An 8-week injury prevention exercise program combined with change-of-direction technique training limits movement patterns associated with anterior cruciate ligament injury risk

Knee ligament sprains are common during change-of-direction (COD) maneuvers in multidirectional team sports. This study aimed to compare the effects of an 8-week injury prevention exercise program containing COD-specific exercises and a similar program containing linear sprint exercises on injury- and performance-related variables during a 135° COD task. We hypothesized that the COD-specific training would lead to (H1) stronger reductions in biomechanical variables associated with anterior cruciate ligament (ACL) injury risk during COD, i.e. knee abduction moment and angle, hip internal rotation angle and lateral trunk lean, and (H2) more effective improvements in COD performance according to the COD completion time, executed angle, ground contact time, and approach speed. Twenty-two sports science students (40% female) completed biomechanical assessments of COD movement strategies before and after participating in two supervised 25-min training sessions per week over 8 weeks. We observed significant 'training x group' interaction effects in support of H1: the COD-specific training but not the linear sprint training led to reduced peak knee abduction moments (interaction, p = 0.027), initial knee abduction (interaction, p < 0.001), and initial lateral trunk lean angles (interaction, p < 0.001) compared to baseline. Although the COD-specific training resulted in sharper executed angles (interaction, p < 0.001), the sprint-specific training group showed reduced COD completion (interaction, p = 0.037) and ground contact times (interaction, p < 0.001). In conclusion, a combination of generic and COD-specific injury prevention training resulted in COD technique adaptations that can help to avoid ACL injury-prone COD movements but may negatively affect COD speed.

Visuomotor Adaptation Deficits in Patients with Essential Tremor

Essential tremor (ET) is a progressive movement disorder whose pathophysiology is not fully understood. Current evidence supports the view that the cerebellum is critically involved in the genesis of the tremor in ET. However, it is still unknown whether cerebellar dysfunction affects not only the control of current movements but also the prediction of future movements through dynamic adaptation toward a changed environment. Here, we tested the capacity of 28 patients with ET to adapt in a visuomotor adaptation task known to depend on intact cerebellar function. We found specific impairments in that task compared to age-matched healthy controls. Adaptation to the visual perturbation was disrupted in ET patients, while de-adaptation, the phase after abrupt removal of the perturbation, developed similarly to control subjects. Baseline tremor-independent motor performance was as well similar to healthy controls, indicating that adaptation deficits in ET patients were not rooted in an inability to perform goal-directed movements. There was no association between clinical severity scores of ET and early visuomotor adaptation abilities. These results provide further evidence that the cerebellum is dysfunctional in ET.

Efficacy of the Digital Therapeutic sinCephalea in the prophylaxis of migraine in patients with episodic migraine: study protocol for a digital, randomized, open-label, standard treatment controlled trial

BACKGROUND

The German government implemented the Digital Healthcare Act in order to bring Digital Therapeutics into standard medical care. This is one of the first regulatory pathways to reimbursement for Digital Therapeutics (DTx). The Digital Therapeutic sinCephalea is intended to act as a prophylactic treatment of migraine by reducing the migraine days. For this, sinCephalea determines personalized nutritional recommendations using continuous glucose monitoring (CGM) data and enables the patients to follow a personalized low-glycemic nutrition. Migraine is a headache disorder with the highest socioeconomic burden. Emerging evidence shows that CGM-based personalized nutritional recommendations are of prophylactic use in episodic migraine. However, prospective data are yet missing to demonstrate clinical effectiveness. This study is designed to fill this gap.

METHODS

Patients between 18 and 65 years of age with proven migraine and a minimal disease severity of 3 migraine days per month are included. After a 4-week baseline phase as a pre-study, patients are randomized to the DTx intervention or a waiting-list control. The objective of the study is to show differences between the intervention and control groups regarding the change of migraine symptoms and of effects of migraine on daily life.

DISCUSSION

To our knowledge, this is the first systematic clinical trial with a fully digital program to enable patients with migraine to follow a personalized low-glycemic nutrition in order to reduce their number of migraine days and the migraine-induced impact on daily life. Designing a clinical study using a digital intervention includes some obstacles, which are addressed in this study approach.

TRIAL REGISTRATION

German Registry of Clinical Studies (Deutsches Register Klinischer Studien) DRKS-ID DRKS00024657. Registered on March 8, 2021.

Motor Sequence Learning Deficits in Idiopathic Parkinson's Disease Are Associated With Increased Substantia Nigra Activity

Previous studies have shown that persons with Parkinson’s disease (pwPD) share specific deficits in learning new sequential movements, but the neural substrates of this impairment remain unclear. In addition, the degree to which striatal dopaminergic denervation in PD affects the cortico-striato-thalamo-cerebellar motor learning network remains unknown. We aimed to answer these questions using fMRI in 16 pwPD and 16 healthy age-matched control subjects while they performed an implicit motor sequence learning task. While learning was absent in both pwPD and controls assessed with reaction time differences between sequential and random trials, larger error-rates during the latter suggest that at least some of the complex sequence was encoded. Moreover, we found that while healthy controls could improve general task performance indexed by decreased reaction times across both sequence and random blocks, pwPD could not, suggesting disease-specific deficits in learning of stimulus-response associations. Using fMRI, we found that this effect in pwPD was correlated with decreased activity in the hippocampus over time. Importantly, activity in the substantia nigra (SN) and adjacent bilateral midbrain was specifically increased during sequence learning in pwPD compared to healthy controls, and significantly correlated with sequence-specific learning deficits. As increased SN activity was also associated (on trend) with higher doses of dopaminergic medication as well as disease duration, the results suggest that learning deficits in PD are associated with disease progression, indexing an increased drive to recruit dopaminergic neurons in the SN, however, unsuccessfully. Finally, there were no differences between pwPD and controls in task modulation of the cortico-striato-thalamo-cerebellar network. However, a restricted nigral-striatal model showed that negative modulation of SN to putamen connection was larger in pwPD compared to controls during random trials, while no differences between the groups were found during sequence learning. We speculate that learning-specific SN recruitment leads to a relative increase in SN- > putamen connectivity, which returns to a pathological reduced state when no learning takes place.

AB0496 AUTOANTIBODIES TARGETING COMPLEMENT RECEPTORS 3A AND 5A1 ARE DECREASED IN ANCA-ASSOCIATED VASCULITIS AND CORRELATE WITH HIGHER RELAPSE RATE

Background:

Activation of the alternative and final common pathways have been shown in ANCA-associated vasculitis (AAV) (1). Circulating titers of C5a are elevated and correlate with disease activity in AAV. Binding to the corresponding G protein-coupled receptor (GPCR) C5aR1 enhances the influx of neutrophils, leading to ROS generation and severe necrotizing of vascular walls (2). Moreover, subsequent interaction of C5a with C5aR1 may represent a proinflammatory amplification loop (3). Blocking of the receptor is protective in a murine model in AAV (4). In humans, avacopan, a C5aR1-inhibitor showed promising results as glucocorticoid-sparing agent in two randomized phase II and one ongoing phase III clinicals trials in AAV (NCT02994927). Notably, disease-specific anti-GPCR autoantibody (aab) signatures have been found in different autoimmune diseases (5).

Objectives:

The aim of the present study was to examine whether (patho)physiological anti-C3aR and anti-C5aR1 aabs correlate with clinical findings in AAV, and whether this is linked to the clinical outcome.

Methods:

Sera and plasma of AAV patients [granulomatosis with polyangiitis (GPA), n=64; microscopic polyangiitis (MPA), n=26; eosinophilic granulomatosis with polyangiitis (EGPA), n=11] were measured by Elisa for circulating autoantibodies against complement receptors C3a (anti-C3aR aab) and C5a (anti-C5aR1 aab) and plasma levels of C3a and C5a. Expression of C3aR and C5aR1 on T-cells was determined using flow cytometry. Clinical data were assessed at the time of serum sampling and during follow-up for 48 months

Results:

GPA displayed low titers of anti-C3aR aab (GPA:5.33±2.54vs. HD:6.47±2.61, P=0.0031). Anti-C5aR1 aab were decreased in AAV, especially in GPA (GPA:1.02±1.07vs. HD:6.63±2.91, P=<0.0001). Plasma levels of C5a and anti-C5aR aab yielded an inverse correlation in AAV (r=-0.6813, P=0.0127). C5aR1 expression was increased on T-cells in GPA (CD4+C5aR1+T-cells: GPA:10.76±2.55%vs. HD:3.44±0.68%, P=0.0021; CD8+C5aR1+T-cells GPA:9.74±2.10%vs.HD:4.11±0.92%, P=0.0198). Reduced titers of anti-C5aR1 aab <0.45U/ml displayed an increased relapse risk for major organ involvement in GPA (HR 12.85, P=0.0014).

Conclusion:

As potential diagnostic marker, anti-C5aR1 aab titer may additionally be useful to monitor disease activity in AAV.

References:

[1]Chen M et al.Complement deposition in renal histopathology of patients with ANCA-associated pauci-immune glomerulonephritis.Nephrol Dial Transpl. 2009;24:1247-1252

[2]Schreiber A et al.C5a receptor mediates neutrophil activation an ANCA-induced glomerulonephritis.J Am Soc Nephrol. 2009; 20:289-298

[3]Lamprecht P et al.: Pathogenetic and clinical aspects of Anti-Neutrophil Cytoplasmic Autoantibody-associated vasculitides.Front Immunol.2018 Apr 9;9-680

[4]Xiao H et al.C5a receptor (CD88) blockade protects against MPO-ANCA GN.J Am Soc Nephrol. 2014;25(2):225-31

[5]Klapa S et al. Decreased endothelin receptor A autoantibody levels are associated with early ischaemic events in patients with giant-cell arteritis.Ann Rheum Dis2019 Oct;78(19):1443-1444

Disclosure of Interests:

Sebastian Klapa Grant/research support from: Actelion, Consultant of: Pfizer, Abbvie, Antje Müller: None declared, Andreas Koch: None declared, Anja Kerstein-Staehle: None declared, Wataru Kaehler: None declared, Harald Heidecke Shareholder of: Cell Trend GmbH, Employee of: Cell Trend GmbH, Speakers bureau: Cell Trend GmbH, Susanne Schinke Speakers bureau: Pfizer, Markus Huber-Lang: None declared, Martin Nitschke: None declared, Silke Pitann: None declared, Christian Karsten: None declared, Gabriela Riemekasten Consultant of: Cell Trend GmbH, Janssen, Actelion, Boehringer Ingelheim, Speakers bureau: Actelion, Novartis, Janssen, Roche, GlaxoSmithKline, Boehringer Ingelheim, Pfizer, Peter Lamprecht: None declared

Disruption of Staphylococcus aureus biofilms using rhamnolipid biosurfactants

Staphylococcus aureus is an important pathogen that has shown ability to establish biofilm communities that can represent a source of contamination and resistance in food processing. Rhamnolipids (RL) have attracted attention as candidates to replace synthetic surfactants, exhibiting high surface activity combined with its microbial origin, biodegradability, and low toxicity. In this work, an RL biosurfactant was evaluated regarding its ability to disrupt or remove S. aureus biofilms established on polystyrene plates using nutrient broth and skim milk as the growth media. Rhamnolipid treatment was performed at different surfactant concentrations and temperatures. Rhamnolipid removes up to 88.9% of milk-based biofilms, whereas for nutrient medium 35% removal was attained. The RL concentration affects the disruption of nutrient medium-based biofilms. High carbohydrate content of milk-based biofilms favors disruption by RL and the organization of RL molecules in solution showed a predominance of aggregates from 1 to 10 and 100 to 1,000 nm in all conditions studied. Biofilm disruption activity of RL is nutrient-specific and dependent on biofilm matrix composition. Staphylococcus aureus biofilms established in milk were significantly reduced using RL at low concentrations and temperatures. These findings suggest potential application of RL in milk (dairy) processing industries where low temperatures are applied.

Cerebellar degeneration affects cortico-cortical connectivity in motor learning networks

The cerebellum plays an important role in motor learning as part of a cortico-striato-cerebellar network. Patients with cerebellar degeneration typically show impairments in different aspects of motor learning, including implicit motor sequence learning. How cerebellar dysfunction affects interactions in this cortico-striato-cerebellar network is poorly understood. The present study investigated the effect of cerebellar degeneration on activity in causal interactions between cortical and subcortical regions involved in motor learning. We found that cerebellar patients showed learning-related increase in activity in two regions known to be involved in learning and memory, namely parahippocampal cortex and cerebellar Crus I. The cerebellar activity increase was observed in non-learners of the patient group whereas learners showed an activity decrease. Dynamic causal modeling analysis revealed that modulation of M1 to cerebellum and putamen to cerebellum connections were significantly more negative for sequence compared to random blocks in controls, replicating our previous results, and did not differ in patients. In addition, a separate analysis revealed a similar effect in connections from SMA and PMC to M1 bilaterally. Again, neural network changes were associated with learning performance in patients. Specifically, learners showed a negative modulation from right SMA to right M1 that was similar to controls, whereas this effect was close to zero in non-learners. These results highlight the role of cerebellum in motor learning and demonstrate the functional role cerebellum plays as part of the cortico-striato-cerebellar network.

Hierarchically structured nerve guidance channels based on poly-3-hydroxybutyrate enhance oriented axonal outgrowth

Traumatic peripheral nerve lesions can cause local anesthesia, paralysis and loss of autonomic control. Reconstruction using engineered nerve guidance conduits (NGCs) is rarely successful due to the sub-optimal characteristics of the conduits. To address the demands of clinical practice, we developed a hierarchically structured NGC from slowly resorbing poly(3-hydroxybutyric acid) (P3HB). The NGC consists of a permeable single-lumen tube and melt-spun fibrillar lumen fillers. Permeable tubes were constructed from P3HB/poly(ɛ-caprolactone) (PCL) blends or poly(3-hydroxybutyric acid-co-4-hydroxybutyric acid) (P(3HB-co-4HB)). Polyvinylpyrrolidone was used as a porogen in solvent-free thermoplastic processing, followed by selective polymer leaching. All tested material compositions showed hydrolytic degradation after 16weeks in phosphate buffered saline, whereas P3HB/PCL tubes maintained mechanical strength compared to (P(3HB-co-4HB)). The porous scaffolds allowed diffusion of large molecules (∼70kDa). In vitro studies demonstrated that mouse fibroblasts survived and proliferated inside closed porous tubes. An in vitro model of axonal regeneration using dorsal root ganglia and sympathetic cervical ganglia demonstrated that the NGCs successfully supported neuron survival and neurite outgrowth. The introduction of fibrillar lumen fillers promoted oriented neurite growth and coating with extracellular matrix proteins further increased ganglia attachment and cell migration. In this study we show that P3HB-based NGCs scaffolds have potential in long gap peripheral nerve repair strategies.

Human corneal endothelial cell sheets for transplantation: thermo-responsive cell culture carriers to meet cell-specific requirements

Corneal endothelial diseases lead to severe vision impairment, motivating the transplantation of donor corneae or corneal endothelial lamellae, which is, however, impeded by endothelial cell loss during processing. Therefore, one prioritized aim in corneal tissue engineering is the generation of transplantable human corneal endothelial cell (HCEC) layers. Thermo-responsive cell culture carriers are widely used for non-enzymatic harvest of cell sheets. The current study presents a novel thermo-responsive carrier based on simultaneous electron beam immobilization and cross-linking of poly(vinyl methyl ether) (PVME) on polymeric surfaces, which allows one to adjust layer thickness, stiffness, switching amplitude and functionalization with bioactive molecules to meet cell type specific requirements. The efficacy of this approach for HCEC, which require elaborate cell culture conditions and are strongly adherent to the substratum, is demonstrated. The developed method may pave the way to tissue engineering of corneal endothelium and significantly improve therapeutic options.

Simvastatin modulates mouse embryonic stem cell-derived chondrogenesis in vitro

It has been studied in detail that cellular differentiation during chondrogenesis can be recapitulated in vitro by differentiation of embryonic stem (ES) cells as embryoid bodies (EBs). We here used this model system of cartilage development to analyze the effect of simvastatin, a potentially embryotoxic substance. Statins are a group of drugs used to treat hypercholesterolaemia. We found that simvastatin activated cartilage nodule formation during EB differentiation. Extended application of simvastatin resulted in enhanced expression of cartilage marker molecules and prolonged persistence of cartilage nodules. Expression of collagen type II was upregulated during simvastatin-induced chondrogenic ES cell differentiation as demonstrated by quantitative real time PCR. However, immunostaining for cartilage marker molecules revealed that cartilage nodules within simvastatin-treated EBs were defective, bearing cavities of cell loss. Furthermore, caspase activity was reduced in comparison to untreated controls indicating reduced apoptosis. Taken together, we may speculate that simvastatin prolongs survival of chondrocytes and disrupts cellular integrity of cartilage nodules during EB development by affecting apoptotic mechanisms. The study underlines that ES cell-derived EBs are a useful in vitro model to screen substances for their embryotoxic and teratogenic potential.

[Transplantation of corneal endothelium--chances and challenges]

BACKGROUND

Endothelial keratoplasty is a promising surgical procedure which may replace penetrating keratoplasty in cases of endothelial cell diseases of the cornea. This method may thereby help to prevent postoperative astigmatism and transplant rejection.

METHODS AND RESULTS

A survey of publications reporting about results after endothelial keratoplasty shows that the main problem of this transplantation technique is a postoperative endothelial cell loss which is comparable to or even higher than that observed in penetrating keratoplasty. Improving surgical techniques led to a reduction of the endothelial cell loss, however, cell-based strategies to prevent postoperative cell loss or to enhance the cell densities of donor corneas or endothelial lamellae are rare.

DISCUSSION

This review presents an overview of clinical results after endothelial keratoplasty. Current strategies in the field of cell biology and tissue cultivation of corneal endothelial cells, genetic manipulation of the corneal endothelium and tissue engineering strategies aiming at the production of transplantable endothelial cell sheets are described.

CONCLUSION

The limited availability of donor corneas makes it mandatory to develop methods in the field of tissue engineering in order to improve corneal endothelial cell survival or to increase corneal endothelial cell density, using interdisciplinary approaches.

Surfactin reduces the adhesion of food-borne pathogenic bacteria to solid surfaces

AIMS

To investigate the effect of the biosurfactants surfactin and rhamnolipids on the adhesion of the food pathogens Listeria monocytogenes, Enterobacter sakazakii and Salmonella Enteritidis to stainless steel and polypropylene surfaces.

METHODS AND RESULTS

Quantification of bacterial adhesion was performed using the crystal violet staining technique. Preconditioning of surfaces with surfactin caused a reduction on the number of adhered cells of Ent. sakazakii and L. monocytogenes on stainless steel. The most significant result was obtained with L. monocytogenes where number of adhered cells was reduced by 10(2) CFU cm(-2). On polypropylene, surfactin showed a significant decrease on the adhesion of all strains. The adsorption of surfactin on polystyrene also reduces the adhesion of L. monocytogenes and Salm. Enteritidis growing cells. For short contact periods using nongrowing cells or longer contact periods with growing cells, surfactin was able to delay bacterial adhesion.

CONCLUSIONS

The prior adsorption of surfactin to solid surfaces contributes on reducing colonization of the pathogenic bacteria.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first work investigating the effect of surfactin on the adhesion of the food pathogens L. monocytogenes, Ent. sakazakii and Salm. Enteritidis to polypropylene and stainless steel surfaces.

Cell entry of arginine-rich peptides is independent of endocytosis

Arginine-rich peptides are a subclass of cell-penetrating peptides that are taken up by living cells and can be detected freely diffusing inside the cytoplasm and nucleoplasm. This phenomenon has been attributed to either an endocytic mode of uptake and a subsequent release from vesicles or to direct membrane penetration (transduction). To distinguish between both possibilities, we have blocked endocytic pathways suggested to be involved in uptake of cell-penetrating peptides. We have then monitored by confocal microscopy the uptake and distribution of the cell-penetrating transactivator of transcription (TAT) peptide into living mammalian cells over time. To prevent side effects of chemical inhibitors, we used genetically engineered cells as well as different temperature. We found that a knockdown of clathrin-mediated endocytosis and a knock-out of caveolin-mediated endocytosis did not affect the ability of TAT to enter cells. In addition, the TAT peptide showed the same intracellular distribution throughout the cytoplasm and nucleus as in control cells. Even incubation of cells at 4 °C did not abrogate TAT uptake nor change its intracellular distribution. We therefore conclude that this distribution results from TAT peptide that directly penetrated (transduced) the plasma membrane. The formation of nonselective pores is unlikely, because simultaneously added fluorophores were not taken up together with the TAT peptide. In summary, although the frequency and kinetics of TAT transduction varied between cell types, it was independent of endocytosis.

Equine arteritis virus is delivered to an acidic compartment of host cells via clathrin-dependent endocytosis

Equine arteritis virus (EAV) is an enveloped, positive-stranded RNA virus belonging to the family Arteriviridae. Infection by EAV requires the release of the viral genome by fusion with the respective target membrane of the host cell. We have investigated the entry pathway of EAV into Baby Hamster Kindey cells (BHK). Infection of cells assessed by the plaque reduction assay was strongly inhibited by substances which interfere with clathrin-dependent endocytosis and by lysosomotropic compounds. Furthermore, infection of BHK cells was suppressed when clathrin-dependent endocytosis was inhibited by expression of antisense RNA of the clathrin-heavy chain before infection. These results strongly suggest that EAV is taken up via clathrin-dependent endocytosis and is delivered to acidic endosomal compartments.

Different extraretinal neuronal mechanisms of smooth pursuit eye movements in schizophrenia: An fMRI study

Smooth pursuit eye movements (SPEM) are necessary to follow slowly moving targets while maintaining foveal fixation. In about 50% of schizophrenic patients SPEM velocity is reduced. In this study we were interested in identifying the cortical mechanisms associated with extraretinal processing of SPEM in schizophrenic patients. During condition A, patients and healthy subjects had to pursue a constantly visible target (10 degrees /s). During condition B the target was blanked out for 1000 ms while subjects were instructed to continue SPEM. Eye movement data were assessed during scanning sessions by a limbus tracker. During condition A, reduced SPEM velocity in patients was associated with reduced activation of the right ventral premotor cortex and increased activation of the left dorsolateral prefrontal cortex, the right thalamus and the Crus II of the left cerebellar hemisphere. During condition B, SPEM velocity was reduced to a similar extent in both groups. While in patients a decrease in activation was observed in the right cerebellar area VIIIA, the activation of the right anterior cingulate, the right superior temporal cortex, and the bilateral frontal eye fields was increased. The results implicate that schizophrenic patients employ different strategies during SPEM both with and without target blanking than healthy subjects. These strategies predominantly involve extraretinal mechanisms.

Ethylene glycol intoxication and xylitol infusion--metabolic steps of oxalate-induced acute renal failure

Acute renal failure is a major complication in patients with increased oxalate serum concentration. To describe the metabolic mechanisms of oxalate-induced glomerular and tubular damage, we report a case of ethylene glycol intoxication as well as a case of xylitol infusion in a patient with previously unknown primary hyperoxaluria type 1. Both patients presented with acute renal failure associated with histologically proven renal oxalate accumulation. This excessive oxalate overloading resulted from elimination and metabolization of ethylene glycol or xylitol. Thus, key enzymes in the elimination pathway of these substances represent targets for pharmacological treatment. Simultaneous hemodialysis is often necessary to reduce oxalate serum concentration. Whereas renal function of the ethylene glycol-poisoned patient recovered, the second patient who received xylitol infusion required chronic hemodialysis due to the unmasked hyperoxaluria type 1. Our cases demonstrate that patients with excessive endogenous oxalate generation are at high risk to develop acute renal failure. Therefore, to prevent end-stage renal failure in these patients, important clinical factors should be considered as indicators for the underlying cause: history of alcohol abuse and severe high anion gap acidosis for ethylene glycol intoxication or history of long-lasting parenteral nutrition for xylitol-associated acute renal failure.

Enhanced human beta-defensin-2 (hBD-2) expression by corticosteroids is independent of NF-kappaB in colonic epithelial cells (CaCo2)

Beta-defensins are small cationic peptides with antimicrobial properties that contribute to innate host defense. Unlike human beta-defensin-1 (hBD-1), which is produced constitutively, human beta-defensin-2 (hBD-2) is expressed after adequate stimulation by cytokines and/or bacterial endotoxins in epithelial tissue and mononuclear phagocytes but may be deficient in patients with Crohn's disease. To further elucidate the role of the intestinal epithelium in antimicrobial host defense, gene regulation of hBD-2 and the interaction with NF-kappaB were analyzed in a cell culture model. Human colonic epithelial cells (CaCo2) were stimulated by pro-inflammatory cytokines (IL-1beta, TNF-alpha, IF-gamma) to induce hBD-2 mRNA transcription. Interactions with NF-kappaB were analyzed using specific inhibitors (sulfasalazine, gliotoxine, dexamethasone) at different concentrations. Defensin mRNA expression was quantified by competitive RT-PCR and antibacterial capacity of supernatants was determined by an antimicrobial assay. HBD-2 mRNA transcription and antimicrobial activity of CaCo2 cells were induced by stimulation with pro-inflammatory cytokines. Induction was not inhibited by sulfasalazine or gliotoxine, whereas dexamethasone further enhanced both gene transcription and antimicrobial capacity. The lack of inhibition of induced hBD-2 expression by specific NF-kappaB antagonists suggests an additional pathway of activation, independent of NF-kappaB. The induction of hBD-2 expression in cytokine-stimulated CaCo2 cells by corticosteroids indicates further immunomodulatory ability of steroid hormones not yet understood.