Thymoquinone accelerates osteoblast differentiation and activates bone morphogenetic protein-2 and ERK pathway

Thymoquinone (TQ), the active component of Nigella sativa L. is well known for its various beneficial effects against several diseases. However, its detailed effect on bone metabolism has not been studied before. Therefore, the aim of the present study is to evaluate the effect of TQ on the proliferation, differentiation, and mineralization of MC3T3-E1 osteoblast cells. Our data shows that TQ induced the proliferation of MC3T3-E1 cells and proved to be non-toxic for up to 72 h of incubation. TQ induced the mineralization of MC3T3-E1 cells as evidenced by an increase in bone nodule formation 14 days post TQ treatment. qRT-PCR analysis shows that TQ induced the expression levels of differentiation related genes including alkaline phosphatase, osteocalcin, and osteopontin, while no effect was seen on collagen 1a1. TQ also induced the expression levels of bone morphogenetic protein-2 (BMP-2) and upregulated the phosphorylation of ERK signaling pathway. In summary, the present study shows for the first time that TQ has anabolic effects on MC3T3-E1 cells and that this effect is mediated by an increase in the expression of BMP-2 along with the involvement of the ERK signaling pathway. This study also reveals that TQ may be beneficial in inducing osteogenesis.     

HAMLET kills tumor cells by apoptosis: structure, cellular mechanisms, and therapy

New cancer treatments should aim to destroy tumor cells without disturbing normal tissue. HAMLET (human alpha-lactalbumin made lethal to tumor cells) offers a new molecular approach to solving this problem, because it induces apoptosis in tumor cells but leaves normal differentiated cells unaffected. After partial unfolding and binding to oleic acid, alpha-lactalbumin forms the HAMLET complex, which enters tumor cells and freezes their metabolic machinery. The cells proceed to fragment their DNA, and they disintegrate with apoptosis-like characteristics. HAMLET kills a wide range of malignant cells in vitro and maintains this activity in vivo in patients with skin papillomas. In addition, HAMLET has striking effects on human glioblastomas in a rat xenograft model. After convection-enhanced delivery, HAMLET diffuses throughout the brain, selectively killing tumor cells and controlling tumor progression without apparent tissue toxicity. HAMLET thus shows great promise as a new therapeutic with the advantage of selectivity for tumor cells and lack of toxicity.     

Genetic variation in the human thrombomodulin promoter locus and prognosis after acute coronary syndrome

INTRODUCTION: Endothelial thrombomodulin (TM) plays a critical role in both anticoagulation and anti-inflammation. An impaired TM cofactor function or reduced TM gene expression could constitute a prethrombotic abnormality leading to acute coronary events. Mutations in the TM gene occur, but their functional consequences on the expression and activity of the gene are not yet fully understood. MATERIALS AND METHODS: We performed a prospective study investigating the prevalence of TM mutations in the promoter region in 182 patients with acute coronary syndrome as well as in a control group. The patients were followed-up after 30 days and after 2 years for acute myocardial infarction (MI) and mortality. RESULTS AND CONCLUSIONS: We identified 10 point mutations and 2 small deletions: -1861 C/A, -1852 C/G, -1803 G/C, -1752 G/C, -1213/1212 delTT, -1089 C/G, -1088 C/T, -1083/1082 delCC, -1066 A/C, -801 C/G, -651 A/C and -52 G/A. Two of the mutations, -1752 G/C and -1213/1212 delTT, were frequent in the patients as well as in the controls, while all the others were rare. The only significant finding was that both -1752 G/C and -1213/1212 delTT were associated with a lower than normal risk of suffering a clinical event among smokers at 30 days and 2 years. We did not gain any support for the hypothesis that TM mutations confer an increased risk of MI or mortality.     

Synovial tissue analysis in clinical trials

Synovial tissue analysis has considerable potential for future randomized controlled trials (RCT). The synovial membrane is the target tissue in treatment strategies of rheumatoid arthritis and other arthropathies. Effective modulation of synovitis is critical when attempting to control symptoms and signs, to prevent joint damage, and to maintain function. In RCT, the systematic evaluation of changes in synovial tissue after commencing treatment enables identification of an early therapeutic effect, using relatively small numbers of patients. This special interest group is working on establishing the evidence to have this endpoint meet the OMERACT filter criteria.     

Dynamics of lipids and polychlorinated biphenyls in a Baltic amphipod (Monoporeia affinis): a field study

Processes such as accumulation and elimination, which control tissue concentration of polychlorinated biphenyls (PCBs), were examined over time in an in situ study of the amphipod Monoporeia affinis. These processes were studied with respect to individual PCB congeners, percentage lipid and composition, and body weight. A secondary objective was to examine the impact of seasonal variability in percentage lipids and lipid composition on PCB concentration in two coexisting Baltic amphipods, M. affinis and Pontoporeia femorata. Polycholorinated biphenyl concentrations tended to be higher in P. femorata than in M. affinis, possibly because of P. femorata's lower respiration rate and larger size. The net accumulation of PCBs was congener dependent and negatively correlated to lipid concentration. The relation between the net concentration change rate of 16 PCB congeners over time and log Kow was not significant during the spring and summer months, a time when lipid accumulation and strong growth occur. In contrast, the net concentration change rate of the corresponding PCB congeners over time during autumn and early winter, that is, from the period before gonad maturation to the period after mating and early embryogenesis, showed a significant relation to tog Kow (r2 = 0.62, p < 0.001, n = 16). During the latter period, amphipod lipid weight was reduced while the PCB body burden increased. Results strongly indicate that elimination rather than accumulation is the main process controlling amphipod body burden. This pattern results in a transfer of PCBs from the female to the developing embryos, which is reflected in high PCB body burden in newly released offspring.     

Protection of Batf3-deficient mice from experimental cerebral malaria correlates with impaired cytotoxic T-cell responses and immune regulation

Excessive inflammatory immune responses during infections with Plasmodium parasites are responsible for severe complications such as cerebral malaria (CM) that can be studied experimentally in mice. Dendritic cells (DCs) activate cytotoxic CD8⁺ T-cells and initiate immune responses against the parasites. Batf3^−/− mice lack a DC subset, which efficiently induces strong CD8 T-cell responses by cross-presentation of exogenous antigens. Here we show that Batf3^−/− mice infected with Plasmodium berghei ANKA (PbA) were protected from experimental CM (ECM), characterized by a stable blood−brain barrier (BBB) and significantly less infiltrated peripheral immune cells in the brain. Importantly, the absence of ECM in Batf3^−/− mice correlated with attenuated responses of cytotoxic T-cells, as their parasite-specific lytic activity as well as the production of interferon gamma and granzyme B were significantly decreased. Remarkably, spleens of ECM-protected Batf3^−/− mice had elevated levels of regulatory immune cells and interleukin 10. Thus, protection from ECM in PbA-infected Batf3^−/− mice was associated with the absence of strong CD8⁺ T-cell activity and induction of immunoregulatory mediators and cells.     

Intraarticular corticosteroids decrease synovial RANKL expression in inflammatory arthritis

OBJECTIVE: Intraarticular corticosteroids are frequently used as successful adjuvant therapy for inflammatory arthritides, but little is known about their effects on molecules that regulate bone biology. We undertook this study to investigate the effect of intraarticular corticosteroids on the synovial expression of RANKL and osteoprotegerin (OPG). METHODS: We evaluated RANKL, OPG, and surface marker expression by immunohistochemical methods in synovial knee biopsy samples obtained from 13 patients with inflammatory arthritis before and 2 weeks following intraarticular injection of triamcinolone hexacetonide. We further investigated the effect of dexamethasone (DEX) on RANKL expression by lymphocytes from rheumatoid arthritis synovial fluids (RA SF), using flow cytometric analysis. Finally, we evaluated the in vitro effect of DEX on RANKL and OPG expression in osteoblast-like cells, by Western blotting. RESULTS: Intraarticular corticosteroids induced a decrease in the number of synovial T cells without influencing the number of macrophages, evaluated as both CD68+ and CD163+ cells. This change was paralleled by a decrease of synovial RANKL expression with a concomitant reduction of the RANKL:OPG ratio. DEX down-regulated RANKL expression on lymphocytes derived from RA SF. Moreover, in vitro pretreatment of osteoblast-like cells with tumor necrosis factor favored an antiresorptive effect of DEX treatment through a similar down-regulation of RANKL expression. CONCLUSION: The decrease in inflammation attributed to intraarticular corticosteroids is accompanied by down-modulation of bone destruction markers. These findings offer a rationale for the beneficial effect of corticosteroids on joint erosion in arthritis.