BDNF或5HTTLPR与抑郁症的研究

抑郁症是以抑郁为主要临床表征的一种精神疾病,近年抑郁症发病率正呈逐年上升趋势,如不加以干预,对患者及患者家庭、社会都会产生重大影响.对于抑郁症发病机制目前尚无定论,现有研究均停留在假说阶段.众多假说中脑源性神经营养因子(BDNF)和5-羟色胺转运体基因连锁多肽性区域(5-HTTLPR)参与抑郁症的病理生理过程,分别发挥重要作用,其基因也是抑郁症的候选基因,本研究对BDNF、5-HTTLPR在抑郁症及抗抑郁治疗等方面的作用进行文献综述.     

Beyond barcoding: A mitochondrial genomics approach to molecular phylogenetics and diagnostics of blowflies (Diptera: Calliphoridae)

Members of the Calliphoridae (blowflies) are significant for medical and veterinary management, due to the ability of some species to consume living flesh as larvae, and for forensic investigations due to the ability of others to develop in corpses. Due to the difficulty of accurately identifying larval blowflies to species there is a need for DNA-based diagnostics for this family, however the widely used DNA-barcoding marker, cox1, has been shown to fail for several groups within this family. Additionally, many phylogenetic relationships within the Calliphoridae are still unresolved, particularly deeper level relationships. Sequencing whole mt genomes has been demonstrated both as an effective method for identifying the most informative diagnostic markers and for resolving phylogenetic relationships. Twenty-seven complete, or nearly so, mt genomes were sequenced representing 13 species, seven genera and four calliphorid subfamilies and a member of the related family Tachinidae. PCR and sequencing primers developed for sequencing one calliphorid species could be reused to sequence related species within the same superfamily with success rates ranging from 61% to 100%, demonstrating the speed and efficiency with which an mt genome dataset can be assembled. Comparison of molecular divergences for each of the 13 protein-coding genes and 2 ribosomal RNA genes, at a range of taxonomic scales identified novel targets for developing as diagnostic markers which were 117–200% more variable than the markers which have been used previously in calliphorids. Phylogenetic analysis of whole mt genome sequences resulted in much stronger support for family and subfamily-level relationships. The Calliphoridae are polyphyletic, with the Polleninae more closely related to the Tachinidae, and the Sarcophagidae are the sister group of the remaining calliphorids. Within the Calliphoridae, there was strong support for the monophyly of the Chrysomyinae and Luciliinae and for the sister-grouping of Luciliinae with Calliphorinae. Relationships within Chrysomya were not well resolved. Whole mt genome data, supported the previously demonstrated paraphyly of Lucilia cuprina with respect to L. sericata and allowed us to conclude that it is due to hybrid introgression prior to the last common ancestor of modern sericata populations, rather than due to recent hybridisation, nuclear pseudogenes or incomplete lineage sorting.     

Kinetic Properties of Bovine Pineal Tryptophan-5-Monooxygenase Activated by an Endogenous Activating Substance

Abstract: We previously reported that an endogenous activating substance different from bovine serum albumin, phospholipids and heparin, exists in the extract from bovine pineal glands and that this substance interacts with tryptophan-5-monooxygenase under reducing conditions with sulfhydryl reagents, to stimulate monooxygenase activity. The present paper reports that the activating substance is of peptide nature; that it is sensitive to trypsin-digestion; and that it does not change the apparent K _m's for substrates, L-tryptophan and oxygen, and coenzyme, reduced biopterin or DMPH₄: but that it increases the V _max 1.5- to 2.3-fold. These results suggest that an activating protein, present in some particles of the cell structure, activates tryptophan-5-monooxygenase under the regulation of a sulfhydryl compound. The apparent K _m's for reduced biopterin and DMPH₄ were 77.2μM and 294 μM, respectively. The apparent K _m's for L-tryptophan and oxygen with reduced biopterin were 15.0 μM and 4.7%, respectively: with DMPH₄, they were 11.0 μM and 8.5%, respectively. Significant inhibition of both L-tryptophan and oxygen was observed with reduced biopterin, but not with DMPH₄ (at the tested concentrations of up to 0.5 MM and 20%, respectively).     

Distribution and characterization of the opioid octapeptide met5-enkephalin-arg6-gly7-leu8 in the gastrointestinal tract of the rat

Summary The distribution and characterization of the opioid octapeptide met⁵-enkephalin-arg⁶-gly⁷-leu⁸ (met⁵-enk-arg⁶-gly⁷-leu⁸) within the gastrointestinal tract of the rat has been determined by immunohistochemistry and radioimmunoassay by use of a newly developed antibody to met⁵-enk-arg⁶-gly⁷-leu⁸. With both techniques, met⁵-enk-arg⁶-gly⁷-leu⁸-immunoreactivity (met⁵-enk-arg⁶-gly⁷-leu⁸IR) was detected in all regions of the gastrointestinal (GI) tract except the esophagus. The highest concentration of immunoreactive met⁵-enk-arg⁶-gly⁷-leu⁸ was observed in the colon, while intermediate concentrations were found in the stomach, duodenum, jejunum, and ileum. Immunostained somata were observed chiefly in the myenteric plexus; immunostained processes were present primarily in the myenteric plexus and the circular muscle layer. This distribution pattern is similar to that previously observed with antiserum to met⁵-enkephalin-arg⁶-phe⁷ (met⁵-enk-arg⁶phe⁷). Chromatographic analysis of met⁵-enk-arg⁶-gly⁷leu⁸-immunoreactive peptides extracted from the GI tract revealed the presence of an immunoreactive peptide of high molecular weight which accounted for approximately three-quarters of met⁵-enk-arg⁶-gly⁷-leu⁸-IR in both stomach and colon. These findings suggest a role for peptides related to the octapeptide met⁵-enk-arg⁶-gly⁷-leu⁸ in the regulation of GI function.     

Selective Staining by the Fluorochrome 5,5'-Diphenyl-9-ethyl-oxacarbocyanine. II. Application to Paraffin Embedded Nervous Tissue

We present a simple and rapid method to label specific structures of neural tissue in paraffin sections. After incubation of deparaffinized sections in the cyanine dye 5,5'-diphenyl-9-ethyl-oxacarbocyanine (DEOC), three different washing and mounting procedures were performed. Incubation in DEOC followed by washes in ethanol and water and mounting in glycerol-gelatin resulted in selective labeling of myelin in the central and peripheral nervous systems. Weak labeling of myelin and axons and staining of nuclei of neurons was seen after incubation in DEOC followed by washes in ethanol and xylene, and mounting in Eukitt. Nuclear proteins, the endoplasmic reticulum and the Golgi apparatus were stained strongly and exclusively after incubation in DEOC, washes in water, ethanol and xylene, and mounting in Eukitt. Thus the absorption pattern of DEOC is changed significantly by solvents applied after the fluorochrome. In any case, fluorescence did not fade even after repeated and intense fluorescence microscopy over a period of 6 months.     

1H, 13C, and 15N resonance assignment of the cAMP-regulated phosphoprotein endosulfine-alpha in free and micelle-bound states

¹³C, ¹⁵N, and ¹H chemical shift assignments are presented for the cAMP-regulated phosphoprotein endosulfine-alpha in its free and micelle-bound states. Secondary chemical shift analysis demonstrates formation of four helices in the micelle-bound state, which are not present in the absence of detergent.     

Crystal structure of Thermus thermophilus Delta1-pyrroline-5-carboxylate dehydrogenase

Delta(1)-pyrroline-5-carboxylate dehydrogenase (P5CDh) plays an important role in the metabolic pathway from proline to glutamate. It irreversibly catalyzes the oxidation of glutamate-gamma-semialdehyde, the product of the non-enzymatic hydrolysis of Delta(1)-pyrroline-5-carboxylate, into glutamate with the reduction of NAD(+) into NADH. We have confirmed the P5CDh activity of the Thermus thermophilus protein TT0033 (TtP5CDh), and determined the crystal structure of the enzyme in the ligand-free form at 1.4 A resolution. To investigate the structural basis of TtP5CDh function, the TtP5CDh structures with NAD(+), with NADH, and with its product glutamate were determined at 1.8 A, 1.9 A, and 1.4 A resolution, respectively. The solved structures suggest an overall view of the P5CDh catalytic mechanism and provide insights into the P5CDh deficiencies in the case of the human type II hyperprolinemia.     

Inhibition of D-serine accumulation in the Xenopus oocyte by expression of the rat ortholog of human 3'-phosphoadenosine 5'-phosphosulfate transporter gene isolated from the neocortex as D-serine modulator-1

D-serine in mammalian brains has been suggested to be an endogenous co-agonist of the NMDA-type glutamate receptor. We have explored the molecules regulating D-serine uptake and release from the rat neocortex cDNA library using a Xenopus oocyte expression system, and isolated a cDNA clone designated as dsm-1 (D-serine modulator-1) encoding a protein that reduces the accumulation of D-serine to the oocyte. dsm-1 is the rat orthologue of the human 3'-phosphoadenosine 5'-phosphosulfate transporter 1 (PAPST1) gene. The hydropathy analysis of the deduced amino acid sequence of the Dsm-1 protein predicts the 10 transmembrane domains with a long hydrophobic stretch in the C-terminal like some amino acid transporters. The dsm-1 mRNA is predominantly expressed in the forebrain areas that are enriched with D-serine and NMDA receptors, and in the liver. The transient expression of dsm-1 in COS-7 cells demonstrates a partially Golgi apparatus-related punctuate distribution throughout the cytoplasm with a concentration near the nucleus. dsm-1-expressing oocytes diminishes the sodium-dependent and -independent accumulation of D-serine and the basal levels of the intrinsic D-serine and increases the rate of release of the pre-loaded D-serine. These findings indicate that dsm-1 may, at least in part, be involved in the D-serine translocation across the vesicular or plasma membranes in the brain, and thereby control the extra- and intracellular contents of D-serine.     

Effect of an epoxy derivative of 2′5′-trioligoadenylate on human neuroblastoma cells

We studied the effect of an epoxy derivative of dephosphorylated 2′,5′-trioligoadenylate (5′,5′ApApAepoxy) resistive to the action of cellular phosphodiesterase on cells of human neuroblastoma IMR 32 cultured in vitro. Twenty-two hours after the addition of 5·10⁻⁶ M 2′,5′ApApAepoxy to the culture medium, the number of cells decreased by 20% (P < 0.05), while the content of protein in these cells increased, on average, by 52% (P < 0.01), as compared with the control. The activities of Na⁺,K⁺-and Ca²⁺, Mg²⁺-ATPases in a microsomal fraction obtained from cells cultured in the presence of 2′, 5′ ApApAepoxy decreased by 50% (P < 0.001) as compared with those in the control cells. Our data indicate that 2′,5′ApApAepoxy possess antiproliferative activity. According to our findings, the antiproliferative effect of 2′,5′ ApApAepoxy can, to a great extent, be explained by the fact that this oligoadenylate derivative significantly modulates the activities of Na⁺,K⁺-and Ca²⁺,Mg²⁺-ATPases. Neirofiziologiya/Neurophysiology, Vol. 38, No. 2, pp. 97–102, March–April, 2006.