Effectiveness of hospital-based low intensity and inspected aerobic training on functionality and cardiorespiratory fitness in unconditioned stroke patients: Importance of submaximal aerobic fitness markers

INTRODUCTION

The purpose of our study was to evaluate the effectiveness of low-to moderate intensity aerobic training on cardiorespiratory functions in chronic unconditioned stroke patients. The oxygen uptake efficiency slope (OUES) and the ventilatory threshold (VO2-VT) could represent the aerobic capacity in submaximal test. Our study examined the application of the submaximal parameters for evaluating aerobic capacity of chronic stroke patients.

MATERIALS AND METHODS

In our assessor-blinded controlled pilot study 37 patients were randomized into 2 groups named: intervention group (IG, n: 21) and control group (CG, n:16), respectively. Cardiorespiratory functions were evaluated by ergospirometer before and after the 4-week (20 days) program. Both groups participated in daily occupational therapy (30 minutes) and conventional, customized physiotherapy CG (60 minutes), IG (30 minutes). Only IG performed aerobic training by bicycles (30 minutes) aiming to reach low-to moderate training intensity. Outcome measures included peak oxygen uptake (VO2 peak), OUES, VO2-VT, functional exercise capacity 6-Minute Walking Test (6MWT) and Functional Independence Measure.

RESULTS

Thirty-five subjects completed the study. The VO2 peak uptake was very low in both groups (IG: 11.9 mL/kg/min, CG: 12.45 mL/kg/min) and did not improve after the program, but submaximal parameters such as VO2-VT (P < .01) and OUES (P < .001) have shown significant improvement, but only in IG regardless of insufficient impact on VO2 peak. Each participant in both groups was unable to permanently reach the moderate intensity zone. Functional Independence Measure changed for the better in both groups, but 6MWT only in the IG.

DISCUSSION AND CONCLUSIONS

Four-week exercise training even at low intensity by lower limb cycle ergometer may provide benefit on aerobic and functional capacity without improvement of VO2 peak on unconditioned chronic stroke patients.

Causes, clinical findings and therapeutic options in chylomicronemia syndrome, a special form of hypertriglyceridemia

The prevalence of hypertriglyceridemia has been increasing worldwide. Attention is drawn to the fact that the frequency of a special hypertriglyceridemia entity, named chylomicronemia syndrome, is variable among its different forms. The monogenic form, termed familial chylomicronemia syndrome, is rare, occuring in 1 in every 1 million persons. On the other hand, the prevalence of the polygenic form of chylomicronemia syndrome is around 1:600. On the basis of the genetical alterations, other factors, such as obesity, alcohol consumption, uncontrolled diabetes mellitus and certain drugs may significantly contribute to the development of the multifactorial form. In this review, we aimed to highlight the recent findings about the clinical and laboratory features, differential diagnosis, as well as the epidemiology of the monogenic and polygenic forms of chylomicronemias. Regarding the therapy, differentiation between the two types of the chylomicronemia syndrome is essential, as well. Thus, proper treatment options of chylomicronemia and hypertriglyceridemia will be also summarized, emphasizing the newest therapeutic approaches, as novel agents may offer solution for the effective treatment of these conditions.

Assessment of Associations Between Serum Lipoprotein (a) Levels and Atherosclerotic Vascular Diseases in Hungarian Patients With Familial Hypercholesterolemia Using Data Mining and Machine Learning

Background and aims: Premature mortality due to atherosclerotic vascular disease is very high in Hungary in comparison with international prevalence rates, though the estimated prevalence of familial hypercholesterolemia (FH) is in line with the data of other European countries. Previous studies have shown that high lipoprotein(a)- Lp(a) levels are associated with an increased risk of atherosclerotic vascular diseases in patients with FH. We aimed to assess the associations of serum Lp(a) levels and such vascular diseases in FH using data mining methods and machine learning techniques in the Northern Great Plain region of Hungary.

Methods: Medical records of 590,500 patients were included in our study. Based on the data from previously diagnosed FH patients using the Dutch Lipid Clinic Network scores (≥7 was evaluated as probable or definite FH), we trained machine learning models to identify FH patients.

Results: We identified 459 patients with FH and 221 of them had data available on Lp(a). Patients with FH had significantly higher Lp(a) levels compared to non-FH subjects [236 (92.5; 698.5) vs. 167 (80.2; 431.5) mg/L, p < .01]. Also 35.3% of FH patients had Lp(a) levels >500 mg/L. Atherosclerotic complications were significantly more frequent in FH patients compared to patients without FH (46.6 vs. 13.9%). However, contrary to several other previous studies, we could not find significant associations between serum Lp(a) levels and atherosclerotic vascular diseases in the studied Hungarian FH patient group.

Conclusion: The extremely high burden of vascular disease is mainly explained by the unhealthy lifestyle of our patients (i.e., high prevalence of smoking, unhealthy diet and physical inactivity resulting in obesity and hypertension). The lack of associations between serum Lp(a) levels and atherosclerotic vascular diseases in Hungarian FH patients may be due to the high prevalence of these risk factors, that mask the deleterious effect of Lp(a).

Smoothelin-Like Protein 1 Regulates Development and Metabolic Transformation of Skeletal Muscle in Hyperthyroidism

Hyperthyroidism triggers a glycolytic shift in skeletal muscle (SKM) by altering the expression of metabolic proteins, which is often accompanied by peripheral insulin resistance. Our previous results show that smoothelin-like protein 1 (SMTNL1), a transcriptional co-regulator, promotes insulin sensitivity in SKM. Our aim was to elucidate the role of SMTNL1 in SKM under physiological and pathological 3,3',5-Triiodo-L-thyronine (T3) concentrations. Human hyper- and euthyroid SKM biopsies were used for microarray analysis and proteome profiler arrays. Expression of genes related to energy production, nucleic acid- and lipid metabolism was changed significantly in hyperthyroid samples. The phosphorylation levels and activity of AMPKα2 and JNK were increased by 15% and 23%, respectively, in the hyperthyroid samples compared to control. Moreover, SMTNL1 expression showed a 6-fold decrease in the hyperthyroid samples and in T3-treated C2C12 cells. Physiological and supraphysiological concentrations of T3 were applied on differentiated C2C12 cells upon SMTNL1 overexpression to assess the activity and expression level of the elements of thyroid hormone signaling, insulin signaling and glucose metabolism. Our results demonstrate that SMTNL1 selectively regulated TRα expression. Overexpression of SMTNL1 induced insulin sensitivity through the inhibition of JNK activity by 40% and hampered the non-genomic effects of T3 by decreasing the activity of ERK1/2 through PKCδ. SMTNL1 overexpression reduced IRS1 Ser307 and Ser612 phosphorylation by 52% and 53%, respectively, in hyperthyroid model to restore the normal responsiveness of glucose transport to insulin. SMTNL1 regulated glucose phosphorylation and balances glycolysis and glycogen synthesis via the downregulation of hexokinase II by 1.3-fold. Additionally, mitochondrial respiration and glycolysis were measured by SeaHorse analysis to determine cellular metabolic function/phenotype of our model system in real-time. T3 overload strongly increased the rate of acidification and a shift to glycolysis, while SMTNL1 overexpression antagonizes the T3 effects. These lines of evidence suggest that SMTNL1 potentially prevents hyperthyroidism-induced changes in SKM, and it holds great promise as a novel therapeutic target in insulin resistance.

An ω-3, but Not an ω-6 Polyunsaturated Fatty Acid Decreases Membrane Dipole Potential and Stimulates Endo-Lysosomal Escape of Penetratin

Although the largely positive intramembrane dipole potential (DP) may substantially influence the function of transmembrane proteins, its investigation is deeply hampered by the lack of measurement techniques suitable for high-throughput examination of living cells. Here, we describe a novel emission ratiometric flow cytometry method based on F66, a 3-hydroxiflavon derivative, and demonstrate that 6-ketocholestanol, cholesterol and 7-dehydrocholesterol, saturated stearic acid (SA) and ω-6 γ-linolenic acid (GLA) increase, while ω-3 α-linolenic acid (ALA) decreases the DP. These changes do not correlate with alterations in cell viability or membrane fluidity. Pretreatment with ALA counteracts, while SA or GLA enhances cholesterol-induced DP elevations. Furthermore, ALA (but not SA or GLA) increases endo-lysosomal escape of penetratin, a cell-penetrating peptide. In summary, we have developed a novel method to measure DP in large quantities of individual living cells and propose ALA as a physiological DP lowering agent facilitating cytoplasmic entry of penetratin.

Identifying patients with familial hypercholesterolemia using data mining methods in the Northern Great Plain region of Hungary

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is one of the most frequent diseases with monogenic inheritance. Previous data indicated that the heterozygous form occurred in 1:250 people. Based on these reports, around 36,000-40,000 people are estimated to have FH in Hungary, however, there are no exact data about the frequency of the disease in our country. Therefore, we initiated a cooperation with a clinical site partner company that provides modern data mining methods, on the basis of medical and statistical records, and we applied them to two major hospitals in the Northern Great Plain region of Hungary to find patients with a possible diagnosis of FH.

METHODS

Medical records of 1,342,124 patients were included in our study. From the mined data, we calculated Dutch Lipid Clinic Network (DLCN) scores for each patient and grouped them according to the criteria to assess the likelihood of the diagnosis of FH. We also calculated the mean lipid levels before the diagnosis and treatment.

RESULTS

We identified 225 patients with a DLCN score of 6-8 (mean total cholesterol: 9.38 ± 3.0 mmol/L, mean LDL-C: 7.61 ± 2.4 mmol/L), and 11,706 patients with a DLCN score of 3-5 (mean total cholesterol: 7.34 ± 1.2 mmol/L, mean LDL-C: 5.26 ± 0.8 mmol/L).

CONCLUSIONS

The analysis of more regional and country-wide data and more frequent measurements of total cholesterol and LDL-C levels would increase the number of FH cases discovered. Data mining seems to be ideal for filtering and screening of FH in Hungary.

Plasminogen Activator Inhibitor-1 Level Correlates with Lipoprotein Subfractions in Obese Nondiabetic Subjects

BACKGROUND

The elevated level of plasminogen activator inhibitor-1 (PAI-1) in obese subjects with metabolic syndrome and in patients with type 2 diabetes is well established. The association of plasma PAI-1 and lipid metabolism is still unclear. The aim of the present study was to determine the relationship between plasma PAI-1 levels and the distribution of lipoprotein subfractions in obese and lean nondiabetic individuals.

SUBJECTS AND METHODS

We enrolled fifty nondiabetic obese patients and thirty-two healthy volunteers. Lipoprotein subfractions were detected with Lipoprint System. Plasma PAI-1, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and myeloperoxidase (MPO) concentrations were determined with enzyme-linked immunosorbent assay (ELISA), while serum paraoxonase-1 (PON1) activities were measured by spectrophotometry.

RESULTS

The TNF-α, IL-6, oxidized low-density lipoprotein (oxLDL), and MPO levels were found to be significantly higher, while PON1 paraoxonase and arylesterase activities were nonsignificantly lower in the obese patients. Strong significant negative correlations were found between plasma PAI-1 concentration and mean LDL size, as well as between PAI-1 concentrations and the levels of the large and intermediate high-density lipoprotein (HDL) subfractions. In multiple regression analysis, PAI-1 was predicted by waist circumference and intermediate HDL subfraction.

CONCLUSION

The significant correlations between PAI-1 levels and lipoprotein subfractions indicate the link between PAI-1 and lipid metabolism in obesity.

Paraoxonase-1 and myeloperoxidase correlate with vascular biomarkers in overweight patients with newly diagnosed untreated hyperlipidaemia

BACKGROUND

In hyperlipidaemic state, increased levels of myeloperoxidase (MPO) and decreased paraoxonase-1 (PON1) activity have been reported; however, their relationships with other atherosclerotic biomarkers have not been completely clarified.

PATIENTS AND METHODS

Serum concentrations of lipid and inflammatory parameters, MPO levels, and PON1 activities were investigated in 167 untreated hyperlipidaemic patients with and without vascular complications and in 32 healthy controls. Additionally, levels of CD40 ligand (sCD40L) and asymmetric dimethyl arginine (ADMA), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1, and oxidized LDL were determined.

RESULTS

We found elevated C-reactive protein (CRP), ADMA, sCD40L, sICAM-1 concentrations, and higher MPO levels in patients with vascular complications compared to those without. The PON1 arylesterase activity correlated negatively with sCD40L, ADMA, and sICAM-1 levels, respectively. In contrast, MPO concentrations showed positive correlations with sCD40L, ADMA, and sICAM-1 levels, respectively.

CONCLUSIONS

It can therefore be stated that PON1 activity and MPO level correlate strongly with the vascular biomarkers, highlighting the importance of the HDL-associated pro- and antioxidant enzymes in the development of endothelial dysfunction and atherogenesis.

Impact of selective LDL apheresis on serum chemerin levels in patients with hypercholesterolemia

Background

Selective low-density lipoprotein (LDL) apheresis is commonly used to treat patients with familial hypercholesterolemia (FH). Chemerin is an adipokine with putative roles in the regulation of lipid metabolism.

Methods

In our pilot study, we measured serum chemerin levels by enzyme-linked immunosorbent assay in six severe heterozygous FH patients before and after their first LDL apheresis treatments using the technique of direct adsorption of lipoproteins (DALI).

Results

The first treatment sessions decreased serum chemerin levels by an average of 27.26 %. While following one patient, 12 months of regular LDL apheresis resulted in a permanent reduction in his serum chemerin level. Changes in the lipoprotein subfractions measured by gel electrophoresis (Lipoprint) correlated with the reduction of chemerin levels. Furthermore, we eluted and then measured chemerin bound to the DALI column.

Conclusion

We conclude that LDL apheresis decreases the circulating level of chemerin by binding the protein to the column and thus improves lipoprotein subfraction pattern.

Paraoxonase-1 and adipokines: Potential links between obesity and atherosclerosis

Oxidative stress and chronic low-grade inflammation are major characteristics of obesity-related disorders. The dominance of pro-oxidant and pro-inflammatory mechanisms triggers insulin resistance and enhances the progression of atherosclerosis. Discovered first as an esterase that hydrolyze organophosphates, human paraoxonase-1 is bound to high-density lipoprotein and inhibits the oxidation of lipoproteins and reduces the degree of inflammation, hence it is considered to act against atherosclerosis. In contrast, the majority of the adipokines secreted from the enlarged white adipose tissue promote the atherosclerotic process; and altered adipokine secretion is now regarded as one of the major contributors of increased cardiovascular morbidity and mortality in obesity. In this review, we detail the correlations between paraoxonase-1 and some selected adipokines, namely leptin, adiponectin and chemerin. Adipokine imbalance leads to decreased paraoxonase-1 activity that results in enhanced atherosclerosis; therefore, altered adipokine secretion may be predictive of cardiovascular complications in obesity. As an active organ secreting biological active substances, white adipose tissue may also act as a "fine-tuner" of immune and endocrine actions attenuating or enhancing reactions triggered by pathogens, inflammation and metabolic stimuli; and obesity, as a chronic noxious state may perturb the proper functioning of this fine-tuning process. Further investigations are of major importance to elucidate the associations between adipokines and paraoxonase-1 and to establish accurate interventions against obesity-related disorders.

High-density lipopoprotein antioxidant capacity, subpopulation distribution and paraoxonase-1 activity in patients with systemic lupus erythematosus

Background

The causes of increased cardiovascular risk in systemic lupus erythematosus (SLE) are not understood thoroughly, although presence of traditional cardiovascular risk factors and disease-specific agents were also proposed. In this study, we investigated the quantitative changes in the lipid profile, as well as qualitative characteristics of high-density lipoprotein (HDL) and markers of inflammation and disease activity in SLE patients.

Methods

Lipoprotein levels were determined in 51 SLE patients and 49 healthy controls, matched in age and gender. HDL antioxidant capacity was determined spectrophotometrically with a cell-free method of hemin-induced low-density lipoprotein (LDL) oxidation. Polyacrylamide gel-electrophoresis was used for HDL subfraction analysis. Human paraoxonase-1 (PON1) activity, apolipoprotein A1 (ApoA1) and oxidized LDL concentrations, as well as interleukin-6, high-sensitivity C-reactive protein, serum amyloid A and monocyte chemotactic protein-1 levels were determined.

Results

HDL-cholesterol and ApoA1 concentrations decreased significantly in SLE subjects. Also, PON1 arylesterase activity (125.65 ± 26.87 vs. 148.35 ± 39.34 U/L, p = 0.001) and total HDL antioxidant capacity (165.82 ± 58.28 % vs. 217.71 ± 54.36 %, p < 0.001) were significantly reduced in patients compared to controls. Additionally, all HDL subfraction concentrations were significantly decreased in patients, while the levels of the examined inflammatory markers were significantly elevated in SLE subjects. The latter correlated positively with disease activity, and negatively with HDL concentration and total HDL antioxidant capacity, respectively. PON1 arylesterase activity and erythrocyte sedimentation rate were independent predictors of total HDL antioxidant capacity.

Conclusions

Induced by the systemic inflammation, altered composition and antioxidant activity may diminish the anti-atherogenic effect of HDL and therefore may contribute to the increased cardiovascular risk of SLE patients.

Strong correlations between circulating chemerin levels and lipoprotein subfractions in nondiabetic obese and nonobese subjects

OBJECTIVE

Chemerin is a recently described adipokine expressed primarily in the white adipose tissue. Compared with lean subjects, circulating chemerin levels are significantly elevated in obese individuals and correlate positively with the prevalence of various cardiovascular risk factors including altered lipoprotein levels. To date, the impact of chemerin on lipoprotein subfractions and its role in atherosclerotic processes are still unclear.

PATIENTS AND METHODS

Fifty nondiabetic obese (NDO) patients and 38 lean controls matched in age and gender were enrolled. Chemerin level was measured by ELISA. Low-density lipoprotein (LDL) and high-density lipoprotein (HDL) subfractions were detected by nongradient polyacrylamide gel electrophoresis (Lipoprint).

RESULTS

We detected significantly higher serum chemerin levels in NDO patients compared with healthy controls (590·1 ± 190·3 ng/ml vs 405 ± 127·1 ng/ml, P < 0·001). A significant positive correlation was found between chemerin and LDL cholesterol levels, while chemerin showed a significant negative correlation with the level of HDL cholesterol. Significant positive correlation was detected between chemerin and the ratio of small dense LDL, while chemerin correlated negatively with the mean LDL size. Also, a significant negative correlation was found between serum chemerin and the ratio of large HDL subfraction, while there were significant positive correlations between chemerin levels and intermediate and small HDL subfraction ratios, respectively.

CONCLUSION

Chemerin may be involved in the regulation of lipoprotein metabolism in obese patients who do not show apparent abnormalities of glucose metabolism. Early changes in the distribution of the lipoprotein subfractions may contribute to the progression of atherosclerosis, leading to increased cardiovascular risk.

Association of chemerin with oxidative stress, inflammation and classical adipokines in non-diabetic obese patients

The prevalence of obesity has been increasing worldwide. Chemerin is a recently discovered adipokine secreted by the enlarged adipose tissue with diverse biological effects that are not well detailed yet. This study aimed to elucidate the potential role of chemerin in oxidative stress and inflammation that are characteristics for excess weight and may eventually lead to insulin resistance and atherosclerotic complications. We also analysed the associations between chemerin and classical adipokines, namely leptin and adiponectin. Therefore, we investigated non-diabetic obese patients without manifest cardiovascular disease and compared their data to healthy lean individuals. Chemerin correlated positively with markers of oxidative stress and inflammation, while it showed a negative correlation with the measure of antioxidant status, characterized by the HDL-linked paraoxonase-1 enzyme. Chemerin also correlated positively with leptin and negatively with adiponectin respectively. In our study population, oxidized low-density lipoprotein and high-sensitivity C-reactive protein were found to be the strongest predictors of chemerin level. We conclude that chemerin may contribute to chronic inflammation and increased oxidative stress in obese individuals, even in the absence of manifest insulin resistance.

Dynamic interplay between metabolic syndrome and immunity

Obesity and its co-morbidities as metabolic syndrome, type 2 diabetes mellitus and cardiovascular diseases are major health problems worldwide. Several reports indicated that nutrient excess and metabolic syndrome are linked with altered immune response. Indeed, metabolic syndrome is characterized by insulin resistance and chronic low-grade inflammation, which conditions are the consequences of the complex interaction between adipocytes and immune cells. Enlarged white adipose tissue is infiltrated by immune cells and secretes various bioactive substances, like adipokines, cytokines and other inflammatory mediators. Due to its special architecture in which metabolic and immune cells are in intimate proximity, metabolic and immunologic pathways are closely integrated in adipose tissue. With the contribution of altered gut microbiota, adipokines and cytokines modulate insulin signaling and immune response leading to adipose tissue inflammation and systemic insulin resistance. In this chapter, we focus on the cellular and molecular mechanisms that lead to impaired insulin sensitivity and chronic low-grade inflammation in obesity. We also detail the potential role of adipokines and immune cells in this deleterious process, and the concerns of vaccination in metabolic syndrome. Finally, we address the links between obesity and gut microbiota as an emerging new field of interest, and scratch the surface of potential therapeutic opportunities.

Increased hair selenium concentration in hyperlipidemic patients

Selenium is an essential trace element with potential anti-atherogenic and antioxidant effects. Experimental data suggest that selenium might be beneficial in the prevention of atherosclerosis and its complications, whereas human epidemiological studies have yielded conflicting results. Data on hair selenium status in hyperlipidemic patients are still lacking. Therefore, we analysed selenium concentrations by X-ray fluorescence in the hair of 81 statin-naïve patients with newly diagnosed Fredrickson-type IIa and IIb hyperlipoproteinemia and compared their data with 43 healthy volunteers. We also assessed the frequency of other classical risk factors of atherosclerosis. Hair selenium levels were found to be significantly higher in hyperlipidemic patients compared with volunteers with normal lipid levels. Also, a significantly increased number of traditional atherosclerosis risk factors were observed in hyperlipidemic patients with hair selenium concentrations above the median in contrast to those with below. Our results suggest that high hair selenium status might be associated with adverse blood lipid profile together with an increased number of traditional risk factors in a selenium-deplete population. These findings warrant further investigations to study the impact of selenium supplementation on the incidence of cardiovascular events.

Patomechanisms of hepatic steatosis

Az elhízás és hozzá társuló kórállapotok, így az inzulinrezisztenciát kísérő nem alkoholos zsírmájbetegség a világ egészségügyi rendszereire jelentős terhet rónak. A betegség kialakulásának első lépése a májban történő trigliceridlerakódást kísérő elzsírosodás, amely később gyulladáshoz, illetve májzsugorhoz és májrákhoz is vezethet. A steatosis hátterében a májba történő nagy mennyiségű zsírsavbeáramlás és a szervben megfigyelhető fokozott lipogenesis, valamint a zsírsav-oxidációs és -szekréciós utak relatív csökkenése áll. Jelen összefoglalónkban ezen molekuláris mechanizmusokra világítunk rá. Ezek megértése fontos adalékul szolgálhat az elhízás és az inzulinrezisztencia mellett kialakuló májbetegség, illetve a következményes kardiometabolikus következmények hátterének tisztázásához.

Impact of lipid lowering therapy on liver function

A cardiovascularis megbetegedések hazánkban is vezetik a morbiditási és mortalitási statisztikákat. Ezen betegségek kialakulásában jelentős szerepet játszik a hyperlipidaemia. A korábbi nagy prospektív multicentrikus tanulmányok azt igazolták, hogy a hatékony lipidcsökkentő kezelés jelentős mértékű cardiovascularis halálozás-összhalálozás csökkenést eredményez. Ez a hatás függ az LDL-C-csökkentés mértékétől, amely gyakran csak a nagy dózisban alkalmazott statinkészítményekkel éri el a kívánt szintet. A nagy dózisban alkalmazott statinok a betegek körülbelül 3%-ában hozhatnak létre májkárosító hatást. A szerzők jelen munkájukban röviden ismertetik a lipidcsökkentő gyógyszerek hatásait, azokat a mechanizmusokat, amelyek a szerek potenciális májkárosító hatásának hátterében állhatnak. Felhívják a figyelmet arra, hogy a korábbi gyakorlattól eltérően, emelkedett transzaminázszintek esetén, sőt, bizonyos májbetegségekben is biztonságosan alkalmazhatóak a lipidcsökkentő készítmények. Természetesen akkor, ha megfelelő dózisban vagy kombinációban alkalmazzuk a gyógyszereket, és figyelemmel vagyunk azon tényezőkre, amelyek fokozhatják a nem kívánt mellékhatásokat. Ezen szempontok betartása mellett magas cardiovascularis rizikójú, egyébként krónikus májbetegségben szenvedők számára is biztosíthatjuk a lipidcsökkentők nyújtotta kedvező hatásokat anélkül, hogy fokoznánk a máj károsodását.

Uncoupling protein-2 modulates the lipid metabolic response to fasting in mice

Uncoupling protein-2 (UCP2) regulates insulin secretion by controlling ATP levels in beta-cells. Although UCP2 deficiency improves glycemic control in mice, increased expression of UCP2 interferes with glucose-stimulated insulin secretion. These observations link UCP2 to beta-cell dysfunction in type 2 diabetes with a perplexing evolutionary role. We found higher residual serum insulin levels and blunted lipid metabolic responses in fasted ucp2(-/-) mice, supporting the concept that UCP2 evolved to suppress insulin effects and to accommodate the fuel switch to fatty acids during starvation. In the absence of UCP2, fasting initially promotes peripheral lipolysis and hepatic fat accumulation at less than expected rates but culminates in protracted steatosis, indicating diminished hepatic utilization and clearance of fatty acids. We conclude that UCP2-mediated control of insulin secretion is a physiologically relevant mechanism of the metabolic response to fasting.

The association between angiotensin II-induced free radical generation and membrane fluidity in neutrophils of patients with metabolic syndrome

Angiotensin II (Ang II) is able to induce free radical generation in neutrophils, which is more elevated in neutrophils of patients with hypercholesterolemia (HC). In addition, the signal processing through angiotensin I (Ang I) receptors is altered. In present study, we compared the Ang II-triggered free radical generation of neutrophils obtained from patients with relatively isolated forms of metabolic syndrome (MS) with membrane-bound cholesterol content and membrane fluidity. We determined the enhancement of Ang II-induced superoxide anion and leukotriene C(4) (LTC(4)) generation, membrane fluidity and cell-bound cholesterol content of neutrophils obtained from 12 control subjects, 11 patients with obesity (Ob), 10 patients with type 2 diabetes mellitus (t2-DM) and 12 patients with HC. The alteration of signal processing was studied after preincubation with different inhibiting drugs. Superoxide anion, LTC(4) production and membrane rigidity were increased in the following order: control < Ob < t2-DM < HC. Both Ang II-induced superoxide anion and LTC(4) generation were decreased in control cells by pertussis toxin and fluvastatin (Flu), whereas in each patient group, mepacrin, verapamil and Flu were effective, suggesting alterations in signal pathways, which may be attributed to isoprenylation. The enhancement of superoxide anion and LTC(4) generation correlated significantly with membrane rigidity, independently from the experimental groups and membrane-bound cholesterol content. Membrane rigidity of neutrophils, obtained from patients with MS, plays a role in Ang II-induced free radical generation independent of intracellular cholesterol homeostasis.

Orlistat increases serum paraoxonase activity in obese patients

BACKGROUND AND AIM

Previous studies have demonstrated that oxidative stress is increased in obese patients. The high-density lipoprotein (HDL) associated human paraoxonase 1 (PON1) can inhibit low-density lipoprotein oxidation and has an antiatherogenic effect. Our objective was to assess the effects of orlistat therapy combined with diet on body mass index (BMI), waist circumference, lipid parameters, blood pressure, serum glucose level and PON1 activity.

METHODS AND RESULTS

A longitudinal, multicenter, randomized study with and without orlistat treatment was performed. One hundred thirty nine otherwise healthy, obese subjects were divided in to two groups: 78 persons received orlistat (120 mg three times a day) combined with diet while 61 persons were kept on diet only. Anthropometrical parameters, serum lipid levels and PON1 activity were measured at baseline and after 6 months of treatment. BMI and waist circumference were reduced more pronouncedly in the orlistat group than in the control group. Patients receiving orlistat also had significantly greater improvements in fasting blood glucose levels and blood pressure. The orlistat-treated group showed a greater reduction in total cholesterol and triglyceride levels. In addition, the serum PON1 activity in these patients was significantly increased compared to the diet-only group.

CONCLUSIONS

The 6-month treatment with orlistat had a beneficial effect on the lipid profile and improved the antioxidant status by increasing serum PON1 activity. However, because of the limited therapeutic effectiveness, obese patients with hypercholesterolemia should receive additional lipid lowering medications.

Neuropeptides induced a pronounced and statin-sensitive dysregulation of mevalonate cycle in human monocytes of patients with hypercholesterolemia

Angiotensin II (Ang II) and leptin generate statin-inhibitable superoxide anion production that accounts for only part of the entire superoxide anion production. In our recent studies, we aimed at elucidating whether Ang II and leptin, affecting the intensity of the mevalonate cycle, are able to increase endogenous cholesterol synthesis. Furthermore, we compared the superoxide anion and cholesterol production capability of monocytes of healthy control volunteers and monocytes obtained from patients with hypercholesterolemia (HC). We also studied the differences of the produced statin-inhibitable superoxide anion and cholesterol synthesis in control and HC-monocytes, depending on the applied stimulating ligands. In control and HC-monocytes--stimulated by Ang II, leptin, fenyl-Me-Leu-Phe (FMLP), phorbol-12-myristate-13-acetate (PMA) and A23187--we determined the proportion of mevalonate cycle-dependent and -independent superoxide and cholesterol production, using lovastatin (Lov), and 25-hydroxycholesterol (25-HC). According to our results; (1) superoxide anion generation in HC-monocytes was elevated after Ang II, leptin and FMLP-stimulation, whereas PMA and A23187-stimulation had lower stimulating effect in HC than in control cells. (2) Cholesterol synthesis was increased only after stimulation with Ang II and leptin. (3) The Ang II and leptin-induced total superoxide anion generation and cholesterol synthesis were more elevated in HC than in control monocytes. (4) In contrast, the increase in Lov and 25-HC sensitive cholesterol synthesis were higher in resting, but lower in stimulated HC monocytes than in control cells. Summarizing our results, we concluded that Ang II and leptin are involved in enhancement of endogenous cholesterol synthesis through a statin-sensitive pathway.

Lack of UCP2 reduces Fas-mediated liver injury in ob/ob mice and reveals importance of cell-specific UCP2 expression

Fatty liver is vulnerable to conditions that challenge hepatocellular energy homeostasis. Lipid-laden hepatocytes highly express uncoupling protein-2 (UCP2), a mitochondrial carrier that competes with adenosine triphosphate (ATP) synthesis by mediating proton leak. However, evidence for a link between UCP2 expression and susceptibility of liver to acute injury is lacking. We asked whether absence of UCP2 protects ob/ob mice from Fas-mediated acute liver damage. UCP2-deficient ob/ob mice (ob/ob:ucp2-/-) and UCP2-competent littermates (ob/ob:ucp2+/+) received a single dose of agonistic anti-Fas antibody (Jo2). Low-dose Jo2 (0.15 mg/kg intraperitoneally) caused less serum alanine aminotransferase (ALT) elevation and lower apoptosis rates in ob/ob:ucp2-/- mice. High-dose Jo2 (0.40 mg/kg intraperitoneally) proved uniformly fatal; however, ob/ob:ucp2-/- mice survived longer with less depletion of liver ATP stores, indicating that fatty hepatocytes may benefit from lack of UCP2 during Jo2 challenge. Although UCP2 reportedly controls mitochondrial oxidant production, its absence had no apparent effect on fatty liver tissue malondialdehyde levels augmented by Jo2. This finding prompted us to determine UCP2 expression in Kupffer cells, a major source of intrahepatic oxidative stress. UCP2 expression was found diminished in Kupffer cells of untreated ob/ob:ucp2+/+ mice, conceivably contributing to increased oxidative stress in fatty liver and limiting the impact of UCP2 ablation. In conclusion, whereas UCP2 abundance in fatty hepatocytes exacerbates Fas-mediated injury by compromising ATP stores, downregulation of UCP2 in Kupffer cells may account for persistent oxidative stress in fatty liver. Our data support a cell-specific approach when considering the therapeutic effects of mitochondrial uncoupling in fatty liver disease.

Enhanced colon tumor induction in uncoupling protein-2 deficient mice is associated with NF-kappaB activation and oxidative stress

Oxidative stress has a complex effect on cancer development. To further study this process, we induced colon tumors with azoxymethane (AOM) in mice deficient for uncoupling protein-2 (UCP2). UCP2 has recently emerged as a negative regulator of mitochondrial oxidant production. When overexpressed, UCP2 protects cells from oxidative stress, while its absence may cause abundance of reactive oxygen species, release of pro-inflammatory cytokines and persistent activation of nuclear factor kappaB (NF-kappaB), a pleiotropic transcription factor with an increasingly recognized role in cancer. Here we show that Ucp2-/- mice develop more aberrant crypt foci and colon tumors than Ucp2+/+ littermates when examined 24 weeks after the completion of treatment with AOM (10 mg/kg i.p. weekly for a total of 6 weeks, n = 8-12). This effect is primarily seen in the proximal colon of Ucp2-/- mice (P < 0.05), in association with changes indicative of increased oxidative stress (increased staining for malondialdehyde and inducible nitric oxide synthase), enhanced NF-kappaB activation (increased levels of phosphorylated IkappaB and increased nuclear presence of p65) and a disrupted balance between intestinal epithelial cell proliferation (greater 5-bromo-2'-deoxy-uridine incorporation rates and increased phosphorylation of ERK1/2 and AKT) and apoptosis (decreased number of terminal deoxynucleotidyltransferase-mediated nick-end-labeling (TUNEL)-positive cells and increased expression of Bcl-2). In conclusion, our findings provide the first in vivo evidence for a link between UCP2 and tumorigenesis and indicate the need for additional studies to assess the role of mitochondrial uncoupling in cancer development.

Different anticancer effects of fluvastatin on primary hepatocellular tumors and metastases in rats

Rats (FLF1) were pretreated with 2 and 20 mg/kg/day fluvastatin (Flu), and after 6 weeks, hepatocellular tumor cells were inoculated under the left renal capsule. At different times, growth and pyruvate kinase (PK) activity of the primary tumors and lymph node metastases were determined. Flu had a dose-dependent inhibitory effect on primary and metastatic tumors, and the inhibitory effect on growth and PK activity in metastases were higher than in primary tumors. Finally, Flu had an earlier inhibitory effect on the early appeared PK activity in metastases than in primary tumors.

Uncoupling protein-2 deficiency promotes oxidant stress and delays liver regeneration in mice

The control of liver regeneration remains elusive. Because reactive oxygen species (ROS) are able to mediate cell growth arrest and activate proteins that inhibit the cell cycle, ROS production may have a negative impact on liver regeneration. We examined how liver regeneration is affected by uncoupling protein-2 (UCP2), an inner mitochondrial membrane carrier that senses and negatively regulates superoxide production. Liver regeneration was monitored up to 5 days and was found to be significantly delayed in UCP2(-/-) mice after partial hepatectomy. Apoptosis rates in UCP2(+/+) and UCP2(- /-) liver remnants were similar, while parameters of cell proliferation indicated a diminished response in UCP2(- /-) mice with corresponding changes in the expression of key cell cycle regulatory proteins and prolonged activation of stress-responsive protein kinase p38. Levels of malondialdehyde, a marker of ROS generation and oxidant stress, were elevated in UCP2(- /-) livers at every examined time point. Liver remnants of UCP2(+ /+) mice 48 hours post-hepatectomy showed a fourfold increase in the expression of UCP2 protein primarily detected in hepatocytes. In conclusion, our results suggest that absent or insufficient UCP2 function in the regenerating liver results in increased ROS production and negatively modulates the control of cell cycle.

HMG CoA reductase inhibitor fluvastatin arrests the development of implanted hepatocarcinoma in rats

BACKGROUND

Fluvastain (Flu) is widely accepted to have anticancer effect although its in vivo chemopreventive ability in cancer has not been studied. The therapeutic and chemopreventive effects of Flu were compared in vivo in the present study.

MATERIALS AND METHODS

Under the left renal capsule of FLF1 hybrid rats 10(6) hepatocarcinoma cells were implanted (He/De14) on sponge disc. The differences in net weight between the left and right kidneys were determined as tumor weights. Flu was administered per os in 0.5, 2 and 20 mg/kg/day doses.

RESULTS

The 21-day pretreatment before tumor implantation with Flu had no effect on tumor development in the absence of Flu treatment after the implantation. The addition of Flu before and after tumor implantation demonstrated a more intensive anticancer effect than in the case of treatment given only after tumor implantation.

CONCLUSION

Flu has in 0.5-20 mg/kg/day doses a therapeutic and also a preventive effect on hepatocarcinoma growth in rats depending on the type of administration.

[Changes in lipid profile and paraoxonase activity in obese patients as a result of orlistat treatment]

257 patients from 33 centres were involved in a six-month study, the aim of which was to assess the effect of orlistat together with a diet. The authors examined how the treatment effected the anthropometrical and lipid parameters, extending the study to the aspect of paraoxonase activity in case of 25 patients. 44 patients dropped out during the study period due to the lack of sufficient diet compliance, whereas 3 patients had to stop the therapy because of the adverse event of flatus with discharge. On the average, the body mass of the patients decreased from 100.8 +/- 18.9 to 91.3 +/- 18.6 kg, i.e. by 9.5 kgs, while their BMI was reduced from 36.1 +/- 5.6 to 32.5 +/- 5.2 kg/m2 and the circumference of the waist changing from 119.1 +/- 20 to 108.3 +/- 15.1 cm, i.e. by 10.8 cms. The blood sugar level significantly decreased from 5.7 to 5.4, while the cholesterol concentration significantly dropped from 5.9 to 5.5, the triglyceride level being reduced from 2.4 to 2.1 mmol/l and blood pressure falling significantly from 136.6/86.9 to 129.9/81.6. All the above changes showed a significant decrease. However, the HDL-cholesterol level did not change. The serum paraoxonase activity significantly increased (143 +/- 49 vs 166 +/- 43 UL) along with the standardised values for HDL (PON/HDL), even compared to the control diet group. From the above results it may be concluded that orlistat tends to have an antioxidant effect.