Chondrocyte cultures from human proximal interphalangeal finger joints

Osteoarthritis (OA) of the hand is a common disease resulting in pain and impaired function. The pathogenesis of hand OA (HOA) is elusive and models to study it have not been described. Chondrocyte culture has been essential to understand cartilage degeneration, which is a hallmark of OA. We investigated the feasibility of human chondrocyte culture derived from proximal interphalangeal (PIP) finger joints. Hyaline cartilage of the PIP and knee joints was obtained from human cadavers. Chondrocytes harvested up to 236 h after death of the donors were viable and expressed chondrocyte‐specific genes. Gene expression comparing chondrocytes from PIP and knee joints using Affymetrix GeneChip arrays resulted in a unique PIP‐specific gene expression pattern. Genes involved in developmental processes including the WNT pathway were differentially expressed between the joints. These findings suggest that our knowledge on chondrocyte biology derived mainly from knee and hip joints may not apply to chondrocytes of the PIP joints and some of the distinctive features of HOA may be caused by the specific properties of PIP chondrocytes. Chondrocyte culture of PIP cartilage is a novel tool to study cartilage degeneration in HOA. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1569–1575, 2016.     

JBP2, a SWI2/SNF2-like protein, regulates de novo telomeric DNA glycosylation in bloodstream form Trypanosoma brucei

Synthesis of the modified thymine base, beta-d-glucosyl-hydroxymethyluracil or J, within telomeric DNA of Trypanosoma brucei correlates with the bloodstream form specific epigenetic silencing of telomeric variant surface glycoprotein genes involved in antigenic variation. In order to analyze the function of base J in the regulation of antigenic variation, we are characterizing the regulatory mechanism of J biosynthesis. We have recently proposed a model in which chromatin remodeling by a SWI2/SNF2-like protein (JBP2) regulates the developmental and de novo site-specific localization of J synthesis within bloodstream form trypanosome DNA. Consistent with this model, we now show that JBP2 (-/-) bloodstream form trypanosomes contain five-fold less base J and are unable to stimulate de novo J synthesis in newly generated telomeric arrays.     

Plasticity of basal ganglia neurocircuitries following perinatal asphyxia: effect of nicotinamide

The potential neuroprotection of nicotinamide on the consequences of perinatal asphyxia was investigated with triple organotypic cultures. Perinatal asphyxia was induced in vivo by immersing foetuses-containing uterine horns removed from ready-to-deliver rats into a water bath for 20 min. Sibling caesarean-delivered pups were used as controls. Three days later tissue from substantia nigra, neostriatum and neocortex was dissected and placed on a coverslip. After a month, the cultures were processed for immunocytochemistry and phenotyped with markers against the NMDA receptor subunit NR1, tyrosine hydroxylase (TH), or neuronal nitric oxide synthase (nNOS). Some cultures were analysed for cell viability. Nicotinamide (0.8 mmol/kg, i.p.) or saline was administered to asphyxia-exposed and caesarean-delivered control pups 24, 48 and 72 h after birth. Perinatal asphyxia produced a decrease of cell viability in substantia nigra, but not in neostriatum or neocortex. Immunocytochemistry confirmed the vulnerability of the substantia nigra, demonstrating that there was a significant decrease in the number of NR1 and TH-positive (+) cells/mm², as well as a decrease in the length of TH⁺ processes, suggesting neurite atrophy. In control cultures, many nNOS⁺ cells were seen, with different features, regional distribution and cell body sizes. Following perinatal asphyxia, there was an increase in the number of nNOS⁺ cells/mm² in substantia nigra, versus a decrease in neostriatum including reduced neurite length, and no apparent changes in neocortex. The main effect of nicotinamide was seen in the neostriatum, preventing the asphyxia-induced decrease in the number of nNOS⁺ cells and neurite length. Nicotinamide also prevented the effect of perinatal asphyxia on TH-positive neurite length. The present results support the idea that nicotinamide can prevent the effects produced by a sustained energy-failure condition, as occurring during perinatal asphyxia. The contribution of VK and PM has been equally relevant.     

Empowering senior citizens for healthy nutrition in Germany: A pilot study

Main goal of this study was to analyse how empowerment processes and bottom‐up activities aimed at healthier food choices and food environment could be initiated among a group of senior citizens (between 60 and 75 years old). The intervention was set up as a pilot study in a rural community (15,000 inhabitants) in the federal state of Bavaria, South Eastern Germany. A process evaluation documented how group formation and empowerment processes developed during the course of the intervention. Extensive field notes were taken in 27 meetings, interviews (n = 13) and focus groups (n = 4) were conducted with participants and key persons at different points of the intervention. Data were analysed using content analysis. The intervention succeeded in motivating senior citizens to participate in regular meetings over 11 months. During the intervention, the group members’ awareness of factors influencing their eating behaviour increased. Furthermore, they developed ideas to improve the community's food environment and accomplished duties needed to implement these ideas. However, initiating empowerment processes, especially in terms of fostering leadership and transferring responsibility, took longer than expected and could be realised only partially. The findings support a further use and evaluation of the empowerment approach for addressing nutritional aspects among senior citizens.     

Mast Cells Trigger Disturbed Bone Healing in Osteoporotic Mice

Mast cells are important tissue-resident sensor and effector immune cells but also play a major role in osteoporosis development. Mast cells are increased in numbers in the bone marrow of postmenopausal osteoporotic patients, and mast cell–deficient mice are protected from ovariectomy (OVX)-induced bone loss. In this study, we showed that mast cell–deficient Mcpt5-Cre R-DTA mice were protected from OVX-induced disturbed fracture healing, indicating a critical role for mast cells in the pathomechanisms of impaired bone repair under estrogen-deficient conditions. We revealed that mast cells trigger the fracture-induced inflammatory response by releasing inflammatory mediators, including interleukin-6, midkine (Mdk), and C-X-C motif chemokine ligand 10 (CXCL10), and promote neutrophil infiltration into the fracture site in OVX mice. Furthermore, mast cells were responsible for reduced osteoblast and increased osteoclast activities in OVX mice callus, as well as increased receptor activator of NF-κB ligand serum levels in OVX mice. Additional in vitro studies with human cells showed that mast cells stimulate osteoclastogenesis by releasing the osteoclastogenic mediators Mdk and CXCL10 in an estrogen-dependent manner, which was mediated via the estrogen receptor alpha on mast cells. In conclusion, mast cells negatively affect the healing of bone fractures under estrogen-deficient conditions. Hence, targeting mast cells might provide a therapeutic strategy to improve disturbed bone repair in postmenopausal osteoporosis. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).     

Investigation of the in vitro toxicological properties of the synthetic cannabimimetic drug CP-47,497-C8

Cannabicyclohexanol (CP-47,497-C8) is a representative of a group of cannabimimetic cyclohexylphenols which is added to herbal mixtures as a cannabis substitute since 2008. Although in the beginning CP-47,497-C8 was the main ingredient of “Spice” and similar products, it was partly replaced by aminoalkylindole-type cannabinoid receptor agonists like JWH-018, JWH-073 or JWH-250, but never completely disappeared from the market. Since information on its toxicological properties is scarce, we investigated the effects of the drug in human derived cell lines. The cytotoxic effects were studied in a panel of assays (SRB, XTT, LDHe and NR tests) in a buccal derived (TR146) and a liver derived (HepG2) cell line. The strongest effects were seen in the two former assays at levels ≥ 7.5 μM indicating that the compound interferes with protein synthesis and causes membrane damage. In additional comet assays, DNA damage was detected at levels ≥ 10 μM. Experiments with lesion specific enzymes showed that these effects are not due to oxidative damage of DNA bases. The negative findings obtained in Salmonella/microsome assays and the positive results of micronucleus tests with the cell lines indicate that the compound does not cause gene mutations but acts on the chromosomal level. In contrast to other synthetic cannabinoids, no indication for estrogenic/antiestrogenic properties was seen in a luciferase assay with bone marrow derived U2-OS cells. In conclusion, our findings show that the drug has only weak cytotoxic properties. However, the induction of chromosomal damage indicates that it may cause adverse effects in users due to its impact on the stability of the genetic material.     

Existential neuroscience: effects of mortality salience on the neurocognitive processing of attractive opposite-sex faces

Being reminded of the inherently finite nature of human existence has been demonstrated to elicit strivings for sexual reproduction and the formation and maintenance of intimate relationships. Recently, it has been proposed that the perception of potential mating partners is influenced by mortality salience. Using functional magnetic resonance imaging, we investigated the neurocognitive processing of attractive opposite-sex faces after priming with death-related words for heterosexual men and women. Significant modulations of behavioral and neural responses were found when participants were requested to decide whether they would like to meet the presented person. Men were more in favor of meeting attractive women after being primed with death-related words compared to a no-prime condition. Increased neural activation could be found under mortality salience in the left anterior insula and the adjacent lateral prefrontal cortex (lPFC) for both men and women. As previously suggested, we believe that the lPFC activation reflects an approach-motivated defense mechanism to overcome concerns that are induced by being reminded of death and dying. Our results provide insight on a neurocognitive level that approach motivation in general, and mating motivation in particular is modulated by mortality salience.