Chronic vagus nerve stimulation in Crohn's disease: a 6-month follow-up pilot study.

The vagus nerve (VN) is a link between the brain and the gut. The VN is a mixed nerve with anti-inflammatory properties through the activation of the hypothalamic-pituitary-adrenal axis by its afferents and by activating the cholinergic anti-inflammatory pathway through its efferents. We have previously shown that VN stimulation (VNS) improves colitis in rats and that the vagal tone is blunted in Crohn's disease (CD) patients. We thus performed a pilot study of chronic VNS in patients with active CD. Seven patients under VNS were followed up for 6 months with a primary endpoint to induce clinical remission and a secondary endpoint to induce biological (CRP and/or fecal calprotectin) and endoscopic remission and to restore vagal tone (heart rate variability). Vagus nerve stimulation was feasible and well-tolerated in all patients. Among the seven patients, two were removed from the study at 3 months for clinical worsening and five evolved toward clinical, biological, and endoscopic remission with a restored vagal tone. These results provide the first evidence that VNS is feasible and appears as an effective tool in the treatment of active CD.

Apolipoprotein A-I and platelet factor 4 are biomarkers for infliximab response in rheumatoid arthritis.

OBJECTIVES: The use of biologicals such as infliximab has dramatically improved the treatment of rheumatoid arthritis (RA). However, factors predictive of therapeutic response need to be identified. A proteomic study was performed prior to infliximab therapy to identify a panel of candidate protein biomarkers of RA predictive of treatment response. METHODS: Plasma profiles of 60 patients with RA (28 non-responders (as defined by the American College of Rheumatology 20% improvement criteria (ACR20)) negative and 32 responders (ACR70 positive) to infliximab) were studied by surface enhanced laser desorption/ionisation time-of-flight mass spectrometry (SELDI-TOF MS) technology on two types of arrays, an anion exchange array (SAX2) and a nickel affinity array (IMAC3-Ni). Biomarker characterisation was carried out using classical biochemical methods (purification by ammonium sulfate precipitation or metal affinity chromatography) and identification by matrix assisted laser desorption/ionisation time-of-flight (MALDI-TOF) MS analysis. RESULTS: Two distinct protein profiles were observed on both arrays and several proteins were differentially expressed in both patient populations. Five proteins at 3.86, 7.77, 7.97, 8.14 and 74.07 kDa were overexpressed in the non-responder group, whereas one at 28 kDa was increased in the responder population (sensitivity>56%, specificity>77.5%). Moreover, combination of several biomarkers improved the sensitivity and specificity of the detection of patient response to over 97%. The 28 kDa protein was characterised as apolipoprotein A-I and the 7.77 kDa biomarker was identified as platelet factor 4. CONCLUSIONS: Six plasma biomarkers are characterised, enabling the detection of patient response to infliximab with high sensitivity and specificity. Apolipoprotein A-1 was predictive of a good response to infliximab, whereas platelet factor 4 was associated with non-responders.

Matrix metalloproteinases and diabetic foot ulcers: the ratio of MMP-1 to TIMP-1 is a predictor of wound healing.

AIMS: Matrix metalloproteinases (MMPs) play a major role in wound healing: they can degrade all components of the extracellular matrix. In diabetic foot ulcers there is an excess of MMPs and a decrease of the tissue inhibitors of MMPs (TIMPs). This imbalance is probably one cause of impaired healing. However, little is known about changes in MMPs during wound healing. METHODS: Sixteen patients with neuropathic diabetic foot ulcers participated. Wound fluid was collected regularly during the 12-week follow-up period, for measurement of MMP-1, MMP-2, MMP-8, MMP-9 and TIMP-1. Results were analysed by the degree of wound healing: good healers (defined by a reduction of at least 82% in initial wound surface at 4 weeks) and poor healers (reduction of less than 82% in wound surface at 4 weeks). RESULTS: In good healers, levels of MMP-8 and -9 secreted by inflammatory cells decreased earlier. The initial levels of MMP-1 were similar in good and poor healers (P = 0.1) but rose significantly at week 2 in good healers (P = 0.039). There was a significant correlation between a high ratio of MMP-1/TIMP-1 and good healing (r = 0.65, P = 0.008). Receiver Operator Curve (ROC) analysis showed that an MMP-1/TIMP-1 ratio of 0.39 best predicted wound healing (sensitivity = 71%, specificity = 87.5%). CONCLUSIONS: A high level of MMP-1 seems essential to wound healing, while an excess of MMP-8 and -9 is deleterious, and could be a target for new topical treatments. The MMP-1/TIMP-1 ratio is a predictor of wound healing in diabetic foot ulcers.

Longitudinal evaluation of a fibrosis index combining MMP-1 and PIIINP compared with MMP-9, TIMP-1 and hyaluronic acid in patients with chronic hepatitis C treated by interferon-alpha and ribavirin.

We have recently described a fibrosis index combining serum procollagen type III N-terminal peptide (PIIINP) and matrix metalloproteinase 1 (MMP-1) concentrations for evaluating the amount of liver fibrosis in chronic hepatitis C patients. The aims of the present study were to validate this score in another cohort of patients and to assess its variations along those of TIMP-1, hyaluronic acid (HA) and MMP-9 during antiviral treatment. Seventy-nine patients treated by interferon-alpha and ribavirin for 24 or 48 weeks were included. A liver biopsy was performed within the 6 months before the start of treatment. Serum markers were measured in serum collected the day of the liver biopsy, at start of treatment, and every 3 months during treatment and a 6-month follow-up period. The PIIINP/MMP-1 index was significantly correlated to the METAVIR fibrosis (r = 0.68, P < 0.001). Its overall diagnostic value defined by the area under the receiver operating characteristics curves was 0.77 for discriminating F1 vs F2F3F4, and 0.81 for discriminating F1F2 vs F3F4, and was better than that observed for HA and TIMP-1. At the end of follow-up, the PIIINP/MMP-1 index significantly decreased in responders and remained stable in nonresponder patients. This decrease occurred early and continued regularly during the treatment period. This variation was because of both a decrease of PIIINP and an increase of MMP-1 concentrations. HA and TIMP-1 serum concentrations were also significantly lower at the end of follow-up in responder patients, but early changes were minimal and not influenced by the response to treatment. Our study shows that a noninvasive index combining PIIINP and MMP-1 is a useful tool to follow-up fibrosis change during and after antiviral therapy chronic hepatitis C patients.

High level production of secreted proteins: example of the human tissue inhibitor of metalloproteinases 1.

The major difficulty for high-throughput screening of therapeutic protein candidates in experimental animal models of pathologies or for structural studies is their fast and efficient production. The tissue inhibitors of metalloproteinases (TIMPs) considered to play a role in many physiological and pathological processes, such as arthritis or cancer, by inhibiting matrix metalloproteinases or acting as signalling molecules, have always been produced with huge difficulties. We hereby propose a new method to overproduce human recombinant TIMP-1 by transient expression in HEK293E cells, followed by a one-step chromatography purification, yielding in only 2 weeks, dozens of milligrams of pure, stable, glycosylated and active protein for in vitro and in vivo studies. This easy to set up, rapid, and efficient method could be applied for any naturally secreted mammalian protein.

CREM and ICER are differentially implicated in trans-synaptic induction of tyrosine hydroxylase gene expression in adrenal medulla and sympathetic ganglia of rat.

Reserpine treatment leads to a trans-synaptic increase of the tyrosine hydroxylase (TH) gene transcription rate, mRNA and protein levels in catecholaminergic tissues including the adrenal medulla (AM) and the superior cervical ganglia (SCG). The TPA-responsive element plays an important role in the trans-synaptically-induced transcription of the TH gene in the AM, whereas it does not appear to be involved in the SCG (Trocmé et al. [1997] J. Neurosci. Res. 48:489-498). In this study, we show that another regulatory sequence of the TH proximal promoter, the cAMP-responsive element (CRE), binds different factors in the AM and in the SCG. To elucidate the dynamics of promoter regulation a complete time course analysis was conducted. Reserpine treatment enhances, between 1 hr and 8 hr after the injection, the expression and the binding of the repressor ICER in the AM, whereas in the SCG it enhances the binding of CREM factors. These results suggest that the mechanisms mediating trans-synaptic induction of the TH gene are different in the AM and SCG. The interplay between positive and negative transcription factors and their kinetics of action are responsive of the long-term regulation of the TH gene.

Intervertebral disk degeneration and herniation: the role of metalloproteinases and cytokines.

This article reviews the role of metabolic factors, including metalloproteinases and cytokines, in the occurrence of degenerative disk disease and disk herniation. Given that mechanical factors alone cannot cause disk degeneration, studies must explore metabolic, genetic, nutritional, and age-related factors. Zinc metalloproteinases exert particularly important effects, not only directly, but also indirectly through promotion of neovascularization. The production of these enzymes is dependent on a number of cytokines and on the cell changes they induce. This complex effect acts both on disk matrix degeneration and on the pain generated by contact between the protruding disk and the nerve roots. However, it can have a favorable effect by promoting resorption of the herniated disk. Available data on the role for mechanical factors on the disk chondrocyte metabolism and on metalloproteinase production show that mechanical and metabolic factors interact closely to produce disk disorders.

TIMP-1/MMP-9 imbalance in an EBV-immortalized B lymphocyte cellular model: evidence for TIMP-1 multifunctional properties.

Tissue inhibitors of metalloproteinases (TIMPs) were initially described as agents controlling metalloproteinase activity. The purpose of this study was to investigate the expression and the roles of TIMP-1 secreted by Epstein-Barr-virus (EBV)-immortalized B lymphocytes. TIMP-1 was isolated from conditioned medium of interleukin (IL)-1beta stimulated EBV-B lymphocytes; purified TIMP-1 was identified by mass spectrometry and immunochemistry. TIMP-1-free MMP-9 was quantified after purification by zymography and enzyme-linked immunosorbent assay. EBV-B lymphocyte-secreted TIMP-1 inhibited MMP-9 gelatinolytic activity resulting in decreased B-cell transmigration as measured in vitro. The release of huge amounts of TIMP-1 in proportion to MMP-9 from B lymphocytes after EBV transformation was shown to be correlated with secretion of IL-10 and dependent on culture time. In contrast, there was little TIMP-1 and almost no IL-10 released from native B cells, suggesting a possible IL-10 mediated autocrine regulation mechanism of TIMP-1 synthesis. The MMP-9/TIMP-1 imbalance observed in the culture medium of EBV-B lymphocytes (TIMP-1>MMP-9) and of native B cells (MMP-9>TIMP-1) is suggestive of a new function for TIMP-1. We propose that TIMP-1 acts as a survival factor controlling B-cell growth and apoptosis through an autocrine regulation process involving IL-10 secreted by EBV-B lymphocytes.

[Focalized matrix proteolysis and inflammation]. / Protéolyse matricielle, protéolyse focalisée et inflammation.

The zinc metalloproteinases (MMPs or matrixins) are capable of damaging most of the constituents of the extra-cellular matrix and the basement membrane. The matrix proteolysis is the result of an imbalance both in the turnover of these constituants and in the ratio of the tissue inhibitors of metalloproteinases (TIMPs) versus metalloproteinases. After a brief description of the nature and structure of MMPs and TIMPs, this article reports on recent progress concerning the intra and extra-cellular activation mechanisms of proenzymes (proMMPs) which bring into play a series of proteolytic activations involving different proteinase families. Two points are stressed: 1) the main sites of focalized matrix proteolysis regulation, illustrated in the cellular interaction of inflammation, and 2) the wide phenotypic variety of MMPs and TIMPs.

CRE and TRE sequences of the rat tyrosine hydroxylase promoter are required for TH basal expression in adult mice but not in the embryo.

Tyrosine hydroxylase (TH), the rate-limiting enzyme in the biosynthesis of catecholamine neurotransmitters, is expressed in a restricted number of areas, and subject to numerous regulations during development and in adulthood. Two transcription factor binding sites present in the proximal region of the TH gene, the TPA-responsive element (TRE) and the c-AMP responsive element (CRE), have been shown to play important roles in TH gene regulation in vitro. In order to elucidate in vivo the role of these two sites, we produced transgenic mice bearing a 5.3-kb fragment from the 5' flanking sequence of the TH gene with mutations in either the CRE-or TRE-sites. Using the intact 5.3-kb fragment fused to two different reporter genes (HSV1-tk and lacZ), we show that this promoter fragment is able to specifically direct expression in catecholaminergic tissues both in adult mice and embryos. Interestingly, the CRE- and TRE-mutated transgenes were not expressed in adult mice, contrary to the situation in embryos where they were specifically expressed in catecholaminergic regions. These results demonstrate that the CRE and TRE play an essential role in basal TH expression in adult tissues in vivo. Moreover, they suggest that distinct transcription factors are involved in TH regulation in developing and adult tissues. In support of this, gel mobility shift experiments revealed a complex present only in embryonic tissues. Taken together, these data highlight the diversity of the mechanisms underlying the establishment and maintenance of the catecholaminergic phenotype.

Human B lymphocytes synthesize the 92-kDa gelatinase, matrix metalloproteinase-9.

Matrix metalloproteinases (MMPs) are involved in the remodeling of connective tissue as well as in disease states associated with acute and chronic inflammation or tumoral metastatic processes. Despite detailed and extensive studies of the mechanisms of lymphocyte extravasation, remarkably little is known about the expression and regulation of metalloproteinases involved in the migratory process. By using zymography and reverse transcription-polymerase chain reaction experiments, we have demonstrated that Epstein-Barr virus-immortalized B lymphocytes are able to secrete a 92-kDa metalloproteinase with gelatinolytic activity which has been purified and identified as being MMP-9. Moreover, the tissue inhibitor of metalloproteinase was shown to be constitutively expressed by the B cells. The expression of 92-kDa gelatinase is mediated by cytokines, growth factors, lipopolysaccharide, concanavalin A, and the tumor promotor phorbol 12-myristate 13-acetate. Time dependence activity increased rapidly up to 24 h of incubation with lipopolysaccharide or concanavalin A stimulation while it requires a delay and more time to have an optimum effect when cytokines were the stimulating agents; transforming growth factor-beta abolished 92-kDa gelatinase production. Both staurosporine and wortmannin are inductive stimuli, and the level of MMP-9 secreted into the media is greater than that observed with other agents except concanavalin A. Elicitation of the chemotactic migration of B cells through a model basement membrane by lipopolysaccharide was shown to be correlated with gelatinase expression and inhibited by 7 mM captopril. Our study indicates that Epstein-Barr virus-B lymphocytes express 92-kDa gelatinase, the production of which can be modified by a variety of physiological and pharmacological signals which have been shown to differ according to the cell type.

AP-1 mediates trans-synaptic induction of tyrosine hydroxylase gene expression in adrenal medulla but not in superior cervical ganglia.

Reserpine treatment leads to a rapid trans-synaptic increase of the tyrosine hydroxylase (TH) gene transcription rate and mRNA levels in catecholaminergic tissues including the adrenal medulla (AM) and the superior cervical ganglia (SCG). In the AM, the formation of a specific protein complex with the TPA-responsive element located in the proximal region of the TH gene was enhanced between 30 min and 8 hr following the injection. This complex appears to contain a member of the Fos family and an antigenically related Jun protein. Moreover, the prolonged and enhanced expression of the c-Fos protein in the AM and its phosphorylation are likely to contribute to the increased TH transcription following reserpine treatment. Most strikingly, in the SCG, the trans-synaptic induction of TH transcription is transduced by totally different mechanisms, since no AP-1 complex and only minute amounts of c-Fos immunoreactivity were detected. Our study provides the first demonstration that, following the same stimulus, the induced expression of a single gene is mediated by different cis- and trans-acting factors in two distinct tissues sharing the same embryonic origin.