CDK11P58和Cyclin D3在损伤后大鼠坐骨神经中的表达变化

为了探讨大鼠坐骨神经损伤对CDKll^p58和Cyclin D3表达的影响，本实验将成年SD大鼠随机分为假手术组和夹伤组，运用Western blot结合免疫荧光组织化学双标技术，观察了坐骨神经损伤后坐骨神经夹伤段、脊髓腰膨大前角和伤侧腓肠肌内CDKll^P58和Cyclin D3的表达变化。结果显示：（1）坐骨神经夹伤后，坐骨神经夹伤段及脊髓腰膨大前角、伤侧腓肠肌中的CDKll^58蛋白的表达先逐渐下降，后又逐渐上升；而Cyclin D3的表达无明显变化；（2）在假手术组的坐骨神经、脊髓腰嘭大前角和腓肠肌内都可观察到CDKll^P58和Cyclin D3的表达；而坐骨神经夹伤后，在上述部位可检测到CDKll^P58的表达强度明显减弱，但Cyclin D3无明显变化；（3）免疫荧光双标结果显示CDKll^P58和Cyclin D3在假手术组的坐骨神经、脊髓腰膨大前角和伤侧腓肠肌内都有共存；而在坐骨神经损伤后这种共存强度明显降低。以上结果提示，坐骨神经损伤可影响坐骨神经及脊髓腰膨大、伤侧腓肠肌内CDKll^P58的表达，但对Cyclin D3无明显影响，表明CDKll^P58可能在周围神经损伤和修复中发挥重要作用。     

CDK11P58和Cyclin D3在损伤后大鼠坐骨神经中的表达变化

为了探讨大鼠坐骨神经损伤对CDK11P58和Cyclin D3表达的影响,本实验将成年SD大鼠随机分为假手术组和夹伤组,运用Western blot结合免疫荧光组织化学双标技术,观察了坐骨神经损伤后坐骨神经夹伤段、脊髓腰膨大前角和伤侧腓肠肌内CDK11P58和Cyclin D3的表达变化.结果显示:(1)坐骨神经夹伤后,坐骨神经夹伤段及脊髓腰膨大前角、伤侧腓肠肌中的CDK11P58蛋白的表达先逐渐下降,后又逐渐上升;而Cyclin D3的表达无明显变化;(2)在假手术组的坐骨神经、脊髓腰膨大前角和腓肠肌内都可观察到CDK11P58和Cyclin D3的表达;而坐骨神经夹伤后,在上述部位可检测到CDK11P58的表达强度明显减弱,但Cyclin D3无明显变化;(3)免疫荧光双标结果显示CDK11P58和Cyclin D3在假手术组的坐骨神经、脊髓腰膨大前角和伤侧腓肠肌内都有共存;而在坐骨神经损伤后这种共存强度明显降低.以上结果提示,坐骨神经损伤可影响坐骨神经及脊髓腰膨大、伤侧腓肠肌内CDK11P58的表达,但对Cyclin D3无明显影响,表明CDK11P58可能在周围神经损伤和修复中发挥重要作用.     

β-1,4半乳糖基转移酶-Ⅰ在钳夹伤后大鼠坐骨神经中表达的变化

为了观察β-1，4-半乳糖基转移酶-Ⅰ（β-1，4-galactosyltransferase-Ⅰ，β-1，4-GalT-Ⅰ）在正常和钳夹伤后大鼠坐骨神经中表达的变化，本研究采用RT—PCR方法，从小鼠坐骨神经中特异性地扩增β-1，4-GalT-ⅠcDNA片段并将其克隆到pGEM-T载体。采用体外转录的方法合成地高辛标记的正、反义β-1，4-GalT-ⅠRNA探针。通过原位杂交和图像分析的方法，观察β-1，4-GalT-ⅠmRNA在正常和夹伤大鼠坐骨神经中的表达及其变化。结果表明：β-1，4-GalT-Ⅰ mRNA在大鼠坐骨神经的髓鞘中表达，在夹伤坐骨神经后1-2d，β-1，4-GalTⅠmRNA在坐骨神经的表达最高，于夹伤后1周开始下降，在夹伤后1个月恢复至正常水平。上述结果提示坐骨神经夹伤后β-1，4-GalTⅠmRNA的表达发生变化，并且主要表达在坐骨神经的Schwann细胞。本研究结果为进一步分析β-1，4-GalT-Ⅰ在周围神经再生中的调控机制奠定了基础。     

Myostatin在小鼠腓肠肌失神经支配萎缩过程中的表达

目的:分析myostatin在腓肠肌失神经支配萎缩过程中的表达变化及其在肌萎缩过程中的作用。方法:采用坐骨神经横断术制备小鼠腓肠肌失神经支配模型,实时荧光定量PCR和Western印迹法分别检测失神经支配不同时段腓肠肌myostatin mRNA和蛋白表达水平,并对失神经前后肌肉湿重比、肌纤维横截面积进行比较。结果:失神经支配1 d时,腓肠肌myostatin mRNA迅速上升,3 d达到高峰,随后逐渐下降,而相应蛋白水平逐渐增高,7 d达到高峰继而逐渐下降,至56 d时mRNA和蛋白水平仍略高于正常水平。结论:腓肠肌失神经支配萎缩过程中myostatin的表达变化是一重要的分子事件。     

阿托伐他汀对心肌梗死大鼠心肌细胞核内FoxO3a表达的影响

目的探讨阿托伐他汀对大鼠心肌梗死(myocardial infarction,MI)后心肌细胞核内FoxO3a表达和心室重构的影响。方法建立大鼠MI模型,24 h后存活大鼠随机分成MI组(n=8)、阿托伐他汀10 mg组[10 mg/(kg.d),Ato组,n=8],同时另设假手术组(Sham组,n=10)。4周后观察左心室质量指数(left ventricular mass index,LVMI),免疫组化染色和RT-PCR检测FoxO3a在左心室非梗死区(non-infarction zone,NIZ)心肌细胞核内蛋白质和mRNA表达水平,流式细胞技术(flow cytometry,FCM)检测FoxO3a蛋白在NIZ心肌细胞核内表达含量。SAS9.1统计软件分析数据。结果 MI组与Sham组相比,LVMI显著增加(P<0.05);左室心肌非梗死区FoxO3a mRNA、FoxO3a蛋白表达(免疫组化)、FCM检测心肌细胞核内蛋白表达量表达均降低(P<0.05)。与MI组相比,Ato组LVMI显著下降(P<0.05);但高于Sham组(P<0.05);与MI组比较Ato组左室心肌非梗死区FoxO3a mRNA、Fox-O3a蛋白表达(免疫组化)、FCM检测心肌细胞核内蛋白表达量表达均显著增高(P<0.05);但低于Sham组(P<0.05)。结论阿托伐他汀能够有效地改善MI后心室重构,机制可能与上调细胞核内FoxO3a表达量有关。     

一氧化氮合酶在坐骨神经夹伤后腓肠肌中的表达变化

目的:探讨外周神经损伤后同侧腓肠肌中3种一氧化氮合酶(nitric oxide synthase,NOS)的表达变化及定位。方法:采用H-E染色及Masson三色染色法分析大鼠坐骨神经夹伤后同侧腓肠肌的病理变化,NADPH-黄递酶组织化学研究其总NOS的改变,并利用Western印迹法、免疫荧光双标法,对3种NOS表达变化及定位进行分析。结果:神经夹伤后相应腓肠肌发生了明显的病理变化且总NOS发生改变,3种NOS变化不尽相同,其表达高峰均约在4周左右。nNOS与神经丝标记物NF-200有共定位,iNOS、eNOS则分别在巨噬细胞、血管内皮细胞中有表达。结论:3种NOS在坐骨神经夹伤后相应腓肠肌中表达变化不同,可能对肌肉损伤及再生修复发挥不同作用。     

大鼠坐骨神经切断后IGF-Ⅰ、BDNF和TrkB在背根节表达的实验研究

目的：观察大鼠坐骨神经切断后IGF-Ⅰ、BDNF及TrkB在背根节（DRG）表达变化规律，探讨三者在神经保护和再生中的作用机制。方法：健康成年雄性Wister大鼠随机分为对照组和实验组，实验组切断右侧大腿坐骨神经后存活3～28d，荧光定量RT-PCR方法检测L4-6背根节（DRG）中IGF-Ⅰ、BDNF和TrkB基因mRNA的表达。结果：坐骨神经损伤后3d，L4-6 DRGIGF-Ⅰ、BDNF和TrkB基因mRNA表达均有不同程度的升高，到7-14d达高峰，后逐渐下降到正常水平。结论：坐骨神经损伤后，IGF-Ⅰ、BDNF和TrkB基因mRNA表达同步变化提示它们在外周神经损伤后神经保护及再生中可能存在相互作用。     

心肌细胞FoxO1特异性敲除对心肌梗死的影响及机制

目的 探讨心肌细胞FoxO1特异性敲除对小鼠急性心肌梗死后纤维瘢痕和心功能的影响。方法 使用他莫昔芬（0.1mg/g/d）对Myh6-ER-Cre+FoxO1loxP/loxP小鼠连续腹腔注射5 d的方法诱导心肌细胞内FoxO1的敲除。H9C2心肌细胞转染FoxO1的siRNA诱导心肌细胞内FoxO1的表达下调。使用Western Blot法检测FoxO1的蛋白表达水平，以明确敲减效率。选取10周左右的心肌细胞FoxO1特异性敲除（CKO组）和注射玉米油的对照小鼠（对照组）通过前降支结扎的方法制备心肌梗死模型。心脏超声检测各组心功能改变，Masson染色检测各组心脏梗死纤维瘢痕面积。TUNEL和心肌细胞标志蛋白α-Actinin免疫荧光双染法检测心肌细胞凋亡情况。realtime-PCR法检测细胞凋亡相关基因的表达。Caspase3/7活性检测心肌细胞活性。结果 Western Blot显示CKO组小鼠心脏组织中FoxO1的表达显著下降，表明敲减成功。术后28 d的生存曲线显示CKO组小鼠的生存率高于对照组。与对照组相比，CKO组的梗死纤维瘢痕的面积显著减小，心功能显著提高（P<...     

转录因子FoxO1、FoxO3a在KKAy胰岛素抵抗糖尿病小鼠肌肉和肝组织中的表达

目的研究FoxO1和FoxO3 a在胰岛素抵抗糖尿病动物模型KKAy小鼠肌肉和肝中的表达,了解它们在胰岛素抵抗机制中所起的作用。方法对照组为16周龄C57BL小鼠7只,实验组为KKAy糖尿病小鼠7只;小鼠4周龄开始普通饲料喂养至12周龄,随后高脂饲料喂养4周,连续2次随机血糖≥16.7 mmol/L诊断为糖尿病。取股四头肌和肝加上组织裂解液B radford法测定蛋白浓度,W estern B lot方法检测肌肉和肝组织中FoxO1和FoxO3 a蛋白的表达。结果KKAy糖尿病小鼠FoxO1肝和肌肉中表达显著高于对照组小鼠;FoxO3 a肝表达对照组和糖尿病组之间没有差别,肌肉组织表达在糖尿病组显著高于对照组。结论FoxO1和FoxO3 a在胰岛素抵抗和糖尿病状态下表达显著增加,可能在胰岛素抵抗和糖尿病的发病机制中起重要作用。     

β-1,4半乳糖基转移酶-I在钳夹伤后大鼠坐骨神经中表达的变化

为了观察β-1,4-半乳糖基转移酶-I(β-1,4-galactosyltransferase-I,β-1,4-GalT-I)在正常和钳夹伤后大鼠坐骨神经中表达的变化,本研究采用RT-PCR方法,从小鼠坐骨神经中特异性地扩增β-1,4-GalT-I cDNA片段并将其克隆到pGEM-T载体。采用体外转录的方法合成地高辛标记的正、反义β-1,4-GalT-I RNA探针。通过原位杂交和图像分析的方法,观察β-1,4-GalT-I mRNA在正常和夹伤大鼠坐骨神经中的表达及其变化。结果表明:β-1,4-GalT-I mRNA在大鼠坐骨神经的髓鞘中表达,在夹伤坐骨神经后1~2d,β-1,4-GalT-I mRNA在坐骨神经的表达最高,于夹伤后1周开始下降,在夹伤后1个月恢复至正常水平。上述结果提示坐骨神经夹伤后β-1,4-GalT-I mRNA的表达发生变化,并且主要表达在坐骨神经的Schwann细胞。本研究结果为进一步分析β-1,4-GalT-I在周围神经再生中的调控机制奠定了基础。     

Investigation of differentially expressed proteins in rat gastrocnemius muscle during denervation–reinnervation

To have a better insight into the molecular events involved in denervation-induced atrophy and reinnervation-induced regeneration of skeletal muscles, it is important to investigate the changes in expression levels of a great multitude of muscle proteins during the process of denervation–reinnervation. In this study, we employed an experimental model of rat sciatic nerve crush to examine the differentially expressed proteins in the rat gastrocnemius muscle at different time points (0, 1, 2, 3, 4 weeks) after sciatic␣nerve crush by using two-dimensional gel electrophoresis (2-DE) followed by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS), collectively referred to as the modern proteomic analysis. The results showed that 16 proteins in the rat gastrocnemius muscle exhibited two distinct types of change pattern in their relative abundance: (1) The relative expression levels of 11 proteins (including alpha actin, myosin heavy chain, etc.)were decreased either within 1 or 2 weeks post-sciatic nerve injury, followed by restoration during the ensuing days until 4 weeks. (2) The other 5 proteins (including alpha enolase, beta enolase, signal peptide peptidase-like 3, etc.) displayed an up-regulation in their relative expression levels within 1 week following sciatic nerve injury, and a subsequent gradual decrease in their relative expression levels until 4 weeks. Moreover, the significance of the changes in expression levels of the 16 proteins during denervation–reinnervation has been selectively discussed.     

Expression of myostatin RNA transcript and protein in gastrocnemius muscle of rats after sciatic nerve resection

Myostatin, a member of the transforming growth factor-beta (TGF-beta) superfamily, has been identified as an inhibitor of skeletal muscle mass. To have an insight into the expression pattern of myostatin and its potential role in skeletal muscle atrophy induced by denervation, we used an animal model of peripheral nerve resection to examine the time-dependent changes in myostatin mRNA and protein levels in the denervated gastrocnemius muscle of rats after sciatic neurectomy by the aid of quantitative real-time RT-PCR and Western blotting, respectively. We also conducted morphometric analyses to measure the wet weight ratio of the denervated muscle (the operated side/contralateral non-operated side) and the cross sectional area of muscle fibers and to observe muscle morphology. The experimental results showed that myostatin mRNA and protein levels in rat gastrocnemius muscle persistently elevated after denervation, despite a fluctuation of myostatin mRNA level at day 3 after denervation, reached their respective peaks at day 28 after denervation, and then depressed slightly until day 56 after denervation. Furthermore, a significant negative linear correlation was found between myostatin abundance and muscle atrophy degree, suggesting that myostatin might probably play an important role in denervation-induced muscle atrophy. Our present study perhaps provides a new window into myostatin regulation in association with a specific type of muscle atrophy.     

陈旧性坐骨神经缺损对大鼠腓肠肌组织蛋白含量及泛素表达的影响

目的：了解陈旧性坐骨神经缺损后肌肉萎缩过程中蛋白质降解的机制。方法：用SD大鼠建立坐骨神经缺损模型,切断大鼠右侧坐骨神经,形成10 mm缺损。测定术后1、2、3、4、6、9及12个月腓肠肌肌总蛋白的含量;免疫组化法观察组织中泛素的表达变化;Western印迹法测定组织中泛素蛋白的表达水平。结果：坐骨神经缺损后腓肠肌肌总蛋白含量随缺损时间延长呈进行性下降;正常腓肠肌组织中泛素呈低表达,随缺损时间延长泛素表达水平增强,持续到9个月,随后呈下调趋势。结论：陈旧性坐骨神经缺损后腓肠肌蛋白的降解、肌总蛋白量下降及肌萎缩可能和泛素-蛋白酶体途径有关。     

PPM1B and P-IKKβ expression levels correlated inversely with rat gastrocnemius atrophy after denervation

Activated inhibitor of nuclear factor-κB kinase β (IKKβ) is necessary and sufficient for denervated skeletal muscle atrophy. Although several studies have shown that Mg²⁺/Mn²⁺-dependent protein phosphatase 1B (PPM1B) inactivated IKKβ, few studies have investigated the role of PPM1B in denervated skeletal muscle. In this study, we aim to explore the expression and significance of PPM1B and phosphorylated IKKβ (P-IKKβ) during atrophy of the denervated gastrocnemius. Thirty young adult female Wistar rats were subjected to right sciatic nerve transection and were sacrificed at 0 (control), 2, 7, 14, and 28 days after denervation surgery. The gastrocnemius was removed from both the denervated and the contralateral limb. The muscle wet weight ratio was calculated as the ratio of the wet weight of the denervated gastrocnemius to that of the contralateral gastrocnemius. RT-PCR and Western blot analysis showed that mRNA and protein levels of PPM1B were significantly lower than those of the control group at different times after the initiation of denervation, while P-IKKβ showed the opposite trends. PPM1B protein expression persistently decreased while P-IKKβ expression persistently increased for 28 days after denervation. PPM1B expression correlated negatively with P-IKKβ expression by the Spearman test, whereas decreasing PPM1B expression correlated positively with the muscle wet weight ratio. The expression levels of PPM1B and P-IKKβ were closely associated with atrophy in skeletal denervated muscle. These results suggest that PPM1B and P-IKKβ could be markers in skeletal muscle atrophy.     

骨髓间充质干细胞移植治疗失神经肌萎缩

背景:外科显微镜手术和一些辅助治疗方法均无法通过修复损伤的神经细胞来有效延缓或治疗失神经肌萎缩。研究发现骨髓间充质干细胞具有定向分化潜能,并且在一定环境因素下能对损伤的组织进行修复,由此推测其可以对失神经萎缩肌肉起到一定的修复作用。目的:探讨移植骨髓间充质干细胞是否能够减轻和延缓失神经肌肉组织萎缩。方法:分离培养SD大鼠骨髓间充质干细胞,取第3代骨髓间充质干细胞经BrdU标记后用于移植治疗。将30只SD大鼠分为3组,每组10只,对每只大鼠左后肢进行手术。假手术组只暴露坐骨神经主干,不钳夹神经,移植治疗组、模型对照组钳夹坐骨神经主干后,向其支配的腓肠肌注射骨髓间充质干细胞悬液和不含胎牛血清的DMEM培养液。骨髓间充质干细胞移植后1,2周,采用BBB评分评价各组大鼠左后肢运动功能;骨髓间充质干细胞移植后14 d,取腓肠肌组织进行苏木精-伊红染色和BrdU免疫组化染色。结果与结论:第3代骨髓间充质干细胞BrdU标记为阳性;标记的骨髓间充质干细胞能在移植治疗组失神经损伤的肌肉组织中存活并起修复作用;相对于模型对照组,移植治疗组失神经肌纤维由相互融合重新恢复规整。结果表明移植骨髓间充质干细胞能够减轻和延缓失神经肌肉组织萎缩。     

臀部肌注致坐骨神经损伤的神经电生理分析

目的：研究臀部肌注致坐骨神经损伤后患肢的运动传导速度和肌电图的改变。方法：回顾性分析65名臀部肌注致坐骨神经损伤患者的患侧腓总神经和胫神经的运动传导速度及胫前肌和腓肠肌的针极肌电图检查。结果：65例中，患侧胫神经异常者15例（23．1％），患侧腓总神经异常者40例（61．5％）。肌注后5天内运动传导速度异常率低于5天后的异常率。患侧胫前肌异常者9例（13．8％），患侧腓肠肌异常者7例（10．8％）。结论：运动神经传导速度和肌电图检查是臀部肌注致坐骨神经损伤的不可缺少的神经电生理指标。     

陈旧性坐骨神经损伤后相关结构的组织学变化

为了观察大鼠陈旧性神经损伤后相关结构的组织学变化,了解陈旧性神经损伤后多长时间仍有修复神经损伤的组织学基础,本实验采用切断成年大鼠右侧坐骨神经,形成10mm缺损。术后1~12月不同时间段取材后,在光镜和电镜下观察相应组织的形态变化。结果显示:(1)坐骨神经损伤后1月,同侧脊髓前角神经元的数目明显减少,但随后未见进一步减少;(2)损伤远侧神经干中,伤后1月时椭圆形核细胞增生,形成B櫣ngner带;2月时B櫣ngner带断裂,梭形核细胞明显增生;6~12月时梭形核细胞明显减少,胶原纤维呈致密平行排列。神经损伤1~12月时,电镜下神经内膜管内出现指样突起的细胞,内膜管下及内膜管之间有大量胶原纤维增生;(3)损伤侧腓肠肌纤维萎缩随损伤时间的延长而加重,伤后4个月肌纤维间结缔组织增生明显。本研究结果提示大鼠坐骨神经损伤后3~4月时,仍有神经修复的组织学基础。     

人工组织神经移植物修复狗缺损坐骨神经后腓肠肌的形态观察

目的 了解复合型医用可降解材料制成的人工组织神经移植物辅加神经再生素修复狗坐骨神经缺损后，腓肠肌的形态变化。方法 将人工组织神经移植物连接在狗的坐骨神经缺损30mm处。以自体神经桥接和神经缺损的狗为对照组Ⅰ和Ⅱ。术后6个月时取腓肠肌进行称重、特殊染色和组织化学染色，显微镜下了解腓肠肌的形态变化并进行图像定量分析，同时了解肌纤维的超微结构变化。结果 术后6个月，实验组腓肠肌的萎缩形态指标变化均轻于对照组Ⅱ，而与对照组Ⅰ相似。结论 经人工组织神经移植物修复缺损的坐骨神经后，使腓肠肌又重新获得神经支配，肌肉萎缩明显减轻。