The chemokines CCL5, CCL2 and CXCL12 play significant roles in the migration of Th1 cells into rheumatoid synovial tissue

As the T-cell population in the synovial tissue (ST) in rheumatoid arthritis (RA) is dominated by T helper (Th) 1 cells, this study was designed to examine whether there is a preferential migration of polarized T cells to ST, and to identify the chemokines responsible for the migration. This was done by developing 10 T-cell clones specific for an arbitrary antigen (mouse immunoglobulin G (IgG)) from the peripheral blood (PB) of a healthy donor sensitized to mouse IgG. The Th polarizations of the clones were determined by measuring secreted interferon-gamma and interleukin-4, following anti-CD3 stimulation. Migration to pools of RA ST cell-derived supernatants was analysed. Expression of the chemokine receptors CCR1, CCR2, CCR3, CCR4, CCR5, CCR6, CCR7, CCR8, CXCR3 and CXCR4 were analysed by flow cytometry. Th1 clones showed significantly higher migration to RA ST cell-derived supernatant compared with Th2 clones. Blocking of either of the chemokines, CCL5 or CCL2, strongly inhibited migration of the Th1 cells between 56 and 77%, while blocking of CXCL12 inhibited migration between 44 and 61%. Blocking of CXCL10 had only a minor inhibitory effect. Our results demonstrate a selective migration of Th1 cells to RA ST supernatant and that blocking either CCL5, CCL2 or CXCL12 significantly inhibits T-cell migration. This indicates that CCL5, CCL2 and CXCL12 play significant roles in attracting Th1 cells towards the RA ST, and may prove potent targets for obstructing T-cell migration to the synovium.     

Cerebrospinal fluid S100B correlates with brain atrophy in Alzheimer's disease

S100B is a predominantly astrocytic protein with dose-dependent cytotoxic and neurotrophic properties encoded on chromosome 21q22.3. Concentrations of S100B were measured in the cerebrospinal fluid (CSF) of 31 patients with Alzheimer's disease (AD), 36 patients with frontotemporal lobe dementia (FTLD) and 49 patients with other non-inflammatory neurological diseases. Additional CSF S100B concentrations were correlated with normalised brain volume measurements in AD and FTLD. CSF S100B was significantly higher in AD (Mean+/-standard deviation=0.4+/-0.2 ng/ml) and FTLD (0.42+/-0.19 ng/ml) patients when compared with control subjects (0.25+/-0.08, P<0.001). In patients with AD, S100B correlated negatively with normalised brain volume (R(S)=-0.53, P<0.001). No such correlation was found for FTLD patients. This study supports the concept that S100B is of pathological relevance for degeneration of the central nervous system in AD.     

Immunogenetics of two new HLA alleles: A*0108 and B*4031

Two new alleles, HLA-A*0108 and B*4031, were identified in north-western European Caucasoid subjects. A*0108 differed from A*010101 by a single substitution (C to T) at position 216 in exon 3, resulting in an amino acid difference of Arg to Trp at position 163. It was present on a haplotype with B*1501/60/70/71; Cw*0303; DRB1*1301; DRB3*0202; DQA1*0103; DQB1*0603 and its product reacted as a normal HLA-A1 specificity. B*4031 differed from B*4001 by two nucleotides in exon 3 (positions 20 (G to C) and 69 (A to G)) resulting in two amino acid differences (Arg to Ser at position 97 and Asn to Asp at position 114). It was found on a haplotype with HLA-A*03; Cw*0304; DRB1*0404/32; DRB4*0101/3/5; DQA1*03; DQB1*0302 and has the HLA-B60 specificity. Both alleles have frequencies of < 0.0002 in the largely north-western European Caucasoid blood donor population resident in Wales.     

Relationship between the serotonin transporter polymorphism and obsessive-compulsive alcohol craving in alcohol-dependent adults: a pilot study

A serotonin deficiency state has been implicated in alcohol-dependent individuals' experience of obsessive-compulsive alcohol craving. Because the serotonin transporter (5-HTT) functions to remove serotonin from the synapse, it is thought that increased reuptake (indicated by the number of high-expressing L_A alleles present in the 5-HTT gene-linked polymorphic region [5-HTTLPR] of the SLC6A4 gene) is associated with an increase in obsessive-compulsive alcohol craving. The current pilot investigation sought to explore this hypothesis by examining the extent to which obsessive-compulsive alcohol craving varies by 5-HTTLPR genotype among participants enrolled in an ongoing pharmacogenetics trial. All participants were screened with a semi-structured diagnostic interview, completed self-report measures of alcohol-related behavior, and underwent peripheral venous blood draw for DNA genotyping. Cross-sectional data obtained at baseline from 176 currently drinking alcohol-dependent individuals were analyzed using multiple regression. Preliminary findings suggest that 5-HTTLPR is not predictive of Obsessive Compulsive Drinking Scale total and factor scores. Although the 5-HTTLPR polymorphism was not related to obsessive-compulsive alcohol craving in this pilot study, additional research is needed to clarify the possible role of serotonergic mechanisms in alcohol craving.     

Engineered cellular response to scaffold architecture in a rabbit trephine defect

Tight control of pore architecture in porous scaffolds for bone repair is critical for a fully elucidated tissue response. Solid freeform fabrication (SFF) enables construction of scaffolds with tightly controlled pore architecture. Four types of porous scaffolds were constructed using SFF and evaluated in an 8-mm rabbit trephine defect at 8 and 16 weeks (n = 6): a lactide/glycolide (50:50) copolymer scaffold with 20% w/w tri-calcium phosphate and random porous architecture (Group 1); another identical design made from poly(desaminotyrosyl-tyrosine ethyl ester carbonate) [poly(DTE carbonate)], a tyrosine-derived pseudo-polyamino acid (Group 2); and two poly(DTE carbonate) scaffolds containing 500 microm pores separated by 500-microm thick walls, one type with solid walls (Group 3), and one type with microporous walls (Group 4). A commercially available coralline scaffold (Interpore) with a 486-microm average pore size and empty defects were used as controls. There was no significant difference in the overall amount of bone ingrowth in any of the devices, as found by radiographic analysis, but patterns of bone formation matched the morphology of the scaffold. These results suggest that controlled scaffold architecture can be superimposed on biomaterial composition to design and construct scaffolds with improved fill time.     

Responses of Single Motor Units in Human Masseter to Transcranial Magnetic Stimulation of Either Hemisphere

The corticobulbar inputs to single masseter motoneurons from the contra- and ipsilateral motor cortex were examined using focal transcranial magnetic stimulation (TMS) with a figure-of-eight stimulating coil. Fine-wire electrodes were inserted into the masseter muscle of six subjects, and the responses of 30 motor units were examined. All were tested with contralateral TMS, and 87 % showed a short-latency excitation in the peristimulus time histogram at 7.0 ± 0.3 ms. The response was a single peak of 1.5 ± 0.2 ms duration, consistent with monosynaptic excitation via a single D- or I₁-wave volley elicited by the stimulus. Increased TMS intensity produced a higher response probability (   n = 13  , paired t test,   P < 0.05  ) but did not affect response latency. Of the remaining motor units tested with contralateral TMS, 7 % did not respond at intensities tested, and 7 % had reduced firing probability without any preceding excitation. Sixteen of these motor units were also tested with ipsilateral TMS and four (25 %) showed short-latency excitation at 6.7 ± 0.6 ms, with a duration of 1.5 ± 0.3 ms. Latency and duration of excitatory peaks for these four motor units did not differ significantly with ipsilateral vs . contralateral TMS (paired t tests,   P > 0.05  ). Of the motor units tested with ipsilateral TMS, 56 % responded with a reduced firing probability without a preceding excitation, and 19 % did not respond. These data suggest that masseter motoneurons receive monosynaptic input from the motor cortex that is asymmetrical from each hemisphere, with most low threshold motoneurons receiving short-latency excitatory input from the contralateral hemisphere only.     

Epidermal growth factor-induced epithelio-mesenchymal transition in human breast carcinoma cells

PMC42-LA cells display an epithelial phenotype: the cells congregate into pavement epithelial sheets in which E-cadherin and beta-catenin are localized at cell-cell borders. They abundantly express cytokeratins, although 5% to 10% of the cells also express the mesenchymal marker vimentin. Stimulation of PMC42-LA cells with epidermal growth factor (EGF) leads to epithelio-mesenchymal transition-like changes including up-regulation of vimentin and down-regulation of E-cadherin. Vimentin expression is seen in virtually all cells, and this increase is abrogated by treatment of cells with an EGF receptor antagonist. The expression of the mesenchyme-associated extracellular matrix molecules fibronectin and chondroitin sulfate proteoglycan also increase in the presence of EGF. PMC42-LA cells adhere rapidly to collagen I, collagen IV, and laminin-1 substrates and markedly more slowly to fibronectin and vitronectin. EGF increases the speed of cell adhesion to most of these extracellular matrix molecules without altering the order of adhesive preference. EGF also caused a time-dependent increase in the motility of PMC42-LA cells, commensurate with the degree of vimentin staining. The increase in motility was at least partly chemokinetic, because it was evident both with and without chemoattractive stimuli. Although E-cadherin staining at cell-cell junctions disappeared in response to EGF, beta-catenin persisted at the cell periphery. Further analysis revealed that N-cadherin was present at the cell-cell junctions of untreated cells and that expression was increased after EGF treatment. N- and E-cadherin are not usually coexpressed in human carcinoma cell lines but can be coexpressed in embryonic tissues, and this may signify an epithelial cell population prone to epithelio-mesenchymal-like responses.