The left-lateralisation of citrate synthase activity in the anterior cingulate cortex of male violent suicide victims.

The anterior cingulate cortex (AC) as a part of prefrontal cortex plays a crucial role in behavioural regulation, which is profoundly disturbed in suicide. Citrate synthase (CS) is a key enzyme of tricarboxylic acid cycle fundamental for brain energetics and neurotransmitter synthesis, which are deteriorated in suicidal behaviour. However, CS activity has not been yet studied in brain structures of suicide victims. CS activity assay was performed bilaterally on frozen samples of the rostral part of the AC of 24 violent suicide completers (21 males and 3 females) with unknown psychiatric diagnosis and 24 non-suicidal controls (20 males and 4 females). Compared to controls, suicide victims revealed decreased CS activity in the right AC, however, insignificant. Further statistical analysis of laterality index revealed the left-lateralisation of CS activity in the AC in male suicides compared to male controls (U-test P = 0.0003, corrected for multiple comparisons). The results were not confounded by postmortem interval, blood alcohol concentration, age, and brain weight. Our findings suggest that disturbed CS activity in the AC plays a role in suicide pathogenesis and correspond with our previous morphological and molecular studies of prefrontal regions in suicide.

Hepatocyte Nuclear Factor-1α Increases Fibrinogen Gene Expression in Liver and Plasma Fibrinogen Concentration in Rats with Experimental Chronic Renal Failure.

Chronic kidney disease (CKD) is associated with elevated plasma fibrinogen concentration. However, the underlying molecular mechanism for elevated plasma fibrinogen concentration in CKD patients has not yet been clarified. We recently found that HNF1α was significantly upregulated in the liver of chronic renal failure (CRF) rats, an experimental model of CKD in patients. Given that the promoter region of the fibrinogen gene possesses potential binding sites for HNF1α, we hypothesized that the upregulation of HNF1α can increase fibrinogen gene expression and consequently plasma fibrinogen concentration in the experimental model of CKD. Here, we found the coordinated upregulation of Aα-chain fibrinogen and Hnfα gene expression in the liver and elevated plasma fibrinogen concentrations in CRF rats, compared with pair-fed and control animals. Liver Aα-chain fibrinogen and HNF1α mRNAs levels correlated positively with (a) liver and plasma fibrinogen levels and (b) liver HNF1α protein levels. The positive correlation between (a) liver Aα-chain fibrinogen mRNA level, (b) liver Aα-chain fibrinogen level, and (c) serum markers of renal function suggest that fibrinogen gene transcription is closely related to the progression of kidney disease. Knockdown of Hnfα in the HepG2 cell line by small interfering RNA (siRNA) led to a decrease in fibrinogen mRNA levels. Clofibrate, an anti-lipidemic drug that reduces plasma fibrinogen concentration in humans, decreased both HNF1α and Aα-chain fibrinogen mRNAs levels in (a) the liver of CRF rats and (b) HepG2 cells. The obtained results suggest that (a) an elevated level of liver HNF1α can play an important role in the upregulation of fibrinogen gene expression in the liver of CRF rats, leading to an elevated concentration of plasma fibrinogen, a protein related to the risk of cardiovascular disease in CKD patients, and (b) fibrates can decrease plasma fibrinogen concentration through inhibition of HNF1α gene expression.

The Physiological and Pathological Role of Acyl-CoA Oxidation.

Fatty acid metabolism, including ß-oxidation (ßOX), plays an important role in human physiology and pathology. ßOX is an essential process in the energy metabolism of most human cells. Moreover, ßOX is also the source of acetyl-CoA, the substrate for (a) ketone bodies synthesis, (b) cholesterol synthesis, (c) phase II detoxication, (d) protein acetylation, and (d) the synthesis of many other compounds, including N-acetylglutamate-an important regulator of urea synthesis. This review describes the current knowledge on the importance of the mitochondrial and peroxisomal ßOX in various organs, including the liver, heart, kidney, lung, gastrointestinal tract, peripheral white blood cells, and other cells. In addition, the diseases associated with a disturbance of fatty acid oxidation (FAO) in the liver, heart, kidney, lung, alimentary tract, and other organs or cells are presented. Special attention was paid to abnormalities of FAO in cancer cells and the diseases caused by mutations in gene-encoding enzymes involved in FAO. Finally, issues related to α- and ω- fatty acid oxidation are discussed.

The Role of Acyl-CoA ß-Oxidation in Brain Metabolism and Neurodegenerative Diseases.

This review highlights the complex role of fatty acid ß-oxidation in brain metabolism. It demonstrates the fundamental importance of fatty acid degradation as a fuel in energy balance and as an essential component in lipid homeostasis, brain aging, and neurodegenerative disorders.

Hepatocyte Nuclear Factor 1α Proinflammatory Effect Linked to the Overexpression of Liver Nuclear Factor-κB in Experimental Model of Chronic Kidney Disease.

Chronic kidney disease (CKD) is associated with low-grade inflammation that activates nuclear factor-κB (NF-κB), which upregulates the expression of numerous NF-κB responsive genes, including the genes encoding IL-6, ICAM-1, VCAM-1, and MCP-1. Herein, we found the coordinated overexpression of genes encoding RelA/p65 (a subunit of NF-κB) and HNF1α in the livers of chronic renal failure (CRF) rats-an experimental model of CKD. The coordinated overexpression of RelA/p65 and HNF1α was associated with a significant increase in IL-6, ICAM-1, VCAM-1, and MCP-1 gene expressions. A positive correlation between liver RelA/p65 mRNA levels and a serum concentration of creatinine and BUN suggest that RelA/p65 gene transcription is tightly related to the progression of renal failure. The knockdown of HNF1α in the HepG2 cell line by siRNA led to a decrease in Rel A/p65 mRNA levels. This was associated with a decrease in IL-6, ICAM-1, VCAM-1, and MCP-1 gene expressions. The simultaneous repression of HNF-1α and RelA/p65 by clofibrate is tightly associated with the downregulation of IL-6, ICAM-1, VCAM-1, and MCP-1 gene expression. In conclusion, our findings suggest that NF-κB could be a downstream component of the HNF1α-initiated signaling pathway in the livers of CRF rats.

Dysregulation of the Renin-Angiotensin-Aldosterone System (RAA) in Patients Infected with SARS-CoV-2-Possible Clinical Consequences.

SARS-CoV-2 impairs the renin-angiotensin-aledosterone system via binding ACE2 enzyme. ACE2 plays a key role in the biosynthesis of angiotensin (1-7), catalyzing the conversion of angiotensin 2 into angiotensin (1-7) and the reaction of angiotensin synthesis (1-9), from which angiotensin is (1-7) produced under the influence of ACE (Angiotensin-Converting Enzyme). Angiotensin 2 is a potent vasoconstrictor and atherogenic molecule converted by ACE2 to reducing inflammation and vasodilating in action angiotensin (1-7). Angiotensin (1-9), that is a product of angiotensin 1 metabolism and precursor of angiotensin (1-7), also exerts cell protective properties. Balance between angiotensin 2 and angiotensin (1-7) regulates blood pressure and ACE2 plays a critical role in this balance. ACE2, unlike ACE, is not inhibited by ACE inhibitors at the doses used in humans during the treatment of arterial hypertension. Membrane ACE2 is one of the receptors that allows SARS-CoV-2 to enter the host cells. ACE2 after SARS-CoV-2 binding is internalized and degraded. Hence ACE2 activity on the cell surface is reduced leading to increase the concentration of angiotensin 2 and decrease the concentration of angiotensin (1-7). Disturbed angiotensins metabolism, changes in ratio between angiotensins with distinct biological activities leading to domination of atherogenic angiotensin 2 can increase the damage to the lungs.

The Causes and Potential Injurious Effects of Elevated Serum Leptin Levels in Chronic Kidney Disease Patients.

Leptin is an adipokine that regulates appetite and body mass and has many other pleiotropic functions, including regulating kidney function. Increased evidence shows that chronic kidney disease (CKD) is associated with hyperleptinemia, but the reasons for this phenomenon are not fully understood. In this review, we focused on potential causes of hyperleptinemia in patients with CKD and the effects of elevated serum leptin levels on patient kidney function and cardiovascular risk. The available data indicate that the increased concentration of leptin in the blood of CKD patients may result from both decreased leptin elimination from the circulation by the kidneys (due to renal dysfunction) and increased leptin production by the adipose tissue. The overproduction of leptin by the adipose tissue could result from: (a) hyperinsulinemia; (b) chronic inflammation; and (c) significant lipid disturbances in CKD patients. Elevated leptin in CKD patients may further deteriorate kidney function and lead to increased cardiovascular risk.

The Pathophysiological Role of CoA.

The importance of coenzyme A (CoA) as a carrier of acyl residues in cell metabolism is well understood. Coenzyme A participates in more than 100 different catabolic and anabolic reactions, including those involved in the metabolism of lipids, carbohydrates, proteins, ethanol, bile acids, and xenobiotics. However, much less is known about the importance of the concentration of this cofactor in various cell compartments and the role of altered CoA concentration in various pathologies. Despite continuous research on these issues, the molecular mechanisms in the regulation of the intracellular level of CoA under pathological conditions are still not well understood. This review summarizes the current knowledge of (a) CoA subcellular concentrations; (b) the roles of CoA synthesis and degradation processes; and (c) protein modification by reversible CoA binding to proteins (CoAlation). Particular attention is paid to (a) the roles of changes in the level of CoA under pathological conditions, such as in neurodegenerative diseases, cancer, myopathies, and infectious diseases; and (b) the beneficial effect of CoA and pantethine (which like CoA is finally converted to Pan and cysteamine), used at pharmacological doses for the treatment of hyperlipidemia.

Hepatocyte nuclear factors as possible C-reactive protein transcriptional inducer in the liver and white adipose tissue of rats with experimental chronic renal failure.

Inflammation related to chronic kidney disease (CKD) is an important clinical problem. We recently determined that hepatocyte nuclear factor 1α (HNF1α) was upregulated in the livers of chronic renal failure (CRF) rats-experimental model of CKD. Considering that the promoter region of gene encoding C-reactive protein (CRP) contains binding sites for HNF1α and that the loss-of-function mutation in the Hnfs1α leads to significant reduction in circulating CRP levels, we hypothesized that HNF1α can activate the Crp in CRF rats. Here, we found coordinated upregulation of genes encoding CRP, interleukin-6 (IL-6), HNF1α, and HNF4α in the livers and white adipose tissue (WAT) of CRF rats, as compared to the pair-fed and control animals. This was accompanied by elevated serum levels of CRP and IL-6. CRP and HNFs' mRNA levels correlated positively with CRP and HNFs' protein levels in the liver and WAT. Similar upregulation of the Crp, Il-6, and Hnfs in the liver and WAT and increased serum CRP and IL-6 concentrations were found in lipopolysaccharide (LPS)-induced systemic inflammation in rats. Moreover, silencing HNF1α in HepG2 cells by small interfering RNA led to decrease in CRP mRNA levels. Our results suggests that (a) HNFs act in concert with IL-6 in the upregulation of CRP production by the liver and WAT, leading to an increase in circulating CRP concentration in CRF rats and (b) CRF-related inflammation plays an important role in the upregulation of genes that encode HNFs and CRP in the liver and WAT of CRF rats.

Up-regulation of liver Pcsk9 gene expression as a possible cause of hypercholesterolemia in experimental chronic renal failure.

Dyslipidemia commonly present in patients with chronic kidney disease (CKD) has been recently linked to increased proprotein convertase subtilisin/kexin type 9 (PCSK9) serum concentration. We tested a hypothesis that increased liver PCSK9 biosynthesis could be partially responsible for the elevated circulating PCSK9 level, and subsequently contribute to hypercholesterolemia observed in subjects with CKD. Rat model of chronic renal failure (CRF) was used in the study. Animals underwent a 5/6 nephrectomy or a sham operation. Liver expression of Pcsk9, sterol regulatory element-binding transcription factor 2 (Srebf-2), and ß-actin were quantified by real-time RT-PCR. Liver protein levels of PCSK9, LDL-receptor (LDL-R), and SREBF-2 were analyzed using Western blotting. Serum PCSK9 concentration was estimated by immunoassay. Rats with an experimental CRF as compared to pair-fed and control ones were characterized by: (a) an up-regulation of liver Pcsk9 and Srebf-2 genes expression with parallel increase of serum PCSK9 concentration; (b) a decrease in liver LDL-R protein level, and (c) an increase of serum total and LDL-cholesterol concentrations. We also found significant correlations between serum creatinine and liver PCSK9 mRNA levels (r = 0.88, p < 0.001) and between serum creatinine and circulating PCSK9 levels (r = 0.73, p < 0.001). The results suggest that a rat model of CRF is associated with an increased liver Pcsk9 gene expression. The coordinated up-regulation of Pcsk9 and Srebf-2 genes expression suggests that SREBF-2 may play a key role in regulation of Pcsk9 gene expression, circulating PCSK9 level, and hypercholesterolemia in experimental CRF.

Upregulation of Pnpla2 and Abhd5 and downregulation of G0s2 gene expression in mesenteric white adipose tissue as a potential reason for elevated concentration of circulating NEFA after removal of retroperitoneal, epididymal, and inguinal adipose tissue.

Elevated concentrations of circulating non-esterified fatty acids (NEFA) were reported in (a) humans with lipodystrophy, (b) humans following bariatric surgery, and (c) transgenic mice with reduced amounts of adipose tissue. Paradoxically, these findings suggest that the reduction of adipose tissue mass is associated with elevated circulating NEFA concentrations. To explain a molecular background of this phenomenon, we analyzed the effects of surgical removal of inguinal, epididymal, and retroperitoneal white adipose tissue (WAT) on (a) circulating NEFA concentrations, (b) expression of Pnpla2, a gene that encodes adipose triglyceride lipase (ATGL), genes encoding abhydrolase domain containing 5 (ABHD5) and G0/G1 switch 2 (G0S2), i.e., a coactivator and inhibitor of ATGL, respectively, and (c) expression of Lipe gene coding hormone-sensitive lipase (HSL) in mesenteric WAT. Reduction of adipose tissue mass resulted in an increase in circulating NEFA concentration, which was associated with (a) an increase in the expressions of Pnpla2 and Abhd5, (b) decrease in G0s2 expression, and (c) upregulation of Lipe expression, all measured on both mRNA and protein levels in mesenteric WAT of male rats. The rate of lipolysis in mesenteric WAT explants and isolated adipocytes from lipectomized rats was significantly higher than that from the controls. In conclusion, upregulation of Pnpla2 expression and activation of ATGL (due to an increase in ABHD5 and decrease in G0S2 levels), as well as a coordinated interplay of these genes with Lipe in mesenteric WAT, contribute, at least in part, to an increase in the concentration of circulating NEFA in rats with reduced fat mass.

Up-Regulation Mttp and Apob Gene Expression in Rat Liver is Related to Post-Lipectomy Hypertriglyceridemia.

BACKGROUND/AIMS: The aim of this study was to explain the molecular basis for elevated concentrations of circulating triglycerides (TAGs) after partial surgical removal of adipose tissue (lipectomy) in rats. METHODS: The levels of mRNA and protein: a) involved in synthesis of fatty acids and TAGs; b) participating in TAG-rich lipoproteins assembly and secretion; and c) transcription factors essential for maintaining TAG homeostasis were determined by RT-PCR and Western Blot in the livers of control and lipectomized rats. RESULTS: Partial lipectomy was associated with increase: a) in serum and liver concentration of TAGs, and b) in the liver levels of mRNA of microsomal TAG transfer protein (MTP) and apolipoprotein B-100 (ApoB- 100). These changes were tightly associated with up-regulation of Hnf1a and Hnf4a gene expression in the liver. Lipectomy was also reflected by a significant increase in the expression of genes encoding: a) fatty acid synthase (FASN), b) glycerol 3-phosphate acyltransferase 1 (GPAT1), diacylglycerol acyltransferases 1 and 2 (DGAT1 and DGAT2), c) spot 14 protein (S14) and SREBP-1 in the liver. CONCLUSION: Coordinated up-regulation of Mttp, Apob, Hnf1a, Hnf4a, Fasn, Gpam and Dgat (1 and 2) gene expressions may contribute to the increase in circulating and liver concentrations of TAGs after lipectomy in an experimental rat model.

High serum chemerin level in CKD patients is related to kidney function, but not to its adipose tissue overproduction.

Chemerin is an adipokine modulating inflammatory response and affecting glucose and lipid metabolism. These disturbances are common in CKD. The aim of the study was: (a) to evaluate circulating chemerin level at different stages of CKD; (b) to measure subcutaneous adipose tissue chemerin gene expression; (c) to estimate the efficiency of renal replacement therapy in serum chemerin removal. 187 patients were included into the study: a) 58 patients with CKD; (b) 29 patients on hemodialysis; (c) 20 patients after kidney transplantation. 80 subjects constituted control group. Serum chemerin concentration was estimated by ELISA. The adipose tissue chemerin mRNA level was measured by RT-qPCR. The mean serum chemerin concentration in CKD patients was 70% higher than in the control group (122.9 ± 33.7 vs. 72.6 ± 20.7 ng/mL; p < 0.001) and it negatively correlated with eGFR (r = -0.71, p < 0.001). The equally high plasma chemerin level was found in HD patients and a HD session decreased it markedly (115.7 ± 17.6 vs. 101.5 ± 16.4 ng/mL; p < 0.001). Only successful kidney transplantation allowed it to get down to the values noted in controls (74.8 ± 16.0 vs. 72.6 ± 20.7 ng/mL; n.s.). The level of subcutaneous adipose tissue chemerin mRNA in CKD patients was not different than in patients of the control group. The study demonstrates that elevated serum chemerin concentration in CKD patients: (a) is related to kidney function, but not to increased chemerin production by subcutaneous adipose tissue, and (b) it can be efficiently corrected by hemodialysis treatment and normalized by kidney transplantation.

The relationship between specific Fatty acids of serum lipids and serum high sensitivity C- reactive protein levels in morbidly obese women.

BACKGROUND/AIMS: The fatty acid profile in plasma lipids contributes to the increase of plasma high sensitivity C-reactive protein (hsCRP), a marker of inflammation and predictor of cardiovascular risk. The aim of this study was to examine the relationship between specific fatty acids (FA) of serum lipids and serum hsCRP in morbidly obese woman. METHODS: The study included 16 morbidly obese (mean BMI= 43 ± 2.2 kg/m(2)) non-diabetic woman awaiting bariatric surgery. FA extracted from serum lipids were methylated and analyzed on GC-MS. Commercially available ELISA kits were used to determine the serum inflammatory markers. RESULTS: We demonstrated that total saturated FA (SFA) and total monounsaturated FA (MUFA) of serum lipids were positively correlated with serum hsCRP, whereas both n-3 and n-6 total polyunsaturated FA (PUFA) were negatively correlated with serum hsCRP. Serum interleukin-6 correlated positively with some SFA and MUFA, whereas negatively with some of PUFA. Positive correlation between serum hsCRP and specific SFA and MUFA or negative correlation with PUFA decreased with the increased FA chain length. The number and localization of double bonds also had impact on these correlations. CONCLUSION: Our findings suggest that individual serum lipid FA levels, depending on the length of FA chain, number and the localization of double bonds are distinctly associated with hsCRP in morbidly obese subjects.

Elevated circulating PCSK-9 concentration in renal failure patients is corrected by renal replacement therapy.

BACKGROUND: A high level of circulating PCSK9 binds to the LDL receptor, reduces its cell's surface density and leads to hypercholesterolemia. The aim of this study was to examine the circulating PCSK9 level in patients with kidney disease. METHODS: Out of the patients treated in our Departments we selected: (a) 44 patients with CKD stage 3 and 4 (b) 29 patients with CKD stage 5 on maintenance hemodialysis treatment; and (c) 20 patients after successful renal transplantation. Thirty-four subjects, without CKD formed the control group. Serum biochemical parameters' concentrations were assayed by a certified laboratory. Serum PCSK9 concentration was estimated by a commercially available ELISA kit. RESULTS: The mean serum concentration of PCSK9 in patients with kidney disease was higher than in the control group (238.7 ± 64.5 vs. 536.7 ± 190.4; p < 0.001). A strong negative correlation between serum PCSK9 concentration and eGFR was found (r = -0.66; p < 0.001), as well as between serum concentrations of PCSK9 and total- (r = 0.482; p < 0.05) or LDL-cholesterol (r = 0.533; p < 0.05), but exclusively in patients not receiving statins. The elevated serum concentration of PCSK9 in patients before hemodialysis session declined afterwards, reaching the values observed in patients after kidney transplantation and in the control group. CONCLUSION: The circulating PCSK9 concentration is increased in patients with CKD; however, this is not accompanied by hypercholesterolemia. The positive correlations between PCSK9/TCh and PCSK9/LDL-Ch have been found only in patients not treated with statins. The elevated circulating PCSK9 level is corrected by maintenance hemodialysis treatment and normalized by a successful kidney transplantation.

Toward Reliable Dipole Moments without Single Excitations: The Role of Orbital Rotations and Dynamical Correlation.

The dipole moment is a crucial molecular property linked to a molecular system's bond polarity and overall electronic structure. To that end, the electronic dipole moment, which results from the electron density of a system, is often used to assess the accuracy and reliability of new electronic structure methods. This work analyses electronic dipole moments computed with the pair coupled cluster doubles (pCCD) ansätze and its linearized coupled cluster (pCCD-LCC) corrections using the canonical Hartree-Fock and pCCD-optimized (localized) orbital bases. The accuracy of pCCD-based dipole moments is assessed against experimental and CCSD(T) reference values using relaxed and unrelaxed density matrices and different basis set sizes. Our test set comprises molecules of various bonding patterns and electronic structures, exposing pCCD-based methods to a wide range of electron correlation effects. Additionally, we investigate the performance of pCCD-in-DFT dipole moments of some model complexes. Finally, our work indicates the importance of orbital relaxation in the pCCD model and shows the limitations of the linearized couple cluster corrections in predicting electronic dipole moments of multiple-bonded systems. Most importantly, pCCD with a linearized CCD correction can reproduce the dipole moment surfaces in singly bonded molecules, which are comparable to the multireference ones.

Association between cytosolic glycerol 3-phosphate dehydrogenase gene expression in human subcutaneous adipose tissue and BMI.

BACKGROUND/AIMS: Cytosolic glycerol 3-phosphate dehydrogenase (cGPDH) is a key enzyme providing glycerol 3-phosphate for triacylglycerol synthesis in adipose tissue and is regarded as a marker for adipocyte differentiation. The aim of this study was to test the hypothesis that an increase in cGPDH gene expression in subcutaneous adipose tissue is associated with obesity. METHODS: mRNA levels in human subcutaneous adipose tissue were analysed by Real-Time PCR. RESULTS: We found that human subcutaneous adipose tissue cGPDH activity and cGPDH mRNA level were greater in obese patients than in lean subjects and were positively correlated with BMI and fat mass. Moreover, a strong positive correlation between subcutaneous adipose tissue cGPDH mRNA level and cGPDH activity was found. The data presented here indicates also that PPARγ mRNA level is positively correlated with body mass index and fat mass as well as with adipose tissue cGPDH mRNA level. Moreover, the association between subcutaneous adipose tissue cGPDH mRNA level and fatty acid translocase (FAT/CD36) mRNA level was also observed. CONCLUSION: The obtained results suggest that in comparison to lean subjects the increase in subcutaneous adipose tissue cGPDH gene expression in the obese, is probably the result of adipose tissue expansion during obesity.

U937 variant cells as a model of apoptosis without cell disintegration.

The variant cell line U937V was originally identified by a higher sensitivity to the cytocidal action of tumor necrosis factor alpha (TNFα) than that of its reference cell line, U937. We noticed that a typical morphological feature of dying U937V cells was the lack of cellular disintegration, which contrasts to the formation of apoptotic bodies seen with dying U937 cells. We found that both TNFα, which induces the extrinsic apoptotic pathway, and etoposide (VP-16), which induces the intrinsic apoptotic pathway, stimulated U937V cell death without cell disintegration. In spite of the distinct morphological differences between the U937 and U937V cells, the basic molecular events of apoptosis, such as internucleosomal DNA degradation, phosphatidylserine exposure on the outer leaflet of the plasma membrane, caspase activation and cytochrome c release, were evident in both cell types when stimulated with both types of apoptosis inducer. In the U937V cells, we noted an accelerated release of cytochrome c, an accelerated decrease in mitochondrial membrane potential, and a more pronounced generation of reactive oxygen species compared to the reference cells. We propose that the U937 and U937V cell lines could serve as excellent comparison models for studies on the mechanisms regulating the processes of cellular disintegration during apoptosis, such as blebbing (zeiosis) and apoptotic body formation.

Cellular toxicity of nicotinamide metabolites.

There are almost 100 different substances called uremic toxins. Nicotinamide derivatives are known as new family of uremic toxins. These uremic compounds play a role in an increased oxidative stress and disturbances in cellular repair processes by inhibiting poly (ADP-ribose) polymerase activity. New members of this family were discovered and described. Their toxic properties were a subject of recent studies. This study evaluated the concentration of 4-pyridone-3-carboxamid-1-ß-ribonucleoside-triphosphate (4PYTP) and 4-pyridone-3-carboxamid-1-ß-ribonucleoside-monophosphate (4PYMP) in erythrocytes of patients with chronic renal failure. Serum and red blood cells were collected from chronic renal failure patients on conservative treatment, those treated with hemodialysis, and at different times from those who underwent kidney transplantation. Healthy volunteers served as a control group. Nicotinamide metabolites were determined using liquid chromatography with mass spectrometry based on originally discovered and described method. Three novel compounds were described: 4-pyridone-3-carboxamid-1-ß-ribonucleoside (4PYR), 4PYMP, and 4PYTP. 4PYR concentration was elevated in the serum, whereas 4PYMP and 4PYTP concentrations were augmented in erythrocytes of dialysis patients. Interestingly, concentrations of these compounds were less elevated during the treatment with erythropoietin-stimulating agents (ESAs). After successful kidney transplantation, concentrations of 4PYR and 4PYMP normalized according to the graft function, whereas that of 4PYTP was still elevated. During the incubation of erythrocytes in the presence of 4PYR, concentration of 4PYMP rose very rapidly while that of 4PYTP increased slowly. Therefore, we hypothesized that 4PYR, as a toxic compound, was actively absorbed by erythrocytes and metabolized to the 4PYMP and 4PYTP, which may interfere with function and life span of these cells.

[Metabolic and regulatory function of fatty acid synthase]. / Metaboliczna i regulacyjna rola syntazy kwasów tluszczowych.

Fatty acid synthase (FAS)--enzyme present in many tissues, catalyses synthesis of palmitate from malonyl-CoA, acetyl-CoA and NADPH. The highest activity of FAS was found in lipogenic tissues (liver, adipose tissue) and in mammary gland during lactation. Palmitate serves as a substrate for synthesis of saturated and unsaturated long chain fatty acids. In turn, fatty acids (including palmitate) are substrates for the synthesis of triacylglycerols (mainly in liver and adipose tissue), membrane lipids and lipids which play a regulatory role. In this review we discuss the structure, regulation and role of FAS in lipogenic tissues. Moreover, this review presents the recently postulated role of FAS in: a) synthesis of natural ligands of PPARalpha; b) feeding behavior; c) endothelial NO production; d) protection of cardiomiocytes from pathological calcium influx; and e) diet induced atherosclerosis. Finally, the role of FAS in the growth of malignant cells is discussed.