Obstructive Jaundice Results in Increased Liver Expression of Uncoupling Protein 2 and Intact Skeletal Muscle Glucose Metabolism in the Rat

Background: A majority of patients with pancreatic cancer have obstructive jaundice and diabetes with skeletal muscle insulin resistance. Surgery for these patients is associated with significant morbidity. Uncoupling protein 2 (UCP2) has been proposed to regulate energy expenditure and promote liver vulnerability. The effects of obstructive jaundice on muscle glucose metabolism and expression of UCP2 in liver and muscle are unknown. Methods: Rats were operated with bile duct ligation (BDL). After 7 days, UCP2 mRNA levels were determined in liver and muscle. Simultaneously, insulin-stimulated glucose transport and glycogen synthesis in skeletal muscle were analyzed in vitro. Results: The jaundiced rats lost more weight than pair-fed controls. UCP2 mRNA levels were increased 5-fold in liver but not in muscle in jaundiced rats compared to pair-fed controls. The jaundiced rats were hypoglycemic and hypoinsulinemic but demonstrated intact or enhanced insulin action on skeletal muscle glucose transport and glycogen synthesis in vitro. Muscle glycogen content was increased in the jaundiced rats. Conclusions: Experimental obstructive jaundice in the rat is associated with increased liver expression of UCP2, rapid weight loss, and intact insulin action on skeletal muscle glucose metabolism. Obstructive jaundice, by upregulated liver UCP2, may contribute to the cachexia and high surgical morbidity observed in these patients, but not to skeletal muscle insulin resistance in pancreatic cancer patients.     

肌糖原合成酶基因多态性与糖尿病及其合并高血压的关系

目的研究肌糖原合成酶基因与非胰岛素依赖型糖尿病（ＮＩＤＤＭ）及其合并高血压的关系。方法采用限制性内切酶Ｘｂａｌ对肌糖原合成酶基因片段的聚合酶链反应（ＰＣＲ）产物酶解的方法，观察１６４例ＮＩＤＤＭ（包括６２例合并高血压病人）的糖原合成酶基因多态性。结果肌糖原合成酶基因型（Ａ１／Ａ１，Ａ１／Ａ２）和等位基因（Ａ１，Ａ２）均与ＮＩＤＤＭ无关，而ＮＩＤＤＭ合并高血压者Ａ２等位基因频率明显高于血压正常的ＮＩＤＤＭ者（Ｐ＜０．０５）。结论糖原合成酶基因多态性作为一种标志，提示与其连锁的基因可能参与ＮＩＤＤＭ病人的高血压的发病。     

奥曲肽诱导人结肠癌细胞凋亡与细胞周期的影响及机制

目的:探讨奥曲肽诱导人结肠癌细胞凋亡与细胞周期的影响及机制。方法:奥曲肽、GSK-3β抑制剂Li Cl单独或联合作用于人结肠癌SW480细胞后,用流式细胞术检测SW480细胞的凋亡与细胞周期,以及用DNA凝胶电泳实验进一步验证细胞凋亡;Western blot检测SW480细胞中GSK-3β、p-GSK3-β(Tyr216)及p-GSK-3β(Ser9)蛋白表达。结果:与未处理的空白对照组SW480比较,奥曲肽处理SW480细胞后,细胞凋亡率与G0/G1细胞明显升高,凝胶电泳出现典型的"梯形"DNA条带,总GSK-3β蛋白与p-GSK3β(Tyr216)表达明显上调,而p-GSK3β(Ser9)蛋白表达明显下降(均P<0.05);Li Cl单独作用对SW480细胞的凋亡与细胞周期无明显影响(均P>0.05),但与奥曲肽联合作用能明显削弱奥曲肽对SW480的促凋亡与细胞周期阻滞作用(均P<0.05)。结论:奥曲肽能有效诱导SW480细胞凋亡与细胞周期阻滞,该作用可能与其上调GSK-3β蛋白的表达,并调节GSK-3β蛋白的磷酸化水平有关。     

清心开窍方对APP/PS1双转基因小鼠学习记忆及海马CA1区Akt、GSK3α、βAPP、Aβ表达的影响

目的:探讨清心开窍方对APP/PS1双转基因小鼠学习记忆能力、海马CA1区神经元形态学的改变,以及对Akt、GSK3α、βAPP、Aβ蛋白表达的影响。方法:选取50只3月龄雄性APP/PS1双转基因小鼠,随机分为模型组、多奈哌齐组(1.67 mg·kg^-1)、清心开窍方高、中、低剂量组(每日给药剂量分别为19、9.5、4.75 g·kg^-1),另取10只同背景同性别同月龄的C57BL/6J小鼠作为对照组,对照组、模型组给予等体积生理盐水灌胃,1次/d,连续灌胃12周。采用Morris水迷宫检测小鼠空间学习记忆能力,透射电镜观察小鼠海马CA1区神经元超微结构,尼氏染色法观察小鼠海马CA1区神经元损伤情况,免疫组织化学染色法检测海马CA1区Akt、GSK3α、βAPP、Aβ蛋白的表达情况。结果:与对照组比较,模型组APP/PS1双转基因小鼠逃避潜伏期延长(P<0.01),穿台次数减少,其海马CA1区神经元超微结构出现严重损伤,锥体细胞数量减少,排列紊乱,尼氏体着色变浅,Akt蛋白表达减少(P<0.01),GSK3α、βAPP、Aβ表达增加(P<0.01);与模型组比较,清心开窍方干预组逃避潜伏期均明显缩短(P<0.01),穿台次数增多,同时比较小鼠在原平台停留的时间和路程百分比均明显增加(P<0.05;P<0.01),其神经元结构较完整,核膜清晰,胞浆内核糖体丰富,线粒体数量增多,且嵴结构完整,锥体细胞数量增多,排列紧密,尼氏体着色较深,同时Akt蛋白表达增加(P<0.01;P<0.05),GSK3α、βAPP、Aβ表达减少(P<0.01;P<0.05)。结论:清心开窍方能够改善APP/PS1双转基因小鼠的学习记忆能力,其机制可能与Akt/GSK3α介导的信号通路相关,它能够激活Akt,抑制GSK3α,降低βAPP、Aβ的生成,减少神经元损伤。     

糖原累积病Ⅵ型和Ⅸa型7例病例报告并文献复习

目的总结糖原累积病(GSD)Ⅵ、Ⅸa型的临床、病理和基因突变情况,提高临床对这两型GSD的认识。方法回顾性收集GSD3例Ⅵ型和4例Ⅸa型患儿的临床资料。结果 (1)7例患儿均为男性,确诊年龄2岁3月至5岁。7例均有肝脏肿大和转氨酶升高,身材矮小1例,空腹低血糖、高乳酸血症和高甘油三酯血症各2例,血酮体增高3例,尿有机酸分析结果阳性2例。7例患儿均有肝细胞弥漫性肿大变形和糖原凝聚,4例有肝脏脂肪变性;3例GSDⅥ型有门管区纤维化、肝硬化表现。3例GSDⅥ型检测到6种PYGL基因突变,c.772+1GA、c.244-1GA、c.730CT(p.L244F)、c.2417_2418del TA(p.I806Sfs X9)为新突变,4例GSDⅨa型检测到4种PHKA2基因突变,c.3529CT(p.Q1177X)、c.3574CT(p.Q1196X)为新突变。(2)复习文献共检索到13篇文献,与本文病例合并后共22例Ⅵ型、99例Ⅸa型GSD。肝脏转氨酶增高和肝脏肿大91.9%~100%,有身材矮小18%~23%、空腹低血糖44%~48%、高甘油三酯血症37%~44%、高乳酸血症35%~72%和血酮体增高50%~56%。肝脏活检均可见肝细胞内糖原凝聚,17%有脂肪变性,Ⅵ型25%、Ⅸa型33%检出肝硬化。报道19种PYGL基因突变,多为点突变,剪切位点突变亦较常见,插入突变少见;43种PHKA2基因突变,突变类型多样。结论肝大伴转氨酶升高的患儿需警惕Ⅵ、Ⅸa型GSD;Ⅵ型患儿可早期存在肝硬化,需要进一步随访。     

Type I glycogen storage disease: Kidney involvement,pathogenesis and its treatment

Type I glycogen storage disease (GSD-I) is due to the deficiency of glucose-6-phosphatase activity in the liver, kidney and intestine. Although kidney enlargement occurs in GSD-I, renal disease has not been considered a major problem until recently. In older patients (more than 20 years of age) whose GSD-I disease has been ineffectively treated, virtually all have disturbed renal function, manifested by persistent proteinuria; many also have hypertension, renal stones, altered creatinine clearance or a progressive renal insufficiency. Glomerular hyperfiltration is seen in the early stage of the renal dysfunction and can occur before proteinuria. In younger GSD-I patients, the hyperfiltration is usually the only renal abnormality found; and, in some patients, microalbuminuria develops before clinical proteinuria. The predominant underlying renal pathology is focal segmental glomerulosclerosis. Renal stones and/or nephrocalcinosis are also common findings. Amyloidosis and Fanconi-like syndrome can occur, but rarely. The risk factors for developing the glomerulosclerosis in GSD-I include hyperfiltration, hypertension, hyperlipidemia and hyperuricemia. Dietary therapy with cornstarch and/or nasogastric infusion of glucose, aimed at maintaining normoglycemia, corrects metabolic abnormalities and improves the proximal renal tubular function. Long-term trial will be needed to assess whether the dietary therapy may prevent the evolution or the progression of the renal disease.     

Regulation of glycogen content in rat pineal gland by norepinephrine

In the rat pineal gland the glycogen stores were cytochemically localized in astrocytes and pinealocytes. Moreover, it was found that norepinephrine (NE) induced a time- and concentration-dependent reduction in pineal glycogen content and yielded lactic acid. The NE effect was prevented by blocking ₁- but not ₂ or β-adrenoceptors. Activation of ₂-adrenoceptors induced a small decrease in glycogen levels that could have pre- and postsynaptic components. Activation of β-adrenoceptors with 10⁻¹²–10⁻³ M isoproterenol (ISO) induced a bell shape concentration-response curve, presumably due to desensitization, since the response induced by 10⁻⁴ M ISO was greater with shorter period of stimulation. On the other hand, activation of ₁-adrenoceptors with 10⁻¹²–10⁻³ M phenylephrine (PHN) induced a hyperbolic concentration-response curve with a maximum at concentrations above 10⁻⁸ M. Moreover, treatment with ISO drastically reduced the response induced by PHN concentrations lower but not higher than 10⁻⁶ M, favoring a concentration-dependent response between 10⁻⁶ and 10⁻⁴ M PHN, similar to that induced by equimolar NE concentrations. Thus, the NE-induced reduction in glycogen content of the rat pineal gland is mainly mediated by ₁-adrenoceptors and modulated by intracellular mechanisms activated by β-adrenoceptors.     

A complex rearrangement in GBE1 causes both perinatal hypoglycemic collapse and late-juvenile-onset neuromuscular degeneration in glycogen storage disease type IV of Norwegian forest cats

Deficiency of glycogen branching enzyme (GBE) activity causes glycogen storage disease type IV (GSD IV), an autosomal recessive error of metabolism. Abnormal glycogen accumulates in myocytes, hepatocytes, and neurons, causing variably progressive, benign to lethal organ dysfunctions. A naturally occurring orthologue of human GSD IV was described previously in Norwegian forest cats (NFC). Here, we report that while most affected kittens die at or soon after birth, presumably due to hypoglycemia, survivors of the perinatal period appear clinically normal until onset of progressive neuromuscular degeneration at 5 months of age. Molecular investigation of affected cats revealed abnormally spliced GBE1 mRNA products and lack of GBE cross-reactive material in liver and muscle. Affected cats are homozygous for a complex rearrangement of genomic DNA in GBE1, constituted by a 334 bp insertion at the site of a 6.2 kb deletion that extends from intron 11 to intron 12 (g. IVS11+1552_IVS12-1339 del6.2kb ins334 bp), removing exon 12. An allele-specific, PCR-based test demonstrates that the rearrangement segregates with the disease in the GSD IV kindred and is not found in unrelated normal cats. Screening of 402 privately owned NFC revealed 58 carriers and 4 affected cats. The molecular characterization of feline GSD IV will enhance further studies of GSD IV pathophysiology and development of novel therapies in this unique animal model.