Trauma induces apoptosis in human thoracolumbar intervertebral discs

BACKGROUND: Vertebral fractures resulting from high energy trauma often comprise the risk of posttraumatic degenerative changes in the affected intervertebral discs (IVD). Particularly in conservatively treated patients, or in cases after implant removal of an exclusively posterior stabilization, consecutive disc degeneration and the associated functional losing of the spinal segment clearly represent detrimental treatment results. In this regard, apoptosis of IVD cells has been suggested to be involved in the critical changes of the extracellular matrix. METHODS: To investigate whether fractures of the vertebrae induce apoptosis in the affected IVD, disc tissue from patients (n = 17) undergoing open reduction and internal fixation of thoracolumbar spine fractures were analysed in regards to caspase activity, apoptosis-receptor expression levels and gene expression of apoptosis-regulating proteins such as Bax and Bcl-2. Healthy IVD tissue (n = 3) obtained from patients undergoing surgical resection of adjacent vertebrae were used as control samples. RESULTS: In contrast to healthy control IVD tissues, samples from traumatic thoracolumbar IVD showed positive TUNEL staining and a significant increase of caspase-3/7 activity. Interestingly, analyses of the initiator caspase-8 and -9 revealed significantly increased activation levels compared to control values, suggesting the coexistent activation of both the extrinsic (receptor-mediated) and intrinsic (mitochondria-mediated) apoptosis pathway. Accordingly, expression levels of the Fas receptor (FasR) mRNA were significantly increased. Although the TNF receptor I (TNFR I) was only slightly upregulated, corresponding TNFα from trauma IVD presented significantly increased mRNA expression values. Furthermore, traumatic IVD cells demonstrated significantly reduced expression of the mitochondria-bound anti-apoptotic Bcl-2, thereby maintaining baseline transcriptional levels of the pro-apoptotic Bax protein when compared to control IVD cells. CONCLUSION: Our data suggest that thoracolumbar fractures induce early caspase-dependent apoptosis in IVD cells of the affected intervertebral disc, in part, by downregulation of the anti-apoptotic protein Bcl-2 (intrinsic apoptosis pathway), as well as signalling via the death receptor complex (TNFR I and FasR)

Expression of matrix metalloproteinase-1 (MMP-1) in Wistar rat's intervertebral disc after experimentally induced scoliotic deformity

<p>Abstract</p> <p>Introduction</p> <p>A scoliotic deformity on intervertebral discs may accelerate degeneration at a molecular level with the production of metalloproteinases (MMPs). In the present experimental study we evaluated the presence of MMP-1 immunohistochemically after application of asymmetric forces in a rat intervertebral disc and the impact of the degree of the deformity on MMP-1 expression.</p> <p>Material-Method</p> <p>Thirty female Wistar rats (aged 2 months old, weighted 200 ± 10 grams) were used. All animals were age, weight and height matched. A mini Ilizarov external fixator was applied at the base of a rat tail under anaesthesia in order to create a scoliotic deformity of the intervertebral disc between the 9^thand 10^thvertebrae. Rats were divided into three groups according to the degree of the deformity. In group I, the deformity was 10°, in group II 30° and in group III 50°. The rats were killed 35 days after surgery. The discs were removed along with the neighbouring vertebral bodies, prepared histologically and stained immunohistochemically. Immunopositivity of disc's cells for MMP-1 was determined using a semi-quantitative scored system.</p> <p>Results</p> <p>MMP-1 immunopositivity was detected in disc cells of annulus fibrosus of all intervertebral disc specimens examined. The percentage of MMP-1 positive disc cells in annulus fibrosus in group I, II and III were 20%, 43% and 75%, respectively. MMP-1 positivity was significantly correlated with the degree of the deformity (p < 0,001). An increase of chondrocyte-like disc cells was observed in the outer annulus fibrosus and at the margin of the intervertebral disc adjacent to the vertebral end plates. The difference in the proportion of MMP-1 positive disc cells between the convex and the concave side was statistically not significant in group I (p = 0,6), in group II this difference was statistically significant (p < 0,01). In group III the concave side showed a remarkable reduction in the number of disc's cells and a severe degeneration of matrix microstructure.</p> <p>Conclusion</p> <p>The present study showed that an experimentally induced scoliotic deformity on a rat tail intervertebral disc results in over-expression of MMP-1, which is dependent on the degree of the deformity and follows a dissimilar distribution between the convex and the concave side.</p

Induction of Tachykinin Production in Airway Epithelia in Response to Viral Infection

The tachykinins are implicated in neurogenic inflammation and the neuropeptide substance P in particular has been shown to be a proinflammatory mediator. A role for the tachykinins in host response to lung challenge has been previously demonstrated but has been focused predominantly on the release of the tachykinins from nerves innervating the lung. We have previously demonstrated the most dramatic phenotype described for the substance P encoding gene preprotachykinin-A (PPT-A) to date in controlling the host immune response to the murine gammaherpesvirus 68, in the lung.In this study we have utilised transgenic mice engineered to co-ordinately express the beta-galactosidase marker gene along with PPT-A to facilitate the tracking of PPT-A expression. Using a combination of these mice and conventional immunohistology we now demonstrate that PPT-A gene expression and substance P peptide are induced in cells of the respiratory tract including tracheal, bronchiolar and alveolar epithelial cells and macrophages after viral infection. This induction was observed 24h post infection, prior to observable inflammation and the expression of pro-inflammatory chemokines in this model. Induced expression of the PPT-A gene and peptide persisted in the lower respiratory tract through day 7 post infection.Non-neuronal PPT-A expression early after infection may have important clinical implications for the progression or management of lung disease or infection aside from the well characterised later involvement of the tachykinins during the inflammatory response

Levosimendan: a cardiovascular drug to prevent liver ischemia-reperfusion injury?

INTRODUCTION: Temporary occlusion of the hepatoduodenal ligament leads to an ischemic-reperfusion (IR) injury in the liver. Levosimendan is a new positive inotropic drug, which induces preconditioning-like adaptive mechanisms due to opening of mitochondrial KATP channels. The aim of this study was to examine possible protective effects of levosimendan in a rat model of hepatic IR injury. MATERIAL AND METHODS: Levosimendan was administered to male Wistar rats 1 hour (early pretreatment) or 24 hours (late pretreatment) before induction of 60-minute segmental liver ischemia. Microcirculation of the liver was monitored by laser Doppler flowmeter. After 24 hours of reperfusion, liver and blood samples were taken for histology, immuno- and enzyme-histochemistry (TUNEL; PARP; NADH-TR) as well as for laboratory tests. Furthermore, liver antioxidant status was assessed and HSP72 expression was measured. RESULTS: In both groups pretreated with levosimendan, significantly better hepatic microcirculation was observed compared to respective IR control groups. Similarly, histological damage was also reduced after levosimendan administration. This observation was supported by significantly lower activities of serum ALT (pearly = 0.02; plate = 0.005), AST (pearly = 0.02; plate = 0.004) and less DNA damage by TUNEL test (pearly = 0.05; plate = 0.034) and PAR positivity (pearly = 0.02; plate = 0.04). Levosimendan pretreatment resulted in significant improvement of liver redox homeostasis. Further, significantly better mitochondrial function was detected in animals receiving late pretreatment. Finally, HSP72 expression was increased by IR injury, but it was not affected by levosimendan pretreatment. CONCLUSION: Levosimendan pretreatment can be hepatoprotective and it could be useful before extensive liver resection

MRI of the lung (2/3). Why … when … how?

Background Among the modalities for lung imaging, proton magnetic resonance imaging (MRI) has been the latest to be introduced into clinical practice. Its value to replace X-ray and computed tomography (CT) when radiation exposure or iodinated contrast material is contra-indicated is well acknowledged: i.e. for paediatric patients and pregnant women or for scientific use. One of the reasons why MRI of the lung is still rarely used, except in a few centres, is the lack of consistent protocols customised to clinical needs. Methods This article makes non-vendor-specific protocol suggestions for general use with state-of-the-art MRI scanners, based on the available literature and a consensus discussion within a panel of experts experienced in lung MRI. Results Various sequences have been successfully tested within scientific or clinical environments. MRI of the lung with appropriate combinations of these sequences comprises morphological and functional imaging aspects in a single examination. It serves in difficult clinical problems encountered in daily routine, such as assessment of the mediastinum and chest wall, and even might challenge molecular imaging techniques in the near future. Conclusion This article helps new users to implement appropriate protocols on their own MRI platforms. Main Messages • MRI of the lung can be readily performed on state-of-the-art 1.5-T MRI scanners. • Protocol suggestions based on the available literature facilitate its use for routine • MRI offers solutions for complicated thoracic masses with atelectasis and chest wall invasion. • MRI is an option for paediatrics and science when CT is contra-indicate

Procyanidin B3 Prevents Articular Cartilage Degeneration and Heterotopic Cartilage Formation in a Mouse Surgical Osteoarthritis Model

Osteoarthritis (OA) is a common disease in the elderly due to an imbalance in cartilage degradation and synthesis. Heterotopic ossification (HO) occurs when ectopic masses of endochondral bone form within the soft tissues around the joints and is triggered by inflammation of the soft tissues. Procyanidin B3 (B3) is a procyanidin dimer that is widely studied due to its high abundance in the human diet and antioxidant activity. Here, we evaluated the role of B3 isolated from grape seeds in the maintenance of chondrocytes in vitro and in vivo. We observed that B3 inhibited H2O2-induced apoptosis in primary chondrocytes, suppressed H2O2- or IL-1ß−induced nitric oxide synthase (iNOS) production, and prevented IL-1ß−induced suppression of chondrocyte differentiation marker gene expression in primary chondrocytes. Moreover, B3 treatment enhanced the early differentiation of ATDC5 cells. To examine whether B3 prevents cartilage destruction in vivo, OA was surgically induced in C57BL/6J mice followed by oral administration of B3 or vehicle control. Daily oral B3 administration protected articular cartilage from OA and prevented chondrocyte apoptosis in surgically-induced OA joints. Furthermore, B3 administration prevented heterotopic cartilage formation near the surgical region. iNOS protein expression was enhanced in the synovial tissues and the pseudocapsule around the surgical region in OA mice fed a control diet, but was reduced in mice that received B3. Together, these data indicated that in the OA model, B3 prevented OA progression and heterotopic cartilage formation, at least in a part through the suppression of iNOS. These results support the potential therapeutic benefits of B3 for treatment of human OA and heterotopic ossification

New developments in osteoarthritis. Posttraumatic osteoarthritis: pathogenesis and pharmacological treatment options

Joint trauma can lead to a spectrum of acute lesions, including osteochondral fractures, ligament or meniscus tears and damage to the articular cartilage. This is often associated with intraarticular bleeding and causes posttraumatic joint inflammation. Although the acute symptoms resolve and some of the lesions can be surgically repaired, joint injury triggers a chronic remodeling process in cartilage and other joint tissues that ultimately manifests as osteoarthritis in a majority of cases. The objective of the present review is to summarize information on pathogenetic mechanisms involved in the acute and chronic consequences of joint trauma and discuss potential pharmacological interventions. The focus of the review is on the early events that follow joint trauma since therapies for posttraumatic joint inflammation are not available and this represents a unique window of opportunity to limit chronic consequences