The Role of OXT,OXTR, AVP,and AVPR1a Gene Expression in the Course of Schizophrenia

Schizophrenia is a serious and chronic mental illness, the symptoms of which usually appear for the first time in late adolescence or early adulthood. To date, much research has been conducted on the etiology of schizophrenia; however, it is still not fully understood. Oxytocin and vasopressin as neuromodulators that regulate social and emotional behavior are promising candidates for determining the vulnerability to schizophrenia. The aim of this study was to evaluate the expression of OXT, OXTR, AVP, and AVPR1a genes at the mRNA and protein levels in patients with schizophrenia. Due to the neurodegenerative nature of schizophrenia, the study group was divided into two subgroups, namely, G1 with a diagnosis that was made between 10 and 15 years after the onset of the illness, and G2 with a diagnosis made up to two years after the onset of the illness. Moreover, the relationship between the examined genes and the severity of schizophrenia symptoms, assessed using PANSS (Positive and Negative Syndrome Scale) and CDSS scales (Clinical Depression Scale for Schizophrenia) was evaluated. The analysis of the expression of the studied genes at the mRNA and protein levels showed statistically significant differences in the expression of all the investigated genes. OXT and AVPR1a gene expression at both the mRNA and protein levels were significantly lower in the schizophrenia group, and OXTR and AVP gene expression at both the mRNA and protein levels was higher in the schizophrenia subjects than in the controls. Furthermore, a significant correlation of OXT gene expression at the mRNA and protein levels with the severity of depressive symptoms in schizophrenia as assessed by CDSS was found.     

Role of G protein-coupled estrogen receptor 1, GPER, in inhibition of oocyte maturation by endogenous estrogens in zebrafish

Estrogen inhibition of oocyte maturation (OM) and the role of GPER (formerly known as GPR30) were investigated in zebrafish. Estradiol-17β (E2) and G-1, a GPER-selective agonist, bound to zebrafish oocyte membranes suggesting the presence of GPER which was confirmed by immunocytochemistry using a specific GPER antibody. Incubation of follicle-enclosed oocytes with an aromatase inhibitor, ATD, and enzymatic and manual removal of the ovarian follicle cell layers significantly increased spontaneous OM which was partially reversed by co-treatment with either 100 nM E2 or G-1. Incubation of denuded oocytes with the GPER antibody blocked the inhibitory effects of estrogens on OM, whereas microinjection of estrogen receptor alpha (ERα) antisense oligonucleotides into the oocytes was ineffective. The results suggest that endogenous estrogens produced by the follicle cells inhibit or delay spontaneous maturation of zebrafish oocytes and that this estrogen action is mediated through GPER. Treatment with E2 and G-1 also attenuated the stimulatory effect of the teleost maturation-inducing steroid, 17,20β-dihyroxy-4-pregnen-3-one (DHP), on OM. Moreover, E2 and G-1 down-regulated the expression of membrane progestin receptor alpha (mPRα), the intermediary in DHP induction of OM. Conversely DHP treatment caused a > 50% decline in GPER mRNA levels. The results suggest that estrogens and GPER are critical components of the endocrine system controlling the onset of OM in zebrafish. A model is proposed for the dual control of the onset of oocyte maturation in teleosts by estrogens and progestins acting through GPER and mPRα, respectively, at different stages of oocyte development.     

Human hemokinin-1 promotes migration of melanoma cells and increases MMP-2 and MT1-MMP expression by activating tumor cell NK1 receptors

Receptors and their regulatory peptides are aberrantly expressed in tumors, suggesting a potential tumor therapy target. Human hemokinin-1 (hHK-1) is a tachykinin peptide ligand of the neurokinin-1 (NK1) receptor which is overexpressed in melanoma and other tumor tissues. Here, we investigated the role of hHK-1 and the NK1 receptor in melanoma cell migration. NK1 receptor expression was associated with melanoma metastatic potential. Treatment with hHK-1 significantly enhanced A375 and B16F10 melanoma cell migration and an NK1 receptor antagonist L732138 blocked this effect. MMP-2 and MT1-MMP expression were up-regulated in hHK-1-treated melanoma cells and cell signaling data suggested that hHK-1 induced phosphorylation of ERK1/2, JNK and p38 by way of PKC or PKA. Kinase activation led to increased MMP-2 and MT1-MMP expression and melanoma cell migration induced by hHK-1. Thus, hHK-1 and the NK1 receptor are critical to melanoma cell migration and each may be a promising chemotherapeutic target.     

Activation of neurokinin-1 receptors up-regulates substance P and neurokinin-1 receptor expression in murine pancreatic acinar cells

Acute pancreatitis (AP) has been associated with an up-regulation of substance P (SP) and neurokinin-1 receptor (NK1R) in the pancreas. Increased SP-NK1R interaction was suggested to be pro-inflammatory during AP. Previously, we showed that caerulein treatment increased SP/NK1R expression in mouse pancreatic acinar cells, but the effect of SP treatment was not evaluated. Pancreatic acinar cells were obtained from pancreas of male swiss mice (25–30 g). We measured mRNA expression of preprotachykinin-A (PPTA) and NK1R following treatment of SP (10⁻⁶M). SP treatment increased PPTA and NK1R expression in isolated pancreatic acinar cells, which was abolished by pretreatment of a selective NK1R antagonist, CP96,345. SP also time dependently increased protein expression of NK1R. Treatment of cells with a specific NK1R agonist, GR73,632, up-regulated SP protein levels in the cells. Using previously established concentrations, pre-treatment of pancreatic acinar cells with Gö6976 (10 nM), rottlerin (5 μM), PD98059 (30 μM), SP600125 (30 μM) or Bay11-7082 (30 μM) significantly inhibited up-regulation of SP and NK1R. These observations suggested that the PKC-ERK/JNK-NF-κB pathway is necessary for the modulation of expression levels. In comparison, pre-treatment of CP96,345 reversed gene expression in SP-induced cells, but not in caerulein-treated cells. Overall, the findings in this study suggested a possible auto-regulatory mechanism of SP/NK1R expression in mouse pancreatic acinar cells, via activation of NK1R. Elevated SP levels during AP might increase the occurrence of a positive feedback loop that contributes to abnormally high expression of SP and NK1R.     

心梗后心肌重构过程中AT_(1A)、AT_2受体表达的变化

为探讨AT1、AT2 受体在心肌重构演变过程中的作用 ,本实验应用免疫组化、电镜技术和图像分析方法 ,观察了大鼠心梗后心肌重构过程中非梗塞区AT1、AT2 受体表达的动态变化。结果显示 ,心梗术后 3d ,电镜显示非梗塞区心肌细胞肌原纤维横纹消失 ,线粒体肿胀 ,成纤维细胞增多 ,免疫组化显示AT1A受体在非梗塞区心肌组织表达明显升高 (P <0 0 0 1) ,AT2 受体表达无明显变化 (P >0 0 5 ) ;心梗术后 14d ,可见心肌细胞肌原纤维横纹 ,心肌细胞间胶原纤维明显增多 ,同时AT1A受体在心肌的表达比心梗术后 3d时减弱 ,但仍高于对照组 (P <0 0 5 ) ,AT2 受体表达明显增加 (P <0 0 0 1)。结果提示 :心梗后非梗塞区心肌AT1A、AT2 受体表达先后上调 ,可能参与介导心肌重构过程     

Proteasomal inhibition causes the formation of protein aggregates containing a wide range of proteins,including nitrated proteins

Mutations in Cu,Zn-superoxide dismutase (SOD-1) are associated with some familial cases of amyotrophic lateral sclerosis (ALS), but it is not known how they result in cell death. We examined effects of overexpression of wild-type SOD-1 or the G37R or G85R mutations on the accumulation of ubiquitinated and nitrated proteins, and on loss of cell viability induced by the proteasome inhibitor, lactacystin. Wild-type SOD-1 had no effect on proteasomal activity, but the mutants decreased it somewhat. Treatment with lactacystin (1 micro m) caused only limited cell viability loss, even though it induced a marked inhibition of proteasomal activities. However, viability loss due to apoptosis was substantial in response to lactacystin when cells were overexpressing a mutant SOD-1. The frequency of cells showing immunoreactivity against ubiquitinated- or nitrated-proteins was enhanced when wild-type and mutant SOD-1 s were overexpressed. Ubiquitinated or nitrated alpha-tubulin, SOD-1, alpha-synuclein and 68K neurofilaments were observed in the aggregates. Similar aggregates were observed in cells overexpressing mutant parkin (Del3-5, T240R and Q311'X). The nitric oxide synthase inhibitor, l-NAME, decreased viability loss and aggregation, suggesting that nitration of proteins may play an important role in aggregation and in the cell death accompanying it.     

Changes in S1P1 and S1P2 expression during embryonal development and primitive endoderm differentiation of F9 cells

Sphingosine 1-phosphate (S1P) is a ligand for S1P family receptors (S1P(1)-S1P(5)). Of these receptors, S1P(1), S1P(2), and S1P(3) are ubiquitously expressed in adult mice, while S1P(4) and S1P(5) are tissue specific. However, little is known of their expression during embryonal development. We performed Northern blot analyses in mouse embryonal tissue and found that such expression is developmentally regulated. We also examined the expression of these receptors during primitive endoderm (PrE) differentiation of mouse F9 embryonal carcinoma (EC) cells, a well-known in vitro endoderm differentiation system. S1P(2) mRNA was abundantly expressed in F9 EC cells, but little S1P(1) and no S1P(3), S1P(4), or S1P(5) mRNA was detectable. However, S1P(1) mRNA expression was induced during EC-to-PrE differentiation. Studies using small interference RNA of S1P(1) indicated that increased S1P(1) expression is required for PrE differentiation. Thus, S1P(1) may play an important function in PrE differentiation that is not substituted for by S1P(2).     

Patient‐specific protein aggregates in myofibrillar myopathies: Laser microdissection and differential proteomics for identification of plaque components

Myofibrillar myopathies (MFMs) are histopathologically characterized by desmin‐positive protein aggregates and myofibrillar degeneration. While about half of all MFM are caused by mutations in genes encoding sarcomeric and extra‐sarcomeric proteins (desmin, filamin C, plectin, VCP, FHL1, ZASP, myotilin, αB‐crystallin, and BAG3), the other half of these diseases is due to still unresolved gene defects. The present study aims at the proteomic characterization of pathological protein aggregates in skeletal muscle biopsies from patients with MFM‐causing gene mutations. The technical strategy is based on the dissection of plaque versus plaque‐free tissue areas from the same individual patient by laser dissection microscopy, filter‐aided sample preparation, iTRAQ‐labeling, and analysis on the peptide level using offline nano‐LC and MALDI‐TOF‐TOF MS/MS for protein identification and quantification. The outlined workflow overcomes limitations of merely qualitative analyses, which cannot discriminate contaminating nonaggregated proteins. Dependent on the MFM causing mutation, different sets of proteins were revealed as genuine (accumulated) plaque components in independent technical replicates: (i) αB‐crystallin, desmin, filamin A/C, myotilin, PRAF3, RTN2, SQSTM, XIRP1, and XIRP2 (patient with defined MFM mutation distinct from FHL1) or (ii) desmin, FHL1, filamin A/C, KBTBD10, NRAP, SQSTM, RL40, XIRP1, and XIRP2 (patient with FHL1 mutation). The results from differential proteomics indicate that plaques from different patients exhibit protein compositions with partial overlap, on the one hand, and mutation‐dependent protein contents on the other. The FHL1 mutation‐specific pattern was validated for four patients with respect to desmin, SQSTM, and FHL1 by immunohistochemistry.     

神经肽Y及其受体Y1、Y2对痛觉调制的研究进展

神经肽Y（neuropeptide Y,NPY）是一种由36个氨基酸残基组成的肽类激素,属胰多肽家族,广泛分布于中枢及外周神经组织的神经元中。NPY主要参与摄食行为、心血管活动、垂体分泌等生理功能的调节。NPY还参与了痛觉调制。NPY受体有Y1、Y2、Y3、Y4、Y5和Y6六种亚型。目前对Y1受体和Y2受体的研究较多,显示Y1受体和Y2受体参与痛觉调制。但现在对NPY在痛觉中的具体作用机制还不清楚。该文对NPY及其Y1受体、Y2受体在痛觉调制中的作用作一概述。     

Modulation of the expression of GABAA receptors in rat cerebellar granule cells by protein tyrosine kinases and protein kinase C

The expression of GABA_A receptors in rat cerebellar granules in culture has been studied by β_2/3 subunit immunocytochemistry and fluorescence confocal microscopy. These cells show labeling all over the cell bodies' plasma membrane and dendrites. Treatment with the protein tyrosine kinase (PTK) inhibitor genistein results in a decrease of the labeling associated with the β_2/3 subunit in both cell bodies and dendrites. No effect was found with an inactive genistein analogue, daidzein. A similar effect was found with a protein kinase C (PKC) activator, phorbol myristate acetate (PMA). The effects of genistein and PMA are additive.The interpretation of the results is that PTK inhibition blocks exocytotic deposit of newly synthesized GABA_A receptors onto the neuronal plasma membrane. On the other hand, PKC activation speeds up endocytotic removal of GABA_A receptors.     

A recombinant, arginine-glycine-aspartic acid (RGD) motif from foot-and-mouth disease virus binds mammalian cells through vitronectin and, to a lower extent, fibronectin receptors

The cell-binding abilities of a recombinant, RGD-containing peptide from foot-and-mouth disease virus (FMDV) have been characterized in HeLa and BHK cells. This peptide represents the aa sequence of the solvent-exposed G-H loop of protein VP1 which is involved in cell recognition and infection. The efficiency of the viral motif in promoting cell attachment and spreading is comparable to that shown by fibronectin or vitronectin. Cell binding is inhibited by a monoclonal antibody directed against a viral, RGD-involving B-cell epitope and also by sera against vitronectin (_Vβ₃/β₅) and fibronectin (₅β₁) receptors. In addition, a synthetic RGD peptide, which is a ligand for both integrins, prevents the cell binding mediated by the FMDV domain. These data demonstrate that the FMDV RGD motif is a potent ligand for cell-receptor integrins and sufficient to promote cell attachment to susceptible cells mainly through the vitronectin receptor.     

FGF-2 increases colony formation, PTH receptor, and IGF-1 mRNA in mouse marrow stromal cells.

FGF-2 stimulates bone formation in vitro and in vivo in rats. However, there are limited studies in mice and no data on the mechanism(s) by which FGF-2 induces bone formation. We assessed whether short-term FGF-2 treatment of marrow stromal cells from young mice would increase alkaline phosphatase-positive (ALP), mineralized colony formation and expression of genes important in osteoblast maturation. Short-term treatment with FGF-2 (0.01-1.0 nM) for the first 3 days of a 14- or 21-day culture period increased the number of ALP mineralized colonies in bone marrow stromal cells. FGF-2 (0.1 nM) increased the mRNAs for type 1 collagen: osteocalcin, runt domain/core binding factor, PTH/PTHR receptor, and insulin-like growth factor 1 (IGF-1) at 14 and 21 days. We conclude that short-term FGF-2 treatment enhances osteoblast maturation in vitro. Furthermore, the anabolic effect of FGF-2 may be attributed in part to regulation of IGF-1 in osteoblasts.