Possible therapeutic targets in cardiac myocyte apoptosis.

Since Kerr described programmed cell death (apoptosis) as a process distinct from necrosis, there have been many studies of apoptosis in disease, especially of immunological origin. Because cardiac myocytes are terminally differentiated cells, they have typically been assumed to die exclusively by necrosis. However, during the last decade this view has been challenged by several studies demonstrating that a significant number of cardiac myocytes undergo apoptosis in myocardial infarction, heart failure, myocarditis, arrhythmogenic right ventricular dysplasia, and immune rejection after cardiac transplantation, as well as in other conditions of stress. These are potentially relevant observations, because apoptosis--unlike necrosis--can be blocked or reversed at early stages. Specific inhibition of this process may confer a considerable degree of cardioprotection, but requires a thorough understanding of the underlying mechanisms. Recent progress includes a better understanding of the importance of mitochondria-initiated events in cardiac myocyte apoptosis, of factors inducing apoptosis in heart failure and during hypoxia, and of the dual pro-apoptotic and anti-apoptotic effects of hypertrophic stimuli such as beta-adrenoceptor agonists, angiotensin converting enzyme inhibitors, nitric oxide and calcineurin. The investigation of cytoprotective and apoptotic signal transduction pathways has revealed important new insights into the roles of the mitogen-activated protein kinases p38, extracellular signal regulated kinase and c-Jun N-terminal kinase in cardiac cell fate. Our present review focuses on the intracellular signal transduction pathways of cardiac myocyte apoptosis and the possibility of specific inhibition of the process.

[Molecular regulation of myocardial apoptosis]. / A szívizom apoptosisának molekuláris szabályozása.

Since apoptosis was described as a process distinct from necrosis, there have been many studies of programmed cell death in diseases, especially immunological diseases. Because cardiac myocytes are terminally differentiated cells, they have typically been assumed to die exclusively by necrosis. However, during the last six to seven years this view has been challenged by several studies demonstrating that a significant number of myocytes undergo apoptosis in myocardial infarction, heart failure, myocarditis, arrhythmogen right ventricular dysplasia, and immune rejection after cardiac transplantation, as well as in other conditions of stress. These are potentially very important observations, because apoptosis--unlike necrosis--can be blocked or reversed at early stages. The tracking of cytoprotective and apoptotic signal transduction pathways has proceeded rapidly with important new insights into the roles of mitochondria-dependent pathway, Bcl-2 protein family, p38 mitogen-activated protein kinase, extracellular signal-regulated kinase and c-Jun N-terminal kinase in cell fate. New studies have demonstrated that specific inhibition of apoptosis and activation of cytoprotective mechanisms, based on the better understanding of the intracellular signaling pathways, can significantly protect cardiac myocytes. This review will assess progress in cardiac myocyte apoptosis research and report on the current status of anti-apoptotic therapy in acute and chronic heart diseases.

Effect of silibinin and vitamin E on restoration of cellular immune response after partial hepatectomy.

Our aim was to study the antioxidant and immunomodulatory effect of silibinin and vitamin E on the early postoperative course in rats that had undergone a partial hepatectomy (PHX). Male Wistar rats that were treated with silibinin (50 mg/b.w.kg i.p.) and/or vitamin E (500 mg/b.w.kg p.o.) were randomised to undergo 70% PHX. At 72 h after operation, Concanavalin A (Con-A) induced lymphocyte proliferation, and lipopolysaccharide (LPS) induced interleukin-1 (IL-1) mitogenicity and tumour necrosis factor-alpha (TNF-alpha) cytotoxicity were measured in the spleen. In addition, total free radical scavenger capacity of the liver was analysed. In PHX animals, Con-A induced lymphocyte proliferation was significantly decreased, and both LPS induced IL-1 and TNF-alpha activity were significantly increased as compared to Sham treated animals. Treatment with silibinin and vitamin E synergistically restored both lymphocyte proliferation (P<0.01) and cytokine activity (P<0.001) in PHX animals. In addition, silibinin and vitamin E synergistically (P<0.001) restored total hepatic free radical scavenger capacity as well as serum levels of AST and gammaGT, that were all markedly decreased in PHX animals. Our results suggest that preoperative treatment with silibinin and/or vitamin E modulates the cellular immunoresponse and restores impaired liver function following PHX, presumably through their antioxidant capacity. This may explain their beneficial effects on the postoperative course of liver repair.

Mild thrombocytopenia as presenting symptom of type 1 Gauchers's disease.

A young woman was examined for a mild thrombocytopenia which was present for some months. No signs of bleeding had so far occurred. Physical examination was normal except for a moderately enlarged spleen. Laboratory investigations showed a low platelet count. There was no evidence of an autoimmune or hematologic disease. Bone narrow aspirate indicated Gaucher's-like cells raising the suspicion of Gaucher's disease. This was further supported by electron microscopic demonstration of Gaucher's bodies in crista biopsy specimens. However, the definitive diagnosis was obtained by verifying deficient lysosomal glucosylceramide-beta-D-glucosidase activity in peripheral blood leukocytes. Upon the absence of neurologic involvement the patient was typical for the adult-onset or type 1 form of Gaucher's disease.

[Drugs affecting apoptosis in the immune system]. / Az immunrendszeri apoptosisra ható gyógyszerek.

Apoptosis is a key feature in the physiological and pathological regulation of the immune system. Concerning its central immunoregulatory roles, it would be reasonable to attempt to influence the progression of autoimmune diseases by pharmacological intervention in the processes of apoptosis. Numerous compounds capable of influencing apoptosis are known, but their exact mechanisms of action are only in part understood. The majority of the known chemicals does not affect apoptosis selectively, but alters the function of the whole organism, therefore considerable side-effects related to the application of these compounds may appear. The complexity of this situation is indicated by findings that the same compound can either induce or inhibit apoptosis depending on the experimental system and concentration studied. Our knowledge will, presumably, be extended in the future that could lead to the safer clinical application of these compounds. In this brief review article we attempt to present a synopsis of the most important agents influencing apoptosis in the immune system from a clinical point of view.

[An adult form of type-I. Gaucher's disease]. / Felnóttkori, I. típusú Gaucher-kór esete.

A young woman with no previous history of any diseases was admitted for further evaluation of a mild thrombocytopenia she has had for some months. No signs of bleeding have so far occurred. Physical examination was normal except for a moderately enlarged spleen. Routine investigations showed lower platelet count. There was no laboratory evidence of disease conditions with autoimmune/inflammatory or hematologic origin. Bone marrow aspirate indicated Gaucher's-like cells raising the suspicion of Gaucher's disease. This was further supported by electron microscopic demonstration of Gaucher's bodies (with the characteristic tubular structures) in crista biopsy specimens. However, definitive diagnosis was obtained by verifying deficient lysosomal glucosylceramide-beta-D-glucosidase activity in peripheral blood leukocytes. Upon the absence of neurologic involvement the patient was typical for the adult form or type-1 Gaucher's disease.

[The role of myocardial apoptosis in the development of heart failure]. / A myocardialis apoptosis szerepe a szívelégtelenség kialakulásában.

Heart failure can result from a variety of causes, including volume or pressure overload and contractile disturbances of the myocardium. Loss of myocytes is an important mechanism in the development of cardiac failure. In general, myocyte death resulting in progressive deterioration of myocardial function is attributed to necrosis, but recently the involvement of programmed cell death (mainly apoptosis) has been suggested. The authors review the possible role of myocardial apoptosis in developing of heart failure. Subcellular genetic regulatory processes as well as the pharmacological susceptibility of programmed cell death are also discussed. In heart failure, significant amount of cardiac myocytes undergoes apoptosis, that unlike necrosis can be prevented. Specific inhibition of this process could mean a considerable part of cardioprotection after thorough understanding of the underlying cellular mechanisms.

Drug-related Churg-Strauss syndrome?

Churg-Strauss syndrome (CSS) is a rare disease belonging to the group of necrotizing vasculitides affecting medium and small vessels, classified together with Wegener granulomatosis and microscopic polyarteritis. The literature is reviewed concerning vasculitides associated with drug use, focusing on CSS. A representative case of CSS is reported, in whom the possibility could not be excluded that oestrogen replacement therapy contributed to the onset of CSS. The case of a 56-year-old female patient is presented who had a history of allergic rhinitis and steroid-dependent asthma for years. To prevent postmenopausal complaints and further loss of bone density, she received oestrogen replacement therapy. After three months of hormone therapy, signs of CSS appeared. Oestrogen administration (1 mg norethisterone acetate, 1 mg oestriol and 2 mg oestradiol daily) was stopped. The diagnosis was confirmed by the clinical appearance, laboratory tests and tissue biopsies. The patient received corticosteroids and cyclophosphamide treatment and subsequently the eosinophil count returned to normal within two weeks and her condition improved significantly.

[Apoptosis in the regulation of immune processes and in the pathogenesis of autoimmune diseases]. / Apoptosis az immunfolyamatok regulációjában és az autoimmun betegségek patogenezisében.

Programmed cell death (mainly apoptosis) is involved in all fundamental processes of the immune system. Furthermore, apoptosis is essential for elimination of autoreactive lymphocytes and is, therefore a mechanism to guarantee self-tolerance. There are several genes directly implicated in the regulation of lymphoid apoptosis. However, certain mouse strains expressing the defective mutants of those genes exhibit immunological dysfunctions resembling human autoimmune disease conditions. Thus, further analyses of such animal models could facilitate the better understanding of immunopathological abnormalities developing in humans.

Effect of the natural bioflavonoid antioxidant silymarin on superoxide dismutase (SOD) activity and expression in vitro.

The in vitro effects of the bioflavonoid antioxidant silymarin on the expression and activity of superoxide dismutase (SOD) enzyme was studied in erythrocytes and lymphocytes from patients with chronic alcoholic liver disease. In vitro incubation with the agent in a concentration corresponding to the usual therapeutic dosage markedly increased the SOD expression of lymphocytes as measured by flow-cytofluorimetry following staining with monoclonal anti-Cu/Zn-SOD antibody and FITC-conjugated anti-mouse Ig, as well as erythrocyte and lymphocyte SOD activities. The data indirectly suggest that antioxidant activity might be one of the important factors in the hepatoprotective action of this bioflavonoid.

Effect of vitamin E on the immunoreactivity of spleen cells in hyperlipidaemic rats.

Atherogenic (lipid-rich) diet suppressed mitogen-induced lymphocyte blastogenic responses in rats. Supplementation with vitamin E completely abolished the suppressive effect of the diet. The atherogenic diet also decreased the tumour necrosis factor alpha (TNF-alpha) activity produced by spleen macrophages, however, vitamin E supplementation failed to abolish this effect. Diet or supplementation had no measurable action on interleukin-1 (IL-1) production of macrophages.

[Cytokine production in patients with systemic lupus erythematosus]. / Systemás lupus erythematosusban szenvedö betegek cytokin termelésének vizsgálata.

The production of different cytokines, namely interleukin-2, interleukin-1 and tumor necrosis factor-alpha produced by peripheral immunocompetent cells was evaluated in patients with systemic lupus erythematosus in active and inactive stage of the disease. The results obtained were compared to healthy controls. It has been found that lymphocytes from both groups of SLE patients produced similarly less interleukin-2 activity. Interleukin-1 activity of monocytes was significantly reduced only in patients with active stage of the disease, whereas tumor necrosis factor-alpha production was diminished even in cases of inactive SLE. The simultaneous detection of the above mentioned cytokines may indicate further details concerning immunoregulatory disturbances of systemic lupus erythematosus.

Effect of the bioflavonoid silymarin on the in vitro activity and expression of superoxide dismutase (SOD) enzyme.

Superoxide dismutase activity and expression of the erythrocytes and lymphocytes of patients suffering from chronic alcoholic liver disease and those of healthy controls were investigated after in vitro incubation with silymarin. It was concluded that silymarin treatment in a concentration achievable by in vivo treatment (10 micrograms/ml) significantly increased the SOD activity of both the erythrocytes and lymphocytes of patients with liver disease, whereas the SOD expression of the lymphocytes enhanced to a considerable extent. These results indirectly indicate that the scavenger silymarin is able to increase the antioxidant protection of the cells by ameliorating the deleterious effects of free radical reactions.

Immunomodulatory and hepatoprotective effects of in vivo treatment with free radical scavengers.

The hepatoprotective and immunomodulatory effects of silymarin and amino-imidazol-carboxamid-phosphate were studied in 60 patients with compensated alcoholic cirrhosis of the liver in a one month double blind clinical trial. Treatment with both drugs normalized the elevated levels of aspartate aminotransferase, alanine aminotransferase and serum bilirubin, markedly reduced the high level of gamma-glutamyl transferase, increased lectin-induced lymphoblasttransformation, decreased the percentage of CD8+ cells and suppressed lymphocytotoxicity. None of these changes occurred in the placebo-treated group. Thus the hepato-protective effects of silymarin and amino-imidazol-carboxamid-phosphate are accompanied by changes in parameters of cellular immunoreactivity of the treated patients.

[Immunomodulator effect of silymarin therapy in chronic alcoholic liver diseases]. / Silymarin kezelés immunmoduláns hatása krónikus alkoholos májbetegségben.

The effects of the hepatoprotective, antioxidant drug silymarin (Legalon) on some cellular immune parameters of patients with histologically proven chronic alcoholic liver disease were studied in a six month double blind study. The lectin induced proliferative activity of the lymphocytes got enhanced, the originally low T cell percentage and the originally high CD8+ cell percentage have been normalized, the antibody-dependent and natural cytotoxicity of the lymphocytes decreased during silymarin therapy. All these changes were significant, while in the placebo group no significant changes occurred, except for a moderate elevation of the T cell percentage. Thus, the immunomodulatory activity of silymarin might be involved in the hepatoprotective action of the drug and improves the depressed immunoreactivity of the patients.

In vivo effect of free radical scavenger hepatoprotective agents on superoxide dismutase (SOD) activity in patients.

The in vivo effects of two hepatoprotective antioxidants (silymarin, and 4-amino-5-imidazole-carboxamide-phosphate) on the expression and activity of superoxide dismutase (SOD) enzyme were studied in erythrocytes from patients with alcoholic cirrhosis. In vivo treatment with any of the drugs markedly increased the SOD expression of lymphocytes as measured by flow-cytofluorimetry following staining with monoclonal anti-Cu, Zn-SOD-antibody and FITC-conjugated anti-mouse Ig, as well as erythrocyte and lymphocyte SOD activities. The data indirectly suggest that antioxidant activity might be one of the important factors in the hepatoprotective action of these agents.

Hepatoprotective and immunological effects of antioxidant drugs.

The hepatoprotective and immunomodulatory effects of silymarin and amino-imidazole-carboxamide-phosphate were studied in 40 patients with alcoholic cirrhosis of the liver in a one-month double-blind clinical trial. Treatment with either of the drugs normalized the elevated levels of aspartate aminotransferase, alanine aminotransferase and serum bilirubin, markedly reduced the high level of gamma-glutamyl transferase, increased lectin-induced lymphoblast transformation, decreased the percentage of OKT8+ cells and suppressed lymphocytotoxicity. None of these changes occurred in the placebo-treated group. Thus, the hepatoprotective effects of silymarin and amino-imidazole-carboxamide-phosphate in alcoholic cirrhosis can partly be attributed to the immunomodulatory activity of the drugs.

[Effect of silimarin (Legalon) therapy on the antioxidant defense mechanism and lipid peroxidation in alcoholic liver disease (double blind protocol)]. / Silymarin (Legalon) kezelés hatása idült alkoholos májbetegek antioxidáns védörendszerére és a lipid peroxidációra (kettös vak protokoll).

A double blind study. Antioxidant and antiperoxidative effects of the free radical scavenger agent silymarin (Legalon) were investigated in patients with chronic alcoholic liver disease in a double blind clinical trial. Six month treatment (at a daily dose of 420 mg) with silymarin significantly enhanced the originally low superoxide dismutase activity of erythrocytes and lymphocytes and also restored the diminished superoxide dismutase expression on lymphocytes as measured by flow-cytofluorimetry. In addition, silymarin therapy markedly increased the serum level of ree--SH groups and the activity of glutathione peroxidase. In contrast, a considerable fall in serum malondialdehyde concentration was detected in patients having received silymarin. However, in case of placebo-treated patients the above mentioned parameters of antioxidant defense system and lipid peroxidation failed to change significantly. These data indirectly suggest that antioxidant, antiperoxidative effects might be important factors in the mechanism of hepatoprotective action of silymarin.

In vitro effect of 4-amino-5-imidazole-carboxamide-phosphate (AICA-P) on the enzyme activity and expression of superoxide dismutase.

Antioxidant effects of a newly developed hepatoprotective agent 4-amino-5-imidazole-carboxamide-phosphate (Aica-P) were studied in an in vitro test system using isolated peripheral blood cells from patients with chronic alcoholic liver disease and from healthy controls. In vitro incubation with the drug in a concentration corresponding to the usual therapeutic dosage enhanced the superoxide dismutase (SOD) activity of erythrocytes and lymphocytes and also increased the superoxide dismutase expression on lymphocytes. These results indirectly suggest that antioxidant capacity may be one of the important factors in the mechanisms of hepatoprotective action of the imidazole derivate Aica-P.

Effect of in vitro Aica-P treatment on certain cellular immune functions.

The effect of the hepatoprotective agent and protein synthesis stimulator 4-amino-5-imidazole-carboxamide-phosphate on the resynthesis of the "E" receptors of T lymphocytes and on certain immunological functions was investigated in vitro. Aica-P treatment enhanced the resynthesis of the "E" receptors after trypsin digestion and inhibited the blastic transformation of the lymphocytes. The results corroborate the observations that Aica-P is able to enhance protein synthesis and to exert immunomodulatory activity.