Amidated Scolopin-2 inhibits proliferation and induces apoptosis of Hela cells in vitro and in vivo.

This study aimed to investigate the effect of Scolopin-2, a cationic antimicrobial peptide from centipede venoms, and amidated Scolopin-2 on Hela cell viability in vitro and in vivo. The cellular proliferation was investigated with the MTT assay. Confocal laser scanning, flow cytometry, and Western blot analysis were employed to localize Scolopin-2-NH2 in Hela cells and to study the caused cells apoptosis. We subcutaneously injected Hela cells into BALB/c nude mice and studied if Scolopin-2-NH2 suppressed tumor growth in the mice. Scolopin-2-NH2 inhibited Hela proliferation in vitro in a dose-dependent manner with an IC50 of 35 µM. In addition, Scolopin-2-NH2 combined with mitochondria and regulated caspase-related apoptosis pathways in Hela cells. Scolopin-2-NH2 significantly suppressed tumor growth in the tumor-bearing mice without side effects, such as weight loss or abnormal changes in tissues, including liver, spleen, kidney, and lung. These results indicate Scolopin-2-NH2 may be a good therapeutic candidate for the treatment of Hela cervical cancer.

Activation of extracellular signal-regulated kinase in the anterior cingulate cortex contributes to the induction and expression of affective pain.

The anterior cingulate cortex (ACC) is implicated in the affective response to noxious stimuli. However, little is known about the molecular mechanisms involved. The present study demonstrated that extracellular signal-regulated kinase (ERK) activation in the ACC plays a crucial role in pain-related negative emotion. Intraplantar formalin injection produced a transient ERK activation in laminae V-VI and a persistent ERK activation in laminae II-III of the rostral ACC (rACC) bilaterally. Using formalin-induced conditioned place avoidance (F-CPA) in rats, which is believed to reflect the pain-related negative emotion, we found that blockade of ERK activation in the rACC with MEK inhibitors prevented the induction of F-CPA. Interestingly, this blockade did not affect formalin-induced two-phase spontaneous nociceptive responses and CPA acquisition induced by electric foot-shock or U69,593, an innocuous aversive agent. Upstream, NMDA receptor, adenylyl cyclase (AC) and phosphokinase A (PKA) activators activated ERK in rACC slices. Consistently, intra-rACC microinjection of AC or PKA inhibitors prevented F-CPA induction. Downstream, phosphorylation of cAMP response element binding protein (CREB) was induced in the rACC by formalin injection and by NMDA, AC and PKA activators in brain slices, which was suppressed by MEK inhibitors. Furthermore, ERK also contributed to the expression of pain-related negative emotion. Thus, when rats were re-exposed to the conditioning context for retrieval of pain experience, ERK and CREB were reactivated in the rACC, and inhibiting ERK activation blocked the expression of F-CPA. All together, our results demonstrate that ERK activation in the rACC is required for the induction and expression of pain-related negative affect.

Sequence polymorphism and evolution of three cetacean MHC genes.

Sequence variability at three major histocompatibility complex (MHC) genes (DQB, DRA, and MHC-I) of cetaceans was investigated in order to get an overall understanding of cetacean MHC evolution. Little sequence variation was detected at the DRA locus, while extensive and considerable variability were found at the MHC-I and DQB loci. Phylogenetic reconstruction and sequence comparison revealed extensive sharing of identical MHC alleles among different species at the three MHC loci examined. Comparisons of phylogenetic trees for these MHC loci with the trees reconstructed only based on non-PBR sites revealed that allelic similarity/identity possibly reflected common ancestry and were not due to adaptive convergence. At the same time, trans-species evolution was also evidenced that the allelic diversity of the three MHC loci clearly pre-dated species divergence events according to the relaxed molecular clock. It may be the forces of balancing selection acting to maintain the high sequence variability and identical alleles in trans-specific manner at the MHC-I and DQB loci.

K+ channels and the cAMP-PKA pathway modulate TGF-beta1-induced migration of rat vascular myofibroblasts.

Our previous studies have indicated that TGF-beta1 exerts its effect on the expression of A-type potassium channels (I(A)) in rat vascular myofibroblasts by activation of protein kinase C during the phenotypic transformation of vascular fibroblasts to myofibroblasts. In the present study, patch-clamp whole-cell recording and transwell-migration assays were used to examine the effects of TGF-beta1- and phorbol 12-myristate 13-acetate (PMA)-induced expression of I(A) channels on myofibroblast migration and its modulation by the protein kinase A (PKA) pathway. Our results reveal that incubation of fibroblasts with TGF-beta1 or PMA up-regulates the expression of I(A) channels and increases myofibroblast migration. Blocking I(A) channel expression by 4-aminopyridine (4-AP) significantly inhibits TGF-beta1- and PMA-induced myofibroblast migration. Incubation of fibroblasts with forskolin does not result in increased expression of I(A) channels but does cause a slight increase in fibroblast migration at higher concentrations. In addition, forskolin increases the TGF-beta1- and PMA-induced myofibroblast migration but inhibits TGF-beta1- and PMA-induced the expression of I(A) channels. Whole-cell current recordings showed that forskolin augments the delayed rectifier outward K(+) (I(K)) current amplitude of fibroblasts, but not the I(A) of myofibroblasts. Our results also indicate that TGF-beta1- and PMA-induced expression of I(A) channels might be related to increase TGF-beta1- or PMA-induced myofibroblast migration. Promoting fibroblast and myofibroblast migration via the PKA pathway does not seem to involve the expression of I(A) channels, but the modulation of I(K) and I(A) channels might be implicated.

[The functional mechanism between the pesticide Pyrimorph and humic acid].

In the present experiment, we mainly discussed the function mechanism between the humic acid and a new kind of fungicide Pyrimorph, aiming to play a positive role in the reduction of contamination caused by pesticides on environment. After the disposition step by step, the humic acid was separated into three parts. Then IR and fluorescence analytical methods were employed to explain the functional mechanism between the pesticide and each part of humic acid. As a result, there are extensive interactions between the three parts of the humic acid and the fungicide Pyrimorph. The interactions between fulvic acid and Pyrimorph are mainly the H-bond and the transfer of the electric charge caused by the C=O of the Pyrimorph and the -OH of the fulvic acid, and the interaction between matomeilon and Pyrimorph is mainly the transfer of the electric charge, and the interaction between humin and Pyrimorph is the weakest. It was showed that the fulvic acid is the most active part in the humic acid. That's to say the intensity of the interaction between the three parts of the humic acid and the fungicide Pyrimorph is smaller and smaller with the order of molecular weight from small to big, namely fulvic acid, matomeilon acid and humin.

[Antibacterial activity of water soluble fraction from Scolopendra subspinipes mutilans].

The water soluble fraction (SWSF) of centipede Scolopendra subspinipes mautilans, injected with Escherichia coli K12 D31 for 3-4 days showed broad-spectrum antimicrobial activity against Gram-positive, Gram-negative bacteria and fungi. It showed strong antibacterial activity against E. coli K12D31 at different temperatures, pH and ionic strengths. It did not show any hemolytic and agglutination activities at the concentration below 600 microg/ml. After E. coli K12 D31 treated with SWSF, the ultrastructure showed that its outer cell wall was broken, surface collapsed and intracellular substances leaked out.

Contributions of the anterior cingulate cortex and amygdala to pain- and fear-conditioned place avoidance in rats.

The pain experience includes a sensory-discriminative and an affective-emotional component. The sensory component of pain has been extensively studied, while data about the negative affective component of pain are quite limited. The anterior cingulate cortex (ACC), and amygdala are thought to be key neural substrates underlying emotional responses. Using formalin-induced conditioned place avoidance (F-CPA) and electric foot-shock conditioned place avoidance (S-CPA) models, the present study observed the effects of bilateral excitotoxic (quinolinic acid 200 nmol/microl) lesions of the ACC and amygdala on pain and fear induced negative emotion, as well as on sensory component of pain. In the place-conditioning paradigm, both intraplantar (i.pl.) injection of formalin and electric foot-shock produced conditioned place avoidance. Excitotoxin-induced lesion of either the ACC or amygdala significantly reduced the magnitude of F-CPA. However, the decrease in the magnitude of S-CPA occurred only in the amygdala, but not ACC lesioned animals. Neither ACC nor amygdala lesion significantly changed formalin-induced acute nociceptive behaviors. These results suggest that the amygdala is involved in both pain- and fear-related negative emotion, and the ACC might play a critical role in the expression of pain-related negative emotion.

[Effects of chronic cadmium loading on the testis and endocrine function of reproduction in male rats].

Sixty healthy Sprague-Dawley male rats were used and divided randomly into control group (group C), cadmium loading group with medium dose (group M) and cadmium loading group with high dose (group H). Groups C, M and H were orally dosed daily with 0, 5 and 10 mg/kg of cadmium for over 6 weeks. Effects of cadmium loading on testis and endocrine function of reproduction in male rats were studied. The results showed that the zinc content decreased slightly in testis and plasma, and the cadmium concentration increased significantly in the testis of groups M and H; while the plasma levels of cadmium and zinc had no obvious difference as compared with those of group C; daily sperm production in the testis of group H decreased markedly during week 3 of cadmium loading, and was significantly lower in groups M and H as compared to that in group C during week 6; alkaline phosphatase (ALP) in group H and lactate dehydrogenase-X (LDH-X) in groups M and H were markedly lower compared to those of group C; plasma testosterone (T) level in both cadmium loading groups decreased and was low or significantly lower than that in group C; follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels had no apparent difference between the three groups. It is suggested that the gradual accumulation of cadmium in testis tissue induced by chronic cadmium loading results in changes in some enzyme activity, a decrease in sperm production, and defect of endocrine function activity in the testis.

[MHC and its application in the population and conservation genetics].

The major histocompatibility complex (MHC),with the highest genetic polymorphism,is a cluster of genes involved in immune response regulation in the vertebrates.MHC can provide information such as population genetic diversity,evolutionary history and population dynamics,and population genetic structure etc. It can also be applied in the captive breeding programme for endangered vertebrate species.

Activation of glycine site and GluN2B subunit of NMDA receptors is necessary for ERK/CREB signaling cascade in rostral anterior cingulate cortex in rats: implications for affective pain.

OBJECTIVE: The rostral anterior cingulate cortex (rACC) is implicated in processing the emotional component of pain. N-methyl-D-aspartate receptors (NMDARs) are highly expressed in the rACC and mediate pain-related affect by activating a signaling pathway that involves cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) and/or extracellular regulated kinase (ERK)/cAMP-response element-binding protein (CREB). The present study investigated the contributions of the NMDAR glycine site and GluN2B subunit to the activation of ERK and CREB both in vitro and in vivo in rat rACC. METHODS: Immunohistochemistry and Western blot analysis were used to separately assess the expression of phospho-ERK (pERK) and phospho-CREB (pCREB) in vitro and in vivo. Double immunostaining was also used to determine the colocalization of pERK and pCREB. RESULTS: Both bath application of NMDA in brain slices in vitro and intraplantar injection of formalin into the rat hindpaw in vivo induced significant up-regulation of pERK and pCREB in the rACC, which was inhibited by the NMDAR antagonist DL-2-amino-5-phospho-novaleric acid. Selective blockade of the NMDAR GluN2B subunit and the glycine-binding site, or degradation of endogenous D-serine, a co-agonist for the glycine site, significantly decreased the up-regulation of pERK and pCREB expression in the rACC. Further, the activated ERK predominantly colocalized with CREB. CONCLUSION: Either the glycine site or the GluN2B subunit of NMDARs participates in the phosphorylation of ERK and CREB induced by bath application of NMDA in brain slices or hindpaw injection of 5% formalin in rats, and these might be fundamental molecular mechanisms underlying pain affect.

Cloning, expression and bioactivity of BAFF from Petaurus breviceps.

B-cell activating factor (BAFF), belonging to the TNF (tumor necrosis factor) family, is crucial for B-cell survival and maturation. In the present study, PbBAFF cDNA was amplified from the sugar glider Petaurus breviceps by RT-PCR and RACE (rapid amplification of cDNA ends) strategies. The open reading frame (ORF) of PbBAFF cDNA encodes a protein consisting of 287-amino acid. The deduced amino acid sequence contains a predicted transmembrane domain, a putative furin protease cleavage site, a potential N-glycosylation site and conserved cysteine residues similar to that identified in other mammalian BAFF. The soluble mature part of PbBAFF (PbsBAFF) showed 88-92% sequence identity with mammalian homologs. The predicted three-dimensional (3D) structural analysis of PbsBAFF analyzed by comparative protein modeling revealed that they are very similar to the 3D structure of human BAFF. Recombinant PbsBAFF fused with His(6) tag was efficiently expressed in Escherichia coli BL21 (DE3). In vitro, purified PbsBAFF co-stimulates the proliferation of human B-cells. These findings indicate PbBAFF, the first BAFF cloned from marsupial, plays an important role in proliferation of B-cells, and phylogenetic analyses reveal that the work is of value with respect to continued refinement of our understanding of mammalian phylogenetic relationships.

Molecular cloning, in vitro expression and bioactivity of quail BAFF.

B cell activating factor (BAFF), belonging to the TNF (tumor necrosis factor) family, is critical for B cell survival and maturation. In the present study, a quail BAFF cDNA, named qBAFF, was amplified from quail spleen by RT-PCR and RACE (rapid amplification of cDNA ends) strategies. The open reading frame (ORF) of qBAFF cDNA encodes a protein consisting of 288-amino acid. The deduced amino acid sequence contains a predicted transmembrane domain and a putative furin protease cleavage site like other identified BAFF homologues. The qBAFF shows 96, 93, 93, 53 and 51% amino acid sequence identity with chicken (cBAFF), goose (gBAFF), duck (dBAFF), human (hBAFF) and mouse BAFF (mBAFF), respectively, with the functional soluble parts of qBAFF is 98, 99, 98, 78 and 71%, respectively. RT-PCR showed that BAFF is expressed in many tissues in the quail, including bursa, spleen, liver, brain, heart, intestine, kidney, thymus and muscle. Recombinant soluble qBAFF (qsBAFF) fused with His(6) tag was efficiently expressed in Escherichia coli BL21 (DE3) and its molecular weight of approximately 19kDa was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. In vitro, purified qsBAFF was able to promote the survival of quail bursa B cells. Our results suggest that qBAFF plays an important role in survival of quail B cells cultured in vitro.

NMDA NR2A and NR2B receptors in the rostral anterior cingulate cortex contribute to pain-related aversion in male rats.

NMDA receptors, which are implicated in pain processing, are highly expressed in forebrain areas including the anterior cingulate cortex (ACC). The ACC has been implicated in the affective response to noxious stimuli. Using a combination of immunohistochemical staining, Western blot, electrophysiological recording and formalin-induced conditioned place avoidance (F-CPA) rat behavioral model that directly reflects the affective component of pain, the present study examined formalin nociceptive conditioning-induced changes in the expressions of NMDA receptor subunits NR1, NR2A, and NR2B in the rostral ACC (rACC) and its possible functional significance. We found that unilateral intraplantar (i.pl.) injection of dilute formalin with or without contextual conditioning exposure markedly increased the expressions of NMDA receptor subunits NR2A and NR2B but not of NR1 in the bilateral rACC. NMDA-evoked currents in rACC neurons were significantly greater in formalin-injected rats than in naïve or normal saline-injected rats. Selectively blocking either NR2A or NR2B subunit in the rACC abolished the acquisition of F-CPA and formalin nociceptive conditioning-induced Fos expression, but it did not affect formalin acute nociceptive behaviors and non-nociceptive fear stimulus-induced CPA. These results suggest that both NMDA receptor subunits NR2A and NR2B in the rACC are critically involved in pain-related aversion. Thus, a new strategy targeted at NMDA NR2A or NR2B subunit might be raised for the prevention of pain-related emotional disturbance.

cAMP/protein kinase A signalling pathway protects against neuronal apoptosis and is associated with modulation of Kv2.1 in cerebellar granule cells.

Previously, we have reported that apoptosis of cerebellar granular neurons induced by incubation in 5 mm K(+) and serum-free medium (LK-S) was associated with an increase in the delayed rectifier K(+) current (I(K)). Here, we show that I(K) associated with apoptotic neurons is mainly encoded by a Kv2.1 subunit. Silencing Kv2.1 expression by small interfering RNA reduces I(K) and increases neuron viability. Forskolin is able to decrease the I(K) amplitude recording from neurons of both the LK-S and control group, and prevents apoptosis of granule cells that are induced by LK-S. Dibutyryl cAMP mimicks the effect of forskolin on the modulation of I(K) and, accordingly, the inhibitor of protein kinase A, H-89, aborts the neuron-protective effect induced by forskolin. Whereas the expression of Kv2.1 was silenced by Kv2.1 small interfering RNA, the inhibition of forskolin on the current amplitude was significantly reduced. Quantitative RT-PCR and whole-cell recording revealed that the expression of Kv2.1 was elevated in the apoptotic neurons, and forskolin significantly depressed the expression of Kv2.1. We conclude that the protection against apoptosis via the protein kinase A pathway is associated with a double modulation on I(K) channel properties and its expression of alpha-subunit that is mainly encoded by the Kv2.1 gene.

Is endogenous D-serine in the rostral anterior cingulate cortex necessary for pain-related negative affect?

Functional activation of NMDA receptors requires co-activation of glutamate- and glycine-binding sites. D-serine is considered to be an endogenous ligand for the glycine site of NMDA receptors. Using a combination of a rat formalin-induced conditioned place avoidance (F-CPA) behavioral model and whole-cell patch-clamp recording in rostral anterior cingulate cortex (rACC) slices, we examined the effects of d-amino acid oxidase (DAAO), an endogenous D-serine-degrading enzyme, and 7-chlorokynurenate (7Cl-KYNA), an antagonist of the glycine site of NMDA receptors, on pain-related aversion. Degradation of endogenous D-serine with DAAO, or selective blockade of the glycine site of NMDA receptors by 7Cl-KYNA, effectively inhibited NMDA-evoked currents in rACC slices. Intra-rACC injection of DAAO (0.1 U) and 7Cl-KYNA (2 and 0.2 mM, 0.6 microL per side) 20 min before F-CPA conditioning greatly attenuated F-CPA scores, but did not affect formalin-induced acute nociceptive behaviors and electric foot shock-induced conditioned place avoidance. This study reveals for the first time that endogenous D-serine plays a critical role in pain-related aversion by activating the glycine site of NMDA receptors in the rACC. Furthermore, these results extend our hypothesis that activation of NMDA receptors in the rACC is necessary for the acquisition of specific pain-related negative emotion. Thus a new and promising strategy for the prevention of chronic pain-induced emotional disturbance might be raised.

GABAergic disinhibition facilitates polysynaptic excitatory transmission in rat anterior cingulate cortex.

Various studies implicate the anterior cingulate cortex (ACC) in processing pain. Combining whole-cell patch clamp recordings in rat ACC slices and a formalin-induced conditioned place avoidance (F-CPA) behavioral model, the present study was to address the effect of GABA(A) receptors on excitatory transmission to ACC layer V neurons and its possible functional significance related to pain. Removal of GABA(A) inhibition by bicuculline (10 microM) induced a novel long-lasting response in layer V neurons, which could be blocked by high divalent extracellular solution and was sensitive to relatively higher rate stimuli. Co-application of NMDA receptor antagonist APV (50 microM) and non-NMDA receptor antagonist DNQX (10 microM) completely blocked the responses. Enhancement of inhibition by intra-ACC microinjection of muscimol abolished the acquisition of F-CPA without affecting formalin-induced acute nociceptive responses. These results suggest that GABA(A) inhibition may be involved in pain-related aversion by modulating glutamate-mediated excitatory transmission in the ACC.