Hierarchy of eosinophil chemoattractants: role of p38 mitogen-activated protein kinase

Several chemoattractants can regulate the recruitment of eosinophils to sites of inflammation, but the hierarchy among them is unknown. We observed here that eosinophil chemotaxis towards eotaxin or 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE) was amplified up to sixfold in the presence of prostaglandin (PG) D2. This effect was only seen in eosinophils, and not in neutrophils or basophils. Pretreatment with the chemoattractant receptor-homologous molecule expressed on TH2 cells (CRTH2) antagonist ramatroban prevented the PGD2 enhancement of eosinophil migrations. In contrast, eotaxin or 5-oxo-ETE inhibited the migration of eosinophils towards PGD2. 5-oxo-ETE enhanced the chemotaxis to eotaxin, while eotaxin had no effect on 5-oxo-ETE-induced migration. 5-oxo-ETE induced the phosphorylation of p38 mitogen-activated protein kinase, and inhibition of p38 mitogen-activated protein kinase by SB-202190 converted the effect of 5-oxo-ETE on the chemotaxis to PGD2 from inhibition to enhancement. The presence of blood or plasma markedly decreased the sensitivity of eosinophils to eotaxin or 5-oxo-ETE, while responses to PGD2 were unaltered. In conclusion, PGD2 might be an initial chemoattractant, since it maintains its potency in the circulation and augments the responsiveness of eosinophils to other chemoattractants. In contrast, eotaxin seems to be an end-point chemoattractant, since it has reduced efficacy in blood and is capable of down-modulating eosinophil responsiveness to other chemoattractants.     

Free energy calculations on snake venom metalloproteinase BaP1

BaP1 is a snake venom metalloproteinase from the venom of Bothrops asper, showing high structural homology with the catalytic domain of human adamalysins and matrix metalloproteinases. It induces the release of cytokines, like interleukin-1 and tumor necrosis factor alpha. Recently, the high-resolution crystal structure of BaP1 with a bound inhibitor became available, representing an interesting model concerning inhibitor design for medicinally important metalloproteinases such as tumor necrosis factor alpha-converting enzyme and MMP13. We here use computational modeling to gain a better understanding about the binding properties of various ligands to BaP1, with a focus on computing ligand binding free energies. The obtained results should be of general significance for future research on medicinally important metalloproteinases. We have investigated the binding of the original inhibitor in detail and calculated its binding strength using MMP/GBSA free energy calculations. Additionally, the binding strengths of alternative ligands have been computed, and two of them are predicted and experimentally verified to strongly inhibit the enzyme. A suggestion for chemical modifications of BaP1 inhibitors could be made to guide future synthesis efforts. Furthermore, a contribution to the proteolytic reaction mechanism of metzincins is given. The pK value of the catalytically active glutamic acid residue 143 has been found to be significantly raised when compared with a free glutamate side chain. Calculations on other matrix metalloproteinases confirmed that this is not confined to BaP1, but seems to be a common feature of metzincins.     

The scale for the assessment and rating of ataxia correlates with dysarthria assessment in Friedreich's ataxia

Dysarthria is an acquired neurogenic sensorimotor speech symptom and an integral part within the clinical spectrum of ataxia syndromes. Ataxia measurements and disability scores generally focus on the assessment of motor functions. Since comprehensive investigations of dysarthria in ataxias are sparse, we assessed dysarthria in ataxia patients using the Frenchay Dysarthria Assessment. The Frenchay Dysarthria Assessment is a ten-item validated test in which eight items focus on the observation of oral structures and speech functions. Fifteen Friedreich's ataxia patients and 15 healthy control individuals were analyzed using clinical and logopedic methodology. All patients underwent neurological assessment applying the Scale for the Assessment and Rating of Ataxia. In Friedreich's ataxia patients, the Frenchay sub-item voice showed to be most affected compared to healthy individuals followed by items such as reflexes, palate, tongue, and intelligibility. Scoring of lips, jaw, and respiration appeared to be mildly affected. Ataxia severity in Friedreich's ataxia patients revealed a significant correlation with the Frenchay dysarthria sum score. The introduction of a binary Adapted Dysarthria Score additionally allowed allocation to distinct dysarthria pattern in ataxias. The Frenchay Dysarthria Assessment proved to be a valid dysarthria measure in Friedreich's ataxia. Its availability in several languages provides a major advantage regarding the applicability in international clinical studies. Shortcomings of the Frenchay test are the multiplicity of items tested and its alphabetic coding. Numerical scoring and condensation of assessments in a modified version may, however, provide an excellent clinical tool for the measurement and scoring of dysarthria in ataxic speech disorders.     

Tormentil for active ulcerative colitis: an open-label, dose-escalating study

BACKGROUND: Tormentil extracts (TE) have antioxidative properties and are used as a complementary therapy for chronic inflammatory bowel disease. In individual patients with ulcerative colitis (UC) positive effects have been observed. GOALS: To assess the safety, pharmacology, and clinical effects of different doses of TE in patients with active UC. STUDY: Sixteen patients with active UC [clinical activity index (CAI) >/=5] received TE in escalating doses of 1200, 1800, 2400 and 3000 mg/d for 3 weeks each. Each treatment phase was followed by a 4-week washout phase. The outcome parameters were side effects, CAI, C-reactive protein, and tannin levels in patient sera. RESULTS: Mild upper abdominal discomfort was experienced by 6 patients (38%), but did not require discontinuation of the medication. During therapy with 2400 mg TE per day, median CAI and C-reactive protein improved from 8 (6 to 10.75) and 8 (3 to 17.75) mg/L at baseline to 4.5 (1.75 to 6) and 3 (3 to 6) mg/L, respectively. During therapy, the CAI decreased in all patients, whereas it increased during the washout phase. Neither undegraded nor metabolized tannins could be detected by liquid-mass spectrometry (LC-MS) in patient sera. CONCLUSIONS: TE appeared safe up to 3000 mg/d. Tannins from TE are not systemically absorbed. The efficacy in patients with UC should be further evaluated.     

ZDHHC9 X-linked intellectual disability: Clinical and molecular characterization

The ZDHHC9 gene encodes the Zinc Finger DHHC-Type Containing 9 protein that functions as a palmitoyltransferase. Variants in this gene have been reported as the cause of Raymond-type X-linked intellectual disability with only 16 families described in the literature. This study reviews molecular and clinical data from previously reported patients and reports the case of a 13-year-old patient with a splicing variant in ZDHHC9 presenting intellectual disability, developmental delay, facial dysmorphisms, and skeletal defects. Although intellectual disability and developmental delay with severe speech delay have been reported in all cases with available clinical data, the remaining clinical signs differ significantly between patients. Missense, nonsense, frameshift, and splicing variants, in addition to large exonic deletions, have been described suggesting a loss of function mechanism. Though variants are distributed in almost all exons, most missense and nonsense variants affect arginine residues located in the cytoplasmic domains of this transmembrane protein, suggesting possible mutational hotspots.