普萘洛尔和恬尔心对脂蛋白代谢的影响

用体外培养人脐静脉内皮细胞单层(EC)观察普茶洛尔、恬尔心对脂蛋白代谢的影响.将等量的高脂蛋白血清分别与两药混合后加于内皮细胞单层培养基上孵化10h,取培养上清液检测甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)、极低密度脂蛋白(VLDL).结果显示:普茶洛尔显著降低LDL水平(P<0.01),对脂蛋白代谢产生有益影响.恬尔心显著降低TG水平(P<0.05),同时亦降低HDL水平(P<0.01),其对脂蛋白代谢的作用尚难评估.     

胆宁片对胆囊胆固醇结石的防治作用

目的：研究胆宁片对胆囊胆固醇结石有无防治作用并初步探讨其机制。方法：豚鼠120只随机均分为4组：胆宁片组建立胆囊胆固醇结石模型后给予胆宁片,同时与熊去氧胆酸(UDCA)组及空白组、致石组对照,测定血、胆汁生化及肝、胆囊病理。结果：胆宁片组成石率为17％显著低于致石组的73％．其致石指数(LI)及血甘油三酯(TG)与肝脂肪变性显著低于致石组。结论：胆宁片对胆囊胆固醇结石有良好的防治作用并可缓解肝脂肪变性。     

低剂量替格瑞洛对稳定性冠心病患者冠脉微循环及外周血MHR、NLR的影响

目的 探讨低剂量替格瑞洛对稳定性冠心病(stable coronary heart disease,SCAD)患者冠脉微循环及外周血单核细胞/高密度脂蛋白胆固醇比值（monocyte/high-density lipoprotein cholesterol ratio,MHR）、中性粒细胞/淋巴细胞比值（neutrophil/lymphocyte ratio,NLR）的影响。方法 将2019年1月-2021年2月在南京脑科医院（胸科院区）就诊的SCAD患者138例,按照随机数表法分成A、B、C三组,每组46例,三组患者采取不同抗血小板策略,A组单纯采用阿司匹林治疗,B组采用阿司匹林联合标准剂量替格瑞洛治疗,C组采用阿司匹林联合低剂量替格瑞洛治疗,连续治疗6个月。对比三组患者治疗前后冠脉微循环阻力指数（microcirculatory resistance, IMR）、血小板微颗粒（platelet microparticles, PMPs）及MHR、NLR水平变化情况,三组患者均随访1年,对比三组患者出血情况。结果 治疗后,三组IMR及PMPs水平均较同组治疗前改善,差异有统计学意义（P<0.05）,三组治疗后IMR及PMPs水平比较,差异有统计学意义（P<0.05）,A组IMR及PMPs水平改善程度优于B、C组,差异有统计学意义（P<0.05）,B、C两组治疗后IMR及PMPs改善程度比较差异无统计学意义（P>0.05）;治疗后,三组MHR及NLR水平均较同组治疗前改善,差异有统计学意义（P<0.05）,三组治疗后MHR及NLR水平比较,差异有统计学意义（P<0.05）,B、C组MHR及NLR水平改善程度优于A组,差异有统计学意义（P<0.05）,B、C两组治疗后MHR及NLR改善程度比较差异无统计学意义（P>0.05）;随访1年期间,三组患者大出血发生率比较无统计学差异（P>0.05）,小出血发生率存在明显差异（P<0.05）,进一步进行组间两两比较,A组和C组患者小出血发生率低于B组（P<0.05）,但A组和C组患者小出血发生率比较无统计学差异（P>0.05）。结论 综上所述,SCAD患者采用低剂量替格瑞洛,能帮助改善患者冠脉微循环、降低血栓形成风险及炎症状态,与标准剂量达到的效果相似,同时还可降低出血风险。     

Sost downregulation and local Wnt signaling are required for the osteogenic response to mechanical loading

Sclerostin, the Wnt signaling antagonist encoded by the Sost gene, is secreted by osteocytes and inhibits bone formation by osteoblasts. Mechanical stimulation reduces sclerostin expression, suggesting that osteocytes might coordinate the osteogenic response to mechanical force by locally unleashing Wnt signaling. To investigate whether sclerostin downregulation is a pre-requisite for load-induced bone formation, we conducted experiments in transgenic mice (TG) engineered to maintain high levels of SOST expression during mechanical loading. This was accomplished by introducing a human SOST transgene driven by the 8 kb fragment of the DMP1 promoter that also provided osteocyte specificity of the transgene. Right ulnae were subjected to in vivo cyclic axial loading at equivalent strains for 1 min/day at 2 Hz; left ulnae served as internal controls. Endogenous murine Sost mRNA expression measured 24 h after 1 loading bout was decreased by about 50% in TG and wild type (WT) littermates. In contrast, human SOST, only expressed in TG mice, remained high after loading. Mice were loaded on 3 consecutive days and bone formation was quantified 16 days after initiation of loading. Periosteal bone formation in control ulnae was similar in WT and TG mice. Loading induced the expected strain-dependent increase in bone formation in WT mice, resulting from increases in both mineralizing surface (MS/BS) and mineral apposition rate (MAR). In contrast, load-induced bone formation was reduced by 70-85% in TG mice, due to lower MS/BS and complete inhibition of MAR. Moreover, Wnt target gene expression induced by loading in WT mice was absent in TG mice. Thus, downregulation of Sost/sclerostin in osteocytes is an obligatory step in the mechanotransduction cascade that activates Wnt signaling and directs osteogenesis to where bone is structurally needed.     

Receptor activator of NF-κB ligand-dependent expression of caveolin-1 in osteoclast precursors, and high dependency of osteoclastogenesis on exogenous lipoprotein

Although extensive studies have done much to clarify the molecular mechanisms of osteoclastogenesis during the last ten years, there may still be unknown molecules associated with osteoclast differentiation. Thus, we used fluorescent differential display to screen for genes whose expression is induced by receptor activator of NF-κB ligand (RANKL), a crucial molecule for osteoclast formation. We identified caveolin-1 (Cav-1) as a RANKL-induced gene. Cav-1 is a major structural protein of caveolae and lipid rafts, cholesterol-enriched microdomains in the plasma membrane (PM). The RANKL-induced Cav-1 was immediately conveyed to lipid rafts. Conversely, expression of flotillin-1 (Flot-1), another scaffolding protein of lipid rafts, was reduced during osteoclastogenesis, indicating conversion of Flot-1-predominant rafts into Cav-1-enriched rafts. However, in vitro osteoclastogenesis of precursor cells from Cav-1-null mice was comparable to that of wild-type mice, while Cav-2 expression in the knockout osteoclasts was maintained. Conversely, Cav-2 gene silencing in Cav-1-null osteoclast precursors using siRNA for Cav-2 increased osteoclast formation, suggesting that the Cav-1/Cav-2 complex may act as a negative regulator for osteoclastogenesis. On the other hand, destruction of lipid rafts by removal of cholesterol from the PM by methyl-ß-cyclodextrin (MCD) treatment caused disordered signal transductions for osteoclastogenesis, such as hyperactivation of Erk1/2 and insensitivity of Akt to RANKL stimulus. The abnormal signaling was reproduced by deleting exogenous lipoproteins from the culture medium, which also resulted in reduced osteoclast formation. In addition, the deletion caused delayed expression of nuclear factor of activated T cells c1 (NFATc1), and depressed its activation in the cytosol and inhibited its translocation into nuclei. Simultaneously, the deletion reduced the level of FcRγ, a trigger protein for initiating the calcium signaling needed to activate NFATc1, and decreased Cav-1 in lipid rafts. These findings indicate that the molecular mechanisms of osteoclastogenesis are highly dependent on extracellular lipoprotein and the integrity of lipid rafts, and suggest possible involvement of cholesterol.     

辛伐他汀对糖尿病大鼠神经病理性疼痛和全身性炎症的影响及其分子机制

目的 探讨辛伐他汀对糖尿病大鼠神经病理性疼痛及全身性炎症的影响及其机制。方法 采用随机数表法将24只SD大鼠随机分为正常+介质(NV)组、糖尿病+介质(DV)组和糖尿病+辛伐他汀(DS)组3组,每组8只,通过腹腔注射链脲佐菌素建立糖尿病大鼠模型;建模后第7、14、21、28天记录各组大鼠的血糖、体质量、机械性刺激缩足阈值(PWMT)和热刺激缩足反射潜伏期(PWTL);建模后第28天取大鼠腰段脊髓背角和血清,Western blot法检测各组大鼠脊髓背角中晚期糖基化终末产物受体(RAGE)的表达,蛋白激酶B(AKT)、细胞外调节蛋白激酶(ERK)、p38和c-Jun氨基末端激酶(JNK)的磷酸化水平,ELISA法检测各组大鼠血清中氧化型低密度脂蛋白(ox-LDL)和白细胞介素1β(IL-1β)浓度。结果 建模后第14、21、28天,DV组的PWMT值分别为(8.6 ± 0.8)、(7.1 ± 1.6)、(7.8 ± 0.8)g,明显低于NV组的(12.0 ± 0.9)(q =8.482,P =0.000)、(11.6 ± 1.5)(q =11.309,P =0.000)、(11.7 ± 1.5)g(q =9.801,P =0.000);建模后第21、28天,DS组的PWMT值分别为(9.4 ± 1.4)(q =5.780,P=0.000)、(9.7 ± 0.9)g(q =4.775,P=0.003),明显高于DV组。建模后第7、14、21、28天,各组间的PWTL值差异均无统计学意义(P均>0.05)。DV组大鼠脊髓背角中RAGE的表达量明显高于NV组(q =6.299,P =0.000)和DS组(q =2.891,P =0.025);DV组大鼠脊髓背角中AKT磷酸化水平明显高于NV组(q =8.915,P =0.000)和DS组(q =4.103,P =0.003)。DV组大鼠脊髓背角中ERK(q =8.313,P =0.000)、p38蛋白(q =2.965,P=0.022)和JNK(q =7.459,P =0.000)的磷酸化水平明显高于NV组;DS组脊髓背角中JNK的磷酸化水平明显低于DV组(q =3.866,P =0.004),ERK(q =1.987,P =0.122)和p38蛋白的磷酸化水平(q =1.260,P =0.375)与DV组差异无统计学意义。DV组大鼠的血清ox-LDL和IL-1β水平分别为(41.86 ± 13.40)ng/ml和(108.16 ± 25.88)pg/ml,均明显高于NV组的(24.66 ± 7.87)ng/ml(q =3.606,P =0.003)和(49.32 ± 28.35)pg/ml(q =5.079,P =0.000);也明显高于DS组的(18.81 ± 5.62)ng/ml(q =4.833,P =0.000)和(32.73 ± 11.73)pg/ml(q =6.510,P =0.000)。结论 辛伐他汀可在一定程度上提高糖尿病大鼠的机械痛阈,其机制可能与抑制糖尿病大鼠脊髓背角中RAGE/AKT的激活和JNK的磷酸化有关。辛伐他汀还可以显著降低糖尿病大鼠血清中ox-LDL和IL-1β的含量,减轻全身性炎症反应。     

低密度脂蛋白-胆固醇达标的冠心病患者脂蛋白(a)水平与冠脉病变复杂程度的相关性研究

目的:探讨低密度脂蛋白-胆固醇达标的冠心病患者脂蛋白（a）水平与冠脉病变复杂程度的相关性。方法:收集低密度脂蛋白-胆固醇已达标的212例行冠脉造影的冠心病患者临床资料,根据SYNTAX评分将患者分为低危组（0～22分）104例和中高危组（≥23分）108例,采用Pearson相关分析血脂指标与SYNTAX评分的相关性,绘制ROC曲线评估脂蛋白（a）对冠脉病变复杂程度的预测价值并确定最佳临界值。采用多因素Logistic回归分析脂蛋白（a）与冠脉病变复杂程度的关系。结果:中高危组脂蛋白（a）水平高于低危组[28.55（13.98,52.00）nmol/L vs.13.55（8.10,33.60）nmol/L（P <0.01）]。Pearson相关分析显示,脂蛋白（a）水平与SYNTAX评分呈正相关（r =0.235,P <0.01）。ROC曲线显示,脂蛋白（a）预测冠状动脉病变复杂程度的曲线下面积为0.653（95%CI:0.580~0.727,P<0.01）,最佳临界值12.70 nmol/L,灵敏度78.7%,特异度49%。多因素Logistic回归分析结果显示,脂蛋白（a）是冠脉病变复杂程度的独立危险因素（OR=2.734,95%CI:1.358~5.504,P <0.01）。结论:低密度脂蛋白-胆固醇达标的冠心病患者中脂蛋白（a）是冠状动脉病变复杂程度的独立危险因素,为冠心病药物治疗提供了新靶点。     

绞股蓝总苷颗粒改善高脂血症C57BL/6J小鼠脂代谢的研究

为评价绞股蓝总苷颗粒以及其与他汀联用的降血脂作用,采用高脂饲料诱导构建高脂血症C57BL/6J小鼠模型。随机分为空白组、模型组、阳性药组(Lip,10 mg/kg)、绞股蓝总苷颗粒低、中、高剂量组(L、M、H,90,120,180 mg/kg),联合组(Lip+H,180 mg/kg+10 mg/kg)。连续给药4周后检测血脂成分、血清ALT、AST及载脂蛋白B(Apo B)含量,H&E染色观察小鼠肝脏病理变化,利用RT-PCR法和Western blot法测定三磷酸腺苷结合盒转运体A1(ABCA1)、肝X受体(LXRα)、胆固醇7α-羟化酶(CYP7A1)和B族Ι型清道夫受体(SR-BΙ)等肝脏胆固醇代谢关键因子蛋白、基因表达水平。结果显示绞股蓝总苷颗粒能显著降低小鼠体重、腹部脂肪质量及血清总胆固醇(TC)、AST水平,并修复受损小鼠肝细胞;联合组能显著降低小鼠TC水平,效果优于绞股蓝总苷颗粒高剂量组和阳性药单用组。此外,绞股蓝总苷颗粒能显著升高ABCA1的蛋白水平,同时上调ABCA1、CYP7A1和SR-BΙ的基因表达。实验结果表明,绞股蓝总苷颗粒能够显著降低血脂,且与阿托伐他汀联用后降脂效果提高,并可降低血清转氨酶,初步探索其降脂机制可能是通过参与胆固醇逆转运调节TC含量。     

自噬在脂质诱导的肾小管上皮细胞损伤中脂质聚集中的作用

目的初步探讨自噬在脂质诱导的肾小管上皮细胞损伤中脂质聚集中的作用。方法将HK-2细胞培养后,分为4组:0μg/ml组(A组)、20μg/ml组(B组)、50μg/ml组(C组)、100μg/ml组(D组)。分别用0μg/ml、20μg/ml、50μg/ml、100μg/ml低密度脂蛋白(low density lipoprotein,LDL)刺激肾小管上皮细胞24 h,用油红O法检测细胞内中性脂质,通过透射电子显微镜下观察自噬体形成,荧光显微镜下观察LC3-GFP融合蛋白示踪自噬形成,Wester blotting检测LC3-Ⅱ、LC3-Ⅰ蛋白。结果①油红O显示在0~100μg/ml浓度范围内LDL随浓度增高刺激细胞内脂质增多;②电镜显示正常HK-2细胞内可见少许自噬泡,在0~50μg/ml浓度范围内随LDL刺激浓度增加,细胞内自噬泡逐渐增多,但达到一定浓度(即100μg/ml)后自噬泡急剧减少;③正常HK-2细胞内可见少许LC3-GFP染色阳性,在0~50μg/ml浓度范围内随LDL刺激浓度增加,细胞内LC3-GFP染色阳性逐渐增多,但达到一定浓度即100μg/ml后LC3-GFP染色阳性急剧减少;④正常HK-2细胞内存在少量的LC3-Ⅰ和LC3-Ⅱ,但以LC3-Ⅰ为主,在0~50μg/ml浓度范围内随LDL刺激浓度增加,LC3-Ⅰ和LC3-Ⅱ均增加,但LC3-Ⅱ增加更明显,50μg/ml LDL组LC3-Ⅰ是0μg/ml LDL组的2倍,LC3-Ⅱ表达是0μg/ml的3倍,差异有统计学意义(均P0.05),LC3-Ⅱ/LC3-Ⅰ比值逐渐增高,分别为0.41,0.82,1.23,差异有统计学意义(均P0.05),但LDL达到100μg/ml后LC3-Ⅰ和LC3-Ⅱ均急剧减少,100μg/ml LDL组LC3-Ⅰ降至与0μg/ml组LDL相同(P0.05),LC3-Ⅱ表达降至为0μg/ml LDL组的1.5倍,LC3-Ⅱ/LC3-Ⅰ比值也急剧下降至0.52,差异有统计学意义(均P0.05)。结论肾小管上皮细胞内自噬与脂质有一定关系,自噬可能参与脂质诱导的肾小管上皮细胞内脂质聚集。