Activation of autophagy promotes the inhibitory effect of curcumin analog EF-24 against MDA-MB-231 cancer cells

Breast cancer is the leading cause of cancer deaths in women worldwide. EF-24, an analog of curcumin, has been shown to possess promising anticancer effects. However, the underlying mechanism remains elusive. In the present study, the inhibitory effect of EF-24 against one breast cancer cell line, MDA-MB-231, and its anti-migration ability were assessed by MTT, wound healing, and Transwell assay. Furthermore, we found that EF-24 could induce initiation of autophagy as evidenced by fluorescence and electron microscope observation. EF-24 also induced mitochondrial apoptosis in MDA-MB-231 cells as detected by Hoechst 33342 staining, flow cytometry analysis, and western blot analysis. In addition, the early autophagy inhibitor 3-MA could reduce the cleavage of PARP protein and protect cells from EF-24-induced apoptosis, while the autophagy inducer (rapamycin) could enhance the anticancer effect of EF-24 in MDA-MB-231 cells, which suggest that EF-24 induces crosstalk between autophagy and apoptosis, which herein participate in the antiproliferative effect of EF-24 in breast cancer cells. Moreover, removal of EF-24-activated ROS with NAC significantly reversed migration ability of MDA-MB-231 cells, indicating that EF-24 exerted an inhibitory effect through a ROS-mediating pathway. These results will help to elucidate the antitumor mechanism of curcumin analogs and to explore future potential clinical applications.

Inhibition of autophagic flux by the curcumin analog EF-24 and its antiproliferative effect on MCF-7 cancer cells

5-Bis[(2-fluorophenyl)methylene]-4-piperidinone (EF-24) is a curcumin analog, which was identified for its physiochemical stability and diverse pharmacological functions. In the present study, EF-24 was added to the breast cancer cell line MCF-7 and its cellular effects were characterized. The results indicated that EF-24 possessed antiproliferative and antimigratory activities on MCF-7 cells as determined by MTT assay, wound healing, and transwell assay, respectively. In addition, the autophagosomal vesicles could be detected by acridine orange staining and electron microscope analysis in EF-24-treated cells. Conversion of LC3-I to LC3-II was also investigated following EF-24 treatment of the cells. However, the expression analysis of p62 and LC3 revealed that EF-24 could inhibit autophagic flux in MCF-7 cells. Confocal microscopy suggested that EF-24 could inhibit the degradation of autophagic vesicles by blocking the fusion of autophagosomes with lysosomes. EF-24 could also induce apoptosis of MCF-7 cells as determined by Hoechst 33342 staining, flow cytometry analysis, and western blot analysis. Moreover, treatment of the cells with the autophagy inhibitor 3-MA enhanced the PARP1 cleavage of EF-24-treated MCF-7 cells, which indicated the crosstalk between autophagy and apoptosis in breast cancer cells. Additional investigation of EF-24 should be performed in future studies to assess its antiproliferation and antimigratory effects on MCF-7 cells. However, the current results provide a solid foundation for the potential in vivo anticancer activity of this compound.

Antiproliferative effect and autophagy induction of curcumin derivative ZYX02-Na on the human lung cancer cells A549

At present, a large number of curcumin derivatives had been produced and identified aiming to replace the curcumin in view of its low bioavailability and stability. Here, a novel curcumin derivative ZYX02-Na was first used to reduce the cell viability of human non-small cell lung cells A549, which was confirmed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry and Western blot analysis showed that ZYX02-Na could lead to cell cycle arrest in G0/G1 phase, which demonstrated that ZYX02-Na inhibited the proliferation of A549 cells. Furthermore, the AMPK/mTOR/4E-BP1 signaling pathway was activated in ZYX02-Na-treated A549 cells. Besides, wounding healing and transwell experiments showed that ZYX02-Na could also inhibited the migration ability of A549 cells. Moreover, we also found that ZYX02-Na could induce autophagy of A549 cells by acridine orange staining, GFP-LC3 subcellular localization observation and Western blotting analysis, respectively. In short, our current studies indicated that ZYX02-Na possessed the antiproliferation effect and autophagy induction on A549 cells, while in vivo anticancer study of ZYX02-Na needs to be done in future.

One novel curcumin derivative ZYX01 induces autophagy of human non-small lung cancer cells A549 through AMPK/ULK1/Beclin-1 signaling pathway

Presently, curcumin derivatives had been paid more attention in view of their high bioavailability or water solubility, which herein possibly replaced the curcumin for their functional applications in future. Here, one novel chemically synthesized curcumin derivative, ZYX01, was used to identify anti-proliferation activity of human non-small lung cancer cells A549 and its anti-proliferative mechanism. Our study showed that ZYX01 could induce autophagic death of A549 cells by morphological observation, MTT assay, acridine orange staining and MDC assay, which possess a dose-and time-dependent manner. ZYX01-treated A549 cells possessed an increase in LC3-II/LC3-I ratio, upregulation of beclin-1 and downregulation of p62 expression. We further confirmed the cellular AMPK/ULK1/Beclin-1 signaling pathway in A549 cells after ZYX01 treatment. The anti-migration effect of ZYX01 in A549 cells was also explored by wound healing assay and transwell experiment. Current results had confirmed that ZYX01 induced A549 cells autophagy through AMPK/ULK1/Beclin-1 pathway and shed light on the future study on the anti-cancer molecular mechanism.

[Study on the risk factors for hemorrhagic transformation of cerebellar infarction after posterior fossa decompression surgery]

Objective: To investigate the related risk factors for hemorrhagic transformation (HT) of cerebellar infarction after posterior fossa decompression surgery. Methods: A total of 91 patients with cerebellar infarction were treated by posterior fossa decompression surgery in Department of Neurosurgery of Jinhua Municipal Central Hospital from Jan 2010 to Jan 2018, were selected as study subjects. The HT group included 17 cases, while the Non-HT group included 74 cases. The clinical data of the two groups were analyzed retrospectively, the univariate and non-conditional lgistic regression analysis were performed to detect the relevant risk factors for hemorrhagic transformation of cerebellar infarction after posterior fossa decompression surgery. Results: By univariate analysis, the differences of these seven risk factors, the large area cerebellar infarction (the diameter of area was larger than 5 cm), pre-op thrombolysis, pre-op mild HT, oral anticoagulants, atrial fibrillation, hyperglycemia and fluctuation of BP in post-op, between two groups were statistically significant (P<0.05). By multivariate logistic analysis, the large area cerebellar infarction (P<0.05), pre-op thrombolysis(P<0.01), pre-op mild HT (P<0.01), oral anticoagulants (P<0.01) were the independent risk factors for post-op HT. Conclusions: The large area cerebellar infarction (the diameter of area was more than 5 cm), pre-op thrombolysis, pre-op mild HT, oral anticoagulants, atrial fibrillation, hyperglycemia and fluctuation of BP in post-op are important risk factors for post-op HT. The large area cerebellar infarction, pre-op thrombolysis, pre-op mild HT, oral anticoagulants are the independent risk factors for post-op HT. A proper pre-op evaluation of these risk factors and an individualized treatment for post-op HT would help a lot with balancing operational risk and improving prognosis.

A novel synthetic curcumin derivative MHMM-41 induces ROS-mediated apoptosis and migration blocking of human lung cancer cells A549

Many curcumin derivatives were produced and characterized to improve the physiochemical instability and low solubility of curcumin. Here, MHMM-41 (a novel curcumin derivative) was used to treat non-small lung cancer cells of human (known as A549) and to identify its anti-proliferative activities. Our results suggested that MHMM-41 display no significant cytotoxicity toward normal human lung fibroblast 2BS cells and mouse embryonal fibroblast 3T3 cells. It also had better anti-proliferative activity than curcumin in A549 cells. Further study showed a significant increase of apoptotic A549 cells in time and dose dependent manners. The activation of caspase-3, 8, 9, 12, Bax and PARP proteins were detected. Consequently, MHMM-41 treatment led to the reduction of mitochondrial membrane potential by JC-1 staining and characteristic nuclei fragmentation by Hoechst 33,342 staining, respectively, which showed that A549 apoptosis could be triggered by the extrinsic and intrinsic mitochondrial pathways. The release of ROS was also measured by flow cytometry. Further, wound healing assay and transwell experiments confirmed the anti-migration ability of MHMM-41 in A549 cells. Our current study suggested the potentials of MHMM-41 to inhibit the A549 cell proliferation. However, the intensive mechanical research on the anti-proliferation of A549 cells needs to be performed in the future.

Oxymatrine induces A549 human non‑small lung cancer cell apoptosis via extrinsic and intrinsic pathways

Oxymatrine is one of the primary natural compounds extracted from the Sophora flavescens, and has been reported to exhibit numerous pharmacological properties including cancer‑preventive and anti‑cancer effects, however the mechanisms as to how oxymatrine exhibits anti‑proliferative activity in non‑small cell lung carcinoma cells remains uncertain. The present study aimed to explore the mechanism of its anti‑cancer effect, and whether it is due to apoptosis induction and anti‑migration in the A549 lung cancer cell line. Detection of morphological alterations, MTT analysis, Hoechst/propidium iodide dual staining and terminal deoxynucleotidyl transferase dUTP nick end labeling assays verified that oxymatrine induced A549 cell apoptosis. The caspase pan‑inhibitor z‑VAD‑FMK resulted in disappearance of oxymatrine‑elicited nuclei fragmentation via Hoechst 33342 staining. JC‑1 staining demonstrated a decrease in mitochondrial membrane potential which further verified the induction of apoptosis by oxymatrine. The caspase‑3, 8 and 9 activities of oxymatrine‑treated cells were activated, which suggested that extrinsic and intrinsic apoptotic pathways were involved in the anti‑proliferative effects of oxymatrine in A549 cells. Furthermore, the wound healing assay verified the anti‑migratory effects of oxymatrine in A549 cells.

In silico identification and characterization of the WRKY gene superfamily in pepper (Capsicum annuum L.)

The WRKY family is one of the most important transcription factor families in plants, involved in the regulation of a broad range of biological roles. The recent releases of whole-genome sequences of pepper (Capsicum annuum L.) allow us to perform a genome-wide identification and characterization of the WRKY family. In this study, 61 CaWRKY proteins were identified in the pepper genome. Based on protein structural and phylogenetic analyses, these proteins were classified into four main groups (I, II, III, and NG), and Group II was further divided into five subgroups (IIa to IIe). Chromosome mapping analysis indicated that CaWRKY genes are distributed across all 12 chromosomes, although the location of four CaWRKYs (CaWRKY58-CaWRKY61) could not be identified. Two pairs of CaWRKYs located on chromosome 01 appear to be tandem duplications. Furthermore, the phylogenetic tree showed a close evolutionary relationship of WRKYs in three species from Solanaceae. In conclusion, this comprehensive analysis of CaWRKYs will provide rich resources for further functional studies in pepper.

CARD9 mutation linked to Corynespora cassiicola infection in a Chinese patient

Corynespora cassiicola is a plant pathogen associated with leaf-spotting disease. The fungus has been found on diverse substrates: leaves, stems and roots of plants; nematode cysts and human skin. It rarely causes human infections. Here we report one case of subcutaneous phaeohyphomycosis caused by C. cassiicola with prominent tissue necrosis in a woman. All of her clinical features pointed towards a genetic linkage. Hence, whole-exome sequencing and Sanger sequencing were performed on this patient. One mutation of CARD9 was detected.

In silico analysis of gene content in tomato genomic regions mapped to the Ty-2 resistance gene

Tomato yellow leaf curl virus is one of the main diseases affecting tomato production worldwide. Previous studies have shown that Ty-2 is an important resistance gene located between molecular markers C2_At2g28250 (82.3 cM) and T0302 (89.0 cM), and exhibits strong resistance to tomato yellow leaf curl virus in Asia. In this study, Ty-2 candidate genes were subjected to bioinformatic analysis for the sequenced tomato genome. We identified 69 genes between molecular markers C2_At2g28250 and T0302, 22 of which were disease-related resistant genes, including nucleotide binding site-leucine-rich repeat disease resistance genes, protease genes (protein kinase, kinase receptor, and protein isomerase), cytochromes, and transcription factors. Expressed sequence tag analysis revealed that 77.3% (17/22) of candidate disease-resistance genes were expressed, involving 143 expressed sequence tags. Based on full-length cDNA sequence analysis, 7 candidate genes were found, 4 of which were involved in tomato responses to pathogens. Microarray expression analysis also showed that most candidate genes were involved in the tomato responses to multiple pathogens, including fungi, viruses, and bacteria. RNA-seq expression analysis revealed that all candidate genes participated in tomato growth and development.

Assessment of the genetic diversity of tomato yellow leaf curl virus

The objective of the present study was to analyze the genetic diversity of tomato yellow leaf curl virus (TYLCV). Representative TYLCV sequences were searched in the National Center for Biotechnology Information database. Comprehensive analysis of TYLCV was performed using bioinformatics by examining gene structure, sequence alignments, phylogeny, GC content, and homology. Forty-eight representative TYLCV sequences were selected from 48 regions in 29 countries. The results showed that all TYLCV sequences were 2752-2794 nucleotides in length, which encoded 6 open reading frames (AV1, AV2, AC1, AC2, AC3, and AC4). GC content ranged from 0.41-0.42. Sequence alignment showed a number of insertions and deletions within these TYLCV sequences. Phylogenetic tree results revealed that the sequences were divided into 10 classes; homology of the sequences ranged from 72.8 to 98.6%. All 48 sequences contained the typical structure of TYLCV, including open reading frames and intergenic regions. These results provide a theoretical basis for the identification and evolution of the virus in the future.

Novel curcumin analogue IHCH exhibits potent anti‑proliferative effects by inducing autophagy in A549 lung cancer cells

Curcumin is a natural polyphenolic compound that exhibits strong antioxidant and anticancer activities; however, low bioavailability has restricted its application in chemotherapeutic trials. The present study aimed to investigate the anticancer effect of the novel curcumin derivative 2E,6E‑2‑(1H‑indol‑3‑yl) methylene)‑6‑(4‑hydroxy‑3‑methoxy benzylidene)‑cyclohexanone (IHCH) on A549 lung cancer cells. Cells were treated with IHCH at different concentrations (1‑40 µM) for different time periods (1‑36 h). Microscopic analysis revealed that IHCH inhibited A549 cell growth and induced the formation of characteristic autophagolysosomes in a dose‑ and time‑dependent manner. Furthermore, the inhibitory rate of IHCH (40 µM) on A549 cell viability was 77.34% after 36 h of treatment. Acridine orange staining revealed an increase in autophagic vacuoles in the IHCH‑treated A549 cells. Monodansylcadaverine staining was used to analyze autophagy rate. Immunocytochemistry revealed an increase in light chain (LC) 3 protein expression in the IHCH‑treated cells and western blot analysis detected the conversion of LC3‑I to LC3‑II, as well as the recruitment of LC3 to autophagosomes in the cytoplasmatic compartment, suggesting the occurrence of autophagy. These findings show that IHCH induced autophagy in A549 cells, which is a novel cell death mechanism induced by curcumin derivatives.

A synthetic curcumin derivative hydrazinobenzoylcurcumin induces autophagy in A549 lung cancer cells

CONTEXT

Curcumin exhibits growth-suppressive activity against a variety of cancer cells, but low bioavailability restricts its application in chemotherapeutic trials. Nowadays, a growing number of curcumin derivatives or analogs are known, hoping to replace curcumin and circumvent this problem. Hydrazinobenzoylcurcumin (HBC) has been synthesized and identified as a potent inhibitor of cell proliferation in previous reports.

OBJECTIVE

This study presents a novel mechanism of cell autophagy induced by HBC in the human non-small lung epithelial carcinoma (A549) cells.

MATERIALS AND METHODS

Cells were cultured and treated with HBC at different concentrations (10-80 μM) and at different time periods (1-24 h). Microscopic analysis was used to detect the morphology changes and autophagolysosomes of A549 cells. An acridine orange staining assay was conducted to evaluate the autophagolysosomes and autophagic vacuoles was analyzed by monodansylcadaverine (MDC) and GFP-LC3 transfection analysis. Western blotting was used to assess the conversion of microtubule-associated protein light chain 3 (LC3).

RESULTS

HBC could induce A549 cells autophagolysosomes formation in a dose and time-dependent manner and the inhibitory rate of HBC (80 μM) on the viability of A549 cells reached 76.68 ± 5.81% after 24 h of treatment. Autophagic vacuoles increased in a concentration-dependent manner in HBC-treated cell. Furthermore, conversion of LC3-I to LC3-II, accumulation of GFP-tagged LC3 positive intracellular vacuoles and increased fusion of autophagosomes with lysosomes suggested the occurrence of autophagy.

CONCLUSION

Our data indicate that HBC induced A549 cell autophagy, which is a novel cell death mechanism induced by curcumin derivatives.

Pterostilbene, a natural small-molecular compound, promotes cytoprotective macroautophagy in vascular endothelial cells

Chemical modulators of macroautophagy (herein referred to as autophagy) have aroused widespread interest among biologists and clinical physicians because of their potential for disease therapy. Pterostilbene (PT), a natural small-molecular compound, has been demonstrated to inhibit oxidized low-density lipoprotein (oxLDL)-induced apoptosis in vascular endothelial cells (VECs). The aim of the present study was to investigate whether and how PT could induce VEC autophagy. PT at 0.5 or 1 μM could effectively induce autophagosome formation in human umbilical vein VECs (HUVECs). PT promoted autophagy via a rapid elevation in intracellular calcium ([Ca(2+)]i) concentration and subsequent AMP-activated protein kinase α1 subunit (AMPKα1) activation, which in turn inhibited mammalian target of rapamycin, a potent inhibitor of autophagy. PT-induced AMPKα1 activation and autophagy were refractory to the depletion of serine/threonine kinase 11 but depended on calcium/calmodulin-dependent protein kinase kinase-β activation. Interestingly, PT stimulated cytoprotective autophagy so as to aid in the removal of accumulated toxic oxLDL and inhibit apoptosis in HUVECs. Our study provides a potent small molecule enhancer of autophagy and a novel useful tool in exploring the molecular mechanisms for crosstalk between apoptosis and autophagy. PT could serve as a potential lead compound for developing a class of autophagy regulator as autophagy-related diseases therapy.

Genomic sequence of mandarin fish rhabdovirus with an unusual small non-transcriptional ORF

The complete genome of mandarin fish Siniperca chuatsi rhabdovirus (SCRV) was cloned and sequenced. It comprises 11,545 nucleotides and contains five genes encoding the nucleoprotein N, the phosphoprotein P, the matrix protein M, the glycoprotein G, and the RNA-dependent RNA polymerase protein L. At the 3' and 5' termini of SCRV genome, leader and trailer sequences show inverse complementarity. The N, P, M and G proteins share the highest sequence identities (ranging from 14.8 to 41.5%) with the respective proteins of rhabdovirus 903/87, the L protein has the highest identity with those of vesiculoviruses, especially with Chandipura virus (44.7%). Phylogenetic analysis of L proteins showed that SCRV clustered with spring vireamia of carp virus (SVCV) and was most closely related to viruses in the genus Vesiculovirus. In addition, an overlapping open reading frame (ORF) predicted to encode a protein similar to vesicular stomatitis virus C protein is present within the P gene of SCRV. Furthermore, an unoverlapping small ORF downstream of M ORF within M gene is predicted (tentatively called orf4). Therefore, the genomic organization of SCRV can be proposed as 3' leader-N-P/C-M-(orf4)-G-L-trailer 5'. Orf4 transcription or translation products could not be detected by northern or Western blot, respectively, though one similar mRNA band to M mRNA was found. This is the first report on one small unoverlapping ORF in M gene of a fish rhabdovirus.

Establishment, characterization, and virus susceptibility of a new marine cell line from red spotted grouper (Epinephelus akaara)

A marine fish cell line from the snout of red spotted grouper Epinephelus akaara, a protogynous hermaphrodite, was established, characterized, and subcultured with more than 60 passages. The grouper snout cell line (GSC) cells multiplied well in Dulbecco's modified Eagle's medium (DMEM) medium supplemented with 10% fetal bovine serum. The optimal growth temperature was 25 degrees C, and morphologically the cells were fibroblastic. Chromosome analysis revealed that the GSC cell line has a normal diploid karyotype with 2n = 8st + 40t. A virus titration study indicated that the cells were susceptible to turbot Scophthalmus Maximus rhabdovirus (SMRV) (10(8.5) TCID(50) ml(-1)), while the viral titer of frog Rana grylio virus 9807 (RGV(9807)) reached 10(3.5) TCID(50) ml(-1). The infection was confirmed by cytopathic effect (CPE), immunofluorescence, and electron microscopy experiments, which detected the viral particles in the cytoplasm of virus-infected cells, respectively. Further, significant fluorescent signals were observed when the GSC cells were transfected with pEGFP vector DNA, indicating their potential utility for transgenic and genetic manipulation studies.

Isolation and characterization of Scophthalmus maximus rhabdovirus

A rhabdovirus associated with a lethal hemorrhagic disease in cultured turbot Scophthalmus maximus Linnaeus was isolated. The virus induced typical cytopathogenic effects (CPE) in 9 of 15 fish cell lines examined and was then propagated and isolated from infected carp leucocyte cells (CLC). Electron microscopy observations revealed that the negatively stained virions had a typical bullet-shaped morphology with one rounded end and one flat base end. The bullet-shaped morphology was more obvious and clear in ultrathin sections of infected cells. Experimental infections also indicated that the S. maximus rhabdovirus (SMRV) was not only a viral pathogen for cultured turbot, but also had the ability to infect other fish species, such as freshwater grass carp. A partial nucleotide sequence of the SMRV polymerase gene was determined by RT-PCR using 2 pairs of degenerate primers designed according to the conserved sequences of rhabdovirus polymerase genes. Homology analysis, amino acid sequence alignment, and phylogenetic relationship analysis of the partial SMRV polymerase sequence indicated that SMRV was genetically distinct from other rhabdoviruses. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the purified SMRV revealed 5 major structural proteins, and their molecular masses were estimated to be about 250, 58, 47, 42, and 28 kDa. Significant serological reactivity differences were also observed between SMRV and its nearest neighbor, spring viremia of carp virus (SVCV). The data suggest that SMRV is likely a novel fish rhabdovirus, although it is closely related to rhabdoviruses in the genus Vesiculovirus.

Characterization and Application of Monoclonal Antibodies against Turbot (Scophthalmus maximus) Rhabdovirus

Five monoclonal antibodies (mAbs), 1G8, 1H9, 2D2, 2D3, and 2F5, against Scophthalmus maximus rhabdovirus (SMRV) were prepared. Characterization of the mAbs included indirect enzyme-linked immunosorbent assay, isotyping, viral inhibition assay, immunofluorescence staining of virus-infected cell cultures, and Western blot analysis. Isotyping revealed that 1G8 and 1H9 were of the IgG2b subclass and that the other three were IgM. 2D2, 2D3, and 2F5 partially inhibited SMRV infection in epithelioma papulosum cyprinid (EPC) cell culture. Western blotting showed that all five mAbs could react with two SMRV proteins with molecular masses of approximately 30 kDa (P) and 26 kDa (M). These two proteins were localized within the cytoplasm of SMRV-infected EPC cells by immunofluorescence assay. Also, progressive foci of viral replication in cell cultures were monitored from 6 to 24 h, using mAb 2D3 as the primary antibody. A flow cytometry procedure was used to detect and quantify SMRV-infected (0.01 PFU/cell) EPC cells with mAb 2D3, and 10.8% of cells could be distinguished as infected 36 h postinfection. Moreover, mAb 2D3 was successfully applied for the detection of viral antigen in cryosections from flounder tissues by immunohistochemistry tests.

Demonstration of the anti-viral activity of garlic extract against human cytomegalovirus in vitro

The in vitro anti-viral activity of garlic extract (GE) on human cytomegalovirus (HCMV) was evaluated by tissue culture, plaque reduction and early antigen assay. A dose dependent inhibitory effect of GE was evident when GE was applied simultaneously with HCMV. But the effect was stronger when the monolayers were pretreated with GE. In addition, the anti-viral effect of GE persisted long in infected cells after its being removed from the culture medium. The strongest anti-viral effect of GE was demonstrated when it was applied continuously. It is therefore recommended that clinical use of GE against HCMV infection should be persistent and the prophylactic use of GE is preferable in immunocompromised patients.

Quantitative characterization of multiple binding sites for phencyclidine and N-allylnormetazocine in membranes from rat and guinea pig brain

Quantitative ligand binding studies have been used to characterize binding sites for N-allylnormetazocine ((+)SKF10,047) (SKF), 1-(1-phenylcyclohexyl) piperidine (PCP), N-[1-(2-thienyl)cyclohexyl]piperidine (TCP) and haloperidol in membranes from the brain of rat and guinea pig under conditions which permitted simultaneous analysis of the binding of both PCP and SKF. Using four labelled ligands (SKF, TCP, PCP and haloperidol), each displaced by the corresponding four unlabelled ligands, four classes of binding sites were observed in membranes from the brain of the rat, corresponding to sigma (sigma), two classes of PCP sites (PCP1, PCP2) and dopamine (D2) sites. The sigma site was suppressed by 50 nM haloperidol, while the PCP1 and PCP2 sites were not. These results were confirmed by studies employing a self- and cross-displacement design and dose-response surfaces for SKF and TCP, with and without blockade by haloperidol of the sigma site. Using mathematical modelling, employing the program LIGAND, it was possible to reject simpler models involving a common "PCP/sigma" site or a model involving only two classes of sites (sigma and PCP). Similar methods were used to identify two classes of sigma binding sites and two classes of PCP binding sites, in membranes prepared from the brain of the guinea pig. The relative potencies of 18 ligands for displacement of (+)[3H]SKF10,047 and [3H]TCP were compared: there were significant qualitative and quantitative differences in the "sigma" binding sites in the brain of rat and guinea pig, while the PCP binding sites were very similar in the two species.

Computer-assisted modeling of multiple dextromethorphan and sigma binding sites in guinea pig brain

Computer-assisted, simultaneous analysis of self- and cross-displacement experiments demonstrated the existence of several binding sites in guinea pig brain for dextromethorphan, (+)-3-(3-hydroxyphenyl)-N-(1-propyl)piperidine ((+)-3-PPP), and 1,3-di-o-tolyl guanidine (DTG). Dextromethorphan binds with high affinity to two sites (R1 Kd 50-83 and R2 Kd 8-19 nM) and with low affinity to two additional sites (R3 and R4). (+)-3-PPP binds to one high-affinity (R1 Kd 24-36 nM), to one intermediate-affinity (R3 Kd 210-320 nM), and to two (R2 and R4) low-affinity sites. DTG binds with almost identical high affinity to two different sites (R1 Kd 22-24 and R3 Kd 13-16 nM). These results confirm that dextromethorphan, (+)-3-PPP, and DTG bind to the common DM1/sigma 1 site (R1). The binding of DTG to two different sites with identical affinities precludes the use of this compound as a specific marker for sigma receptors. Besides, haloperidol displaces labeled ligands from both high-affinity DTG sites (R1 and R3) with high affinity. Thus, haloperidol sensitivity should not be used as the single criterion to identify a putative receptor. The resolution of these novel sites also may provide new insights into the multiple effects of antipsychotic drugs. In addition, this investigation has important implications regarding the methods that must be applied to characterize multiple binding sites and their relations with putative receptors.

Differential modulation by cations of sigma and phencyclidine binding sites in rat brain

The present investigation attempted to differentiate haloperidol-sensitive sigma sites (sigma H) from phencyclidine (PCP) binding sites in rat brain membranes. We studied the effects of several cations at physiologically relevant concentrations on the binding of radioligands selective for sigma H sites ([3H]haloperidol, [3H](+)3-PPP**), and [3H](+)SKF10,047), or for PCP sites ([3H]PCP and [3H]TCP). The PCP sites displayed a markedly greater sensitivity to cations than sigma H sites. This property was reflected by a greater extent of inhibition of the binding of PCP-selective relative to sigma H-selective ligands at a given cation concentration, as well as by lower IC50's and by steeper slopes of the cation dose-response curves. Divalent cations were approximately 100 times more potent than monovalent cations. All cations were inhibitory, except Sr2+ and Ba2+ which, at micromolar concentrations, enhanced PCP binding but not sigma H binding. Thus, PCP-selective sites appeared to be distinct from sigma H sites with regards to several aspects of cation modulation. This is consistent with the view that PCP and sigma H sites are distinct molecular entities. Further, the marked cation sensitivity of the PCP site is consistent with the current hypothesis according to which the PCP site is linked to the N-methyl-D-aspartate (NMDA) receptor-cation channel complex.

L-homocysteate stimulates [3H]MK-801 binding to the phencyclidine recognition site and is thus an agonist for the N-methyl-D-aspartate-operated cation channel

Rat brain synaptosomal membranes that are depleted of endogenous excitatory amino acids cannot bind [(+)-5-methyl-10, 11-dihydro-5H-dibenzo(a,d]cyclohept-5,10-imine maleate] ([3H]MK-801). However, they do so upon the restoration of excitatory amino acid agonists such as L-glutamate. [3H]MK-801 provides a molecular probe which is specific for a binding site located within the ionophore of the N-methyl-D-aspartate-type excitatory amino acid receptor, [3H]MK-801 does not bind to non-N-methyl-D-aspartate excitatory amino acid receptors. Exploiting [3H]MK-801 binding as a quantitative measure of agonist activity with respect to ability of inducing the open channel conformation, the present study demonstrates that L-homocysteate is an agonist almost equivalent to L-glutamate in terms of efficacy (maximal N-methyl-D-aspartate response) as well as potency (EC50). The effect of L-homocysteate was dose-dependent, stereospecific (L-homocysteate greater than DL-homocysteate greater than D-homocysteate), suppressible by the N-methyl-D-aspartate-selective competitive antagonist (+/-)-3(2-carboxy-piperazine-4-yl)propyl-l-phosphonate, and potentiated by the N-methyl-D-aspartate-selective "allosteric" modulator glycine. The demonstrated inactivity of L-homocysteine (and virtually all naturally occurring, non-acidic amino acids) implies that the omega-sulphonic acid moiety is an acceptable substitute for the omega carboxyl group for activating the N-methyl-D-aspartate receptor. While the potency of L-homocysteate at N-methyl-D-aspartate receptors was by a factor of only 1.6 smaller than that of L-glutamate, the affinity of L-homocysteate for kainate-type excitatory amino acid receptors was approximately four-fold lower than that of L-glutamate.(ABSTRACT TRUNCATED AT 250 WORDS)

Rigid spine syndrome. Report of 4 cases

Four cases of rigid spine syndrome are reported for the first time in China. They are 2 males and 2 females. One girl has a positive family history. Limitation of flexion of the cervical and dorsolumbar spine, contractures of joints, especially the elbow joints, extreme flattening of the chest and scoliosis are the prominent symptoms of this syndrome. The clinical criteria for this rigid spine syndrome tally with those described by Dubowitz (1965). Symptomatology, diagnosis, differential diagnosis and genetics are discussed. However, the question whether rigid spine syndrome is a single, well defined disease entity remains to be explored.

Comparison between transcutaneous nerve stimulation analgesic effect and electroacupuncture analgesic effect in rabbits

To compare Transcutaneous Nerve Stimulation Analgesia (TNSA) with Electroacupuncture Analgesia (AA), we observed their effect and mechanism parallelly. The results are as follows: 1. Both TNSA and AA can produce significant current-dependent analgesia. The latency of AA is shorter than that of TNSA. 2. Under the present condition (lower-frequency, lower-intensity) naloxone can antagonize partly AA but not TNSA. 3. TNSA effect could be blocked partly by deep or intradermal injection of procaine into points. However, AA effect could be almost blocked completely by deep injection and not by intradermal injection of procaine.

Lower CSF level of dynorphin(1-8) immunoreactivity in schizophrenic patients

Using a highly specific and sensitive radioimmunoassay for dynorphin(1-8) (D 1-8), and a singly blind test design, we measured D(1-8) immunoreactivity (ir D 1-8) in CSF of 35 first break cases of acute schizophrenic patients. All patients were free of psychotropic medication for at least one week before the study. Another 31 neurological patients suffered from cervical arthrosis, tumor, myelopathy etc. were studied as controls. The ir D(1-8) in CSF of schizophrenic patients were significantly lower than that of controls (91.8 +/- 5.6, means +/- S.E.M., and 131.9 +/- 6.8 fmol/ml CSF respectively, p less than 0.001).