‘Antiflammins’: Two nonapeptide fragments of uteroglobin and lipocortin I have no phospholipase A2 -inhibitory and anti-inflammatory activity

AbstractThe ‘antiflammin’ nonapeptides P1 and P2 [(1988) Nature 335, 726-730] were synthesized and tested for inhibition of phospholipase A2 and release of prostaglandin E2, and leukotriene C4 in stimulated cells in vitro, and in vivo for anti-inflammatory activity in rats with carrageenan-induced paw oedema. Porcine pancreatic phospholipase A2, was not inhibited at concentrations of 0.5–50 μM. Prostaglandin E2, and leukotriene C4 release by mouse macrophages stimulated with zymosan or ATP was not affected up to a concentration of 10 μm, nor was prostaglandin release by interleukin 1β-stimulated mesangial cells and angiotensin II-stimulated smooth muscle cells. Both peptides exhibited no anti-inflammatory activity in carrageenan-induced rat paw oedema after topical (250 μg/paw) or systemic administration (1 or 4 mgkg s.c.). These results do not support the claim of potent phospholipase A2-inhibitory and anti-imflammatory activity of the ‘antiflammins’ P1 and P2 [1]

Warfarin Anticoagulation Exacerbates the Risk of Hemorrhagic Transformation after rt-PA Treatment in Experimental Stroke: Therapeutic Potential of PCC

Background: Oral anticoagulant therapy (OAT) with warfarin is the standard of stroke prevention in patients with atrial fibrillation. Approximately 30% of patients with cardioembolic strokes are on OAT at the time of symptom onset. We investigated whether warfarin exacerbates the risk of thrombolysis-associated hemorrhagic transformation (HT) in a mouse model of ischemic stroke. Methods: 62 C57BL/6 mice were used for this study. To achieve effective anticoagulation, warfarin was administered orally. We performed right middle cerebral artery occlusion (MCAO) for 3 h and assessed functional deficit and HT blood volume after 24 h. Results: In non-anticoagulated mice, treatment with rt-PA (10 mg/kg i.v.) after 3 h MCAO led to a 5-fold higher degree of HT compared to vehicle-treated controls (4.0±0.5 µl vs. 0.8±0.1, p<0.001). Mice on warfarin revealed larger amounts of HT after rt-PA treatment in comparison to non-anticoagulated mice (9.2±3.2 µl vs. 2.8±1.0, p<0.05). The rapid reversal of anticoagulation by means of prothrombin complex concentrates (PCC, 100 IU/kg) at the end of the 3 h MCAO period, but prior to rt-PA administration, neutralized the exacerbated risk of HT as compared to sham-treated controls (3.8±0.7 µl vs. 15.0±3.8, p<0.001). Conclusion: In view of the vastly increased risk of HT, it seems to be justified to withhold tPA therapy in effectively anticoagulated patients with acute ischemic stroke. The rapid reversal of anticoagulation with PCC prior to tPA application reduces the risk attributed to warfarin pretreatment and may constitute an interesting therapeutic option

Cystathionine γ Lyase Sulfhydrates the RNA Binding Protein Human Antigen R to Preserve Endothelial Cell Function and Delay Atherogenesis

Hydrogen sulfide (H2S), generated by cystathionine γ lyase (CSE), is an important endogenous regulator of vascular function. The aim of the present study was to investigate the control and consequences of CSE activity in endothelial cells under physiological and proatherogenic conditions

Biological effects of rinsing morsellised bone grafts before and after impaction

Rinsing bone grafts before or both before and after impaction might have different effects on the incorporation of the graft. Rinsing again after impaction might negatively influence bone induction if growth factors released by impaction are washed away. We studied if transforming growth factor-βs (TGF-βs) and bone morphogenetic proteins (BMPs) are released from the mineralised matrix by impaction and if these released growth factors induce osteogenic differentiation in human mesenchymal stem cells (hMSCs). Rinsed morsellised bone allografts were impacted in a cylinder and the escaping fluid was collected. The fluid was analysed for the presence of TGF-βs and BMPs, and the osteoinductive capacity was tested on hMSCs. Abundant TGF-β was present in the fluid. No BMPs could be detected. Osteogenic differentiation of hMSCs was inhibited by the fluid. Results from our study leave us only able to speculate whether rinsing grafts again after impaction has a beneficial effect on the incorporation process or not

IFN-gamma Impairs Release of IL-8 by IL-1beta-stimulated A549 Lung Carcinoma Cells

Background Production of interferon (IFN)-gamma is key to efficient anti-tumor immunity. The present study was set out to investigate effects of IFNgamma on the release of the potent pro-angiogenic mediator IL-8 by human A549 lung carcinoma cells. Methods A549 cells were cultured and stimulated with interleukin (IL)-1beta alone or in combination with IFNgamma. IL-8 production by these cells was analyzed with enzyme linked immuno sorbent assay (ELISA). mRNA-expression was analyzed by real-time PCR and RNase protection assay (RPA), respectively. Expression of inhibitor-kappaBalpha, cellular IL-8, and cyclooxygenase-2 was analyzed by Western blot analysis. Results Here we demonstrate that IFNgamma efficiently reduced IL-8 secretion under the influence of IL-1beta. Surprisingly, real-time PCR analysis and RPA revealed that the inhibitory effect of IFNgamma on IL-8 was not associated with significant changes in mRNA levels. These observations concurred with lack of a modulatory activity of IFNgamma on IL-1beta-induced NF-kappaB activation as assessed by cellular IkappaB levels. Moreover, analysis of intracellular IL-8 suggests that IFNgamma modulated IL-8 secretion by action on the posttranslational level. In contrast to IL-8, IL-1beta-induced cyclooxygenase-2 expression and release of IL-6 were not affected by IFNgamma indicating that modulation of IL-1beta action by this cytokine displays specificity. Conclusions Data presented herein agree with an angiostatic role of IFNgamma as seen in rodent models of solid tumors and suggest that increasing T helper type 1 (Th1)-like functions in lung cancer patients e.g. by local delivery of IFNgamma may mediate therapeutic benefit via mechanisms that potentially include modulation of pro-angiogenic IL-8

The expression of TGFβ1 mRNA in the early stage of the midpalatal suture cartilage expansion

INTRODUCTION: The application of an orthodontic expansion force induces bone formation at the midpalatal suture because of cell proliferation and differentiation. Expansion forces may stimulate the production of osteoinductive cytokines, such as transforming growth factor β1 (TGFβ1), in the progenitor cells. OBJECTIVES: This study determined the role of TGFβ1 in the early stage of midpalatal suture cartilage expansion. METHODS: A rectangular orthodontic appliance was placed between the right and left upper molars of 4-week-old rats. The initial expansion force was 50 g. Animals in the control and experimental groups were sacrified on days 0, 2, and 5 and 6 µmm thick sections were prepared for an in situ hybridization technique. RESULTS: Two days after the application of force, prechondroblastic and undifferentiated mesenchymal cells distributed along the inner side of the cartilaginous tissue had high levels of TGFβ1 transcription. On day 5, the TGFβ1 transcription was found in osteocytes and osteoblastic cells on the surface of newly formed bone. Immunohistochemistry using Osteocalcin-Pro (OC-Pro) confirmed osteoblastic activity. Conclusions: Results suggest that the expansion of midpalatal suture cartilage induces differentiation of osteochondroprogenitor cells into osteoblasts after stimulation by cytokine productio

Bone mineral density and cytokine levels during interferon therapy in children with chronic hepatitis B: does interferon therapy prevent from osteoporosis?

BACKGROUND: Our aim was to determinate bone mineral density (BMD), levels of biochemical markers and cytokines in children with chronic hepatitis B treated with interferon (IFN)-alpha and to investigate effect of IFN-alpha therapy on these variables. To the best of our knowledge, this is first study carried out about BMD and cytokine levels in pediatric patients with chronic hepatitis B treated with IFN-alpha. METHODS: BMD, levels of parathyroid hormone (PTH), osteocalcin, C-terminal cross-linking telopeptide of type I collagen (CTX), calcium, alkaline phosphates (ALP), cytokines as TNF-alpha, interleukin (IL)-1(β), IL-2r, IL-6, and IL-8 were studied in 54 children with chronic hepatitis B (4–15 years old) treated with interferon alone (n = 19) or in combination with lamivudine (n = 35) for six months and as controls in 50 age-matched healthy children. RESULTS: There was no significant difference in respect to serum IL-1(β), TNF-α and osteocalcin levels while serum IL-2r (p = 0.002), IL-6 (p = 0.001), IL-8 (p = 0.013), PTH (p = 0.029), and CTX (p = 0.021) levels were higher in children with chronic hepatitis B than in healthy controls. BMD of femur neck (p = 0.012) and trochanter (p = 0.046) in patients were higher than in healthy controls. There was a statistically significant correlation between serum IL-1(β )and osteocalcin (r = -0.355, p < 0.01); between serum IL-8 and CTX levels (r = 0.372, p = 0.01), and ALP (r = 0.361, p = 0.01); between serum ALP and femur neck BMD (r = 0.303, p = 0.05), and trochanter BMD (r = 0.365, p = 0.01); between spine BMD and IL-2R (r = -0.330, p < 0.05). CONCLUSION: In conclusion, our study suggest that BMD of femur, serum IL-2r, IL-6, IL-8, PTH, and CTX levels were higher in children with chronic hepatitis B treated with IFN-alpha alone or combination with lamivudine than in healthy children. High femur BMD measurements found in patients may suggest that IFN-alpha therapy in children with chronic hepatitis B could contribute indirectly to prevent from hip osteoporosis. Additionally, further investigations on effects of IFN-alpha for bone structure in children should be performed in the future

A Method for Efficient Calculation of Diffusion and Reactions of Lipophilic Compounds in Complex Cell Geometry

A general description of effects of toxic compounds in mammalian cells is facing several problems. Firstly, most toxic compounds are hydrophobic and partition phenomena strongly influence their behaviour. Secondly, cells display considerable heterogeneity regarding the presence, activity and distribution of enzymes participating in the metabolism of foreign compounds i.e. bioactivation/biotransformation. Thirdly, cellular architecture varies greatly. Taken together, complexity at several levels has to be addressed to arrive at efficient in silico modelling based on physicochemical properties, metabolic preferences and cell characteristics. In order to understand the cellular behaviour of toxic foreign compounds we have developed a mathematical model that addresses these issues. In order to make the system numerically treatable, methods motivated by homogenization techniques have been applied. These tools reduce the complexity of mathematical models of cell dynamics considerably thus allowing to solve efficiently the partial differential equations in the model numerically on a personal computer. Compared to a compartment model with well-stirred compartments, our model affords a more realistic representation. Numerical results concerning metabolism and chemical solvolysis of a polycyclic aromatic hydrocarbon carcinogen show good agreement with results from measurements in V79 cell culture. The model can easily be extended and refined to include more reactants, and/or more complex reaction chains, enzyme distribution etc, and is therefore suitable for modelling cellular metabolism involving membrane partitioning also at higher levels of complexity

Control of Bone Mass and Remodeling by PTH Receptor Signaling in Osteocytes

Osteocytes, former osteoblasts buried within bone, are thought to orchestrate skeletal adaptation to mechanical stimuli. However, it remains unknown whether hormones control skeletal homeostasis through actions on osteocytes. Parathyroid hormone (PTH) stimulates bone remodeling and may cause bone loss or bone gain depending on the balance between bone resorption and formation. Herein, we demonstrate that transgenic mice expressing a constitutively active PTH receptor exclusively in osteocytes exhibit increased bone mass and bone remodeling, as well as reduced expression of the osteocyte-derived Wnt antagonist sclerostin, increased Wnt signaling, increased osteoclast and osteoblast number, and decreased osteoblast apoptosis. Deletion of the Wnt co-receptor LDL related receptor 5 (LRP5) attenuates the high bone mass phenotype but not the increase in bone remodeling induced by the transgene. These findings demonstrate that PTH receptor signaling in osteocytes increases bone mass and the rate of bone remodeling through LRP5-dependent and -independent mechanisms, respectively

Cancer Treatment and Bone Health

Considerable advances in oncology over recent decades have led to improved survival, while raising concerns about long-term consequences of anticancer treatments. In patients with breast or prostate malignancies, bone health is a major issue due to the high risk of bone metastases and the frequent prolonged use of hormone therapies that alter physiological bone turnover, leading to increased fracture risk. Thus, the onset of cancer treatment-induced bone loss (CTIBL) should be considered by clinicians and recent guidelines should be routinely applied to these patients. In particular, baseline and periodic follow-up evaluations of bone health parameters enable the identification of patients at high risk of osteoporosis and fractures, which can be prevented by the use of bone-targeting agents (BTAs), calcium and vitamin D supplementation and modifications of lifestyle. This review will focus upon the pathophysiology of breast and prostate cancer treatment-induced bone loss and the most recent evidence about effective preventive and therapeutic strategies