induced lung damage observed in HC was significantly improved in HE. CONCLUSION: This study suggests that intratracheal administration of endotoxin significantly attenuated hyperoxia-induced lung injury in neonatal rats.     

Fasudil, a Rho-associated protein kinase inhibitor, attenuates retinal ischemia and reperfusion injury in rats

Abnormal activation of Rho kinase (ROCK) plays a vital role in the pathogenesis of ischemia/reperfusion (I/R)-induced retinal injury. The aim of this study was to investigate whether fasudil, a potent inhibitor of ROCK, has a protective effect on retinal I/R injury in rats and to explore the possible underlying mechanisms. Forty adult Sprague-Dawley rats were randomly assigned into sham, I/R injury model (I/R), model plus normal saline (control), and model plus fasudil (fasudil) groups. Rats in the control and fasudil groups were intravitreously injected with normal saline and fasudil, respectively, 5 min prior to the induction of ischemia. Retinal ischemia was induced by increasing the intraocular pressure to 100 mmHg for 60 min. Overall retinal thickness and retinal cell apoptosis was evaluated by histological analysis and the TUNEL assay, respectively. The protein expression of caspase-3 and the Bax/Bcl-2 mRNA ratio were also examined. Moreover, the retinal expression of inducible nitric oxide synthase (iNOS) was determined by immunohistochemical staining, quantitative real-time RT-PCR and Western blot analysis. Fasudil attenuated the I/R-induced apoptosis of retinal cells in the inner nuclear and ganglion cells of the rat retina. Fasudil significantly decreased the Bax/Bcl-2 mRNA ratio and the expression of caspase-3 and iNOS compared to the control group (P<0.05). Seven days after I/R, the overall retinal thickness in the fasudil group was significantly greater compared to that in the control group (P<0.05). In conclusion, fasudil can protect the rat retina from I/R injury by inhibiting apoptosis and iNOS expression, suggesting that fasudil may have a therapeutic potential for the prevention of retinal diseases associated with I/R.     

持续吸入高浓度氧对新生大鼠肺的影响

目的探讨持续吸入高浓度氧对新生大鼠发育中肺的影响.方法新生鼠生后分别于85%以上氧和空气中持续暴露,于1、3、7、14、21d,动态观察肺组织病理学改变和胶原染色面积的变化;肺组织SOD活性和MDA含量.结果与空气对照组比较,高氧组肺泡发育过程受阻,肺损伤逐渐加重,最终纤维化;胶原染色阳性面积7d时高于对照组,随时间延长而逐渐增加;MDA含量在吸氧3d时升高,7d时最高,以后下降;SOD活性的改变较迟,7d时增高,持续增加,21d仍高于对照.结论高氧可引起肺的氧化损伤,使新生鼠肺发育受阻,最终出现胶原增加的纤维化改变.     

IGF-I和IGF-IR在高氧致新生鼠慢性肺疾病中的动态表达及其作用

目的研究IGF-I、IGF-IR在高氧致新生鼠慢性肺疾病（CLD）中的表达及作用。方法将足月新生大鼠144只随机分为高氧组和空气组,分别于实验1d,3d,7d,10d,14d,21d应用免疫组化和RT-PCR技术检测IGF-I、IGF-IR的动态表达。结果CLD时IGF-I和IGF-IR呈动态变化,高氧组和空气组比较,在实验3d～10d IGF-I和IGF-IR表达明显降低（P〈0.05）,14d和21d表达明显增强（P〈0.05）。结论IGF-I和IGF-IR是肺泡发育的正向调节因子,与CLD时肺泡分隔受阻、肺泡成熟障碍和肺纤维化有关。     

PCNA在CLD新生鼠肺成纤维细胞中的动态表达及意义

目的探讨增殖细胞核抗原（proliferatingeellnuelearantigen,PCNA）在CLD新生鼠肺成纤维细胞中的动态表达及意义。方法足月新生SD大鼠于生后12h内分别持续吸入85%高氧和空气,于3、7、14、21天随机处死后动物,无菌条件下采集肺组织,进行LF细胞的原代培养,应用MTT法检测细胞增殖活力。免疫组化法检测PCNA蛋白表达;Real-time PCR法检测PCNAmRNA含量。结果 MTT结果显示,高氧使得LF增殖活力增强;生后3d空气组和高氧组PCNA蛋白及mRNA的表达无统计学差异。生后7d时高氧组PCNA蛋白及mRNA的表达较空气组增加（P〈0.05）;14d、21d时增加明显（P〈0.01）。结论体内高氧使LF增殖活力增加,最终导致肺间质纤维化。     

Neonatal hyperoxia alters the pulmonary alveolar and capillary structure of 40-day-old rats

High inspired oxygen concentrations during the neonatal period profoundly inhibit rat lung development, an effect that is partly reversed during recovery in air. Persistent effects of neonatal hyperoxia on the size and number of alveoli or the structure of pulmonary capillaries have not been well defined. Using light and electron microscopic morphometry plus quantitative three-dimensional reconstructions of alveoli, we examined the lungs of 40-day-old rats that were exposed to more than 95% oxygen for the first 7 days after birth. Neonatal hyperoxia administered to rats resulted in abnormally enlarged air spaces at age 40 days. The fraction of the lung consisting of parenchyma was significantly increased and alveolar surface area was 13% lower than controls. There was an abnormal enlargement of alveolar ducts, which reduced by 24% the relative amount of air in the alveoli, compared to that in the alveolar ducts. The number of alveoli per lung and the mean volume of an alveolus were not different between the groups, but alveolar size class distributions were different, with significantly more very small and very large alveoli in 40-day-old rats after neonatal hyperoxia. By scanning electron microscopy, the alveolar surface of the exposed animals had a corrugated appearance, which was especially evident along alveolar ducts. Transmission electron microscopy revealed a greater density of capillaries, particularly in the alveolar regions close to terminal airways. Based on a random sample of the entire parenchymal region, capillary blood volume per cm2 of alveolar basal lamina was 18% greater. The results demonstrate that neonatal exposure to hyperoxia can cause abnormalities in the pulmonary alveolar and capillary structure of 40-day-old rats, and that these changes are similar to some features of broncho-pulmonary dysplasia.     

Erythropoietin attenuates hyperoxia-induced lung injury by down-modulating inflammation in neonatal rats

This study was done to determine whether recombinant human erythropoietin (rhEPO) treatment could attenuate hyperoxia-induced lung injury, and if so, whether this protective effect is mediated by the down-modulation of inflammation in neonatal rats. Newborn Sprague Dawley rat pups were subjected to 14 days of hyperoxia (>95% oxygen) within 10 hr after birth. Treatment with rhEPO significantly attenuated the mortality and reduced body weight gain caused by hyperoxia. With rhEPO treatment, given 3 unit/gm intraperitoneally at 4th, 5th, and 6th postnatal day, hyperoxia- induced alterations in lung pathology such as decreased radial alveolar count, increased mean linear intercept, and fibrosis were significantly improved, and the inflammatory changes such as myeloperoxidase activity and tumor necrosis factor-alpha expression were also significantly attenuated. In summary, rhEPO treatment significantly attenuated hyperoxia-induced lung injury by down-modulating the inflammatory responses in neonatal rats.     

盐酸法舒地尔通过活化Akt与抑制PTEN减轻顺铂导致的肾小管上皮细胞凋亡

 目的: 探讨盐酸法舒地尔(fasudil)能否通过活化Akt并抑制PTEN减轻顺铂(CP)导致的肾小管上皮细胞凋亡。方法: 健康雄性SD大鼠随机分为3组(每组12只),包括正常对照(control)组、CP组及CP+fasudil组。生理盐水或顺铂腹腔注射96 h后处死SD 大鼠,留取血液和肾脏组织,检测血尿素氮(BUN)、血清肌酐(sCr)水平。PAS染色光镜观察肾脏形态结构的变化;TUNEL染色检测肾小管上皮细胞凋亡;分别采用Western blotting法和/或免疫组化技术检测Rho蛋白激酶1(ROCK1)、PTEN、Akt 蛋白表达变化及磷酸化Akt(p-Akt)水平。结果: 与control组比较,CP组与CP+fasudil组大鼠的BUN及sCr水平、凋亡细胞阳性率、ROCK1及PTEN蛋白表达均显著升高(P<0.05),而p-Akt表达则显著减少(P<0.05);PAS染色光镜示CP组肾脏组织结构出现明显损伤性变化;与CP组比较,CP+fasudil组的sCr水平、凋亡细胞阳性率、ROCK1及PTEN蛋白表达均显著下调(P<0.05),而p-Akt水平则显著增高(P<0.05);此外,肾脏病理损伤减轻。 结论: 盐酸法舒地尔可以减轻顺铂引起肾小管上皮细胞凋亡,其机制可能与活化Akt及抑制PTEN蛋白表达相关。     

Impacts of Rho kinase inhibitor Fasudil on Rho/ROCK signaling pathway in rabbits with optic nerve injury

Objective: The aim of this study was to study the impacts of Rho kinase inhibitor Fasudil on expressions of Rho/ROCK signaling pathway associated genes in rabbits with optic nerve injury (ONI), and to explore the therapeutic mechanisms towards ONI. Methods: The rabbit ONI model was established, then the rabbits were divided into model group (treated with saline), control group (treated with dexamethasone, Dex), and intervention group (treated with Fasudil, Fas). The eyeball and optic nerve were sampled at 3, 7, 14 and 21 days after injury. The morphological changes of retina and optic nerve were observed. The expressions of RhoA, Caspase-3, Rock 2 and Nogo-A gene were determined by immunohistochemistry and real-time polymerase chain reaction (RT-PCR) methods. Results: At different time after injury, there were significant differences of RhoA, Caspase-3, Rock 2 and Nogo-A gene expression among three groups (P < 0.05). Conclusions: After ONI, Fas can decrease the expression of Caspase-3 gene, and down-regulate the expressions of Nogo-A and Rock 2 gene. Therefore, it can treat ONI through affecting the Rho/ROCK signaling pathway.     

法舒地尔通过抑制兔尿道成纤维细胞Rho/ROCK通路激活减少尿道损伤后狭窄的发生

目的:研究法舒地尔对创伤后兔尿道狭窄发生的影响及机制,观察兔尿道成纤维细胞活力、迁移以及细胞外基质合成情况。方法:利用显微外科技术建立兔尿道创伤动物模型,分为5组:假手术组,手术组,不同剂量(3 mg/kg、10 mg/kg、30 mg/kg)法舒地尔组,术后3个月逆行尿道造影测量狭窄直径。从兔尿道瘢痕组织提取成纤维细胞进行传代培养,培养液中分别加入TGF-β1(10μg/L)和/或法舒地尔(12.5μmol/L,25μmol/L,50μmol/L)。MTT比色法检测细胞活力;用Transwell小室实验检测细胞迁移能力;Western blot法检测各组Rho相关激酶(ROCK)、α-平滑肌肌动蛋白(α-SMA)以及胶原蛋白Ⅰ和Ⅲ的表达情况。结果:法舒地尔显著减少尿道损伤后狭窄发生(P0.05)。随着法舒地尔浓度的增加,成纤维细胞的活力受到抑制,细胞迁移能力逐渐减弱,ROCK、α-SMA以及胶原蛋白Ⅰ和Ⅲ的表达受到抑制;法舒地尔对兔尿道成纤维细胞外基质及ROCK表达起抑制作用,并呈剂量依赖性(P0.05)。结论:法舒地尔可以通过下调TGF-β1诱导的兔尿道成纤维细胞Rho/ROCK通路,抑制细胞外基质形成,减少尿道损伤后狭窄的发生。     

维甲酸对高氧暴露新生大鼠肺组织角化细胞生长因子及其受体表达的影响

目的: 探讨高氧暴露新生大鼠肺组织结构的变化和角化细胞生长因子(KGF)及其受体(KGFR)的表达情况及维甲酸(RA)对其的影响。方法: 将出生24 h内SD大鼠90只随机分为3组,Ⅰ组:空气+生理盐水(NS);Ⅱ组:高氧+NS;Ⅲ组:高氧+RA。Ⅱ、Ⅲ组持续暴露于85% O₂中,Ⅰ组置于空气中;Ⅲ组每天腹腔注射RA,Ⅰ、Ⅱ组每天腹腔注射NS。分别于生后3、7、14 d取肺标本,用HE染色法观察肺组织结构变化及辐射状肺泡计数(RAC);RT-PCR检测KGF和KGFR mRNA表达强度和免疫组织化学法检测KGF蛋白表达水平。结果: (1)生后第14 d,Ⅱ、Ⅲ组较Ⅰ组RAC值显著减少(P<0.05),但Ⅲ组较Ⅱ组明显增高(P<0.05)。(2)与Ⅰ组相比,Ⅱ组3 d时,KGF mRNA表达明显增强(P<0.05);其后开始下降,7 d仍高于Ⅰ组(P<0.05);14 d时较Ⅰ组有所降低(P<0.05);Ⅲ组各时点表达量均高于同期Ⅱ组(P<0.05)。3 d时,各组KGFR mRNA表达量无明显差异;7 d、14 d时,Ⅱ、Ⅲ组表达量明显低于Ⅰ组(均P<0.05),且Ⅱ组和Ⅲ组之间无显著差异(P>0.05)。(3)KGF阳性细胞主要分布在部分肺泡壁及肺泡周围血管内皮细胞和间质细胞。KGF蛋白表达强度与其mRNA表达变化相似。结论: RA可促进肺组织KGF表达,改善高氧所致肺发育受阻。对未成熟肺高氧损伤有一定的保护作用。     

卡托普利对高氧新生儿肺损伤保护作用的实验研究

目的探讨ACE抑制剂卡托普利(CPT) 对高氧致新生儿慢性肺疾病(CLD)的影响.方法新生Wistar大鼠随机分为3组:治疗组即高氧 卡托普利(HO CPT),单纯高氧组(HO),正常对照组(NC).治疗组和高氧组每日分别胃管内灌注CPT(50mg/kg/d) 和生理盐水进行干预;对照组胃管内灌注生理盐水代替.各组动物均于胃管内灌注后7、14、21d分别处死16只,其中8只取肺组织做HE染色;另外8只行支气管肺泡灌洗(BAL),收集BALF检测细胞数及总蛋白含量;利用显微镜图像分析系统测定各组肺泡间隔宽度.结果 CPT能显著减轻肺泡炎和肺纤维化的程度,肺泡间隔宽度、BALF中细胞数和总蛋白水平可间接反应肺组织的损伤程度.结论 CPT能减轻高氧诱导的大鼠肺泡炎和肺纤维化.     

Neonatal hyperoxia causes pulmonary vascular disease and shortens life span in aging mice

Bronchopulmonary dysplasia is a chronic lung disease observed in premature infants requiring oxygen supplementation and ventilation. Although the use of exogenous surfactant and protective ventilation strategies has improved survival, the long-term pulmonary consequences of neonatal hyperoxia are unknown. Here, we investigate whether neonatal hyperoxia alters pulmonary function in aging mice. By 67 weeks of age, mice exposed to 100% oxygen between postnatal days 1 to 4 showed significantly a shortened life span (56.6% survival, n = 53) compared to siblings exposed to room air as neonates (100% survival, n = 47). Survivors had increased lung compliance and decreased elastance. There was also right ventricular hypertrophy and pathological evidence for pulmonary hypertension, defined by reduction of the distal microvasculature and the presence of numerous dilated arterioles expressing von Willebrand factor and α-smooth muscle actin. Consistent with recent literature implicating bone morphogenetic protein (BMP) signaling in pulmonary vascular disease, BMP receptors and downstream phospho-Smad1/5/8 were reduced in lungs of aging mice exposed to neonatal oxygen. BMP signaling alterations were not observed in 8-week-old mice. These data suggest that loss of BMP signaling in aged mice exposed to neonatal oxygen is associated with a shortened life span, pulmonary vascular disease, and associated cardiac failure. People exposed to hyperoxia as neonates may be at increased risk for pulmonary hypertension.     

Connective tissue growth factor antibody therapy attenuates hyperoxia-induced lung injury in neonatal rats

Despite recent advances in neonatal intensive care and surfactant therapy, bronchopulmonary dysplasia (BPD) continues to be one of the most common long-term pulmonary complications associated with preterm birth. Clinical efforts to prevent and treat BPD have been largely unsuccessful due to its multifactorial nature and poorly understood disease process. Connective tissue growth factor (CTGF) is a matricellular protein that plays an important role in tissue development and remodeling. Previous studies have demonstrated that hyperoxia exposure up-regulates CTGF expression in neonatal rat lungs. Whether CTGF overexpression plays a role in the pathogenesis of BPD, and whether CTGF antagonism has a therapeutic potential for BPD, are unknown. In the present study, we examined CTGF expression in lung autopsy specimens from patients with BPD and control subjects with no BPD. We assessed the effect of a CTGF-neutralizing monoclonal antibody (CTGF Ab) on preventing hyperoxia-induced lung injury in neonatal rats. Our study demonstrates that CTGF expression is increased in BPD lungs. In newborn rats, exposure to 90% oxygen for 14 days resulted in activation of β-catenin signaling, decreased alveolarization and vascular development, and physiological and histological evidence of pulmonary hypertension (PH). However, treatment with CTGF Ab prevented β-catenin signaling activation, improved alveolarization and vascular development, and attenuated PH during hyperoxia. These data indicate that CTGF-β-catenin signaling plays a critical role in the pathogenesis of experimental BPD. CTGF antagonism may offer a novel therapeutic strategy to alleviate BPD and PH in neonates.     

法舒地尔抑制氧化应激反应减轻2型糖尿病大鼠心肌纤维化简

 目的 探讨RhoA/ROCK通路在糖尿病大鼠心肌纤维化形成中的作用。方法 高脂饮食联合腹腔注射小剂量链脲佐菌素(STZ)建立2型糖尿病大鼠模型。实验分为对照（NC）组,糖尿病（DM）组和法舒地尔干预（DF）组（每天腹腔注射10mg/kg,分两次注射）。24周末,应用HE染色观察大鼠心脏组织形态;电子显微镜观察心肌的超微结构;Masson染色观察心肌胶原沉积情况;羟脯氨酸(HYP)检测心肌胶原含量;测定超氧化物歧化酶（SOD）活力和丙二醛（MDA）含量;免疫组化法检测一氧化氮合酶（eNOS）表达;Western blot法检测心肌中磷酸化肌球蛋白磷酸酯酶靶点亚单位1（MYPT1）表达,代表ROCK活性。 结果 糖尿病组大鼠较对照组大鼠心肌组织ROCK活性明显增强（P<0.01）,MDA含量增高(P<0.01),SOD活力降低(P<0.01),eNOS表达明显下调(P<0.01),心肌胶原明显增多(P<0.01)。法舒地尔干预组大鼠较糖尿病组心肌组织ROCK活性显著降低（P<0.01）,MDA含量降低(P<0.05),SOD活力增加(P<0.01), eNOS表达上调(P<0.05),心肌胶原明显减少(P<0.01)。结论 ROCK抑制剂法舒地尔抑制心肌组织氧化应激反应并上调eNOS表达,有效地减轻2型糖尿病大鼠心肌纤维化。     

Early bronchopulmonary lesions in rat lung after normobaric 100% oxygen exposure and their evolution

Summary In order to clarify the early phenomena involved in the lung reaction to hyperoxia, twenty adult male rats were exposed to 100% oxygen at 1 ATA. Morphological pulmonary lesions were detectable after only 24 h hyperoxia, and included vasoconstriction and perivascular oedema, bronchiolar constriction, and pericyte reaction. The lesions were irregularly scattered within the lung parenchyma and occurred preferentially in areas centred on bronchiolo-vascular stems. Even at the latest stages, pulmonary heterogeneity was obvious, from the coexistence of areas damaged at different times. Neuro-epithelial-bodies were found under the bronchiolar epithelium; the morphological aspect of the neuro-endocrine cells observed was consistent with hyperoxia-induced modulation of their secretory activity. Taken together, our findings show the speed of development of hyperoxia-induced pulmonary changes and raise some pathogenic considerations.     

Rho激酶抑制剂对压力超负荷大鼠心肌纤维化的影响

目的:观察Rho激酶抑制剂法舒地尔对大鼠心肌纤维化的影响。方法:采用腹主动脉缩窄术制备SD大鼠心肌纤维化模型,动脉夹闭4周后,随机分为4组:假手术组(Sham组)、模型组(Model组)、法舒地尔高剂量(FH,30mg/Kg/天)组和法舒地尔低剂量(FL,10mg/Kg/天)组。术后8周末,计算各组大鼠心脏质量指数(HWI)、左室质量指数(LVWI),观察心肌组织HE染色和Masson染色,碱水解法测定心肌组织羟脯氨酸(HYP)含量,免疫组化分析磷酸化的肌球蛋白磷酸酶靶蛋白亚基1(p-MYPT1)、转化生长因子β1(TGF-β1)和结缔组织生长因子(CTGF)水平。结果:与Sham组相比,Model组大鼠LVWI及HYP含量显著升高(P<0.01),心肌细胞排列紊乱,间质大量胶原纤维沉积,心肌组织p-MYPT1水平升高(P<0.01),TGF-β1、CTGF表达升高(P<0.01);与Model组相比,FH组和FL组大鼠LVWI及HYP含量降低(P<0.05),间质胶原蛋白沉积程度减轻,心肌组织p-MYPT1、TGF-β1、CTGF水平均降低(P<0.05或P<0.01)。结论:Rho激酶参与压力超负荷诱导的大鼠心肌纤维化,法舒地尔抑制心肌纤维化进展的作用与TGF-β1和CTGF水平的降低有关。     

Glutamate mediates hyperoxia-induced newborn rat lung injury through N-methyl-D-aspartate receptors

Our laboratory found that the N-methyl-D-aspartate receptor (NMDAR) antagonist, MK-801, was able to decrease hyperoxia-induced lung damage. To further search for direct evidence of glutamate and its NMDARs participating in hyperoxia-induced lung injury, the amount of glutamate in the bronchoalveolar lavage fluid and the expression of NMDAR 2D in lung tissue were tracked in newborn rats that were exposed to 95% oxygen for 1, 3, and 7 days. The protective effect of MK-801 was then observed at different hyperoxia exposure times. As demonstrated by RT-PCR, NMDAR 2D expression was much higher in hyperoxia exposure on the third and the seventh days than in the air control group. The levels of glutamate in the bronchoalveolar lavage fluid on the first and third days of hyperoxia exposure were significantly higher than in the air control group. MK-801 alleviated lung injury and inflammatory reaction induced by 95% O(2) for 3 and 7 days. These results indicate that large amounts of endogenous glutamate from the lungs were released, and its NMDAR were expressed strongly under conditions of high oxygen concentration. We conclude that the endogenous glutamate mediated newborn rat lung damage induced by hyperoxia through NMDARs.     

Fasudil alleviates LPS-induced lung injury by restoring aquaporin 5 expression and inhibiting inflammation in lungs

Fasudil, a selective rho kinase (ROCK) inhibitor, has been reported to play a beneficial role in systemic inflammation in acute lung injury, but its mechanism for ameliorating pulmonary edema and inflammation remains unclear. Using hematoxylin-and-eosin (H&E) staining, immunohistochemistry, enzyme-linked immunosorbent assay, quantitative real time PCR and Western blotting, we found that fasudil attenuated LPS-induced lung injury, decreased lung edema, and suppressed inflammatory responses including leukocyte infiltration and IL-6 production. Further, fasudil upregulated LPS-induced aquaporin 5 reduction and inhibited NF-kB activation in the lungs of mice. Our results suggest that fasudil could restore the expression of aquaporin 5 to eliminate LPS-induced lung edema and prevent LPS-induced pulmonary inflammation by blocking the inflammatory pathway. Collectively, blockade of the ROCK pathway by fasudil may be a potential strategy for the treatment of acute lung injury.