Human ciliary neurotrophic factor (CNTF) is a neurotrophic cytokine that exerts a neuroprotective effect in multiple sclerosis and amyotrophic lateral sclerosis. Clinical application of human CNTF, however, was prevented by high toxicity at higher dosages. Human CNTF elicits cellular responses by induction of a receptor complex consisting of the CNTF ␣-receptor (CNTFR), which is not involved in signal transduction, and the ␤-receptors gp130 and leukemia inhibitory factor receptor (LIFR). Previous studies with rat CNTF demonstrated that rat CNTF is unable to interact with the human interleukin-6 ␣-receptor, whereas at high concentrations, it can directly induce a signaling heterodimer of human gp130 and human LIFR in the absence of the CNTF receptor. Here, we demonstrate that human CNTF cannot directly induce a heterodimer of human gp130 and LIFR. However, human CNTF can use both the membrane-bound and the soluble human IL-6R as a substitute for its cognate ␣-receptor and thus widen the target spectrum of human CNTF. Engineering a CNTFRspecific human CNTF variant may therefore be a prerequisite to improving the safety profile of CNTF.

Adiponectin and intracellular 5′adenosine monophosphate-activated protein kinase (AMPK) are important modulators of glucose and fat metabolism. Cinnamon exerts beneficial effects by improving insulin sensitivity and blood lipids, e.g., through increasing adiponectin concentrations and AMPK activation. The underlying mechanism is unknown. The Gi/Go-protein-coupled receptor (GPR) 109A stimulates adiponectin secretion after binding its ligand niacin. Trans-cinnamic acid (tCA), a compound of cinnamon is another ligand. We hypothesize whether AMPK activation and adiponectin secretion by tCA is transmitted by GPR signaling. Differentiated 3T3-L1 cells were incubated with pertussis toxin (PTX), an inhibitor of Gi/Go-protein-coupling, and treated with different tCA concentrations. Treatment with tCA increased adiponectin and the pAMPK/AMPK ratio (p ≤ 0.001). PTX incubation abolished the increased pAMPK/AMPK ratio and adiponectin secretion. The latter remained increased compared to controls (p ≤ 0.002). tCA treatment stimulated adiponectin secretion and AMPK activation; the inhibitory effect of PTX suggests GPR is involved in tCA stimulated signaling.

Defensins are a predominant class of antimicrobial peptides, which act as endogenous antibiotics. Defensins are classified into three distinct sub-families: θ -, β-, and α-defensins. Synthesis of α-defensin has been confirmed only in primates and glires to date and is presumably unique for a few tissues, including neutrophils and Paneth cells of the small intestine. Antimicrobial activities of these peptides were shown against a wide variety of microbes including bacteria, fungi, viruses and protozoan parasites. In the present study, we report the characterization of the equine α-defensin DEFA (defensin α) 1. Transcription analysis revealed that the transcript of the gene is present in the small intestine only. An alignment with known α-defensins from primates and glires displayed a homology with Paneth-cell-specific α-defensins. DEFA1 was recombinantly expressed in Escherichia coli and subsequently analysed structurally by CD and molecular modelling. To examine the antimicrobial properties, a radial diffusion assay was performed with 12 different micro-organisms and the LD 90 (lethal dose killing 90 % of target organism) and MBC (minimal bactericidal concentration) values were examined. DEFA1 showed an antimicrobial activity against different Grampositive and Gram-negative bacteria and against the yeast Candida albicans. Using viable bacteria in combination with a membrane-impermeable fluorescent dye, as well as depolarization of liposomes as a minimalistic system, it became evident that membrane permeabilization is at least an essential part of the peptide's mode of action.

27Human psoriasin (S100A7) has originally been described as a member of the family of S100 28 calcium-binding proteins which is overexpressed in patients suffering from psoriasis. The 29 bovine homolog was first identified as a cow-derived respiratory allergen. As Escherichia 30 coli-mastitis is a common problem in dairy cattle, and human psoriasin was found to exhibit 31 antimicrobial activity preferentially against E. coli, we examined whether the bovine mRNA 32 is expressed in the mammary gland. The antimicrobial activity of the recombinant bovine psoriasin is comparable with human 39 psoriasin and also limited to E. coli. 40Psoriasin appears to be a part of the local host defense mechanism in the udder, is a putative 41 candidate for a cow-specific factor influencing mastitis susceptibility, and a possible 42 alternative to convential antibiotics.

The transition period in dairy cows (3 weeks prepartum until 3 weeks postpartum) is associated with substantial mobilization of energy stores, which is often associated with metabolic diseases. Nicotinic acid (NA) is an antilipolytic and lipid-lowering compound used to treat dyslipidaemia in humans, and it also reduces non-esterified fatty acids in cattle. In mice the G-protein coupled receptor 109A (GPR109A) ligand NA positively affects the secretion of adiponectin, an important modulator of glucose and fat metabolism. In cattle, the corresponding data linking NA to adiponectin are missing. Our objective was to examine the effects of NA on adiponectin and AMPK protein abundance and the expression of mRNAs of related genes such as chemerin, an adipokine that enhances adiponectin secretion in vitro. Differentiated bovine adipocytes were incubated with pertussis toxin (PTX) to verify the involvement of GPR signaling, and treated with 10 or 15 µM NA for 12 or 24 h. NA increased adiponectin concentrations (p ≤ 0.001) and the mRNA abundances of GPR109A (p ≤ 0.05) and chemerin (p ≤ 0.01). Pre-incubation with PTX reduced the adiponectin response to NA (p ≤ 0.001). The NA-stimulated secretion of adiponectin and the mRNA expression of chemerin in the bovine adipocytes were suggestive of GPR signaling-dependent improved insulin sensitivity and/or adipocyte metabolism in dairy cows.