Jacek Kurzepa

Astrocytic activation in relation to inflammatory markers during clinical exacerbation of relapsing-remitting multiple sclerosis

SummaryThe study aimed to assay the cerebrospinal fluid (CSF) levels of protein S100B, a biomarker of astrocyte activation in relation to kynurenic acid (KYNA) and nitric oxide (NO) metabolites, nitrate/nitrite (NOx) concentrations in acute relapse multiple sclerosis (MS) patients. Twenty relapsing-remitting MS (RR-MS) patients and 10 controls were enrolled. RR-MS patients were assessed on the expanded disability status scale (EDSS) and underwent lumbar puncture. The CSF KYNA, NOx and S100B levels were significantly higher in RR-MS group compared to controls (p = 0.01, 0.001, 0.04, respectively). There was a significant correlation between CSF S100B and KYNA (p = 0.01) but not NOx (p > 0.05) in RR-MS. CSF KYNA, NOx or S100B concentrations did not correlate with disease characteristics of MS patients.Our study suggests the activation of the kynurenine pathway leading to the increase of neuroprotective KYNA in the CSF of MS patients during acute relapse what contrasts with chronic phases of the disease.

The significance of matrix metalloproteinase (MMP)-2 and MMP-9 in the ischemic stroke

There is a continuous urgent need to explore the pathogenesis and biochemical changes within the infarcted area during acute ischemic stroke (IS). Matrix metalloproteinases (MMPs), prevailing extracellular endopeptideses, can digest proteins located extracellulary, e.g. collagen, proteoglycans, elastin or fibronectin. Among MMPs, gelatinases (MMP-2 and MMP-9) are the most investigated enzymes. Gelatinases possess the ability to active numerous pro-inflammatory agents as chemokine CXCL-8, interleukin 1β or tumor necrosis factor α. Moreover, due to digestion of collagen type IV (the component of basal membranes) and tight junction proteins (TJPs) they facilitate to cross the endothelium by leukocytes. Due to the significant role of gelatinases during brain ischemia, their selective inhibition seems to be an interesting kind of treatment of acute stroke. The synthetic inhibitors of gelatineses decrease the infarct volume in animal models of IS. In clinical practice statins, the lipid-lowering drugs possess the ability to inhibit the activity of MMP-9 during acute IS. This review briefly provides the most important information about the involvement of MMP-2 and MMP-9 in the pathogenesis of brain ischemia.

Role of MMP-2 and MMP-9 and their natural inhibitors in liver fibrosis, chronic pancreatitis and non-specific inflammatory bowel diseases

BACKGROUND There is a growing evidence that matrix metalloproteinase (MMP)-2 and MMP-9 (gelatinases) play an important role in the pathogenesis of numerous disorders, especially with inflammatory etiology and extracellular matrix (ECM) remodeling. Despite the fact that gelatinases involve in liver cirrhosis is provided in the literature, their role in the pathogenesis of chronic pancreatitis and non-specific inflammatory bowel diseases is still under investigation. DATA SOURCES We carried out a PubMed search of English-language articles relevant to the involvement of gelatinases in the pathogenesis of liver fibrosis, pancreatitis, and non-specific inflammatory bowel diseases. RESULTS The decreased activity of gelatinases, especially MMP-2, is related to the development of liver fibrosis, probably due to the decrease of capability for ECM remodeling. Similar situation can be found in chronic pancreatitis; however, reports on this matter are rare. The presence of non-specific inflammatory bowel diseases results in MMP-9 activity elevation. CONCLUSION The fluctuation of gelatinases activity during liver fibrosis, chronic pancreatitis and non-specific inflammatory bowel diseases is observed, but the exact role of these enzymes demands further studies.

SERUM BILIRUBIN AND URIC ACID LEVELS AS THE BAD PROGNOSTIC FACTORS IN THE ISCHEMIC STROKE

Bilirubin (Bil) and uric acid (UA) are the endogenous antioxidant compounds possibly involved in the pathogenesis of ischemic stroke (IS). Our goal was to find the relationship between serum Bil and UA levels with clinical presentation and outcomes of patients suffering from IS. Forty-three patients (mean age: 71.9 years, ± 12.1; women: 48.8%) with confirmed IS were enrolled. Stroke severity was assessed by the National Institutes of Health Stroke Scale (NIHSS) after 1, 3, 5, and 10 days and functional disability was assessed three months after stroke onset using the Barthel Index (BI). Serum Bil and UA levels were measured 1, 3, 5, and 10 days after stroke. The difference between NIHSS scores from days 1 and 10 (improvement ratio) inversely correlated with the average UA serum level (r = −0.48, p < .01) but not with the average Bil level. Negative correlations were observed between the BI measured three months after stroke compared to the average Bil serum level (r = −0.5, p < .01). However, no relationship between BI and UA level was observed. Our results indicated that Bil and UA levels are poor prognostic factors for ischemic stroke.

Humoral response against glial derived antigens in Parkinson's disease

To check whether glial cells have the ability to elicit adaptive immune response in Parkinsons disease and whether a change in this immune response can be observed over time. There is an increasing evidence that glial cells are involved in the neurodegenerative process in PD, in addition to neuronal structures. Measurement of autoantibodies against proteins of oligodendrocytes may serve as an indirect method to assess the level of glial cells activation or degeneration under in vivo conditions. Serum samples from 26 PD patients were collected twice, at baseline and after mean of 13 months. In addition, serum samples from 13 healthy controls matched for age and gender were assessed at one time point. IgG and IgM autoantibodies against myelin-oligodendrocyticglycoprotein (MOG), myelin basic protein (MBP), myelin-associated glycoprotein (MAG) and proteolipoprotein (PLP) were measured in all investigated subjects by a commercially available ELISA system (Mediagnost, Germany). In a group of PD significant decrease of IgG titers was observed for anti-MAG autoantibodies over the investigated time period (p<0.05). For IgM antibodies, we observed statistically significant decrease in anti-MAG autoantibodies in the follow-up period (p<0.05) and increase in anti-MBP and anti-PLP autoantibodies (p<0.05). All antibody titers differed significantly between healthy control subjects and PD patients. Our study provides the evidence for the presence of humoral response against some glial derived antigens in PD. The increasing levels of anti MBP IgG and IgM might point to the value of this marker for monitoring disease progression.

Matrix metalloproteinase-9 contributes to the increase of tau protein in serum during acute ischemic stroke

Previous studies indicate that tau protein, a marker of damage to neurons, is present in the serum of healthy patients at a concentration approximately 40 percent that of patients with ischemic stroke We assumed that increased serum activity of gelatinases (matrix metalloproteinase [MMP]-2 and MMP-9) can influence the level of tau protein in serum, probably due to disruption of the blood-brain barrier. We obtained blood sera from 31 patients admitted within the first 24 hours of ischemic stroke on days 1, 5 and 10, following the onset of stroke. Tau protein was detected in the serum of 12 patients (38.7 percent). The highest MMP-9 activity was recorded on day 5 (p < 0.05). Serum gelatinase activity did not differ between tau protein-positive or -negative individuals. However, a high degree of correlation between mean MMP-9 activity and the maximum tau protein level was observed for patients with detectable tau protein (r = 0.71, p = 0.009). Our study suggests that MMP-9 can increase the tau protein level in the sera of patients during acute ischemic stroke.

Erythropoietin inhibits liver gelatinases during galactosamine-induced hepatic damage in rats

Matrix metalloproteinase (MMP)-2 and -9 (gelatinases) participate in extracellular protein remodeling. Moreover, they are involved in the development of hepatic fibrosis. The goal of this study was to evaluate liver gelatinase activities after erythropoietin (Epo) treatment (1U/dose, sc) in experimentally damaged livers of rats treated with D-galactosamine (Gal, 800 mg/kg/dose, ip). Sixty rats were divided into six equal groups: I - received 5 doses of Epo and a single dose of Gal [the experiment duration (ED): 10 days]; II - received 5 doses of Epo and 3 doses of Gal (ED: 14 days); III - received only 5 doses of Epo (ED: 9 days); IV - received 3 doses of Gal (ED: 5 days);V - received a single dose of Gal (ED: 1 day); VI - control group (ED: 9 days). The animals were sacrificed and the livers were collected 48 h after the last drug administration. The activity of gelatinases was measured using gelatin zymography. No fluctuations in gelatinase activities were observed after the administration of a single dose of Gal in comparison to the control group. However, a significant increase in gelatinase activities was observed after treatment with three doses of Gal. Five doses of Epo administrated before Gal treatment prevented elevated gelatinase activities: MMP-9 activity was comparable to control, and MMP-2 activity was decreased (group II). The gelatinase activities was lower in group I and II in comparison to the control group. These results revealed that Epo decreases MMP-2 and MMP-9 activity, suggesting that it is a hepatoprotective agent against hepatic damage induced by galactosamine injection.

Xanthohumol inhibits the extracellular signal regulated kinase (ERK) signalling pathway and suppresses cell growth of lung adenocarcinoma cells

Aberrant activation of the Ras/MEK/ERK signaling pathway has been frequently observed in non-small-cell lung carcinoma (NSCLC) and its important role in cancer progression and malignant transformation has been documented. Hence, the ERK1/2 kinase cascade becomes a potential molecular target in cancer treatment. Xanthohumol (XN, a prenylated chalcone derived from hope cones) is known to possess a broad spectrum of chemopreventive and anticancer activities. In our studies, the MTT and BrdU assays revealed that XN demonstrated greater antiproliferative activity against A549 lung adenocarcinoma cells than against the lung adenocarcinoma H1563 cell line. We observed that XN was able to suppress the activities of ERK1/2 and p90RSK kinases, followed by inhibition of phosphorylation and activation of the CREB protein. Additionally, the XN treatment of the cancer cells caused upregulation of key cell cycle regulators p53 and p21 as well as downregulation of cyclin D1. As a result, the cytotoxic effect of XN was attributed to the cell cycle arrest at G1 phase and induction of apoptosis indicated by increased caspase-3 activity. Thus, XN might be a promising anticancer drug candidate against lung carcinomas.

The effect of recombinant tissue plasminogen activator on MMP-2 and MMP-9 activities in vitro

Abstract One of the most significant side effects during recombinant tissue plasminogen activator (rtPA) for acute stroke treatment is intracranial bleeding. Gelatinases [matrix metalloproteinase (MMP)-2 and MMP-9] are one of the agents involved in the blood–brain barrier destruction resulting in secondary bleeding into the ischemic area during stroke. Previous papers revealed that patients with high baseline MMP-9 serum level have higher risk of intracranial bleeding after thrombolytic therapy. Our objective was to evaluate rtPA influence on serum MMP-2 and MMP-9 activities in vitro. Nine sera obtained from healthy donors were applied for experiment. The commercially available rtPA (Actylise) were diluted with included solvent and additionally with phosphate-buffered saline (PBS) to get concentrations: 2, 4, 8, and 16 μg/ml. Next, 100 μl of serum was mixed with equal proportion with different concentrations of rtPA to obtain final rtPA concentrations: 1, 2, 4, and 8 μg/ml. The sera together with rtPA were incubated for 1 or 2 hours at 37°C. The activity of gelatinases was estimated with zymography. The activities of MMP-9 (92 kDa) and MMP-2 (72 kDa) were increased by incubation with rtPA in a dose-dependent manner. Simultaneously, the activity of band at 200 kDa (MMP-9/MMP-9 homodimer) was decreased. The activity of gelatinases incubated for 2 hours was elevated in comparison with 1-hour incubation; however, the increase was observed even for sample without rtPA. In conclusion, this study showed that rtPA can increase the biological activity of MMP-2 and MMP-9 on posttranslational level.

Matrix metalloproteinases and atherosclerosis

Matrix metalloproteinases (MMPs), a family of proteolytic enzymes that degrade extracellular matrix (ECM), seem to have an important role in pathogenesis of atherosclerosis. Released by inflammatory cells and smooth muscle cells, MMPs regulate the vascular remodeling process. The expression and activity of MMPs is regulated at the level of transcription by a variety of cytokines, proenzyme activation by several cellular and serum proteases, as well as by endogenous and exogenous inhibitors. Overproduction of MMPs could promote arteriosclerosis, leading to atherosclerotic plaque formation, and plaque rupture, resulting in clinical consequences such as myocardial infarction, or critical limb ischemia. Increased plasma levels of some MMPs are now regarded as potential biomarkers of atherosclerosis and cardiovascular risk. The potential significance of MMP inhibitors in atherosclerosis therapy is discussed.