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[EN] Hypertension induces significant aortic remodelling, often adaptive but sometimes not. To identify immuno-mechanical mechanisms responsible for differential remodelling, we studied thoracic aortas from 129S6/SvEvTac and C57BL/6 J mice before and after continuous 14-day angiotensin II infusion, which elevated blood pressure similarly in both strains. Histological and biomechanical assessments of excised vessels were similar at baseline, suggesting a common homeostatic set-point for mean wall stress. Histology further revealed near mechano-adaptive remodelling of the hypertensive 129S6/SvEvTac aortas, but a grossly maladaptive remodelling of C57BL/6 J aortas. Bulk RNA sequencing suggested that increased smooth muscle contractile processes promoted mechano-adaptation of 129S6/SvEvTac aortas while immune processes prevented adaptation of C57BL/6 J aortas. Functional studies confirmed an increased vasoconstrictive capacity of the former while immunohistochemistry demonstrated marked increases in inflammatory cells in the latter. We then used multiple computational biomechanical models to test the hypothesis that excessive adventitial wall stress correlates with inflammatory cell infiltration. These models consistently predicted that increased vasoconstriction against an increased pressure coupled with modest deposition of new matrix thickens the wall appropriately, restoring wall stress towards homeostatic consistent with adaptive remodelling. By contrast, insufficient vasoconstriction permits high wall stresses and exuberant inflammation-driven matrix deposition, especially in the adventitia, reflecting compromised homeostasis and gross maladaptation., This work was supported by grants from NIH (grant nos. R01HL105297, P01 HL134605, U01 HL142518, R01 HL146723), Netherlands Organisation for Scientific Research (grant no. Rubicon 452172006) and the European Union¿s Horizon 2020 research and innovation program (grant no. 793805)

Transforming growth factor-β1 (TGF-β1) is a potent inducer of fibroblast to myofibroblast differentiation and contributes to the pro-fibrotic microenvironment during cardiac remodeling. Fibroblast growth factor-2 (FGF-2) is a growth factor secreted by adipose tissue-derived stromal cells (ASC) which can antagonize TGF-β1 signaling. We hypothesized that TGF-β1-induced cardiac fibroblast to myofibroblast differentiation is abrogated by FGF-2 and ASC conditioned medium (ASC-CMed). Our experiments demonstrated that TGF-β1 treatment-induced cardiac fibroblast differentiation into myofibroblasts, as evidenced by the formation of contractile stress fibers rich in αSMA. FGF-2 blocked the differentiation, as evidenced by the reduction in gene (TAGLN, p ACTA2, p = 0.0056) and protein (αSMA, p = 0.0338) expression of mesenchymal markers and extracellular matrix components gene expression (COL1A1, p COL3A1, p = 0.0029). ASC-CMed did not block myofibroblast differentiation. The treatment with FGF-2 increased matrix metalloproteinases gene expression (MMP1, p MMP14, p = 0.0027) and decreased the expression of tissue inhibitor of metalloproteinase gene TIMP2 (p = 0.0023). ASC-CMed did not influence these genes. The proliferation of TGF-β1-induced human cardiac fibroblasts was restored by both FGF-2 (p = 0.0002) and ASC-CMed (p = 0.0121). The present study supports the anti-fibrotic effects of FGF-2 through the blockage of cardiac fibroblast differentiation into myofibroblasts. ASC-CMed, however, did not replicate the anti-fibrotic effects of FGF-2 in vitro.

[EN] Arteries are exposed to relentless pulsatile haemodynamic loads, but via mechanical homeostasis they tend to maintain near optimal structure, properties and function over long periods in maturity in health. Numerous insults can compromise such homeostatic tendencies, however, resulting in maladaptations or disease. Chronic inflammation can be counted among the detrimental insults experienced by arteries, yet inflammation can also play important homeostatic roles. In this paper, we present a new theoretical model of complementary mechanobiological and immunobiological control of vascular geometry and composition, and thus properties and function. We motivate and illustrate the model using data for aortic remodelling in a common mouse model of induced hypertension. Predictions match the available data well, noting a need for increased data for further parameter refinement. The overall approach and conclusions are general, however, and help to unify two previously disparate literatures, thus leading to deeper insight into the separate and overlapping roles of mechanobiology and immunobiology in vascular health and disease., This work was supported, in part, by grants from the US National Institutes of Health (grant nos. R01 HL105297, P01 HL134605, R01 HL146723)

Skeletal muscle plasticity is reflected by a dynamic balance between protein synthesis and breakdown, with basal muscle tissue protein synthesis rates ranging between 0.02 and 0.09%/h. Though it is evident that other musculoskeletal tissues should also express some level of plasticity, data on protein synthesis rates of most of these tissues in vivo in humans is limited. Six otherwise healthy patients (62±3 y), scheduled to undergo unilateral total knee arthroplasty, were subjected to primed continuous intravenous infusions with L-[ring-13C6]-Phenylalanine throughout the surgical procedure. Tissue samples obtained during surgery included muscle, tendon, cruciate ligaments, cartilage, bone, menisci, fat, and synovium. Tissue-specific fractional protein synthesis rates (%/h) were assessed by measuring the incorporation of L-[ring-13C6]-Phenylalanine in tissue protein and were compared with muscle tissue protein synthesis rates using a paired t test. Tendon, bone, cartilage, Hoffa's fat pad, anterior and posterior cruciate ligament, and menisci tissue protein synthesis rates averaged 0.06±0.01, 0.03±0.01, 0.04±0.01, 0.11±0.03, 0.07±0.02, 0.04±0.01, and 0.04±0.01%/h, respectively, and did not significantly differ from skeletal muscle protein synthesis rates (0.04±0.01%/h; P>0.05). Synovium derived protein (0.13±0.03%/h) and intercondylar notch bone tissue protein synthesis rates (0.03±0.01%/h) were respectively higher and lower compared to skeletal muscle protein synthesis rates (P

Background Atopic dermatitis (AD) is a common inflammatory skin disease in both adults and children. Whilst topical calcineurin inhibitors (TCIs), tacrolimus ointment and pimecrolimus cream, have proven efficacy for the treatment of AD, it is important to involve experts to obtain their opinion on its optimal treatment. Objective Methods Using a modified Delphi approach, this project aimed to generate consensus amongst experts on the use of TCIs in the treatment of AD, with a focus on the differentiation between tacrolimus and pimecrolimus. Six expert dermatologists from different European countries participated in this project based on their experience with AD and its treatment, which was evaluated by literature analysis and expert opinion. Consensus amongst the experts was generated using a modified Delphi approach, consisting of three distinct phases, during which a web meeting (June 2017), two online rounds of blinded Delphi voting (July-September 2017) and a face-to-face meeting (November 2017) were conducted. The consensus statements concerned two main topics: (i) Background of AD; and (ii) TCIs in AD. Hot topics in the treatment of AD not supported by meta-analysis, clinical trials or large observational studies were also discussed based on clinical experience. Results Conclusion In total, 25 consensus statements were defined and validated: eight statements on the general background of AD and 17 statements on the use of TCIs in AD, including their mechanism of action and therapeutic indications in AD, efficacy in adult and paediatric AD patients, pharmacokinetics, incidence of adverse events and safety concerns. Hot topics on the use of TCIs for the treatment of AD included cream vs. ointment, dosages, TCIs contact allergy, burning sensation management, superinfection and vaccination concerns. Topical calcineurin inhibitors are a suitable therapy for AD, and selection of the specific TCI should be based on factors which differentiate tacrolimus from pimecrolimus.

With the increasing incidence of fractures now, and in the future, the absolute number of bone-healing complications such as nonunion development will also increase. Next to fracture-dependent factors such as large bone loss volumes and inadequate stabilization, the nutritional state of these patients is a major influential factor for the fracture repair process. In this review, we will focus on the influence of protein/amino acid malnutrition and its influence on fracture healing. Mainly, the arginine-citrulline-nitric oxide metabolism is of importance since it can affect fracture healing via several precursors of collagen formation, and through nitric oxide synthases it has influences on the bio-molecular inflammatory responses and the local capillary growth and circulation.

Titanium dioxide as a food additive (E171) has been demonstrated to facilitate growth of chemically induced colorectal tumours in vivo and induce transcriptomic changes suggestive of an immune system impairment and cancer development. The present study aimed to investigate the molecular mechanisms behind the tumour stimulatory effects of E171 in combination with azoxymethane (AOM)/dextran sodium sulphate (DSS) and compare these results to a recent study performed under the same conditions with E171 only. BALB/c mice underwent exposure to 5 mg/kgbw/day of E171 by gavage for 2, 7, 14, and 21 days. Whole genome mRNA microarray analyses on the distal colon were performed. The results show that E171 induced a downregulation of genes involved in the innate and adaptive immune system, suggesting impairment of this system. In addition, over time, signalling genes involved in colorectal cancer and other types of cancers were modulated. In relation to cancer development, effects potentially associated with oxidative stress were observed through modulation of genes related to antioxidant production. E171 affected genes involved in biotransformation of xenobiotics which can form reactive intermediates resulting in toxicological effects. These transcriptomics data reflect the early biological responses induced by E171 which precede tumour formation in an AOM/DSS mouse model.

Patellar tendinopathy (PT) is a common overuse injury of the patellar tendon in jumping athletes. In a recent large cross-sectional study from 2008 several factors were identified that may be associated with the etiology of PT. However, because of the study design no conclusions could be drawn about causal relations. The primary aim of the current study is to investigate whether the factors identified in the previous 2008 study can also be prospectively recognized as predictors of symptomatic PT in 2011. Nine hundred twenty-six Dutch elite and non-elite basketball and volleyball players from the previous study were invited again to complete an online survey about knee complaints and risk factors for PT in 2011. The logistic regression included 385 athletes of which 51 (13%) developed PT since 2008. Male gender [odds ratio (OR) 2.0, 95% confidence interval (CI) 1.1-3.5] was found to be a risk factor for developing PT. No sports-related variables could be identified to increase the risk of developing PT, but some evidence was found for performing heavy physically demanding work, like being a nurse or a physical education teacher (OR 2.3, 95% CI 0.9-6.3). These findings indicate that, when considering preventive measures, it is important to take into account the total tendon load.

Photoderivatives of riboflavin can modulate the proliferation and survival of cancer cells. In this work, we examined the influence of riboflavin and photoderivatives on osteoblast differentiation induced by ascorbic acid and beta-glycerophosphate. These compounds decreased the osteoblast proliferation, increased the alkaline phosphatase activity, promoted a reduction in matrix metalloproteinase-2 activity and the decreased in the OPG/RANKL ratio. The effects of flavins on osteoblasts were unrelated to the antioxidant activity of these compounds. The biological activity of osteogenic medium containing riboflavin and its photoderivatives involved the activation of different signaling pathways (AKT, FAK, CaMKII), caspases-3, -8 and -9, and up-regulation of the expression and/or stabilization of osteoblastic transcription factors (Runx2 and beta-catenin). These findings suggest a potential use of flavins as adjuvants to improve bone metabolism. (C) 2010 Elsevier Ltd. All rights reserved.

A one-year, randomized, double-blind study was conducted in 80 patients with atopic dermatitis treated with tacrolimus ointment or a corticosteroid regimen (hydrocortisone acetate 1% ointment for head and neck, hydrocortisone butyrate 0.1% ointment for trunk and limbs) to compare efficacy and safety, and effects on Th2-reactivity. The study was completed by 36/40 patients in the tacrolimus group, and 31/40 patients in the corticosteroid group. In both groups affected body surface area, eczema area and severity index, and transepidermal water loss decreased at months 6 and 12. Tacrolimus was superior for all efficacy scores at month 6, and in the head and neck area at month 12. Recall antigen reactivity increased at month 12 in both groups. Adverse events were reported by 40/40 patients in the tacrolimus, and by 34/40 patients in the corticosteroid group. Long-term treatment with topical tacrolimus or a corticosteroid regimen improves atopic dermatitis and recall antigen reactivity, suggesting an improvement in the Th1/Th2-balance. Key words: atopic dermatitis; hydrocortisone butyrate; randomized controlled trial; recall antigen; tacrolimus ointment.

Chronic liver injury of various etiologies can cause liver fibrosis, which is characterized by the progressive accumulation of connective tissue in the liver. As no effective treatment for liver fibrosis is available yet, extensive research is ongoing to further study the mechanisms underlying the development of disease- or toxicity-induced liver fibrosis and to identify potential pro- or anti-fibrotic properties of compounds. This review gives an overview of the in vitro methods that are currently available for this purpose. The first focus is on cell culture models, since the majority of in vitro research uses these systems. Both primary cells and cell lines as well as the use of different culture matrices and co-culture models are discussed. Second, the use of precision-cut liver slices, which recently came into attention as in vitro model for the study of fibrosis, is discussed. The overview clearly shows that continuous optimization and adaptation have extended the potential of in vitro models for liver fibrosis during the past years. By combining the use of the different cell and tissue culture models, the mechanisms underlying multicellular fibrosis development can be studied in vitro and potential pro- or anti-fibrotic properties of compounds can be identified both on single liver cell types and in human liver tissue. (C) 2007 Elsevier Ltd. All rights reserved.

Chronic liver injury of various etiologies can cause liver fibrosis, which is characterized by the progressive accumulation of connective tissue in the liver. As no effective treatment for liver fibrosis is available yet, extensive research is ongoing to further study the mechanisms underlying the development of disease- or toxicity-induced liver fibrosis and to identify potential pro- or anti-fibrotic properties of compounds. This review gives an overview of the in vitro methods that are currently available for this purpose. The first focus is on cell culture models, since the majority of in vitro research uses these systems. Both primary cells and cell lines as well as the use of different culture matrices and co-culture models are discussed. Second, the use of precision-cut liver slices, which recently came into attention as in vitro model for the study of fibrosis, is discussed. The overview clearly shows that continuous optimization and adaptation have extended the potential of in vitro models for liver fibrosis during the past years. By combining the use of the different cell and tissue culture models, the mechanisms underlying multicellular fibrosis development can be studied in vitro and potential pro- or anti-fibrotic properties of compounds can be identified both on single liver cell types and in human liver tissue. (C) 2007 Elsevier Ltd. All rights reserved.

Patellar tendinopathy (PT) is a common overuse injury of the patellar tendon in jumping athletes. In a recent large cross-sectional study from 2008 several factors were identified that may be associated with the etiology of PT. However, because of the study design no conclusions could be drawn about causal relations. The primary aim of the current study is to investigate whether the factors identified in the previous 2008 study can also be prospectively recognized as predictors of symptomatic PT in 2011. Nine hundred twenty-six Dutch elite and non-elite basketball and volleyball players from the previous study were invited again to complete an online survey about knee complaints and risk factors for PT in 2011. The logistic regression included 385 athletes of which 51 (13%) developed PT since 2008. Male gender [odds ratio (OR) 2.0, 95% confidence interval (CI) 1.1-3.5] was found to be a risk factor for developing PT. No sports-related variables could be identified to increase the risk of developing PT, but some evidence was found for performing heavy physically demanding work, like being a nurse or a physical education teacher (OR 2.3, 95% CI 0.9-6.3). These findings indicate that, when considering preventive measures, it is important to take into account the total tendon load.

Background Anastomotic leakage (AL) remains the most dreaded complication after colorectal surgery and causes high morbidity and mortality. The pathophysiology of AL remains unclear, despite numerous studies that have been conducted on animals and humans, probably due to the undetermined healing process of colorectal anastomoses. Increasing basic knowledge on this healing process may shed more light on causal factors of AL, and additionally reduce the quantity and accelerate the quality of experimental studies. In this debate article, our aim was to provide different perspectives on what is known about the colorectal healing process in relation to wound healing and AL. Discussion Since knowledge on anastomotic healing is lacking, it remains difficult to conclude which factors are essential in preventing AL. This is essential information in the framework of humane animal research, where the focus should lie on Replacement, Reduction and Refinement (3Rs). While many researchers compare anastomotic healing with wound healing in the skin, there are substantial recognized differences, e.g. other collagen subtypes and different components involved. Summary Based on our findings in literature as well as discussions with experts, we advocate stop considering anastomotic healing in the gastrointestinal tract and cutaneous healing as a similar process. Furthermore, intervention studies should at least address the anastomotic healing process in terms of histology and certain surrogate markers. Finally, the anastomotic healing process ought to be further elucidated – with modern techniques to achieve 3Rs in animal research - to provide starting points for potential interventions that can prevent AL.

Objective. Progressive destruction of articular cartilage is a hallmark of osteoarthritis (OA) and rheumatoid arthritis (RA). Age-related changes in cartilage may influence tissue destruction and thus progression of the disease. Therefore, the effect of age-related accumulation of advanced glycation end products (AGEs) on cartilage susceptibility to proteolytic degradation by matrix metalloproteinases (MMPs) present in synovial fluid (SF) of OA and RA patients was studied.Methods. Cartilage was incubated with APMA-activated SF obtained from OA or RA patients, and tissue degradation was assessed by colorimetric measurement of glycosaminoglycan (GAG) release. Cartilage degradation was related to the level of AGEs in cartilage from donors of different ages (33-83 years) and in cartilage with in vitro-enhanced AGE levels (by incubation with ribose). MMP activity in SF was measured using a fluorogenic substrate. AGE levels were assessed by high-performance liquid chromatography measurement of the glycation product pentosidine.Results. In cartilage from donors ages 33-83 years, a strong correlation was found between the age-related increase in pentosidine and the decrease in MMP-mediated tissue degradation (r = -0.74, P 0.8). In addition, decreased MMP-mediated GAG release was proportional to increased pentosidine levels after in vitro enhancement of glycation (r = -0.27, P Conclusion. Increased cartilage AGEs resulted in decreased cartilage degradation by MMPs from SF, indicating that aged cartilage is less sensitive than young cartilage to MMP-mediated cartilage degradation, such as occurs in OA and RA. Therefore, the level of cartilage glycation may influence the progression of these diseases.

In acute liver failure (ALF), the hyperdynamic circulation is believed to be the result of overproduction of nitric oxide (NO) in the splanchnic circulation. However, it has been suggested that arginine concentrations (the substrate for NO) are believed to be decreased, limiting substrate availability for NO production. To characterize the metabolic fate of arginine in early-phase ALF, we systematically assessed its interorgan transport and metabolism and measured the endogenous NO synthase inhibitor asymmetric dimethylarginine (ADMA) in a porcine model of ALF. Female adult pigs (23–30 kg) were randomized to sham ( N = 8) or hepatic devascularization ALF ( N = 8) procedure for 6 h. We measured plasma arginine, citrulline, ornithine levels; arginase activity, NO, and ADMA. Whole body metabolic rates and interorgan flux measurements were calculated using stable isotope-labeled amino acids. Plasma arginine decreased >85% of the basal level at t = 6 h ( P < 0.001), whereas citrulline and ornithine progressively increased in ALF ( P < 0.001 and P < 0.001, vs. sham respectively). No difference was found between the groups in the whole body rate of appearance of arginine or NO. However, ALF showed a significant increase in de novo arginine synthesis ( P < 0.05). Interorgan data showed citrulline net intestinal production and renal consumption that was related to net renal production of arginine and ornithine. Both plasma arginase activity and plasma ADMA levels significantly increased in ALF ( P < 0.001). In this model of early-phase ALF, arginine deficiency or higher ADMA levels do not limit whole body NO production. Arginine deficiency is caused by arginase-related arginine clearance in which arginine production is stimulated de novo.

Background: Adipose tissue engineering has been hampered by the inability to culture mature adipocytes. Adipose-derived stem cell (ASC) culture opens the way for the preparation of human 3-D hypodermis in large quantities. These models play a role in obesity-related active molecules and slimming agent screening. Moreover, they contribute to a better understanding of the mechanisms underpinning obesity. Materials and Methods: Freshly extracted ASC from fat tissue were characterized by flow cytometry for CD73, CD90, CD105, HLA-ABC, CD14 and CD45 markers and by Western blot for pref-1. Their differentiation in mature adipocytes was followed by lipid and adiponectin secretion or by oil red O staining and radioimmunoassay. Neosynthesized extracellular matrix (ECM) of 3-D hypodermis was investigated by immunohistochemistry (collagen type I, V and VI) and transmission electron microscopy. Results: Our results demonstrate that the culture of preadipocytes in proliferation medium for 15 days followed by 16 days of culture in differentiation medium allowed production of the thickest single-layer hypodermis in which preadipocytes and mature adipocytes coexist and synthesize adiponectin and ECM components. Functionality of our 3-D single-layer hypodermis was demonstrated both by a 3.5-fold glycerol production after its stimulation with norepinephrine (adrenergic agonist) and by its slimming after caffeine treatment versus the nontreated 3-D hypodermis. Conclusion: This economic 3-D model, easy to prepare and giving reproducible results after the treatment of actives, is useful for pharmacotoxicological trials as an alternative to animal experimentation.

Background: The prevalence of jumper’s knee among nonelite athletes from different sports is unknown. Purpose: This study was undertaken to determine the prevalence of jumper’s knee in nonelite athletes from different sports and to determine potential risk factors for jumper’s knee. Design: Cohort study (prevalence); Level of evidence, 2. Methods: The authors interviewed 891 male and female nonelite athletes from 7 popular sports in The Netherlands: basketball, volleyball, handball, korfball, soccer, field hockey, and track and field. Using a specially developed questionnaire, information was obtained about individual characteristics (age, height, and weight), training background, previous and actual knee problems, and the VISA-P (Victorian Institute of Sport Assessment–Patella) score. Results: The overall prevalence of current jumper’s knee was 8.5% (78 of 891 athletes), showing a significant difference between sports with different loading characteristics. Prevalence was highest among volleyball players (14.4%) and lowest among soccer players (2.5%); it was significantly higher among male athletes (51 of 502 [10.2%]) than female athletes (25 of 389 [6.4%]) (χ2 = 3.91, P = .048). The mean duration of symptoms was 18.9 months (standard deviation [SD], 21.6; median value, 12.0; range, 2.0-59.8). The mean VISA-P score of the athletes with jumper’s knee was 71.4 (SD, 13.8). Athletes with jumper’s knee were significantly younger, taller, and heavier than those without jumper’s knee. Conclusion: Prevalence of jumper’s knee is high among nonelite athletes and varies between 14.4% and 2.5% for different sports. Jumper’s knee is almost twice as common among male nonelite athletes compared with female athletes. Different sport-specific loading characteristics of the knee extensor apparatus, a younger age, a taller body stature, and higher body weight seem to be risk factors associated with patellar tendinopathy.

The present study investigates the effect of transosseous low-intensity pulsed ultrasound (LiUS) on the healing at tendon graft-bone interface, in molecular and histological level. The anterior cruciate ligament (ACL) in both knees of 52 New Zealand White rabbits was excised and replaced with the long digital extensor. A custom-made ultrasound transducer was implanted onto the medial tibial condyle, adjacent to the surface of the bone tunnel at both knees of the rabbits. The LiUS-treated right knees received 200-mu s bursts of 1 MHz sine waves at a pulse repetition rate of 1 kHz and with 30 MW/cm(2) spatial-average temporal-average intensity for 20 min daily (study group), while the left knee received no LiUS (control group). Thirty-six rabbits were used to perform semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis from both study and control groups for transforming growth factor-beta 1 (TGF-beta 1), biglycan and collagen I. RT-PCR products showed statistically significant upregulation of biglycan and collagen I gene expression in the study group, while TGF-beta 1 gene expression exhibited a bimodal profile. Histological examination performed in 16 rabbits from both groups supported the findings of the molecular analysis, indicating a faster healing rate and a more efficient ligamentization process after ultrasound treatment. These findings suggest that transosseous application of LiUS enhances the healing rate of the tendon graft-bone interface, possibly by affecting the expression levels of genes significant for the tendon to bone healing process. (E-mail: malizos@med.uth.gr) (c) 2009 World Federation for Ultrasound in Medicine & Biology. Ultrasound in Medicine and Biology

BackgroundIn asthma, higher chymase positive mast cell (MC-C) numbers are associated with less airway obstruction. In COPD, the distribution of MC-C and tryptase positive mast cells (MC-T) in central and peripheral airways, and their relation with lung function, is unknown. We compared MC-T and MC-C distributions in COPD and controls without airflow limitation, and determined their relation with lung function.MethodsLung tissue sections from 19 COPD patients (median [interquartile range] FEV1% predicted 56 [23–75]) and 10 controls were stained for tryptase and chymase. Numbers of MC-T and MC-C were determined in different regions of central and peripheral airways and percentage of degranulation was determined.ResultsCOPD patients had lower MC-T numbers in the subepithelial area of central airways than controls. In COPD, MC-T numbers in the airway wall and more specifically in the epithelium and subepithelial area of peripheral airways correlated positively with FEV1/VC (Spearman's rho (rs) 0.47, p = 0.05 and rs0.48, p = 0.05, respectively); MC-C numbers in airway smooth muscle of peripheral airways correlated positively with FEV1% predicted (rs0.57, p = 0.02). Both in COPD patients and controls the percentage of degranulated MC-T and MC-C mast cells was higher in peripheral than in central airways (all p < 0.05), but this was not different between the groups.ConclusionMore MC-T and MC-C in peripheral airways correlate with better lung function in COPD patients. It is yet to determine whether this reflects a protective association of mast cells with COPD pathogenesis, or that other explanations are to be considered.

Bone marrow-derived cells (BMDC) have been proposed to exert beneficial effects after renal ischemia/reperfusion injury (IRI) by engraftment in the tubular epithelium. However, BMDC can give rise to myofibroblasts and may contribute to fibrosis. BMDC contribution to the renal interstitial myofibroblast population in relation to fibrotic changes after IRI in rats was investigated. A model of unilateral renal IRI (45 min of ischemia) was used in F344 rats that were reconstituted with R26-human placental alkaline phosphatase transgenic BM to quantify BMDC contribution to the renal interstitial myofibroblast population over time. After IRI, transient increases in collagen III transcription and interstitial protein deposition were observed, peaking on days 7 and 28, respectively. Interstitial infiltrates of BMDC and myofibroblasts reached a maximum on day 7 and gradually decreased afterward. Over time, an average of 32% of all interstitial a-smooth muscle actin-positive myofibroblasts coexpressed R26-human placental alkaline phosphatase and, therefore, were derived from the BM. BMD myofibroblasts produced procollagen I protein and therefore were functional. The postischemic kidney environment was profibrotic, as demonstrated by increased transcription of TGF-beta and decreased transcription of bone morphogenic protein-7. TGF-beta protein was present predominantly in interstitial myofibroblasts but not in BMD myofibroblasts. In conclusion, functional BMD myofibroblasts infiltrate in the postischemic renal interstitium and are involved in extracellular matrix production.

One of the most potent pro-fibrotic cytokines is transforming growth factor (TGF beta). TGF beta is involved in the activation of fibroblasts into myofibroblasts, resulting in the hallmark of fibrosis: the pathological accumulation of collagen. Interleukin-1 beta (IL1 beta) can influence the severity of fibrosis, however much less is known about the direct effects on fibroblasts. Using lung and dermal fibroblasts, we have investigated the effects of IL1 beta, TGF beta 1, and IL1 beta in combination with TGF beta 1 on myofibroblast formation, collagen synthesis and collagen modification (including prolyl hydroxylase, lysyl hydroxylase and lysyl oxidase), and matrix metalloproteinases (MMPs). We found that IL1 beta alone has no obvious pro-fibrotic effect on fibroblasts. However, IL1 beta is able to inhibit the TGF beta 1-induced myofibroblast formation as well as collagen synthesis. Glioma-associated oncogene homolog 1 (GLI1), the Hedgehog transcription factor that is involved in the transformation of fibroblasts into myofibroblasts is upregulated by TGF beta 1. The addition of IL1 beta reduced the expression of GLI1 and thereby also indirectly inhibits myofibroblast formation. Other potentially anti-fibrotic effects of IL1 beta that were observed are the increased levels of MMP1, -2, -9 and -14 produced by fibroblasts exposed to TGF beta 1/IL1 beta in comparison with fibroblasts exposed to TGF beta 1 alone. In addition, IL1 beta decreased the TGF beta 1-induced upregulation of lysyl oxidase, an enzyme involved in collagen cross-linking. Furthermore, we found that lung and dermal fibroblasts do not always behave identically towards IL1 beta. Suppression of COL1A1 by IL1 beta in the presence of TGF beta 1 is more pronounced in lung fibroblasts compared to dermal fibroblasts, whereas a higher upregulation of MMP1 is seen in dermal fibroblasts. The role of IL1 beta in fibrosis should be reconsidered, and the differences in phenotypical properties of fibroblasts derived from different organs should be taken into account in future anti-fibrotic treatment regimes.

Objective. Progressive destruction of articular cartilage is a hallmark of osteoarthritis (OA) and rheumatoid arthritis (RA). Age-related changes in cartilage may influence tissue destruction and thus progression of the disease. Therefore, the effect of age-related accumulation of advanced glycation end products (AGEs) on cartilage susceptibility to proteolytic degradation by matrix metalloproteinases (MMPs) present in synovial fluid (SF) of OA and RA patients was studied. Methods. Cartilage was incubated with APMA-activated SF obtained from OA or RA patients, and tissue degradation was assessed by colorimetric measurement of glycosaminoglycan (GAG) release. Cartilage degradation was related to the level of AGEs in cartilage from donors of different ages (33-83 years) and in cartilage with in vitro-enhanced AGE levels (by incubation with ribose). MMP activity in SF was measured using a fluorogenic substrate. AGE levels were assessed by high-performance liquid chromatography measurement of the glycation product pentosidine. Results. In cartilage from donors ages 33-83 years, a strong correlation was found between the age-related increase in pentosidine and the decrease in MMP-mediated tissue degradation (r = -0.74, P 0.8). In addition, decreased MMP-mediated GAG release was proportional to increased pentosidine levels after in vitro enhancement of glycation (r = -0.27, P

The aim of this study was to compare the clinical and histopathological effects of tripeptide copper complex (TCC) and two different doses of laser application (helium-neon laser, 1 and 3 J cm(-2)) on wound healing with untreated control wounds. Experimental wounds were created on a total of 24 New Zealand white rabbits and topical TCC or laser was applied for 28 days. The wounds were observed daily, and planimetry was performed on days 7, 14, 21 and 28 to measure the unhealed wound area and percentage of total wound healing. Biopsies were taken weekly to evaluate the inflammatory response and the level of neovascularization. The median time for the first observable granulation tissue was shorter (P < 0.05) in the low and high dose laser groups than in the control group (3 and 2.66 vs. 4.5 days), but was not different between the TCC and control groups (4.16 vs. 4.5 days). Filling of the open wound to skin level with granulation tissue was faster (P < 0.05) in the TCC and high dose laser groups than in the control group (14 and 16 vs. 25 days), but was not different between the low dose laser and control groups (23 vs. 25 days). The average time for healing was shorter (P < 0.05) in the TCC and high dose laser groups (29.8 and 30.2 vs. 34.6 days), but was not different between the low dose laser and control groups (33.8 vs. 34.6 days). Histopathologically, wound healing was characterized by a decrease in the neutrophil counts and an increase in neovascularization. The TCC and high dose laser groups had greater neutrophil and vessel counts than in the control group, suggesting a more beneficial effect for wound healing.