Visfatin alters the cytokine and matrix-degrading enzyme profile during osteogenic and adipogenic MSC differentiation.

OBJECTIVES: Age-related bone loss is associated with bone marrow adiposity. Adipokines (e.g., visfatin, resistin, leptin) are adipocyte-derived factors with immunomodulatory properties and might influence differentiation of bone marrow-derived mesenchymal stem cells (MSC) in osteoarthritis (OA) and osteoporosis (OP). Thus, the presence of adipokines and MMPs in bone marrow and their effects on MSC differentiation were analyzed. METHODS: MSC and ribonucleic acid (RNA) were isolated from femoral heads after hip replacement surgery of OA or osteoporotic femoral neck fracture (FF) patients. Bone structural parameters were evaluated by microcomputed tomography (µCT). MSC were differentiated towards adipocytes or osteoblasts with/without adipokines. Gene expression (adipokines, bone marker genes, MMPs, TIMPs) and cytokine production was evaluated by realtime-polymerase chain reaction (realtime-PCR) and enzyme-linked immunosorbent assay (ELISA). Matrix mineralization was quantified using Alizarin red S staining. RESULTS: µCT showed an osteoporotic phenotype of FF compared to OA bone (reduced trabecular thickness and increased ratio of bone surface vs volume of solid bone). Visfatin and leptin were increased in FF vs OA. Visfatin induced the secretion of IL-6, IL-8, and MCP-1 during osteogenic and adipogenic differentiation. In contrast to resistin and leptin, visfatin increased MMP2 and MMP13 during adipogenesis. In osteogenically differentiated cells, MMPs and TIMPs were reduced by visfatin. Visfatin significantly increased matrix mineralization during osteogenesis, whereas collagen type I expression was reduced. CONCLUSION: Visfatin-mediated increase of matrix mineralization and reduced collagen type I expression could contribute to bone fragility. Visfatin is involved in impaired bone remodeling at the adipose tissue/bone interface through induction of proinflammatory factors and dysregulated MMP/TIMP balance during MSC differentiation.

A chromosome-wide QTL study on BTA29 affecting temperament traits in German Angus beef cattle and mapping of DRD4.

The behaviour of beef cattle is important for the safety and welfare of stockmen and animals. Ten microsatellites spanning BTA29 and, in addition, the candidate gene, dopamine receptor D4 gene, were analysed in 545 German Angus calves of six sires and included in a quantitative trait locus (QTL) study on the basis of three different behaviour tests. A putative QTL for the score while entering the scale (ScE) was detected at BMS764. The DRD4 fragment was mapped in the distal region of BTA29 15.3 cM distal of ILSTS081. The results clearly indicate that BTA29 with a putative QTL in the proximal part and the candidate gene, DRD4, in the distal part plays an important role in the regulation of temperament. During the study one of the sires was detected to be a blood chimera.

Genetic variation in monoamine oxidase A and analysis of association with behaviour traits in beef cattle.

Husbandry of beef cattle requires animals that do not behave aggressively or timidly. The enzyme monoamine oxidase A and the coding gene (MAOA) play an important role in the complex regulation of behaviour. The complete coding region and a part of the non-coding sequence of the bovine MAOA gene have been analysed in 20 German Angus and 20 German Simmental bulls and cows with the aim of detecting genetic variability. These two cattle breeds are known to differ regarding their behaviour during handling. Five single nucleotide polymorphisms (SNPs) were identified, three of which were found in the coding region of the gene (exons III and XV). One of the SNPs located in exon XV (NC_007331.3:g.80340C>T) was found to be a non-synonymous mutation. The minor allele frequency of this resulting amino acid substitution was significantly different between 543 German Angus and 417 German Simmental calves (0.39 and 0.49, respectively). The potential functional impact of this polymorphism has been tested by in silico analysis, as well as by association analysis using behaviour scores of the genotyped calves for three behaviour tests that assessed the animals' temperament during tethering, weighing or social separation. In silico analysis did not deliver consistent results arguing for or against a functional impact of the studied amino acid substitution on the function of the biological protein. No significant association was found between this MAOA polymorphism and the behaviour-related scores analysed in the study.