Halina Ostrowska - Academia.edu (original) (raw)
Papers by Halina Ostrowska
STRESZCZENIE Celem pracy bylo określenie przydatności oznaczania aktywności ChT-L proteasomu 20S ... more STRESZCZENIE Celem pracy bylo określenie przydatności oznaczania aktywności ChT-L proteasomu 20S u pacjentow z nowo rozpoznanym szpiczakiem plazmocytowym (MM). Material do badan stanowilo osocze 41 pacjentow z nowo rozpoznanym szpiczakiem plazmocytowym. Aktywnośc ChT-L proteasomu 20S oznaczano przy uzyciu fluorogennego substratu Suc-LeuLeu-Val-Tyr-AMC w obecności SDS jako selektywnego aktywatora enzymu chymotrypsynopodobnego. Przeprowdzone badania wykazaly podwyzszoną aktywnośc ChTL proteasomu 20S u pacjentow z nowo rozpoznanym szpiczakiem plazmocytowym w porownaniu z grupą kontrolną osob zdrowych (mediana 1,24 U/mg; zakres 0,67–3,61 U/mg vs mediana 1,09 U/mg; zakres 0,67–1,62 U/mg). Znamiennie wyzszą aktywnośc ChT-L proteasomu 20S wykazano u pacjentow z III stopniem zaawansowania choroby wg ISS (mediana 1,25 U/mg; p=0,048). Stwierdzono istnienie korelacji pomiedzy aktywnością ChT-L proteasomu 20S a stezeniem β2-mikroglobuliny (p=0,007). Aktywnośc ChT-L proteasomu 20S nie zalezala o...
International Journal of Molecular Sciences, 2020
Psoriasis is a skin disease that is accompanied by oxidative stress resulting in modification of ... more Psoriasis is a skin disease that is accompanied by oxidative stress resulting in modification of cell components, including proteins. Therefore, we investigated the relationship between the intensity of oxidative stress and the expression and activity of the proteasomal system as well as autophagy, responsible for the degradation of oxidatively modified proteins in the blood cells of patients with psoriasis. Our results showed that the caspase-like, trypsin-like, and chymotrypsin-like activity of the 20S proteasome in lymphocytes, erythrocytes, and granulocytes was lower, while the expression of constitutive proteasome and immunoproteasome subunits in lymphocytes was increased cells of psoriatic patients compared to healthy subjects. Conversely, the expression of constitutive subunits in erythrocytes, and both constitutive and immunoproteasomal subunits in granulocytes were reduced. However, a significant increase in the autophagy flux (assessed using LC3BII/LC3BI ratio) independent...
Mediators of Inflammation, 2018
Surgical tissue damage and the accompanying inflammatory response lead to proteasome activation, ... more Surgical tissue damage and the accompanying inflammatory response lead to proteasome activation, initiation of damaged protein degradation, and induction of acute-phase inflammatory response. The aim of this study was to investigate the rate of change in proteasome chymotrypsin-like (ChT-L) activity and C-reactive protein concentration depending on the degree of tissue damage and their correlation with prealbumin concentrations in children before and after abdominal surgery. This experimental study included children who underwent abdominal surgery between 2015 and 2017. Plasma prealbumin concentrations and C-reactive protein levels (CRP) were determined by standard biochemical laboratory procedures. Proteasome activity was assessed using a Suc-Leu-Leu-Val-Tyr-AMC peptide substrate. Elevation of plasma proteasome activity was noted in children after laparoscopic and open abdominal surgeries. However, 20S proteasome activity in children undergoing conventional open surgery was signifi...
Scandinavian Journal of Clinical and Laboratory Investigation, 2017
Abstract Operations of varying duration cause the release of a number of inflammatory mediators, ... more Abstract Operations of varying duration cause the release of a number of inflammatory mediators, in particular cytokines which lead to proteasome and acute-phase reactions. The purpose of this novel human study, was to characterize inflammatory response in children undergoing laparoscopic cholecystectomy, by analyzing changes in selected inflammatory mediators: C-reactive protein concentration and circulating 20S proteasome activity following surgical injury and to correlate them with the duration of the surgical procedure. Plasma C-reactive protein concentration (CRP) was determined by standard biochemical laboratory procedures. Proteasome activity in the plasma of children was assessed using Suc-Leu-Leu-Val-Tyr-AMC peptide substrate. Statistically significant increase in the plasma proteasome activity and C-reactive protein concentration, was noted (p < .05) in children after laparoscopic cholecystectomy. We found the correlation between the 20S proteasome activity and the length of the procedure. In children undergoing longer lasting laparoscopic cholecystectomy the proteasome activity was much higher than in patients having shorter surgical procedure. The CRP concentration and 20S proteasome activity significantly increase after surgery, but only 20S proteasome activity correlate with the length of the surgery. This may confirm that CRP is only an indicator of pathological state, while the function of the proteasomes is more complex because of their participation in the processes of repair and wound healing, and in the removal of damaged proteins.
Blood, 2006
The proteasome-dependent proteolytic pathway plays a crucial role in pathogenesis of hematologic ... more The proteasome-dependent proteolytic pathway plays a crucial role in pathogenesis of hematologic malignancy, and as such it is a novel target for therapeutic drugs. High proteasome levels measured by conventional technique ELISA have been demonstrated in human malignant cells and in the plasma of patients with some hemopoietic malignancies and solid tumors. The objective of this study was to evaluate the activity of the 20S proteasome in the plasma from patients with hematologic malignancy. The study included normal subjects (n=15) and untreated patients with acute lymphoblastic leukemia (ALL, n=13), acute myeloblastic leukemia (AML, n=21), multiple myeloma (MM, n= 26) and chronic lymphocytic leukemia (CLL, n=30). The 20S proteasome activity in plasma (50μg of protein) was assayed spectrofluorimetrically using synthetic peptide substrate, Suc-Leu-Leu-Val-Tyr-AMC (100μmol/L) in the presence of 0.03% SDS that selectively activates the chymotrypsin-like activity of 20S proteasome. Enzy...
Annals of Hematology, 2018
Proteasome inhibitors (PIs) such as bortezomib constitute an important part of the modern standar... more Proteasome inhibitors (PIs) such as bortezomib constitute an important part of the modern standard therapy for multiple myeloma (MM). In this study, we set out to assess whether proteasome concentration and chymotrypsin-like (ChT-L) activity could serve as potential biomarkers defining the likelihood of response to treatment with bortezomib, in order to identify patients who are more likely to respond to treatment with PI. We analysed proteasome concentration and ChT-L activity in the plasma of 78 patients with newly diagnosed MM during treatment with or without proteasome inhibitors. Values of all the studied parameters in the group of responders decreased sharply from the initial levels already after the third cycle of chemotherapy and remained significantly lower until the end of treatment. On the other hand, in the group of non-responders, there was an increase in the measured proteasome parameters already after the third cycle, and they remained high during the next cycles of therapy. We also showed that high baseline proteasome ChT-L activity values might prognosticate longer progression-free survival (PFS) in patients treated with PI. Our findings demonstrate that measuring plasma proteasome ChT-L activity can be used as a powerful biomarker for predicting clinical response to treatment and PFS in patients with newly diagnosed MM.
Journal of Cellular Physiology, 2017
The Akt substrate of 160 kDa (AS160) is a key regulator of GLUT4 translocation from intracellular... more The Akt substrate of 160 kDa (AS160) is a key regulator of GLUT4 translocation from intracellular depots to the plasma membrane in myocytes. Likely, AS160 also controls LCFAs transport, which requires relocation of fatty acid transporters. The aim of the present study was to determine the impact of AS160 knockdown on lipid milieu in L6 myotubes incubated with palmitate (PA). Therefore, we compared two different settings, namely: 1) AS160 knockdown prior to palmitate incubation (pre‐PA‐silencing, AS160−/PA); 2) palmitate incubation with subsequent AS160 knockdown (post‐PA‐silencing, PA/AS160−). The efficiency of AS160 silencing was checked at mRNA and protein levels. The expression and localization of FA transporters were determined using Western Blot and immunofluorescence analyses. Intracellular lipid content (FFA, DAG, TAG, and PL) and FA composition were estimated by GLC, whereas basal palmitate uptake was analyzed by means of scintigraphy. Both groups with silenced AS160 were ch...
Molecular and Cellular Biochemistry, 2016
Advances in Medical Sciences, 2015
Children are exposed to many hazards and risks as they grow and develop into adulthood. Still inj... more Children are exposed to many hazards and risks as they grow and develop into adulthood. Still injuries are the leading cause of death and disability for children and teenagers [1-3]. A novel approach in conservative treatment is looking for new targets for interventions designed to attenuate results of injuries in children. Muscle protein wasting is a prominent feature of the metabolic response to a variety of catabolic disease states including trauma and burns, and its important clinical consequences have been widely recognized [4-6]. Ubiquitin-proteasome system is principal enzyme system responsible for protein degradation, which has been reported to be abundantly expressed in the various cell types [7,8]. Proteasomes which constitute up to 3% of all cellular protein content, are the multicatalytic enzymes, which are responsible for the degradation of intracellular proteins, and modulate many regulatory proteins that affect inflammatory processes, viral shedding, the cell cycle, growth, and differentiation [8-10]. They consist of a cylinder-shaped multimeric protein complex (20S proteasome core particle, 20S proteasome) that can be singly or doubly capped by a 19S regulator complex when ATP/Mg 2+ is present and is then termed 26S proteasome [11]. Proteins are first conjugated to multiple molecules of ubiquitin, whereafter they are recognized and broken down by the 26S proteasome. The proteolytic core of the 26S proteasome is the 20S proteasome which is a barrel-shaped particle consisting of four stacked rings with seven subunits in each ring [12]. The subunits of the outer ring are called a-subunits and those of the inner rings are called bsubunits. The functions of the a-subunits include interaction
Roczniki Akademii Medycznej w Białymstoku = Annales Academiae Medicae Bialostocensis
Aldehydes (formaldehyde and acetaldehyde) inhibit the fibrinolytic, caseinolytic and amidolytic a... more Aldehydes (formaldehyde and acetaldehyde) inhibit the fibrinolytic, caseinolytic and amidolytic activity of blood plasma euglobulins. Alcohols (methanol, ethanol, propanol and iso-propanol) and sodium salts of organic acids (formate, acetate and propionate) show inhibitory activity towards the fibrinolytic activity of euglobulins only at small degree and at high concentrations.
Medycyna wieku rozwojowego
THE AIM of our study was: to determine the proteasome 20S activity in plasma of patients treated ... more THE AIM of our study was: to determine the proteasome 20S activity in plasma of patients treated for acute lymphoblastic leukaemia. Plasma proteasome activity was measured in children (n=16) at two points: at diagnosis and on the 33rd day using the spectrophotometric method with peptidic substrate and selective proteasome activator 0.03% SDS. 1. At diagnosis we observed high activity of the proteasome 20S in comparison to control (p<0.005). After haematological remission the proteasome 20S activity lowered by about 50% (p<0.05). 3. We did not find the influence of immunophenotype, initial leucocytosis, LDH activity and hepatosplenomegaly on initial proteasome values. Dynamic changes of the proteasome 20S activity confirm its participation in cancerogenic process. Proteasome 20S activity may be an effective indicator in the monitoring of anticancer treatment.
Roczniki Akademii Medycznej w Białymstoku (1995), 2004
A long-lasting renal ischemia, followed by the left renal artery clipping (two-kidney, one clip G... more A long-lasting renal ischemia, followed by the left renal artery clipping (two-kidney, one clip Goldblatt model in rats) led to a marked decrease in proteasome chymotrypsin-like activity in the ischemic kidney. This activity was, however, significantly raised upon the stimulation with an artificial 20S proteasome activator SDS (0.025%). No changes were observed in either the levels of the constitutive 20S proteasome subunit (alpha5) or of its protein activator, PA28alpha, in the kidneys by Western blot. These preliminary results indicate that an inhibition of proteasome activity may result from a dissociation of the active proteasome complexes into the inactive 20S proteasome and its endogenous activators after a long-lasting renal ischemia.
Roczniki Akademii Medycznej w Białymstoku (1995), 2003
Previous in vitro studies have demonstrated that a potent antihypertensive agent ebelactone B inh... more Previous in vitro studies have demonstrated that a potent antihypertensive agent ebelactone B inhibits cathepsin A/deamidase activity. The aim of our studies was to assess the effects of this inhibitor on cathepsin A activity in intact platelets and on platelet activation events. PRP or washed human platelets from healthy volunteers were pre-incubated with different concentrations of ebelactone B (1-10 microM) for 10-60 min. Cathepsin A activity in platelets was assayed colorimetrically using Cbz-Phe-Ala at pH 5.5. Expression of platelet activation markers GpIIb/IIIa and P-selectin on non-activated or agonist-activated platelets (ADP, TRAP) was measured by flow cytometry. Pre-treatment of platelets for up to 60 minutes with 10 mumol/l ebelactone B, that effectively inhibits cathepsin A activity in platelet lysate, did not affect this activity in intact platelets. Exposure of PRP to 10 mumol/l ebelactone B alone, or before platelet activation with ADP or TRAP caused only a small but ...
Roczniki Akademii Medycznej w Białymstoku (1995), 2003
Increase in intracellular chymotrypsin activity was reported during acute pancreatitis. Beside ch... more Increase in intracellular chymotrypsin activity was reported during acute pancreatitis. Beside chymotrypsin, there are at least two enzymes with chymotrypsin-like activity: proteasome and lysosomal cathepsin A. Until now it is not known whether and to what extent they contribute to increases in chymotrypsin activity in acute pancreatitis. Our aim was to study organ chymotrypsin-like activities during experimental acute pancreatitis. Rat cerulein model of acute pancreatitis was used. The chymotrypsin-like activities were assessed in pancreas, liver, lung, heart, spleen and kidney using highly selective synthetic substrates of the proteasome and the cathepsin A, at neutral and acidic pH. Determinations after addition of selective inhibitor were also performed. During acute pancreatitis we found in the pancreas an increase only in neutral chymotrypsin-like activity, as compared to the control animals. In other organs neutral chymotrypsin-like activity did not increase, and in kidney it...
Acta biochimica Polonica, 1990
Ethanol and acetaldehyde inhibited the activity of cathepsin A. In vitro ethanol did not release ... more Ethanol and acetaldehyde inhibited the activity of cathepsin A. In vitro ethanol did not release cathepsin A from liver lysosomes whereas acetaldehyde of high concentration did. Intoxication of rats with ethanol and acetaldehyde evoked a transient increase of free and bound cathepsin A.
Leukemia Research, 2014
The ubiquitin-proteasome pathway is implicated in the pathogenesis of many haematologic malignanc... more The ubiquitin-proteasome pathway is implicated in the pathogenesis of many haematologic malignancies, including multiple myeloma. Under conditions of rapid cell turnover and growth rate, proteasomes are returned into circulation. The measurement of their levels or activity could offer a new approach to diagnosis, prognosis and monitoring of anticancer treatment in carcinoma patients. We analysed proteasome concentration and chymotrypsin-like (ChT-L) activity in the plasma of 64 patients with a newly diagnosed multiple myeloma and 30 healthy volunteers. The values were found to be significantly higher in the studied patients and advanced disease stages compared to the control group, and decreased significant after chemotherapy. Both proteasome concentration and ChT-L activity correlated with adverse prognostic factors, such as lactate dehydrogenase and β2-macroglobulin. We also showed that proteasome concentration positively correlates with IL-6 level, as opposed to proteasome ChT-L activity. Of note, higher proteasome ChT-L activity, unlike the concentration, was proved to be an indicator of a shorter progression free survival, constituting thereby an important prognostic marker.
Tumor Biology, 2011
The chymotrypsin-like (ChT-L) activity is one of the key regulators of intracellular protein degr... more The chymotrypsin-like (ChT-L) activity is one of the key regulators of intracellular protein degradation. Elevated proteasome ChT-L activity has recently been reported in plasma of patients with leukemia and myelodysplastic syndrome and suggested to have a prognostic significance. The aim of the present study was to evaluate plasma proteasome ChT-L activity in patients with newly diagnosed solid tumors at early and advanced stages of the disease. The activity was assayed using the fluorogenic peptide substrate, Suc-Leu-Leu-Val-Tyr-AMC, in a cohort of 155 patients with early/ advanced rectal (n=43/29), gastric (n=6/13), and breast (n=37/27) cancer and compared with that in normal individuals (n = 55). The median plasma proteasome ChT-L activity was elevated by 20-32% in patients with advanced stage of rectal, gastric, and breast cancer compared with healthy donors. The difference turned out to be statistically significant (P <0.001). By contrast, values in patients with early stage of malignancies were not significantly different from those observed in normal individuals. We also found that plasma proteasome activity correlated with serum carcinoembryonic antigen levels in the group of patients with rectal cancer (r=0.433, P<0.05). Elevated plasma proteasome ChT-L activity is indicative of advanced stage of rectal, gastric, and breast cancer. However, the activity does not seem to be a parameter with clinically relevant potential in terms of early detection of cancer in this subset of patients.
Thrombosis Research, 1997
CathepsinA-like enzymereleasedfrom human plateletsby thrombinhydrolyzedat the highest rate Cbz-Ph... more CathepsinA-like enzymereleasedfrom human plateletsby thrombinhydrolyzedat the highest rate Cbz-Phe-Ala, Cbz-Phe-Met and Cbz-Phe-Leu, did not require activatorsand was inhibitedby DFP, DCI and mercurialcompounds(mersalylacid, PCMS, PCMB and HgC12).The optimumactivity of secreted enzyme was at pH 5.0-6.0. Cbz-Glu-Tyrwas also hydrolyzedat lower pH with optimum at pH 3.5. These enzymaticpropertiesare the same as those of cathepsinA solubilizedfrom whole plateletsand purifiedfrom other mammaliancells and tissues. High specific activity of secreted cathepsin A, and a broad pH range of activity may have a significancein extracellularproteolysisin local sites of ischemia.Large portion of cathepsinA-like activitywas not secretableby high concentrationof thrombin and was sedimented with platelet aggregates. No activity of lysosomal carboxypeptidasesB and prolylcarboxypeptidase was detectablein supematantsand pelletsof thrombin-stimulatedplatelets.
STRESZCZENIE Celem pracy bylo określenie przydatności oznaczania aktywności ChT-L proteasomu 20S ... more STRESZCZENIE Celem pracy bylo określenie przydatności oznaczania aktywności ChT-L proteasomu 20S u pacjentow z nowo rozpoznanym szpiczakiem plazmocytowym (MM). Material do badan stanowilo osocze 41 pacjentow z nowo rozpoznanym szpiczakiem plazmocytowym. Aktywnośc ChT-L proteasomu 20S oznaczano przy uzyciu fluorogennego substratu Suc-LeuLeu-Val-Tyr-AMC w obecności SDS jako selektywnego aktywatora enzymu chymotrypsynopodobnego. Przeprowdzone badania wykazaly podwyzszoną aktywnośc ChTL proteasomu 20S u pacjentow z nowo rozpoznanym szpiczakiem plazmocytowym w porownaniu z grupą kontrolną osob zdrowych (mediana 1,24 U/mg; zakres 0,67–3,61 U/mg vs mediana 1,09 U/mg; zakres 0,67–1,62 U/mg). Znamiennie wyzszą aktywnośc ChT-L proteasomu 20S wykazano u pacjentow z III stopniem zaawansowania choroby wg ISS (mediana 1,25 U/mg; p=0,048). Stwierdzono istnienie korelacji pomiedzy aktywnością ChT-L proteasomu 20S a stezeniem β2-mikroglobuliny (p=0,007). Aktywnośc ChT-L proteasomu 20S nie zalezala o...
International Journal of Molecular Sciences, 2020
Psoriasis is a skin disease that is accompanied by oxidative stress resulting in modification of ... more Psoriasis is a skin disease that is accompanied by oxidative stress resulting in modification of cell components, including proteins. Therefore, we investigated the relationship between the intensity of oxidative stress and the expression and activity of the proteasomal system as well as autophagy, responsible for the degradation of oxidatively modified proteins in the blood cells of patients with psoriasis. Our results showed that the caspase-like, trypsin-like, and chymotrypsin-like activity of the 20S proteasome in lymphocytes, erythrocytes, and granulocytes was lower, while the expression of constitutive proteasome and immunoproteasome subunits in lymphocytes was increased cells of psoriatic patients compared to healthy subjects. Conversely, the expression of constitutive subunits in erythrocytes, and both constitutive and immunoproteasomal subunits in granulocytes were reduced. However, a significant increase in the autophagy flux (assessed using LC3BII/LC3BI ratio) independent...
Mediators of Inflammation, 2018
Surgical tissue damage and the accompanying inflammatory response lead to proteasome activation, ... more Surgical tissue damage and the accompanying inflammatory response lead to proteasome activation, initiation of damaged protein degradation, and induction of acute-phase inflammatory response. The aim of this study was to investigate the rate of change in proteasome chymotrypsin-like (ChT-L) activity and C-reactive protein concentration depending on the degree of tissue damage and their correlation with prealbumin concentrations in children before and after abdominal surgery. This experimental study included children who underwent abdominal surgery between 2015 and 2017. Plasma prealbumin concentrations and C-reactive protein levels (CRP) were determined by standard biochemical laboratory procedures. Proteasome activity was assessed using a Suc-Leu-Leu-Val-Tyr-AMC peptide substrate. Elevation of plasma proteasome activity was noted in children after laparoscopic and open abdominal surgeries. However, 20S proteasome activity in children undergoing conventional open surgery was signifi...
Scandinavian Journal of Clinical and Laboratory Investigation, 2017
Abstract Operations of varying duration cause the release of a number of inflammatory mediators, ... more Abstract Operations of varying duration cause the release of a number of inflammatory mediators, in particular cytokines which lead to proteasome and acute-phase reactions. The purpose of this novel human study, was to characterize inflammatory response in children undergoing laparoscopic cholecystectomy, by analyzing changes in selected inflammatory mediators: C-reactive protein concentration and circulating 20S proteasome activity following surgical injury and to correlate them with the duration of the surgical procedure. Plasma C-reactive protein concentration (CRP) was determined by standard biochemical laboratory procedures. Proteasome activity in the plasma of children was assessed using Suc-Leu-Leu-Val-Tyr-AMC peptide substrate. Statistically significant increase in the plasma proteasome activity and C-reactive protein concentration, was noted (p < .05) in children after laparoscopic cholecystectomy. We found the correlation between the 20S proteasome activity and the length of the procedure. In children undergoing longer lasting laparoscopic cholecystectomy the proteasome activity was much higher than in patients having shorter surgical procedure. The CRP concentration and 20S proteasome activity significantly increase after surgery, but only 20S proteasome activity correlate with the length of the surgery. This may confirm that CRP is only an indicator of pathological state, while the function of the proteasomes is more complex because of their participation in the processes of repair and wound healing, and in the removal of damaged proteins.
Blood, 2006
The proteasome-dependent proteolytic pathway plays a crucial role in pathogenesis of hematologic ... more The proteasome-dependent proteolytic pathway plays a crucial role in pathogenesis of hematologic malignancy, and as such it is a novel target for therapeutic drugs. High proteasome levels measured by conventional technique ELISA have been demonstrated in human malignant cells and in the plasma of patients with some hemopoietic malignancies and solid tumors. The objective of this study was to evaluate the activity of the 20S proteasome in the plasma from patients with hematologic malignancy. The study included normal subjects (n=15) and untreated patients with acute lymphoblastic leukemia (ALL, n=13), acute myeloblastic leukemia (AML, n=21), multiple myeloma (MM, n= 26) and chronic lymphocytic leukemia (CLL, n=30). The 20S proteasome activity in plasma (50μg of protein) was assayed spectrofluorimetrically using synthetic peptide substrate, Suc-Leu-Leu-Val-Tyr-AMC (100μmol/L) in the presence of 0.03% SDS that selectively activates the chymotrypsin-like activity of 20S proteasome. Enzy...
Annals of Hematology, 2018
Proteasome inhibitors (PIs) such as bortezomib constitute an important part of the modern standar... more Proteasome inhibitors (PIs) such as bortezomib constitute an important part of the modern standard therapy for multiple myeloma (MM). In this study, we set out to assess whether proteasome concentration and chymotrypsin-like (ChT-L) activity could serve as potential biomarkers defining the likelihood of response to treatment with bortezomib, in order to identify patients who are more likely to respond to treatment with PI. We analysed proteasome concentration and ChT-L activity in the plasma of 78 patients with newly diagnosed MM during treatment with or without proteasome inhibitors. Values of all the studied parameters in the group of responders decreased sharply from the initial levels already after the third cycle of chemotherapy and remained significantly lower until the end of treatment. On the other hand, in the group of non-responders, there was an increase in the measured proteasome parameters already after the third cycle, and they remained high during the next cycles of therapy. We also showed that high baseline proteasome ChT-L activity values might prognosticate longer progression-free survival (PFS) in patients treated with PI. Our findings demonstrate that measuring plasma proteasome ChT-L activity can be used as a powerful biomarker for predicting clinical response to treatment and PFS in patients with newly diagnosed MM.
Journal of Cellular Physiology, 2017
The Akt substrate of 160 kDa (AS160) is a key regulator of GLUT4 translocation from intracellular... more The Akt substrate of 160 kDa (AS160) is a key regulator of GLUT4 translocation from intracellular depots to the plasma membrane in myocytes. Likely, AS160 also controls LCFAs transport, which requires relocation of fatty acid transporters. The aim of the present study was to determine the impact of AS160 knockdown on lipid milieu in L6 myotubes incubated with palmitate (PA). Therefore, we compared two different settings, namely: 1) AS160 knockdown prior to palmitate incubation (pre‐PA‐silencing, AS160−/PA); 2) palmitate incubation with subsequent AS160 knockdown (post‐PA‐silencing, PA/AS160−). The efficiency of AS160 silencing was checked at mRNA and protein levels. The expression and localization of FA transporters were determined using Western Blot and immunofluorescence analyses. Intracellular lipid content (FFA, DAG, TAG, and PL) and FA composition were estimated by GLC, whereas basal palmitate uptake was analyzed by means of scintigraphy. Both groups with silenced AS160 were ch...
Molecular and Cellular Biochemistry, 2016
Advances in Medical Sciences, 2015
Children are exposed to many hazards and risks as they grow and develop into adulthood. Still inj... more Children are exposed to many hazards and risks as they grow and develop into adulthood. Still injuries are the leading cause of death and disability for children and teenagers [1-3]. A novel approach in conservative treatment is looking for new targets for interventions designed to attenuate results of injuries in children. Muscle protein wasting is a prominent feature of the metabolic response to a variety of catabolic disease states including trauma and burns, and its important clinical consequences have been widely recognized [4-6]. Ubiquitin-proteasome system is principal enzyme system responsible for protein degradation, which has been reported to be abundantly expressed in the various cell types [7,8]. Proteasomes which constitute up to 3% of all cellular protein content, are the multicatalytic enzymes, which are responsible for the degradation of intracellular proteins, and modulate many regulatory proteins that affect inflammatory processes, viral shedding, the cell cycle, growth, and differentiation [8-10]. They consist of a cylinder-shaped multimeric protein complex (20S proteasome core particle, 20S proteasome) that can be singly or doubly capped by a 19S regulator complex when ATP/Mg 2+ is present and is then termed 26S proteasome [11]. Proteins are first conjugated to multiple molecules of ubiquitin, whereafter they are recognized and broken down by the 26S proteasome. The proteolytic core of the 26S proteasome is the 20S proteasome which is a barrel-shaped particle consisting of four stacked rings with seven subunits in each ring [12]. The subunits of the outer ring are called a-subunits and those of the inner rings are called bsubunits. The functions of the a-subunits include interaction
Roczniki Akademii Medycznej w Białymstoku = Annales Academiae Medicae Bialostocensis
Aldehydes (formaldehyde and acetaldehyde) inhibit the fibrinolytic, caseinolytic and amidolytic a... more Aldehydes (formaldehyde and acetaldehyde) inhibit the fibrinolytic, caseinolytic and amidolytic activity of blood plasma euglobulins. Alcohols (methanol, ethanol, propanol and iso-propanol) and sodium salts of organic acids (formate, acetate and propionate) show inhibitory activity towards the fibrinolytic activity of euglobulins only at small degree and at high concentrations.
Medycyna wieku rozwojowego
THE AIM of our study was: to determine the proteasome 20S activity in plasma of patients treated ... more THE AIM of our study was: to determine the proteasome 20S activity in plasma of patients treated for acute lymphoblastic leukaemia. Plasma proteasome activity was measured in children (n=16) at two points: at diagnosis and on the 33rd day using the spectrophotometric method with peptidic substrate and selective proteasome activator 0.03% SDS. 1. At diagnosis we observed high activity of the proteasome 20S in comparison to control (p<0.005). After haematological remission the proteasome 20S activity lowered by about 50% (p<0.05). 3. We did not find the influence of immunophenotype, initial leucocytosis, LDH activity and hepatosplenomegaly on initial proteasome values. Dynamic changes of the proteasome 20S activity confirm its participation in cancerogenic process. Proteasome 20S activity may be an effective indicator in the monitoring of anticancer treatment.
Roczniki Akademii Medycznej w Białymstoku (1995), 2004
A long-lasting renal ischemia, followed by the left renal artery clipping (two-kidney, one clip G... more A long-lasting renal ischemia, followed by the left renal artery clipping (two-kidney, one clip Goldblatt model in rats) led to a marked decrease in proteasome chymotrypsin-like activity in the ischemic kidney. This activity was, however, significantly raised upon the stimulation with an artificial 20S proteasome activator SDS (0.025%). No changes were observed in either the levels of the constitutive 20S proteasome subunit (alpha5) or of its protein activator, PA28alpha, in the kidneys by Western blot. These preliminary results indicate that an inhibition of proteasome activity may result from a dissociation of the active proteasome complexes into the inactive 20S proteasome and its endogenous activators after a long-lasting renal ischemia.
Roczniki Akademii Medycznej w Białymstoku (1995), 2003
Previous in vitro studies have demonstrated that a potent antihypertensive agent ebelactone B inh... more Previous in vitro studies have demonstrated that a potent antihypertensive agent ebelactone B inhibits cathepsin A/deamidase activity. The aim of our studies was to assess the effects of this inhibitor on cathepsin A activity in intact platelets and on platelet activation events. PRP or washed human platelets from healthy volunteers were pre-incubated with different concentrations of ebelactone B (1-10 microM) for 10-60 min. Cathepsin A activity in platelets was assayed colorimetrically using Cbz-Phe-Ala at pH 5.5. Expression of platelet activation markers GpIIb/IIIa and P-selectin on non-activated or agonist-activated platelets (ADP, TRAP) was measured by flow cytometry. Pre-treatment of platelets for up to 60 minutes with 10 mumol/l ebelactone B, that effectively inhibits cathepsin A activity in platelet lysate, did not affect this activity in intact platelets. Exposure of PRP to 10 mumol/l ebelactone B alone, or before platelet activation with ADP or TRAP caused only a small but ...
Roczniki Akademii Medycznej w Białymstoku (1995), 2003
Increase in intracellular chymotrypsin activity was reported during acute pancreatitis. Beside ch... more Increase in intracellular chymotrypsin activity was reported during acute pancreatitis. Beside chymotrypsin, there are at least two enzymes with chymotrypsin-like activity: proteasome and lysosomal cathepsin A. Until now it is not known whether and to what extent they contribute to increases in chymotrypsin activity in acute pancreatitis. Our aim was to study organ chymotrypsin-like activities during experimental acute pancreatitis. Rat cerulein model of acute pancreatitis was used. The chymotrypsin-like activities were assessed in pancreas, liver, lung, heart, spleen and kidney using highly selective synthetic substrates of the proteasome and the cathepsin A, at neutral and acidic pH. Determinations after addition of selective inhibitor were also performed. During acute pancreatitis we found in the pancreas an increase only in neutral chymotrypsin-like activity, as compared to the control animals. In other organs neutral chymotrypsin-like activity did not increase, and in kidney it...
Acta biochimica Polonica, 1990
Ethanol and acetaldehyde inhibited the activity of cathepsin A. In vitro ethanol did not release ... more Ethanol and acetaldehyde inhibited the activity of cathepsin A. In vitro ethanol did not release cathepsin A from liver lysosomes whereas acetaldehyde of high concentration did. Intoxication of rats with ethanol and acetaldehyde evoked a transient increase of free and bound cathepsin A.
Leukemia Research, 2014
The ubiquitin-proteasome pathway is implicated in the pathogenesis of many haematologic malignanc... more The ubiquitin-proteasome pathway is implicated in the pathogenesis of many haematologic malignancies, including multiple myeloma. Under conditions of rapid cell turnover and growth rate, proteasomes are returned into circulation. The measurement of their levels or activity could offer a new approach to diagnosis, prognosis and monitoring of anticancer treatment in carcinoma patients. We analysed proteasome concentration and chymotrypsin-like (ChT-L) activity in the plasma of 64 patients with a newly diagnosed multiple myeloma and 30 healthy volunteers. The values were found to be significantly higher in the studied patients and advanced disease stages compared to the control group, and decreased significant after chemotherapy. Both proteasome concentration and ChT-L activity correlated with adverse prognostic factors, such as lactate dehydrogenase and β2-macroglobulin. We also showed that proteasome concentration positively correlates with IL-6 level, as opposed to proteasome ChT-L activity. Of note, higher proteasome ChT-L activity, unlike the concentration, was proved to be an indicator of a shorter progression free survival, constituting thereby an important prognostic marker.
Tumor Biology, 2011
The chymotrypsin-like (ChT-L) activity is one of the key regulators of intracellular protein degr... more The chymotrypsin-like (ChT-L) activity is one of the key regulators of intracellular protein degradation. Elevated proteasome ChT-L activity has recently been reported in plasma of patients with leukemia and myelodysplastic syndrome and suggested to have a prognostic significance. The aim of the present study was to evaluate plasma proteasome ChT-L activity in patients with newly diagnosed solid tumors at early and advanced stages of the disease. The activity was assayed using the fluorogenic peptide substrate, Suc-Leu-Leu-Val-Tyr-AMC, in a cohort of 155 patients with early/ advanced rectal (n=43/29), gastric (n=6/13), and breast (n=37/27) cancer and compared with that in normal individuals (n = 55). The median plasma proteasome ChT-L activity was elevated by 20-32% in patients with advanced stage of rectal, gastric, and breast cancer compared with healthy donors. The difference turned out to be statistically significant (P <0.001). By contrast, values in patients with early stage of malignancies were not significantly different from those observed in normal individuals. We also found that plasma proteasome activity correlated with serum carcinoembryonic antigen levels in the group of patients with rectal cancer (r=0.433, P<0.05). Elevated plasma proteasome ChT-L activity is indicative of advanced stage of rectal, gastric, and breast cancer. However, the activity does not seem to be a parameter with clinically relevant potential in terms of early detection of cancer in this subset of patients.
Thrombosis Research, 1997
CathepsinA-like enzymereleasedfrom human plateletsby thrombinhydrolyzedat the highest rate Cbz-Ph... more CathepsinA-like enzymereleasedfrom human plateletsby thrombinhydrolyzedat the highest rate Cbz-Phe-Ala, Cbz-Phe-Met and Cbz-Phe-Leu, did not require activatorsand was inhibitedby DFP, DCI and mercurialcompounds(mersalylacid, PCMS, PCMB and HgC12).The optimumactivity of secreted enzyme was at pH 5.0-6.0. Cbz-Glu-Tyrwas also hydrolyzedat lower pH with optimum at pH 3.5. These enzymaticpropertiesare the same as those of cathepsinA solubilizedfrom whole plateletsand purifiedfrom other mammaliancells and tissues. High specific activity of secreted cathepsin A, and a broad pH range of activity may have a significancein extracellularproteolysisin local sites of ischemia.Large portion of cathepsinA-like activitywas not secretableby high concentrationof thrombin and was sedimented with platelet aggregates. No activity of lysosomal carboxypeptidasesB and prolylcarboxypeptidase was detectablein supematantsand pelletsof thrombin-stimulatedplatelets.