Monoclonal antibody against macrophage colony-stimulating factor suppresses circulating monocytes and tissue macrophage function but does not alter cell infiltration/activation in cutaneous lesions or clinical outcomes in patients with cutaneous lupus erythematosus

This study's objective was to assess the effects of PD-0360324, a fully human immunoglobulin G2 monoclonal antibody against macrophage colony-stimulating factor in cutaneous lupus erythematosus (CLE). Patients with active subacute CLE or discoid lupus erythematosus were randomized to receive 100 or 150 mg PD-0360324 or placebo via intravenous infusion every 2 weeks for 3 months. Blood and urine samples were obtained pre- and post-treatment to analyse pharmacokinetics and pharmacodynamic changes in CD14(+) CD16(+) monocytes, urinary N-terminal telopeptide (uNTX), alanine/aspartate aminotransferases (ALT/AST) and creatine kinase (CK); tissue biopsy samples were taken to evaluate macrophage populations and T cells using immunohistochemistry. Clinical efficacy assessments included the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI). Among 28 randomized/analysed patients, peak/trough plasma concentrations increased in a greater-than-dose-proportional manner with dose increases from 100 to 150 mg. Statistically significant differences were observed between active treatment and placebo groups in changes from baseline in CD14(+) CD16(+) cells, uNTX, ALT, AST and CK levels at most time-points. The numbers, density and activation states of tissue macrophages and T cells did not change from baseline to treatment end. No between-group differences were seen in CLASI. Patients receiving PD-0360324 reported significantly more adverse events than those receiving placebo, but no serious adverse events. In patients with CLE, 100 and 150 mg PD-0360324 every 2 weeks for 3 months suppressed a subset of circulating monocytes and altered activity of some tissue macrophages without affecting cell populations in CLE skin lesions or improving clinical end-points.

Yi Qi Qing Re Gao-containing serum inhibits lipopolysaccharide-induced rat mesangial cell proliferation by suppressing the Wnt pathway and TGF-β1 expression

The aim of the present study was to investigate the effect of Yi Qi Qing Re Gao-containing serum (YQ-S) on rat mesangial cell (MC) proliferation and to investigate the underlying mechanism. MCs were divided into the control, lipopolysaccharide (LPS)-stimulated, YQ-S and fosinopril-containing serum (For-S) groups, and cultured for 48 h. An MTT assay was used to evaluate the proliferation of MCs. In addition, reverse transcription-quantitative polymerase chain reaction and western blot analysis were conducted to detect the expression levels of Wnt4, β-catenin and transforming growth factor (TGF)-β1 in MCs. The results indicated that YQ-S inhibited LPS-induced MC proliferation. The Wnt4 and TGF-β1 mRNA expression levels were reduced in the YQ-S group (P<0.01 or P<0.05). Furthermore, the Wnt4, β-catenin and TGF-β1 protein expression levels were suppressed in the YQ-S group (P<0.01 or P<0.05). Therefore, YQ-S appears to inhibit MC proliferation, and its mechanism may involve the inhibition of the Wnt signaling pathway and downregulation of TGF-β1 expression.

Endometrial microbiome at the time of embryo transfer: next-generation sequencing of the 16S ribosomal subunit

PURPOSE

Characterization of the human microbiome has become more precise with the application of powerful molecular tools utilizing the unique 16S ribosomal subunit's hypervariable regions to greatly increase sensitivity. The microbiome of the lower genital tract can prognosticate obstetrical outcome while the upper reproductive tract remains poorly characterized. Here, the endometrial microbiome at the time of single embryo transfer (SET) is characterized by reproductive outcome.

METHODS

Consecutive patients undergoing euploid, SET was included in the analysis. After embryo transfer, performed as per routine, the most distal 5-mm portion of the transfer catheter was sterilely placed in a DNA free PCR tube. Next-generation sequencing of the bacteria specific 16S ribosome gene was performed, allowing genus and species calls for microorganisms.

RESULTS

Taxonomy assignments were made on 35 samples from 33 patients and 2 Escherichia coli controls. Of the 33 patients, 18 had ongoing pregnancies and 15 did not. There were a total of 278 different genus calls present across patient samples. The microbiome at time of transfer for those patients with ongoing pregnancy vs. those without ongoing pregnancy was characterized by top genera by sum fraction. Lactobacillus was the top species call for both outcomes.

CONCLUSIONS

The data presented here show the microbiome at the time of embryo transfer can successfully be characterized without altering standard clinical practice. This novel approach, both in specimen collection and analysis, is the first step toward the goal of determining physiologic from pathophysiologic microbiota. Further studies will help delineate if differences in the microbiome at the time of embryo transfer have a reliable impact on pregnancy outcome.

[Expression characteristics of epithelial markers in human embryonic stem cells differentiating into keratinocytes]

OBJECTIVE

To differentiate human embryonic stem cells (hESCs) into keratinocytes (K-hESCs) and analyse the expression characteristics of biomarkers of K-hESCs.

METHODS

The hESCs of line H9 were seeded on matrigel in mTeSR1 medium. The hESCs were directly differentiated into keratinocytes in epithelial differentiation medium with bone morphogenetic protein 4, retinoic acid and N2 supplement. The karyotype of K-hESCs was analyzed, comparing the gene expression differences of K-hESCs with human gingival epithelial cells (HGECs), human immortalized oral epithelial cells (HIOECs) and HaCaT by Real-time PCR. Molecular characteristics of the cell differentiation were observed throughout the process by immunocytochemical techniques.

RESULTS

H9-hESCs were successfully differentiated into the cells that exhibited characteristics of keratinocytes in epithelial differentiation medium. The karyotype of K-hESCs was 46, XX; and the keratinocyte gene p63 expression in K-hESCs was significantly lower than that in HaCaT (P < 0.05), but there was no significant difference of p63 expression in K-hESCs, comparing with that in HGECs and HIOECs (P > 0.05).

CONCLUSION

H9-hESCs could be directly differentiated into K-hESCs. The gene expression of K-hESCs was similar to that of epithelial cells in the early stage of monolayer cells differentiation with high proliferative activity.

Association between macrophage migration inhibitory factor rs1007888 and GDM

We investigated the association between macrophage migration inhibitory factor (MIF) rs1007888 single-nucleotide polymorphisms and the genetic susceptibility to gestational diabetes mellitus (GDM). A total of 240 GDM pregnant women (GDM group) and 330 healthy pregnant women (control group) were included in the study. Differences in the MIF rs1007888 genotype and allele frequencies and differences between fasting blood glucose, fasting insulin, homeostatic model assessment (HOMA)-insulin resistance, and HOMA-b levels of pregnant women with different genotypes were compared. MIF genotype distributions were significantly different in the GDM group compared to the control group (P < 0.05). No significant difference was observed in the allele distributions of MIF rs1007888 between the GDM group and control group (P > 0.05). GDM patients had higher fasting blood glucose, fasting insulin, and HOMA-insulin resistance levels, but lower HOMA-b levels than normal gestational women (P < 0.05). Fasting blood glucose, fasting insulin, and HOMA-insulin resistance in pregnant women with the GG genotype were significantly higher than those with GA and AA genotypes, while HOMA-b in pregnant women with the GG genotype was lower (all P < 0.05). Our findings demonstrated the associations among MIF polymorphism rs1007888, insulin resistance, and pancreatic β cell functions in GDM patients. The GG genotype of MIF rs1007888 may be a genetic susceptibility factor in the pathogenesis of GDM.

In vivo Toll-like receptor 5 (TLR5) imaging with radiolabeled anti-TLR5 monoclonal antibody in rapamycin-treated mouse allogeneic skin transplantation model

BACKGROUND

In organ transplantation, increasing evidence, both in experimental and human studies, indicates that Toll-like receptor (TLR) activation is involved in the innate immune recognition of allograft. TLR5, the only protein recognition receptor of TLRs, is indicated potentially to be the immune regulation target. This study was designed to determine whether TLR5 could be a biomarker for in vivo allograft visualization, after immunosuppressant rapamycin treatment, using radiolabeled sodium iodide ((131) I)-anti-TLR5 monoclonal antibody (mAb).

METHODS

BALB/c mice were transplanted with C57BL/6 skin, with/without rapamycin treatment (the rapamycin-treated group and the phosphate buffered saline [PBS]-rejection group, respectively). In vivo dynamic whole-body phosphor-autoradiography and ex vivo biodistribution studies were conducted after (131) I-anti-TLR5 mAb injection.

RESULTS

Dynamic phosphor-autoradiography imaging showed clear graft localization from 12 h onward. At 72 h after injection, graft uptake quantified from images was higher for the rapamycin-treated group (26,448 ± 904 digital light units [DLU]/mm(2) ), compared with the PBS-treated allo-rejection group (9176 ± 576 DLU/mm(2) ). Treatment with anti-TLR5 mAb inhibited graft uptake. Organ biodistribution study reflected the same tendency, and (131) I-anti-TLR5 mAb uptake reached a maximum of 12.05 ± 1.86 %ID/g (percent injected dose per gram) at 1 h, and graft-to-native skin ratio reached 8.10 ± 0.10 %ID/g at 72 h after injection in rapamycin-treated grafts.

CONCLUSION

Radiolabeled anti-TLR5 mAb showed higher uptake in allo-treated grafts compared with allo-rejection grafts, which was proved by non-invasive dynamic phosphor-autoradiography imaging, and invasive ex vivo biodistribution. Radiolabeled anti-TLR5 mAb is a new tracer for non-invasive in vivo imaging of TLR5 in rapamycin-treated allograft.

On-chip lithium cells for electrical and structural characterization of single nanowire electrodes

We present a transmission electron microscopy (TEM)-compatible, hybrid nanomachined, on-chip construct for probing the structural and electrical changes in individual nanowire electrodes during lithium insertion. We have assembled arrays of individual β-phase manganese dioxide (β-MnO2) nanowires (NWs), which are employed as a model material system, into functional electrochemical cells through a combination of bottom-up (dielectrophoresis) and top-down (silicon nanomachining) unit processes. The on-chip NWs are electrochemically lithiated inside a helium-filled glovebox and their electrical conductivity is studied as a function of incremental lithium loading during initial lithiation. We observe a dramatic reduction in NW conductivity (on the order of two to three orders in magnitude), which is not reversed when the lithium is extracted from the nanoelectrode. This conductivity change is attributed to an increase in lattice disorder within the material, which is observed from TEM images of the lithiated NWs. Furthermore, electron energy loss spectroscopy (EELS) was employed to confirm the reduction in valence state of manganese, which occurs due to the transformation of MnO2 to LixMnO2.

Plasma-based proteomics reveals lipid metabolic and immunoregulatory dysregulation in post-stroke depression

BACKGROUND

Post-stroke depression (PSD) is the most common psychiatric complication facing stroke survivors and has been associated with increased distress, physical disability, poor rehabilitation, and suicidal ideation. However, the pathophysiological mechanisms underlying PSD remain unknown, and no objective laboratory-based test is available to aid PSD diagnosis or monitor progression.

METHODS

Here, an isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic approach was performed to identify differentially expressed proteins in plasma samples obtained from PSD, stroke, and healthy control subjects.

RESULTS

The significantly differentiated proteins were primarily involved in lipid metabolism and immunoregulation. Six proteins associated with these processes--apolipoprotein A-IV (ApoA-IV), apolipoprotein C-II (ApoC-II), C-reactive protein (CRP), gelsolin, haptoglobin, and leucine-rich alpha-2-glycoprotein (LRG)--were selected for Western blotting validation. ApoA-IV expression was significantly upregulated in PSD as compared to stroke subjects. ApoC-II, LRG, and CRP expression were significantly downregulated in both PSD and HC subjects relative to stroke subjects. Gelsolin and haptoglobin expression were significantly dysregulated across all three groups with the following expression profiles: gelsolin, healthy control>PSD>stroke subjects; haptoglobin, stroke>PSD>healthy control.

CONCLUSIONS

Early perturbation of lipid metabolism and immunoregulation may be involved in the pathophysiology of PSD. The combination of increased gelsolin levels accompanied by decreased haptoglobin levels shows promise as a plasma-based diagnostic biomarker panel for detecting increased PSD risk in post-stroke patients.

Prospective Study of Serum 25-hydroxy Vitamin D and Tooth Loss

Vitamin D deficiency and oral diseases (periodontitis, caries, and tooth loss) are highly prevalent in Germany. Previous studies suggested that vitamin D might be a modifiable and protective factor for periodontitis, caries, and tooth loss. However, prospective studies investigating such associations are limited. We explored the association between the concentration of serum 25-hydroxy vitamin D (25OHD) and incidence of tooth loss, progression of clinical attachment loss (CAL) ≥ 3 mm, and progression of restorative and caries status in a population-based longitudinal study. We analyzed data from 1,904 participants from the Study of Health in Pomerania with a five-year follow-up. Generalized estimating equation models were applied to evaluate tooth-specific associations between serum 25OHD and incidence of tooth loss, progression of CAL ≥ 3 mm, and progression of restorative and caries status. Age, sex, education, smoking status, alcohol drinking, waist circumference, dental visit frequency, reasons of dental visit, vitamin D or calcium supplements, and season of blood draw were considered as confounders. Serum 25OHD was inversely associated with incidence of tooth loss. A significant dose-response relationship (p = .0022) was observed across the quintiles of serum 25OHD. After adjusting for multiple confounders, each 10-µg/L increase of serum 25OHD was associated with a 13% decreased risk of tooth loss (risk ratio: 0.87; 95% confidence interval: 0.79, 0.96). The association was attenuated for changes of CAL ≥ 3 mm when adjusting for multiple confounders. No significant association was found between serum 25OHD and caries progression. Vitamin D might be a protective factor for tooth loss. The effect might partially be mediated by its effect on periodontitis.

PDZ and LIM domain protein 1(PDLIM1)/CLP36 promotes breast cancer cell migration, invasion and metastasis through interaction with α-actinin

Increased CLP36 expression has been found to be closely associated with breast cancer progression. However, whether and how it contributes to malignant behavior of breast cancer cells were not known. We show here that CLP36 is critical for promoting breast cancer cell migration and invasion in vitro and metastasis in vivo, whereas it is dispensable for breast cell proliferation and anchorage independent growth in vitro and tumor growth in vivo. CLP36 interacted with both α-actinin-1 and -4 in breast cancer cells. Depletion of either α-actinin-1 or -4 inhibited breast cancer cell migration. Furthermore, mutations inhibiting the α-actinin-binding activity abolished the ability of CLP36 to promote breast cancer cell migration. Finally, depletion of CLP36 or disruption of the CLP36-α-actinin complex in breast cancer cells substantially inhibited Cdc42 activation, cell polarization and migration. Our results identify CLP36 as an important regulator of breast cancer cell migration and metastasis, and shed light on how increased CLP36 expression contributes to progression of breast cancer.

Proteomics reveal energy metabolism and mitogen-activated protein kinase signal transduction perturbation in human Borna disease virus Hu-H1-infected oligodendroglial cells

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A human strain of BDV (BDV Hu-H1) was used to infect human oligodendroglial cells (OL cells).

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Energy metabolism was the most significantly altered pathway in BDV Hu-H1-infected OL cells.

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The Raf/MEK/ERK signaling cascade was significantly perturbed in BDV Hu-H1-infected OL cells.

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BDV Hu-H1caused constitutive activation of the ERK1/2 pathway, but cell proliferation was down-regulated at the same time.

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BDV Hu-H1 manages to down-regulate cell proliferation, in the presence of activated but not translocated ERK–RSK complex.

Borna disease virus (BDV) is a neurotropic, non-cytolytic RNA virus which replicates in the cell nucleus targeting mainly hippocampal neurons, but also astroglial and oligodendroglial cells in the brain. BDV is associated with a large spectrum of neuropsychiatric pathologies in animals. Its relationship to human neuropsychiatric illness still remains controversial. We could recently demonstrate that human BDV strain Hu-H1 promoted apoptosis and inhibited cell proliferation in a human oligodendroglial cell line (OL cells) whereas laboratory BDV strain V acted contrariwise. Here, differential protein expression between BDV Hu-H1-infected OL cells and non-infected OL cells was assessed through a proteomics approach, using two-dimensional electrophoresis followed by matrix-assisted laser desorption ionization-time of flight tandem mass spectrometry. A total of 63 differential host proteins were identified in BDV Hu-H1-infected OL cells compared to non-infected OL cells. We found that most changes referred to alterations related to the pentose phosphate pathway, glyoxylate and dicarboxylate metabolism, the tricarboxylic acid (TCA) cycle, and glycolysis /gluconeogenesis. By manual querying, two differential proteins were found to be associated with mitogen-activated protein kinase (MAPK) signal transduction. Five key signaling proteins of this pathway (i.e., p-Raf, p-MEK, p-ERK1/2, p-RSK, and p-MSK) were selected for Western blotting validation. p-ERK1/2 and p-RSK were found to be significantly up-regulated, and p-MSK was found to be significantly down-regulated in BDV Hu-H1-infected OL cells compared to non-infected OL cell. Although BDV Hu-H1 constitutively activated the ERK–RSK pathway, host cell proliferation and nuclear translocation of activated pERK in BDV Hu-H1-infected OL cells were impaired. These findings indicate that BDV Hu-H1 infection of human oligodendroglial cells significantly perturbs host energy metabolism, activates the downstream ERK–RSK complex of the Raf/MEK/ERK signaling cascade, and disturbs host cell proliferation possibly through impaired nuclear translocation of pERK, a finding which warrants further research.

Adenosine 5'-monophosphate ameliorates D-galactosamine/lipopolysaccharide-induced liver injury through an adenosine receptor-independent mechanism in mice

D-galactosamine (GalN)/lipopolysaccharide (LPS)-induced lethality and acute liver failure is dependent on endogenously produced inflammatory cytokines. Adenosine has been proven to be a central role in the regulation of inflammatory response. It is not entirely clear that which adenosine action is actually crucial to limiting inflammatory tissue destruction. Here we showed that GalN/LPS challenge elevated hepatic adenosine and induced lethality in adenosine receptor-deficient mice with equal efficiency as wild-type mice. In GalN/LPS-treated mice, pretreatment with adenosine 5'-monophosphate (5'-AMP) significantly elevated hepatic adenosine level and reduced mortality through decreasing cytokine and chemokine production. In RAW264.7 cells, 5'-AMP treatment inhibited the production of inflammatory cytokines, which is not mediated through adenosine receptors. 5'-AMP failed to attenuate LPS-induced nuclear factor-κB (NF-κB) p65 nuclear translocation, but reduced LPS-induced recruitment of NF-κB p65 to inflammatory gene promoters and decreased LPS-induced enrichment of H3K4 dimethylation at the tumor necrosis factor-α (TNF-α) promoter, which was involved in 5'-AMP-induced elevation of cellular adenosine and a decline of methylation potential. In vitro biochemical analysis revealed that adenosine directly attenuated recruitment of NF-κB to the TNF-α and interleukin-6 promoters. Our findings demonstrate that 5'-AMP-inhibiting inflammatory response is not mediated by adenosine receptors and it may represent a potential protective agent for amelioration of LPS-induced liver injury.

Efficacy and safety of traditional chinese medicine (Shenqi particle) for patients with idiopathic membranous nephropathy: a multicenter randomized controlled clinical trial

BACKGROUND

To compare the safety and efficacy of the traditional Chinese medicine Shenqi particle and standard therapy with prednisone and cyclophosphamide (control) in adult patients with idiopathic membranous nephropathy (IMN).

STUDY DESIGN

Open-label, multicenter, parallel, randomized, controlled clinical trial.

SETTING & PARTICIPANTS

From April 2008 to February 2011, a total of 190 patients with biopsy-proven IMN from 7 hospitals in China participated in the study. All patients had nephrotic syndrome with estimated glomerular filtration rate (eGFR) >30 mL/min/1.73 m(2).

INTERVENTION

Shenqi particle (9.6 g 3 times per day) or prednisone (1 mg/kg/d tapering to 0.17 mg/kg/d) and cyclophosphamide (total dose of 9-12 g per square meter of body surface area) for 48 weeks.

OUTCOMES

Primary outcomes included complete remission, defined as proteinuria (24-hour urine protein excretion) ≤0.3 g/d, or partial remission, defined as proteinuria with protein excretion >0.3-<3.5 g/d and a 50% reduction from its peak value at 48 weeks. Secondary outcomes included serum albumin level, eGFR, doubling of serum creatinine level, end-stage renal disease, and death.

RESULTS

Baseline values for proteinuria and eGFR were 5.34 ± 2.74 g/d and 84.0 ± 27.4 mL/min/1.73 m(2) for the Shenqi particle group and 5.33 ± 2.47 g/d and 83.8 ± 24.9 mL/min/1.73 m(2) for the control group, respectively. 132 patients (63 Shenqi particle group, 69 control group) completed the study. Change in urinary protein excretion in the Shenqi particle group was -3.01 (95% CI, -3.68 to -2.34) g/d, and in the control group, -3.28 (95% CI, -3.98 to -2.58) g/d; the mean difference between groups was 0.27 (95% CI, -0.70 to 1.23) g/d (P = 0.6). Changes in eGFR were 12.3 (95% CI, 4.99 to 19.6) mL/min/1.73 m(2) in the Shenqi particle group and -2.8 (95% CI, -10.32 to 4.77) mL/min/1.73 m(2) in the control group; the mean difference between groups was 15.1 (95% CI, 4.56 to 25.55) mL/min/1.73 m(2) (P = 0.005). Severe adverse events occurred in only the control group (14.5%) and included lung infection, liver injury, and pneumonia.

LIMITATIONS

High rate of loss to follow-up and lack of observation period prior to the study.

CONCLUSIONS

Shenqi particle may be a promising alternative therapy for adults with IMN and nephrotic syndrome.

S-allyl cysteine restores erectile function through inhibition of reactive oxygen species generation in diabetic rats

Excessive production of reactive oxygen species (ROS) by an overactive nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system in penile tissue is an important mechanism of erectile dysfunction (ED). S-allyl cysteine (SAC), a bioactive component derived from garlic, was recently reported to exert versatile antioxidant properties. We hypothesized that SAC would be able to resolve diabetes-related ED by reducing ROS generation, and designed this study to investigate this possibility as well as to determine the related underlying mechanisms. A streptozotocin-induced diabetes rat model was established and used for comparative analysis of 4-week treatment regimens with insulin or SAC. The ratio of maximal intracavernous pressure (ICP) to mean arterial blood pressure (MAP) was measured to determine erectile function. Differential levels of ROS, NADPH oxidase subunits, nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signalling pathway, and apoptosis were evaluated in cavernous tissues. Max ICP/MAP was found to be markedly decreased in untreated diabetic rats; SAC, but not insulin, treatment restored the ratio to baseline (in non-diabetic untreated controls). The corpus cavernosum of untreated diabetic rats showed increased p47(phox) and p67(phox) expression, ROS production and penile apoptotic index, and decreased phospho-endothelial nitric oxide synthase (phospho-eNOS, Ser1177) expression, cGMP concentration, B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein (Bax) ratio and smooth muscle cell number. SAC treatment normalized all the diabetes-induced effects, whereas insulin treatment partially normalized the alterations, but produced no effects on P47(phox) expression, penile ROS level, apoptotic index, Bcl-2/Bax ratio and smooth muscle cell number. Collectively, these data indicate that SAC treatment can restore erectile function in diabetic rats by preventing ROS formation through modulation of NADPH oxidase subunit expression. Furthermore, the poor efficacy of conventional insulin treatment for diabetic ED may be associated with an elevated level of ROS in penile tissue.

Characteristics and molecular basis of celecoxib modulation on K(v)7 potassium channels

BACKGROUND AND PURPOSE

Celecoxib is a selective cyclooxygenase-2 (COX-2) inhibitor used for the treatment of pain and inflammation. Emerging and accumulating evidence suggests that celecoxib can affect cellular targets other than COX, such as ion channels. In this study, we characterized the effects of celecoxib on K(v)7 K(+) channels and compared its effects with the well-established K(v)7 channel opener retigabine.

EXPERIMENTAL APPROACH

A perforated whole-cell patch technique was used to record K(v)7currents expressed in HEK 293 cells and M-type currents from rat superior cervical ganglion neurons.

KEY RESULTS

Celecoxib enhanced K(v)7.2-7.4, K(v)7.2/7.3 and K(v)7.3/7.5 currents but inhibited K(v)7.1 and K(v)7.1/KCNE1 currents and these effects were concentration dependent. The IC(50) value for inhibition of K(v)7.1 channels was approximately 4 µM and the EC(50) values for activation of K(v)7.2-7.4, K(v)7.2/K(v)7.3 and K(v)7.3/K(v)7.5 channels were approximately 2-5 µM. The effects of celecoxib were manifested by increasing current amplitudes, shifting the voltage-dependent activation curve in a more negative direction and slowing the deactivation of K(v)7 currents. 2,5-Dimethyl-celecoxib, a celecoxib analogue devoid of COX inhibition activity, has similar but greater effects on K(v)7currents. K(v)7.2(A235T) and K(v) 7.2(W236L) mutant channels, which have greatly attenuated responses to retigabine, showed a reversed response to celecoxib, from activation to inhibition.

CONCLUSIONS AND IMPLICATIONS

These results suggest that K(v)7 channels are targets of celecoxib action and provide new mechanistic evidence for understanding the effects of celecoxib. They also provide a new approach to developing K(v)7 modulators and for studying the structure-function relationship of K(v)7 channels.

Effect of thyroxine on synaptotagmin 1 and SNAP-25 expression in dorsal hippocampus of adult-onset hypothyroid rats

Adult-onset hypothyroidism causes cognitive dysfunctions of learning and memory, in which many synaptic proteins in hippocampus are involved. In our work, we studied the effect of adult-onset hypothyroidism on the expression of synaptotagmin 1 (syt 1) and SNAP-25 in dorsal hippocampus as well as its recovery by levothyroxine (L-T(4)) replacement therapy. Rats were divided into 4 groups: control, hypothyroidism, and hypothyroid rats treated with 5 μg T(4)/100 g body weight (BW) and 20 μg L-T(4)/100 g BW, respectively. Protein levels of syt 1 and SNAP-25 in dorsal hippocampus were determined by Western blot and immunohistochemistry. The immunoblot analysis indicated that syt 1 was expressed at a significantly lower level in hypothyroid rats, while the level of SNAP-25 was much higher compared to controls. Furthermore, using immunostaining, we found that on the one hand, expression of syt 1 was significantly down-regulated in the examined layers of CA1 and CA3 subregions but not dentate gyrus (DG); however, on the other hand, expression of SNAP-25 was up-regulated in the layers of CA1, CA3, and DG. Two-week treatment with 20 μg LT(4)/ 100 g BW fully restored the levels of syt 1 and SNAP-25 to the normal level, which was more effective than 5 μg LT(4)/ 100 g BW that partially restored the levels of both proteins. These results suggest that adult-onset hypothyroidism caused down-regulation of syt 1 and up-regulation of SNAP- 25 level in dorsal hippocampus, which could be restored by L-T(4) treatment, and the recovery degree is related to the LT(4) dosage.

Regulation of mixed lineage kinase 3 is required for Neurofibromatosis-2-mediated growth suppression in human cancer

The Neurofibromatosis-2 (NF2) tumor suppressor merlin negatively regulates cell proliferation in numerous cell types. We have previously shown that the NF2 protein (merlin/schwannomin) associates with mixed lineage kinase 3 (MLK3), a mitogen-activated protein kinase (MAPK) kinase kinase that is required for the proliferation of normal and neoplastic cells. In this study, we show that merlin inhibits MLK3 activity, as well as the activation of its downstream effectors, B-Raf, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK). The ability of merlin to regulate MLK3 activity requires a direct association between MLK3 and residues in the C-terminal region of merlin. Merlin integrates Rho GTPase family signaling with MAPK activity by inhibiting the binding between MLK3 and its upstream activator, Cdc42. Furthermore, we demonstrate that MLK3 is required for merlin-mediated suppression of cell proliferation and invasion. Collectively, these results establish merlin as a potent inhibitor of MLK3, ERK and JNK activation in cancer, and provide a mechanistic link between deregulated MAPK and Rho GTPase signaling in NF2 growth control.