Cysteine Cathepsins in the secretory vesicle produce active peptides: Cathepsin L generates peptide neurotransmitters and cathepsin B produces beta-amyloid of Alzheimer's disease

Recent new findings indicate significant biological roles of cysteine cathepsin proteases in secretory vesicles for production of biologically active peptides. Notably, cathepsin L in secretory vesicles functions as a key protease for proteolytic processing of proneuropeptides (and prohormones) into active neuropeptides that are released to mediate cell-cell communication in the nervous system for neurotransmission. Moreover, cathepsin B in secretory vesicles has been recently identified as a β-secretase for production of neurotoxic β- amyloid (Aβ) peptides that accumulate in Alzheimer's disease (AD), participating as a notable factor in the severe memory loss in AD. These secretory vesicle functions of cathepsins L and B for production of biologically active peptides contrast with the well-known role of cathepsin proteases in lysosomes for the degradation of proteins to result in their inactivation. The unique secretory vesicle proteome indicates proteins of distinct functional categories that provide the intravesicular environment for support of cysteine cathepsin functions. Features of the secretory vesicle protein systems insure optimized intravesicular conditions that support the proteolytic activity of cathepsins. These new findings of recently discovered biological roles of cathepsins L and B indicate their significance in human health and disease. This article is part of a Special Issue entitled: Proteolysis 50 years after the discovery of lysosome.     

Molecular genetics of schizophrenia: past, present and future

Schizophrenia is a severe neuropsychiatric disorder with a polygenic mode of inheritance which is also governed by non-genetic factors. Candidate genes identified on the basis of biochemical and pharmacological evidence are being tested for linkage and association studies. Neurotransmitters, especially dopamine and serotonin have been widely implicated in its etiology. Genome scan of all human chromosomes with closely spaced polymorphic markers is being used for linkage studies. The completion and availability of the first draft of Human Genome Sequence has provided a treasure-trove that can be utilized to gain insight into the so far inaccessible regions of the human genome. Significant technological advances for identification of single nucleotide polymorphisms (SNPs) and use of microarrays have further strengthened research methodologies for genetic analysis of complex traits. In this review, we summarize the evolution of schizophrenia genetics from the past to the present, current trends and future direction of research.     

Protease Pathways in Peptide Neurotransmission and Neurodegenerative Diseases

1. Recent research demonstrates the critical importance of neuroproteases for the production of peptide neurotransmitters, and for the production of toxic peptides in major neurodegenerative diseases that include Alzheimer's (AD) and Huntington's diseases. This review describes the strategies utilized to identify the appropriate proteases responsible for producing active peptides for neurotransmission, with application of such approaches for defining protease mechanisms in neurodegenerative diseases.2. Integration of multidisciplinary approaches in neurobiology, biochemistry, chemistry, proteomics, molecular biology, and genetics has been utilized for neuroprotease studies. These investigations have identified secretory vesicle cathepsin L for the production of the enkephalin opioid peptide neurotransmitter and other neuropeptides. Furthermore, new results using these strategies have identified secretory vesicle cathepsin B for the production of β-amyloid (Aβ) in the major regulated secretory pathway that provides activity-dependent secretion of Aβ peptides, which accumulate in AD.3. CNS neuroproteases that participate in peptide neurotransmission and in neurodegenerative diseases represent new candidate drug targets that may be explored in future research for the development of novel therapeutic agents for neurological conditions.     

雌激素对情绪的影响：心理、神经、内分泌研究

雌激素通过复杂的生理和心理学机制对中枢神经系统施加影响.生理学方面包括：雌激素在杏仁核、海马和前额叶等这些与情绪认知相关的重要脑区内影响神经递质的产生和效能;雌激素可以作用于下丘脑-垂体-肾上腺轴,改变情绪性行为;雌激素受体的基因转录也可以调节情绪性行为的变化.雌激素也通过神经心理学的因素影响情绪加工：雌激素可以提高情绪编码技能,提升表情识别的准确性;雌激素能够影响情绪的唤醒,改变个体情绪体验的强度.未来的研究要融合心理、神经和内分泌等各种因素,以解决女性情绪障碍这一难题.     

灵孢多糖辅助治疗抑郁症的作用及机制

目的：建立大鼠抑郁模型,研究和探讨灵孢多糖注射液辅助治疗抑郁症的作用及机制。方法：将48只SD大鼠随机分为正常组、抑郁组、生理盐水组及灵孢多糖（低剂量、中剂量、高剂量）治疗组各8只。应用慢性应激刺激的方法诱导抑郁组、生理盐水组、灵孢多糖治疗组大鼠抑郁,通过行为学指标评估建模是否成功。建模成功后,在生理盐水组中注射生理盐水;在灵孢多糖治疗组中分别注射低、中、高剂量灵孢多糖注射液,比较各组间的疗效差异。采用免疫组化的方法测定大鼠脑内多巴胺、去甲肾上腺素、5-羟色胺、酪氨酸羟化酶等单胺类神经递质含量的表达情况。结果：成功的建立了大鼠抑郁模型,抑郁组中大鼠各项行为学指标与正常组相比均明显减少,差异有统计学意义（P〈0．05）;灵孢多糖治疗组大鼠脑内的多巴胺、去甲肾上腺素、5一羟色胺、酪氨酸羟化酶与抑郁组、生理盐水组大鼠脑内的含量均明显升高,差异有统计学意义（P〈0．05）。结论：灵孢多糖注射液对改善抑郁症状有良好的疗效,具有辅助治疗抑郁症的作用。     

缺氧小鼠脑中神经节苷脂和单胺类神经递质水平

脑缺氧和缺氧后的再灌注常导致一系列复杂的生理生化改变．通过小鼠重复缺氧后,观察其脑组织中的神经节苷脂和单胺类递质水平变化情况,发现重复缺氧时,随着缺氧次数的增加,a．神经节苷脂水平（以唾液酸含量表示）非常明显地持续下降(P<0.01),其中GM1与GD1b相对组分百分比值下降尤为突出(GM1:P<0.05,GD1b:P<0.01); b.单胺类神经递质中NE和DOPA水平下降,DA和HIAA水平升高(P<0.01)．结果提示脑组织经重复缺氧后,中枢神经组织细胞膜受到一定程度的损伤,其结果可能影响到单胺类神经递质的合成、释放、重摄取和贮存的全过程;据此推测脑组织缺氧时神经节苷脂与单胺类神经递质水平改变时存在着相互联系．     

妊娠期给予可卡因对母体和胎儿的影响: 小鼠动物模型

探讨妊娠期给予可卡因对母体和胎儿的影响。妊娠小鼠分为3组：可卡因注射组（每日两次注射盐酸可卡因10mg/kg,COC);盐水对照组（每日两次注射生理盐水10ml/kg,SAL);饮食对照组（每日两次注射生理盐水10ml/kg,饮食参考可卡因给药组,SPF）。用高压液相色谱分析法检测胎鼠血中可卡因浓度及纹状体中神经递质多巴胺和5－羟色胺的含量,并结合HE染色观察胎鼠肝脏和胎盘的形态学改变。尽管COC和SPF组母鼠摄食量和体重增长量均降低,但是仅仅COC组胎鼠的体重和脑重减少。高压液相色谱分析结果显示,在COC组胎鼠血浆中可检测出可卡因,并伴有纹状体神经递质含量的异常增高。同时,也观察到了COC组胎盘和肝脏的形态学变化。本研究表明,妊娠期给予可卡因能引起妊娠母体营养不良,子代脑、肝脏和胎盘发育异常;可卡因引起的胎儿发育异常是由可卡因的毒性作用而不是母体营养不良产生的。     

通督调神针法联合丹参川芎嗪注射液对脑卒中后抑郁患者血清神经营养指标和单胺类神经递质的影响

摘要 目的：探讨丹参川芎嗪注射液联合通督调神针法对脑卒中后抑郁（PSD）患者血清神经营养指标和单胺类神经递质的影响。方法：病例选取自2020年3月-2021年9月期间东莞市中医院针灸科收治的98例PSD患者,入选的患者根据随机数字表法分为对照组（丹参川芎嗪注射液治疗,49例）和研究组（通督调神针法联合丹参川芎嗪注射液治疗,49例）,两组均治疗6周。观察两组治疗6周后的临床疗效,对比两组中医证候积分、汉密尔顿抑郁量表（HAMD）-17、巴氏指数（BI）、血清神经营养指标[胰岛素样生长因子-1（IGF-1）、脑源性神经营养因子（BDNF）]和单胺类神经递质[去甲肾上腺素（NE）、5-羟色胺（5-HT）和多巴胺（DA）]变化,记录两组不良反应发生率。结果：研究组的临床总有效率为91.84%（45/49）,优于对照组的67.35%（33/49）,差异有统计学意义（P<0.05）。研究组治疗6周后中医证候总积分、HAMD-17评分低于对照组,BI评分高于对照组（P<0.05）。研究组治疗6周后IGF-1低于对照组,BDNF高于对照组（P<0.05）。研究组治疗6周后NE、5-HT、DA高于对照组（P<0.05）。两组不良反应发生率对比无统计学差异（P>0.05）。结论：通督调神针法联合丹参川芎嗪注射液治疗PSD患者,可促进症状改善,调节神经营养指标,促进单胺类神经递质表达,是一种安全有效的治疗方案。     

Effects of long-term recovery from transient cerebral ischemia in rat brain: Tissue levels of acetylcholine,monoamines, and their metabolites

Concentrations of acetylcholine and the monoaminergic neurotransmitters dopamine, serotonin and their respective metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), 4-hydroxy-3-methoxyphenylacetic acid (HVA), 5-hydroxyindolacetic acid (5-HIAA) and choline were simultaneously determined in the corpus striatum of rats after 15 min. complete cerebral ischemia (CCI) and in different intervals (1, 24, 48, 72, 96 hours) of postischemic cerebral reperfusion. Results were compared to respective sham-operated control animals. After 15 min. CCI acetylcholine concentration decreased to 15%, and dopamine concentration to 56% of the control values. The metabolite levels of DOPAC decreased to 40% and HVA to 64% of the control values. Acetylcholine, dopamine, serotonin and choline concentrations were not changed significantly after reperfusion. The metabolites HVA and 5-HIAA showed their maximum increases after 1 and 24 hours of reperfusion, additionally HVA was decreased both, after 72 and 96 hours of reperfusion. The data indicate that surprisingly little permanent damage could be caused by a 15 min. ischemia in the striatum. Tissue levels of the neurotransmitters appeared differentially altered but similarly regulated during ischemia and subsequent recirculation. Acetylcholine and dopamin levels decreased profoundly during ischemia. However, acetylcholine levels could be compensated rapidly during reperfusion, whereas the dopaminergic system showed a long-lasting change in its turnover rate. Although serotonin levels were unaffected by CCI, there was an increase of its presumed turnover rate during reperfusion.     

Glutamate uptake system in the presynaptic vesicle: Glutamic acid analogs as inhibitors and alternate substrates

A variety of naturally occurring amino acids, their isomers, and synthetic analogs were tested for their ability to inhibit uptake of [³H]glutamate into presynaptic vesicles from bovine cerebral cortex. Strongest inhibition (K_i<1mM) was observed fortrans-1-aminocyclopentane-1,3-dicarboxylic acid (t-ACPD) anderythro-4-methyl-L-glutamic acid (MGlu), while 4-methylene-L-glutamic acid (MeGlu) was only moderately inhibitory (Ki=3mM), indicating that the synaptic vesicle glutamate translocator has higher affinity forrans-ACPD and MGlu than for glutamate. A few other amino acids, e.g., 4-hydroxyglutamic acid, S-carboxyethyl cysteine, and 5-fluorotryptophan, were slightly inhibitory; alll- anddl-isomers of protein amino acids and longer chain acidic amino acids were without measurable inhibition. Potassium tetrathionate and S-sulfocysteine exhibited strong to moderate noncompetitive or irreversible inhibition. Inhibition by t-ACPD, MGlu, or MeGlu was competitive with glutamic acid. Each of these competitive inhibitors was also taken up by the vesicle preparation in an ATP-dependent manner, as indicated by their being recovered unchanged from filtered vesicles. Similar results were obtained with reconstituted vesicles, while glutamate uptake by partially purified rat synaptosomes was inhibited only by MGlu. These results indicate that the glutamate translocator of presynaptic vesicles has stringent structural requirements distinct from those of the plasma membrane translocator and the metabotropic type of postsynaptic glutamate receptor. They further suggest possible structural requirements of pharmacologically significant compounds that can substitute for glutamic acid in the presynaptic side of glutamatergic synapses, thus serving to moderate or control glutamate excitation and associated excitotoxic effects in these neurons.Special issue dedicated to Dr. Paul Greengard