miR-186-5p修饰骨髓间充质干细胞通过下调FZD3对脊髓损伤大鼠具有神经保护作用

目的 探讨miR-186-5p修饰的骨髓间充质干细胞对脊髓损伤大鼠的神经保护作用及可能机制.方法 40只SD大鼠随机分为假手术组(Sham组)、脊髓损伤模型组(SCI组)、骨髓间充质干细胞移植组(BMSCs组)和miR-186-5p修饰的骨髓间充质干细胞移植组(miR+BMSCs组),每组10只;除了Sham组,其余三组通过Allen's法建立SCI大鼠模型,移植后第1、7、14、21天对各组大鼠进行运动功能(BBB)评分;HE染色观察各组大鼠脊髓损伤病理学变化;IF检测NeuN表达情况;ELISA检测NT-3含量变化;利用qRT-PCR检测各组大鼠miR-186-5p的表达;荧光素酶实验验证miR-186-5p与FZD3的关系;Western blot方法检测损伤脊髓组织中的FZD3、β-catenin、c-Myc、cyclinD1的表达水平变化.结果 与SCI组相比,BMSCs组和miR+BMSCs组的BBB评分、损伤脊髓组织中NeuN的表达、NT-3的表达以及β-catenin、c-Myc、cyclinD1的蛋白表达均明显升高(P＜0.05),FZD3的蛋白表达明显下降(P＜0.05).FZD3被预测并确认为miR-186-5p的靶基因.与BMSCs组相比,miR+BMSCs组的BBB评分、损伤脊髓组织中NeuN的表达、NT-3的表达以及β-catenin、c-Myc、cyclinD1的蛋白表达显著升高(P＜0.05),FZD3的蛋白表达呈下降趋势(P＜0.05).结论 miR-186-5p修饰的骨髓间充质干细胞移植可通过下调FZD3对SCI大鼠的神经提供保护作用.     

蛇床子素激活wnt/β-catenin信号通路抑制急性脊髓损伤大鼠神经细胞凋亡

目的探讨蛇床子素对脊髓损伤大鼠神经细胞凋亡的影响及可能机制。方法将45只SD大鼠平均分为假手术组(Sham)、脊髓损伤组(SCI)与蛇床子素治疗组(Ost),采用Allen法建立大鼠SCI模型。建模7d后评估各组大鼠后肢运动功能,并检测脊髓含水量。TUNEL方法检测脊髓神经细胞凋亡;Western blot和qRTPCR检测Wnt-1、GSK-3β、β-catenin表达。结果急性脊髓损伤导致大鼠后肢功能障碍,脊髓细胞发生凋亡,蛇床子素可以减少急性脊髓损伤大鼠神经细胞凋亡,抑制炎症反应,改善后肢功能,减轻脊髓损伤,同时可以下调GSK-3β表达水平,上调Wnt-1和β-catenin蛋白表达水平。结论蛇床子素通过激活wnt/β-catenin信号通路抑制神经细胞凋亡,促进大鼠运动功能恢复。     

盐酸羟考酮激活Nrf2/Keap1/HO-1信号通路抑制氧化应激缓解大鼠神经病理性疼痛

目的 探讨盐酸羟考酮对脊髓损伤大鼠氧化应激的影响及神经性病理疼痛的作用。方法 30只SD大鼠随机分为假手术组（Sham组）、脊髓损伤模型组（SCI组）和盐酸羟考酮组（OHI组）,Allen’s方法建立脊髓损伤大鼠模型。于实验开始前1d及造模后1d、3d、7d、14d对各组大鼠进行BBB评分,进行热缩爪潜伏期和机械性缩爪潜伏期的测定;利用HE染色观察脊髓损伤病理变化;免疫荧光法检测活性氧ROS的表达;ELISA检测血清中SOD、MDA、GSH-PX的含量;TUNEL法检测细胞凋亡情况;Western blot法检测Nrf2、Keap1、HO-1的表达水平。结果 盐酸羟考酮抑制SCI大鼠病理损伤,缓解神经病理性疼痛,抑制ROS的释放,抑制MDA的分泌,促进SOD、GSH-PX的释放,上调Nrf2、HO-1的表达,下调Keap1的表达。结论 盐酸羟考酮通过激活Nrf2/Keap1/HO-1信号通路抑制氧化应激,缓解SCI大鼠神经病理性头痛,降低病理损伤。     

活性氧在脊髓损伤中的作用及损伤机制

目的研究脊髓损伤(SCI)后脊髓组织中丙二醛(MDA)的动态水平变化和神经细胞凋亡及其凋亡相关因子表达的变化,探讨活性氧(ROS)在SCI后的作用及其分子机制。方法成年雄性大鼠132只,用改良的Allen法复制大鼠急性SCI模型,致大鼠脊髓(T10)中度挫伤,采用化学比色法测定不同时间段受损脊髓组织的MDA含量;免疫组织化学法分析受损脊髓组织区域凋亡相关因子Caspase-3、Bcl-2和Bax的表达变化;荧光原位缺口末端标记法(TUNEL)检测细胞凋亡。结果SCI后6h,脊髓组织中MDA含量明显增高并维持到损伤后5d,期间在6h和3d出现两次高峰,7d基本恢复正常;SCI后6h脊髓组织中凋亡细胞开始增多,3d达高峰,以后逐渐减少,各时间点与假手术组比较有显著性的差异;Bcl-2和Bax蛋白损伤后6h开始有较多的表达,以后快速增多,5d达高峰,然后逐渐回落。Caspase-3蛋白在损伤后6h开始增多,3d达高峰,以后逐渐减少。3种凋亡相关因子在各时间点与假手术组比较有显著性差异;甲基强的松龙(MPSS)治疗组与SCI组比较:MDA含量、凋亡细胞数、凋亡因子Caspase-3和Bax表达减少,Bcl-2表达增加,并且在部分时间点有显著性差异。结论在SCI后ROS可能通过促进Caspase-3表达和降低Bcl-2/Bax之间的比值诱导神经细胞凋亡,从而加重了SCI继发性损伤。     

葛根素对大鼠急性脊髓损伤后神经元功能的影响及作用机制研究

目的 探讨葛根素改善急性脊髓损伤大鼠神经元功能的作用机制。方法 将50只大鼠随机分为假手术组、模型组、葛根素组、PRDM5过表达及葛根素+PRDM5过表达组,每组10只,采用Allen法建立急性脊髓损伤大鼠模型。采用运动功能评分对大鼠后肢运动功能进行评分;肉眼及HE染色观察脊髓组织形态和病理变化;TUNEL染色检测神经元凋亡;免疫荧光染色检测大鼠脊髓组织神经元核抗原(NeuN)、脑源神经营养因子(BDNF)及突触素1(synapsin I)表达;Western blot检测大鼠脊髓组织PRDM5、Wnt1、β-catenin、GSK-3β、p-GSK-3β蛋白表达。结果 与模型组比较,葛根素组运动功能评分显著升高,脊髓损伤段淤血面积及结构破坏明显减轻,炎症浸润现象减轻,出现一定量髓鞘再生。大鼠脊髓组织神经元凋亡明显减少,NeuN、BDNF、synapsin I表达明显增加,PRDM5、GSK-3β蛋白表达水平明显降低,Wnt1、p-GSK-3β、β-catenin蛋白表达水平明显升高;且葛根素能够部分逆转PRDM5的作用。结论 葛根素可能通过抑制PRDM5表达,进而激活Wnt/β-ca...     

大鼠脊髓全横断损伤后Wnt信号基因的表达

目的探讨大鼠脊髓全横断损伤后,Wnt信号基因在不同时相脊髓表达的变化及意义。方法成年健康Wistar大鼠30只,随机分为假手术组(sham组)和脊髓损伤组(SCI组),SCI组分为术后1d、3d、7d、14d、21d组,每组5只。SCI组大鼠T11脊髓段做全横断损伤,sham组仅行椎板切除术,术后大鼠进行BBB运动功能评分。采用半定量RT-PCR方法检测脊髓损伤组织中Wnt信号基因的表达。结果SCI组所有动物在术后均表现为双后肢瘫痪,BBB运动功能评分明显低于sham组。SCI组在脊髓横断术后1d、3d、7d Wnt3a表达均较sham组明显增加;尾侧端Wnt3a较同时相头侧端的表达多,且在21d又出现明显的升高。在sham组和SCI组均未检测到神经基因蛋白1(Ngn1)的表达。发状分裂相关增强子1(Hes1)的表达在SCI后第1d较sham组有明显的下降,第3d出现升高,之后逐渐下降。结论Wnt信号可能参与了脊髓损伤后修复再生的过程。     

利拉鲁肽通过抑制线粒体凋亡途径对大鼠脊髓损伤的保护作用

目的:研究利拉鲁肽注射液对大鼠脊髓损伤(spinal cord injury,SCI)后线粒体氧化损伤、细胞色素C(Cyt-C)、caspase-3及细胞凋亡的影响。方法:将36只健康SD大鼠随机分为假手术组(Sham组)、脊髓损伤组(SCI组,生理盐水50μg/kg,腹腔注射)、利拉鲁肽组(50μg/kg,腹腔注射),每组12只。采用Allen’s法制作SCI模型,假手术组仅行椎板切除,其余二组行椎板切除并打击。模型建立24 h后取受损脊髓,提取脊髓组织线粒体,分别检测丙二醛(MDA)、谷胱甘肽(GSH)的含量、Cyt-C与caspase-3表达,JC-1法测定线粒体膜电位的变化,TUNEL染色法检测细胞的凋亡情况。结果:利拉鲁肽组较SCI模型组脊髓组织线粒体中GSH的含量明显有所升高,而MDA的含量明显降低(P0.01),JC-1法示利拉鲁肽组大鼠线粒体膜电位较SCI模型组明显有所提高(P0.01)。Western Blot法和TUNEL法分别显示利拉鲁肽组大鼠脊髓内Cyt-C、caspase-3的表达和细胞凋亡数较SCI模型组明显有所减少(P0.01)。结论:利拉鲁肽能够改善SCI后线粒体氧化损伤,保护线粒体膜电位,减少Cyt-C释放,降低caspase-3表达,抑制细胞凋亡,对SCI起到保护作用。     

Wnt3a减轻黑素细胞iMC65氧化应激损伤

目的探讨Wnt3a对氧化应激损伤的i MC65黑素细胞的保护作用及机制。方法将黑素细胞分成对照组,Wnt3a组,H2O2处理组,Wnt3a干预组,750μmol/L的H2O2作用模拟黑素细胞的氧化应激损伤。MTT实验检测细胞活性,流式细胞术检测细胞凋亡率和细胞产生活性氧(ROS),荧光素酶报告基因检测Nrf2/ARE通路的激活,Western blot检测Nrf2/ARE通路的相关蛋白表达。结果与对照组相比,H2O2处理组的细胞活性明显下降(P0.01),凋亡比率明显上升(P0.01),ROS的产生明显增加(P0.01)。而Wnt3a干预组能显著缓解H2O2处理组细胞活性的降低(P0.05)、降低凋亡比率(P0.05),减少ROS的产生(P0.05)。Wnt3a也能上调Nrf2和HO-1蛋白水平的表达。结论 Wnt3a可以保护氧化应激状态下的黑素细胞,其机制可能与激活Nrf2/ARE有关。     

许旺细胞联合C5a受体拮抗剂移植脊髓损伤大鼠的电生理及后肢功能变化

背景：C5a通过增强脊髓损伤后早期炎症反应参与了脊髓损伤后的继发性损伤,C5a受体拮抗剂能有效阻断这一过程。 目的：观察许旺细胞移植联合C5a受体拮抗剂对脊髓损伤大鼠神经功能恢复的影响。 方法：Wistar大鼠80只建立脊髓损伤动物模型后随机分成4组。①空白对照组尾静脉注射培养液组+腹腔注射生理盐水。②细胞移植组尾静脉注射许旺细胞。③C5a受体拮抗剂组腹腔注入C5a受体拮抗剂。④联合组尾静脉注射许旺细胞,同时腹腔注入C5a受体拮抗剂。 结果与结论：下肢运动功能评价联合移植组优于细胞移植组和C5a受体拮抗剂组,细胞移植组和C5a受体拮抗剂组优于对照组。细胞移植组和联合组有SRY基因表达。HRP阳性神经纤维数：联合组>胞移植组与C5a受体拮抗剂组>空白对照组,且各组之间差异有显著性意义(P < 0.01)。联合组大鼠体感诱发电位及运动诱发电位的潜伏期、波幅明显优于其他3组(P < 0.05或P < 0.01)。提示许旺细胞移植和C5a受体拮抗剂联合应用可促进脊髓损伤大鼠神经突触的再生,改善其肢体运动功能和电生理功能。     

长托宁联合米非司酮通过下调Wnt/β-catenin通路调节子宫肌瘤大鼠雌激素减轻子宫损伤

目的 探讨长托宁联合米非司酮对子宫肌瘤大鼠子宫损伤的改善作用及可能的机制。方法50只SD大鼠随机分成对照组、模型组、长托宁组、米非司酮组及长托宁联合米非司酮组,每组10只。HE染色观察子宫组织形态学变化;ELISA方法检测血清炎症因子、雌激素和孕激素水平;TUNEL方法检测子宫组织细胞凋亡;Western blot检测Wnt信号通路相关蛋白的表达。结果 与对照组相比,模型组大鼠子宫组织形态学病理变化明显,血清TNF-α水平升高,IL-6和IL-2水平降低,血清雌二醇、孕激素和黄体生成素水平升高;子宫组织细胞凋亡水平降低;Wnt5b和β-catenin蛋白表达水平升高。长托宁联合米非司酮治疗改善子宫肌瘤大鼠子宫组织形态,降低血清TNF-α、雌二醇、孕激素和黄体生成素水平,升高IL-6、IL-2、子宫组织细胞凋亡水平,降低Wnt5b和β-catenin蛋白表达水平。结论 长托宁联合米非司酮减轻子宫肌瘤大鼠子宫损伤,其机制可能与抑制Wnt/β-catenin信号通路有关。     

Pain and Effusion and Quadriceps Activation and Strength

Context:

Quadriceps dysfunction is a common consequence of knee joint injury and disease, yet its causes remain elusive.

Objective:

To determine the effects of pain on quadriceps strength and activation and to learn if simultaneous pain and knee joint effusion affect the magnitude of quadriceps dysfunction.

Design:

Crossover study.

Setting:

University research laboratory.

Patients or Other Participants:

Fourteen (8 men, 6 women; age = 23.6 ± 4.8 years, height = 170.3 ± 9.16 cm, mass = 72.9 ± 11.84 kg) healthy volunteers.

Intervention(s):

All participants were tested under 4 randomized conditions: normal knee, effused knee, painful knee, and effused and painful knee.

Main Outcome Measure(s):

Quadriceps strength (Nm/kg) and activation (central activation ratio) were assessed after each condition was induced.

Results:

Quadriceps strength and activation were highest under the normal knee condition and differed from the 3 experimental knee conditions (P < .05). No differences were noted among the 3 experimental knee conditions for either variable (P > .05).

Conclusions:

Both pain and effusion led to quadriceps dysfunction, but the interaction of the 2 stimuli did not increase the magnitude of the strength or activation deficits. Therefore, pain and effusion can be considered equally potent in eliciting quadriceps inhibition. Given that pain and effusion accompany numerous knee conditions, the prevalence of quadriceps dysfunction is likely high.Key Words: arthrogenic muscle inhibition, central activation failure, voluntary activation, muscles

Key Points

• Knee pain and effusion resulted in arthrogenic muscle inhibition and weakness of the quadriceps.
• The simultaneous presence of pain and effusion did not increase the magnitude of quadriceps dysfunction.
• To reduce arthrogenic muscle inhibition and improve muscle strength, clinicians should employ interventions that target removing both pain and effusion.

Quadriceps weakness is a common consequence of traumatic knee joint injury^1,2 and chronic degenerative knee joint conditions.^3,4 Arthrogenic muscle inhibition (AMI), a neurologic decline in muscle activation, results in quadriceps weakness and hinders rehabilitation by preventing gains in strength.⁵ The inability to reverse AMI and restore muscle function can lead to decreased physical abilities,⁶ biomechanical deficits,⁷ and possibly reinjury.⁵ Furthermore, researchers^8,9 have suggested that quadriceps weakness resulting from AMI may place patients at risk for developing osteoarthritis in the knee. In light of the substantial influence of quadriceps AMI on these clinically relevant outcomes, we need to improve our understanding of the factors that contribute to this neurologic decline in muscle activity so efforts to target and reverse it can be implemented and gains in strength can be achieved more easily.Joint injury and disease are accompanied by numerous sequelae (ie, pain, swelling, tissue damage, inflammation), so ascertaining which one ultimately leads to neurologic muscle dysfunction is difficult. Whereas a joint effusion can result in AMI,^10–12 the effects of pain are less understood despite many clinicians attributing AMI to pain. Using techniques that introduce knee pain without accompanying injury may provide insights into the role of pain in eliciting AMI.The degree of knee joint damage may play a role in the quantity of AMI that manifests. Hurley et al^13,14 demonstrated that quadriceps AMI, measured using an interpolated-twitch technique, was greater in patients with extensive traumatic knee injury (eg, fractured tibial plateau, ruptured medial collateral ligament, and medial meniscectomy) than patients with isolated joint trauma (ie, isolated anterior cruciate ligament [ACL] rupture). Similarly, patients with more knee joint symptoms (ie, greater number of symptoms and increased severity of symptoms) may present with greater magnitudes of quadriceps inhibition. Recently, investigators¹⁵ have suggested that patients with more pain display less quadriceps strength, supporting this tenet. Given that effusion and pain often present simultaneously with joint injuries and diseases, such as ACL injury and osteoarthritis, examining both the isolated and cumulative effects of these sequelae appears warranted to determine if they influence the magnitude of muscle inhibition.Experimental joint-effusion and pain models are safe and effective experimental methods that allow for the isolated examination of their effects on muscle function. The effusion model, whereby sterile saline is injected directly into the knee joint capsule,⁷ produces a clinically relevant magnitude of the joint effusion that may be present with traumatic injury. Effusion is thought to activate group II afferents responding to stretch or pressure,^16–18 which in turn may facilitate group Ib interneurons and result in quadriceps AMI.⁵ The pain model involves injecting hypertonic saline into the infrapatellar fat pad to produce anteromedial knee pain similar to that described in patients with patellofemoral pain syndrome.¹⁹ Pain is considered to initiate AMI through activation of group III and IV afferents that act as nocioceptors to signal damage or potential damage to joint structures.^16–18 The firing of these afferents then may lead to facilitation of group Ib interneurons, the flexion reflex, or the gamma loop, ultimately resulting in quadriceps inhibition.²⁰ Thus, these models allow us to create symptoms that are associated with knee injury and have the added benefit of providing a way to examine their effects in isolation.Therefore, the purpose of our study was to determine the effects of pain on quadriceps strength and activation and to learn if simultaneous pain and knee joint effusion would affect the magnitude of quadriceps dysfunction. We hypothesized that pain alone would result in quadriceps inhibition and that the magnitude of inhibition would be greater when effusion and pain were present simultaneously.     

即早基因c-fos与脑血管病及学习记忆

即早基因c-fos是广泛存在于原核细胞和真核细胞的高度保守基因.在正常情况下,c-fos基因参与细胞生长、分化、信息传递、学习和记忆等生理过程,而在病理情况下c-fos基因表达及调控变化与多种疾病的发生和发展有关.C-fos在中枢神经系统的某些部位可有基础水平的表达,但表达很低,当受到如脑缺血、脑出血、痫性发作、应激等刺激后,其在数十分钟内做出反应,在对外界刺激-转录耦联的信忠传递过程中起着核内第三信使的重要作用.     

Opportunities and challenges in the prevention and control of cancer and other chronic diseases: children's diet and nutrition and weight and physical activity

OBJECTIVE: The purpose of this article is to review the role of behavioral research in disease prevention and control, with a particular emphasis on lifestyle- and behavior-related cancer and chronic disease risk factors--specifically, relationships among diet and nutrition and weight and physical activity with adult cancer, and tracking developmental origins of these health-promoting and health-compromising behaviors from childhood into adulthood. METHOD: After reviewing the background of the field of cancer prevention and control and establishing plausibility for the role of child health behavior in adult cancer risk, studies selected from the pediatric published literature are reviewed. Articles were retrieved, selected, and summarized to illustrate that results from separate but related fields of study are combinable to yield insights into the prevention and control of cancer and other chronic diseases in adulthood through the conduct of nonintervention and intervention research with children in clinical, public health, and other contexts. RESULTS: As illustrated by the evidence presented in this review, there are numerous reasons (biological, psychological, and social), opportunities (school and community, health care, and family settings), and approaches (nonintervention and intervention) to understand and impact behavior change in children's diet and nutrition and weight and physical activity. CONCLUSIONS: Further development and evaluation of behavioral science intervention protocols conducted with children are necessary to understand the efficacy of these approaches and their public health impact on proximal and distal cancer, cancer-related, and chronic disease outcomes before diffusion. It is clear that more attention should be paid to early life and early developmental phases in cancer prevention.