The impact of nutritional supplementation and resistance training on the health functioning of free-living Chilean elders: results of 18 months of follow-up

Body composition changes and loss of functionality in the elderly are related to substandard diets and progressive sedentariness. The aim of this study was to assess the impact of an 18-mo nutritional supplementation and resistance training program on health functioning of elders. Healthy elders aged > or = 70 y were studied. Half of the subjects received a nutritional supplement. Half of the supplemented and nonsupplemented subjects were randomly assigned to a resistance exercise training program. Every 6 mo, a full assessment was performed. A total of 149 subjects were considered eligible for the study and 98 (31 supplemented and trained, 26 supplemented, 16 trained and 25 without supplementation or training) completed 18 mo of follow-up. Compliance with the supplement was 48%, and trained subjects attended 56% of programmed sessions. Activities of daily living remained constant in the supplemented subjects and decreased in the other groups. Body weight and fat-free mass did not change. Fat mass increased from 22.2 +/- 7.6 to 24.1 +/- 7.7 kg in all groups. Bone mineral density decreased less in both supplemented groups than in the nonsupplemented groups (ANOVA, P < 0.01). Serum cholesterol remained constant in both supplemented groups and in the trained groups, but it increased in the control group (ANOVA, P < 0.05). Upper and lower limb strength, walking capacity and maximal inspiratory pressure increased in trained subjects. In conclusion, patients who were receiving nutritional supplementation and resistance training maintained functionality, bone mineral density and serum cholesterol levels and improved their muscle strength.

Growth inhibition and differentiation induction in murine erythroleukemia cells by 4-hydroxynonenal

4-Hydroxynonenal (HNE) is one of the major end products of lipid peroxidation. Here we show that the exposure of murine erythroleukemia (MEL) cells to 1 microM HNE, for 10.5 h over 2 days, induces a differentiation comparable with that observed in cells exposed to DMSO for the whole experiment (7 days). The exposure of MEL cells for the same length of time demonstrates a higher degree of differentiation in HNE-treated than in DMSO-treated MEL cells. The protooncogene c-myc is down-modulated early, in HNE-induced MEL cells as well as in DMSO-treated cells. However, ornithine decarboxylase gene expression first increases and then decreases, during the lowering of the proliferation rate. These findings indicate that HNE, at a concentration physiologically found in many normal tissues and in the plasma, induces MEL cell differentiation by modulation of specific gene expression.

Effect of bioactive aldehydes on cell proliferation and c-myc expression in HL-60 human leukemic cells

Lipid peroxidation produces several toxic carbonyls, including biologically active aldehydes. In previous studies, we demonstrated that 4-hydroxynonenal (HNE), one of the major products of lipoperoxidation, inhibited growth and c-myc expression in K562 and HL-60 human leukemic cells. In this study, we compared the HNE effects with those of 4-hydroxyoctenal (HOE), 4-hydroxyundecenal (HUE; different lengths of the lipophilic tail), and the analogous aldehydes 2-trans-nonanal (lacking the OH group) and nonenal (lacking the OH group and the trans CC double bond), on HL-60 cell proliferation and c-myc expression. HUE and HOE inhibited growth and c-myc expression in a dose-dependent fashion, with an effectiveness comparable with that of HNE, whereas 2-nonenal and nonanal did not affect these parameters. Our results showed that different aldehydes produced from lipid peroxidation may contribute to growth inhibition by c-myc downregulation and that the molecular features involved seem to be the hydroxy group and the trans CC double bond.

Low serum folate but normal homocysteine levels in patients with atherosclerotic vascular disease and matched healthy controls

Mild hyperhomocysteinemia has been considered a cardiovascular risk factor. However, recent prospective studies have not demonstrated that hyperhomocysteinemia or the underlying genetic defect on methylentetrahydrofolate reductase is associated with a higher risk of coronary or peripheral artery disease. We compared serum homocysteine, folate, and vitamin B(12) levels of patients with coronary and peripheral vascular disease with those of age- and sex-matched healthy individuals. Subjects taking multivitamins, with diabetes mellitus, or serum creatinine levels over 1.5 mg/dL were excluded from the study. Homocysteine was measured by fluorimetric high-performance liquid chromatography. Serum folate and vitamin B(12) levels were measured by an ion-capture method. We studied 32 patients with peripheral vascular disease (10 female), aged 69.6 +/- 11 y, 24 age- and sex-matched control subjects, 52 patients with coronary artery disease (7 female), aged 59.5 +/- 10.4 y, and 42 age- and sex-matched control subjects. Serum homocysteine levels were 11.7 +/- 7.4 and 9.3 +/- 4.5 micromol/L in vascular patients and in the control counterparts, respectively (not significant). The levels for coronary patients and the control counterparts were 9.0 +/- 3.9 and 8.6 +/- 3.6 micromol/L, respectively (not significant). Folate levels were 4.48 +/- 2.42 and 7.14 +/- 4.04 ng/mL in vascular patients and control subjects, respectively (P < 0.02); the levels in coronary patients and control counterparts were 5.15 +/- 1.9 and 6.59 +/- 2.49 ng/mL, respectively (P < 0.01). No differences in vitamin B(12) or tocopherol levels were observed between patients and control subjects. There were no differences in homocysteine levels, but lower serum folate levels were observed when comparing patients with atherosclerotic vascular disease and healthy control subjects.

4-Hydroxynonenal-induced MEL cell differentiation involves PKC activity translocation

4-Hydroxynonenal (HNE) is a highly reactive aldehyde, produced by cellular lipid peroxidation, able to inhibit proliferation and to induce differentiation in MEL cells at concentrations similar to those detected in several normal tissues. Inducer-mediated differentiation of murine erythroleukemia (MEL) cells is a multiple step process characterized by modulation of several genes as well as by a transient increase in the amount of membrane-associated protein kinase C (PKC) activity. Here we demonstrate that a rapid translocation of PKC activity from cytosol to the membranes occurs during the differentiation induced by HNE. When PKC is completely translocated by phorbol-12-myristate-13-acetate (TPA), the degree of HNE-induced MEL cells differentiation is highly decreased. However, if TPA is washed out from the culture medium before the exposition to the aldehyde, HNE gradually resumes its differentiative ability. The incubation of cells with a selective inhibitor of PKC activity, bisindolylmaleimide GF 109203X, partially prevents the HNE-induced differentiation in MEL cells. In conclusion, our results demonstrate that HNE-induced MEL cell differentiation is preceded by a rapid translocation of PKC activity, and that the inhibition of this phenomenon prevents the onset of terminal differentiation.

Effect of 4-hydroxynonenal, a product of lipid peroxidation, on natural cell mediated cytotoxicity

Lipid peroxidation of cell membrane yields a variety of final products whose a quantitatively important component is 4-hydroxynonenal (HNE). Previous studies performed in our laboratory suggest that HNE may play a physiological role in the control of cellular proliferation and/or differentiation. This appears to be further supported by our recent findings showing that pre-treatment of K562 cells with a physiological concentration of HNE leads to a marked reduction of susceptibility of NK cells. The observed regulatory effects of HNE on tumor cell growth and susceptibility to natural immune resistance, led us to try to better understand the immunotoxicological properties of this aldehyde. The present study analyses the effects of HNE on NK-mediated cytotoxicity. Treatment of MNC as effector cells with concentrations of HNE ranging from 0.001 to 1 microM for 1 h, did not produce noticeable effects on NK activity. Therefore, this aldehyde at physiological concentrations is able to differentiate tumor cells and to down-regulate target susceptibility to NK effectors from one side. On the other side, it is not able to modify the efficiency of the NK function. Moreover, HNE concentrations higher than 1 microM showed significant and concentration-dependent inhibition of NK activity. However, this effect is reversible and can be antagonized, at least in part, by treatment of effector cells with HNE in combination with beta-interferon.

Nutritional support in alcoholic cirrhotic patients improves host defenses

BACKGROUND

Malnutrition is usual in patients with alcoholic liver disease and is associated with a poor outcome. Nutritional support decreases nutrition-associated complications.

AIM

To demonstrate that nutritional support in ambulatory alcoholic cirrhotic patients improves host defenses.

METHODS

Thirty-one male outpatients with alcoholic cirrhosis CHILD-PUGH B or C were included. Twenty-five subjects completed six months consuming daily a nutritional supplement (Ensure, 1000 Kcal and 35 g protein), in addition to their regular diet. At entrance and every three months, a clinical assessment, nutritional evaluation and indirect calorimetry were performed. Liver function tests and LPS-induced monocyte production of cytokines, salivary secretory IgA, lactulose/mannitol ratio and breath hydrogen tests were also measured in these intervals. Delayed cutaneous hypersensitivity and IgG and IgM antibody response to endotoxin were assessed at entrance and at the end of the study.

RESULTS

Patients drank 85% of the provided supplement as an average. REE, total body fat and serum albumin increased, basal breath hydrogen decreased and cellular immunity improved significantly during the follow up period (p< or =0.03). All the other parameters remained unchanged throughout the study. Six patients (16.2%) died during the study, five due to upper gastrointestinal bleeding.

CONCLUSION

Nutritional support in alcoholic cirrhotic patients improves nutritional status and cell mediated immunity.

4-Hydroxy-2,3-nonenal as a signal for cell function and differentiation

4-Hydroxy-2,3-nonenal (HNE) is a biologically active aldehydic end product of oxidative decomposition of omega-3 and omega-6 polyunsaturated fatty acids of membrane phospholipids, a process referred to as lipid peroxidation. HNE has been detected in several experimental and clinical conditions in which oxidative stress has been reported to occur and several authors have suggested that HNE and related 4-hydroxy-2,3-alkenals (HAKs) of different chain length may act not only as toxic and mutagenic mediators of oxidative stress-related injury but also as biological signals in normal and pathological conditions. In this paper we will review the literature supporting the concept that HNE and HAKs may act as signal molecules able to modulate biological events such as chemotaxis, signal transduction, gene expression, cell proliferation and cell differentiation.

Inhibition of D1, D2, and A-cyclin expression in HL-60 cells by the lipid peroxydation product 4-hydroxynonenal

4-Hydroxynonenal (HNE), a product of lipid peroxidation, is an highly reactive aldehyde that, at concentration similar to those found in normal cells, blocks proliferation and induces a granulocytic-like differentiation in HL-60 cells. These effects are accompained by a marked increase in the proportion G0/G1 cells. The mechanisms of HNE action were investigated by analyzing the expression of the cyclins and cyclin-dependent protein kinases (CDKs), controlling the cell cycle progression. Data obtained by exposing cells to dimethyl sulfoxide (DMSO) were used for comparison. 4-Hydroxynonenal downregulated both mRNA and protein contents of cyclins D1, D2, and A until 24 h from the treatments, whereas DMSO inhibited cyclin D1 and D2 expression until the end of experiment (2 days) and induces an increase of cyclin A until 1 day. Cyclins B and E, and protein kinase CDK2 and CDK4 expressions were not affected by HNE, whereas DMSO induced an increase of cyclin E, B, and CDK2 from 8 h to 1 day. These data are in agreement with previous results indicating a different time-course of accumulation in G0/G1 phases of cells treated with HNE and DMSO and suggest that the HNE inhibitory effect on proliferation and cell cycle progression may depend by the downregulation of D1, D2, and A cyclin expression.

[Nutritional status and energy expenditure in elders of differing socioeconomic level]

BACKGROUND

Income and socioeconomic status can influence nutritional status of individuals. Since elders are a more vulnerable group to nutritional deficiencies, socioeconomic status could have a special relevance on nutrition of elderly people.

AIM

To assess the influence of socioeconomic status on the nutritional status of elders.

MATERIAL AND METHODS

Elders of both sexes of high socioeconomic level and age and sex matched elders of low socioeconomic status were studied. Anthropometry, body composition using double beam X ray absorptiometry, resting energy expenditure using an open circuit indirect calorimeter, routine biochemistry, blood levels of folic acid, vitamin B12 and homocysteine were measured in all subjects.

RESULTS

Fourteen female elders of high socioeconomic level, 14 females of low level and 12 males of each level were studied. Mean age of females and males was 71.5 +/- 3.7 and 73.9 +/- 4.2 years old respectively. Males and females of high socioeconomic status were taller than their counterparts of low status. Females of high socioeconomic status had a lower body mass index than their pairs of low status (26.3 +/- 3.8 and 30.2 +/- 5.6 kg/m2 respectively p < 0.02). Men of high economic status had a higher fat mass than their pairs of low level (20.3 +/- 3.5 and 15.1 +/- 5.5 kg respectively, p < 0.005). No differences in resting energy expenditure in women of differing socioeconomic level were observed. Men of high level had a higher energy expenditure that their counterparts of low level (36.0 +/- 4.9 and 32.8 +/- 2.2 Kcal/kg lean body mass/day respectively, p < 0.02). Low level male elders had higher serum total cholesterol and triglycerides. Folic acid, vitamin B12 and homocysteine levels were within normal limits. Dietary intake showed deficiencies in calorie, protein and vitamin intake in all subjects.

CONCLUSIONS

In this group of elders, low socioeconomic level did not produce a significant impact on nutritional status.

4-Hydroxy-2,3-nonenal as a signal for cell function and differentiation

4-Hydroxy-2,3-nonenal (HNE) is a biologically active aldehydic end product of oxidative decomposition of omega-3 and omega-6 polyunsaturated fatty acids of membrane phospholipids, a process referred to as lipid peroxidation. HNE has been detected in several experimental and clinical conditions in which oxidative stress has been reported to occur and several authors have suggested that HNE and related 4-hydroxy-2,3-alkenals (HAKs) of different chain length may act not only as toxic and mutagenic mediators of oxidative stress-related injury but also as biological signals in normal and pathological conditions. In this paper we will review the literature supporting the concept that HNE and HAKs may act as signal molecules able to modulate biological events such as chemotaxis, signal transduction, gene expression, cell proliferation and cell differentiation.

4-Hydroxynonenal as a biological signal: molecular basis and pathophysiological implications

Reactive oxygen intermediates (ROI) and other pro-oxidant agents are known to elicit, in vivo and in vitro, oxidative decomposition of omega-3 and omega-6 polyunsaturated fatty acids of membrane phospholipids (i.e, lipid peroxidation). This leads to the formation of a complex mixture of aldehydic end-products, including malonyldialdehyde (MDA), 4-hydroxy-2,3-nonenal (HNE), and other 4-hydroxy-2,3-alkenals (HAKs) of different chain length. These aldehydic molecules have been considered originally as ultimate mediators of toxic effects elicited by oxidative stress occurring in biological material. Experimental and clinical evidence coming from different laboratories now suggests that HNE and HAKs can also act as bioactive molecules in either physiological and pathological conditions. These aldehydic compounds can affect and modulate, at very low and nontoxic concentrations, several cell functions, including signal transduction, gene expression, cell proliferation, and, more generally, the response of the target cell(s). In this review article, we would like to offer an up-to-date review on this particular aspect of oxidative stress--dependent modulation of cellular functions-as well as to offer comments on the related pathophysiological implications, with special reference to human conditions of disease.

Effect of 4-hydroxynonenal, a product of lipid peroxidation, on NK susceptibility of human K562 target cells

4-Hydroxynonenal (HNE) is one of the major breakdown products generated by lipid peroxidation of cellular membranes. The level of lipid peroxidation and the concentration of its products are inversely related to the rate of cell proliferation and directly related to the level of cell differentiation. It has been reported that HNE inhibits DNA synthesis, ornithine decarboxylase (ODC) activity and c-myc expression in different leukemic cells lines. It has also been demonstrated that HNE inhibits proliferation and induces differentiation in HL60 cell line. In the present study the effects of HNE, at concentrations close to those found in the normal tissues, on the NK susceptibility of human K562 target cells were analyzed. Repeated treatments at 45 minutes intervals with 1 microM HNE were performed to maintain the cells in the presence of the aldehyde for 12 hours. The effect of HNE was compared with that obtained in Haemin-treated cells. HNE causes a strong inhibition of cells growth (53% vs. 34% with Haemin) without affecting cell viability. We further investigated the NK susceptibility of K562 cell line upon in vitro treatment with HNE. Cytotoxic activity of mononuclear cells (MNC) from peripheral blood of healthy donors was determined by 4 hours Cr51-release assay. The results obtained, expressed in terms of percentage of specific lysis at different E:T ratios and in terms of KC (10(6)) at the E:T ratio of 50:1, show that HNE treatment of K562 cells leads to a marked reduction of susceptibility to NK cells; this decrease is very close to that found in the K562 cells treated with Haemin used as inducer. Similar results were obtained using MNC pre-treated with beta-interferon (IFN) as effector cells. MNC show a reduced capacity to lyse HNE-treated cells also under the enhancing cytolytic effect of IFN. These results are in line with data obtained with several common inducers of differentiation such as DMSO, retinoic acid or others.

[Quality control of bone densitometry: precision, reproducibility, and clinical application]

Dual energy x-ray absorptiometry (DEXA) is one of the most widely used methods for bone mineral density (BMD), total body mass (TBM), total body fat (TBF), percentage of total body fat (%TBF) and total body fat-free mass (TBFFM) measurements. We investigated the in vitro and in vivo accuracy and precision of DEXA in repeated measurements of a lumbar spine phantom and in 30 healthy volunteers. Based on precision, the minimal significant variability (MSV) at 95% confidence level between 2 measurements of the same object or subject was calculated. In vitro accuracy and MSV were 99.8 and 0.9% respectively. In vivo indexes were 99.4 and 0.9% for whole-body BMD, 98.6 and 2% for lumbar spine BMD, 96.6 and 4.8% for femoral neck BMD, 98 and 2.8% for major trochanter BMD, 96 and 5.7% for Ward's triangle BMD, 99.5 and 0.7% for TBM, 98 and 2.9% for TBF, 97.9 and 3% for %TBF and 99 and 1.4% for TBFFM. Our findings indicate that DEXA is a very reliable instrument and in order to be 95% confident of a real change between 2 scans a difference of at least the calculated MSV must be measured.

4-hydroxynonenal specifically inhibits c-myb but does not affect c-fos expressions in HL-60 cells

4-Hydroxynonenal, an aldehyde produced from lipid peroxidation of cellular membranes, inhibits growth and induces differentiation of HL-60 human leukemic cell line. Since it is highly unstable in the culture medium, its effectiveness is increased when added repeatedly to the cell suspension. We have previously demonstrated that HNE inhibits c-myc but not N-ras expression in HL-60 cells. Here we investigate its effect on the expression of c-myb and c-fos, two early genes involved in the induction of myeloid and monocytic differentiation. Moreover, since c-fos is directly correlated with the intracellular level of cAMP, we also analysed the cAMP concentration after aldehyde treatment. HNE significantly inhibits c-myb expression during and after repeated treatments. A single administration of 1 microM HNE decreases c-myb mRNA at 1 hour whereas 10 microM HNE inhibits c-myb expression from 3 to 6 hours after treatment, and then the expression returns to the control level. By contrast, c-fos expression and intracellular cAMP concentration do not show any significant change after HNE treatments.

Enzymatic pattern of aldehyde metabolism during HL-60 cell differentiation

A number of metabolic changes, including modification of different enzyme activities, are linked to the acquisition of differentiated phenotype in HL-60 cells. Enzymes metabolizing aldehydes contribute to maintaining the intracellular steady-state concentration of aldehydes derived from lipid peroxidation. 4-Hydroxynonenal is one of the most important aldehydes produced by this process, and it is able to inhibit proliferation and induce differentiation of HL-60 human leukemic cells. We have now demonstrated that, after induction of HL-60 cell differentiation by 4-hydroxynonenal or DMSO, glutathione transferase activity increases in parallel to the degree of differentiation induction. Moreover, in 4-hydroxynonenal- or DMSO-treated cells, the concentration of reduced glutathione decreases five days after treatment. The rise of glutathione transferase activity, as well as the decrease of reduced glutathione, are possibly linked to the increase of detoxification capability of differentiated cells.

Effect of 4-Hydroxynonenal on cell cycle progression and expression of differentiation-associated antigens in HL-60 cells

4-Hydroxynonenal (HNE) is a highly reactive aldehyde produced by lipid peroxidation of cellular membranes that inhibits growth and induces differentiation in HL-60 cells. Its mechanisms of action were investigated by analyzing the cell cycle distribution and the appearance of differentiated phenotypes in HL-60 cells. Data obtained by exposing cells to DMSO for 7.5 h (same time as for HNE treatment) or for the whole length of the experiments (5 d) were used for comparison. HNE induced a marked increase in the proportion of G0/G1 cells after 1 and 2 d. The brief DMSO treatment did not affect the distribution, whereas continuous exposure led to a progressive accumulation of cells in G0/G1 (maximal at day 5). The proportion of phagocytic cells gradually increased in HNE-treated and DMSO long-exposed cultures from day 2 and peaked at day 5 (35 and 63%, respectively), whereas the effect of the brief DMSO treatment was negligible. The expression of CD11b and CD67 increased in cells treated with HNE or continuously exposed to DMSO, whereas CD36 was expressed at low levels on both treatments. These results indicate that the pathway of the granulocytic differentiation induced by HNE in HL-60 cells differs from that of DMSO: with HNE, growth inhibition precedes the onset of differentiation, whereas in DMSO-treated cells the two processes are chronologically associated.

Protein quality and urea kinetics in prepubertal Chilean schoolboys

Urea kinetics were measured non-invasively in 12 Chilean schoolboys aged 8-10 years who were receiving one of two diets, either predominantly animal protein or predominantly vegetable protein. Both the diets provided an equivalent level of gross protein, 1.2 g/kg/day. The study diets were given for 10 days to enable adaptation to take place. On the eighth day a single oral dose of 15N15N-urea, 100 mg, was given and the amount of label excreted as 15N15-urea in urine over the subsequent 48 hours was measured. There was little difference in any aspect of urea kinetics between the two diets with urea production (animal, 173 +/- 50 mgN/kg/day; vegetable 179 +/- 53 mgN/kg/day), urea excretion (animal, 86 +/- 19 mgN/kg/day; vegetable, 105 +/- 13 mgN/kg/day), urea nitrogen hydrolysis (animal, 87 +/- 49 mgN/kg/day; vegetable, 74 +/- 42 mgN/kg/day), and the salvaged urea-nitrogen derived from hydrolysis which returned to urea formation (animal, 12 +/- 5 mgN/kg/day; vegetable, 17 +/- 9 mgN/kg/day) all being similar. A very high proportion of the salvage nitrogen derived from urea hydrolysis was maintained within the metabolic pool, about 80%, which was equivalent to 0.4 g protein/kg/day. This is the first time urea kinetics have been measured in children of this age and shows that 57% of the ura produced is excreted in urine on average with about 43% of the urea-nitrogen being salvaged for further metabolic interaction. It is concluded that the vegetable based protein diet taken habitually by Chilean children is metabolically equivalent in terms of urea kinetics to a diet based upon animal protein at this level of intake, but that high rates of salvage of urea nitrogen are found on both diets.

[Biological quality of a milk substitute for school children based on refined flour subjected to enzymatic hydrolysis]

The biological quality of an experimental milk substitute based on a raw wheat flour subjected to enzymatic hydrolysis in comparison to a control product based on extruded flours and milk protein was studied in 35 <<healthy>> female school age children. The girls were fed their customary diet during 2 consecutive 14 and 12 day periods, and randomized to the experimental and control products in a double blind crossover fashion. Apparent absorption of protein, energy, calcium and phosphorus was evaluated. Mean nitrogen intake from the experimental product was significantly lower (223 vs 244 mg/Kg/d p<0.0001). Absorbed nitrogen was also lower (187 vs 203 mg&kg/d p<0.0001). Energy intake and excretion were similar with both products; 96 and 95% of intake was absorbed for experimental and control products respectively. The mean calcium intake was significantly lower than the experimental product (39.7 vs 60.2 mg/kg/d p<0.0001). Absorbed calcium from the experimental product was 50% of control (20.7 vs. 39.5 mg/Kg/d p<0.0001). Phosphorus intake was also lower with the experimental product relative to control (22.0 vs 27.8 mg/Kg/d p<0.0001) and absorbed P was 13.1 vs 16.5 mg/Kg/d respectively. Both products were well tolerated. We conclude that the experimental product based on wheat flour does not differ significantly in protein and energy digestibility but calcium and phosphorus absorption and digestibility are significantly lower limiting its use in school feeding programs.

Inhibition of c-myc expression induced by 4-hydroxynonenal, a product of lipid peroxidation, in the HL-60 human leukemic cell line

4-Hydroxynonenal is a highly reactive aldehyde, produced by cellular lipid peroxidation, able to inhibit cell proliferation "in vitro" and "in vivo". Its concentration in non proliferating cells ranges up to 1 microM, whereas in the highly undifferentiated tumour cells, it is very low or undetectable. We have now demonstrated that micromolar concentrations of 4-hydroxynonenal inhibit c-myc but not N-ras expression in HL-60 human leukemic cells. This inhibitory effect is observed after an incubation of 1 hour with both 1 and 10 microM aldehyde. Moreover, we report that down-regulation of c-myc expression increases when repeated additions of 1 microM 4-hydroxynonenal are performed, to maintain the cells in presence of aldehyde for 7.5 hours. These results indicate that not only the concentration but also the length of exposure to the aldehyde is important in determining the extent of the c-myc expression inhibition and suggest a role of lipid peroxidation products in the control of gene expression.

Control of neoplastic cell proliferation and differentiation by restoration of 4-hydroxynonenal physiological concentrations

Several studies point to the existence of an inverse correlation between cellular lipid peroxidation and both cell proliferation and neoplastic transformation. In anaplastic cell lines products of membrane lipid peroxidation are very low or undetectable. Furthermore numerous results demonstrate effect of lipid peroxidation products on central biochemical pathways and intracellular signalling at physiological concentrations. 4-hydroxynonenal (HNE) is one of the most active products of lipid peroxidation. The restoration of HNE physiological concentrations in neoplastic cells may inhibit cell proliferation and modulate cell re-differentiation. This review try to summarize and critically discuss the effects of physiological concentrations of HNE on normal and neoplastic cell line.

Sweet lupin protein quality in young men

The protein quality of Lupinus albus cv Multolupa was evaluated in young adult males using the nitrogen balance technique at graded levels of N intake, and compared with egg protein. Lupin protein was consumed at levels of 0.4, 0.6 and 0.8 g/(kg.d) and egg protein at 0.3, 0.45 and 0.6 g/(kg.d). Each period started with 1 d of consuming a protein-free diet; the next 6 d were used as adaptation and the last 4 d for balance. The levels of protein intake were randomly assigned by a modified Latin square. Energy intake was individually adjusted. Mean apparent N digestibility values of lupin protein were 78.8, 76.1 and 70.2% for the levels of 0.8, 0.6 and 0.4 g protein(kg.d), respectively, and 83.8, 78.3 and 67.1% for egg protein consumed at levels of 0.6, 0.45 and 0.3 g protein/(kg.d), respectively. The N balance results obtained when subjects consumed lupin were 16.4, 0.2 and -15.1 mg N/(kg.d) for protein intakes of 0.8, 0.6 and 0.4 g/(kg.d), respectively. Those obtained for egg consumption were 12.6, -3.6 and -17.1 mg N/(kg.d) for protein intakes of 0.6, 0.45 and 0.3 g/(kg.d), respectively. The linear regressions of intake and absorbed N to retained N for lupin were: N retained = -43.41 + 0.50 N intake and N retained = -36.30 + 0.53 N absorbed. The corresponding regressions for egg were: N retained = -45.0 + 0.65 N intake and N retained = -30.65 + 0.58 N absorbed. The net protein utilization of lupin was 77% that of egg protein.

4-Hydroxynonenal, a product of cellular lipid peroxidation, which modulates c-myc and globin gene expression in K562 erythroleukemic cells

Several studies point to the existence of an inverse correlation between cellular lipid peroxidation and both cell proliferation and neoplastic transformation. Here, we show that 4-hydroxynonenal (HNE) concentrations close to the level found in normal cells (in the range of 1 and 3 microM) can specifically induce changes in the expression of c-myc and gamma-globin mRNA in K562 cells, without inducing any toxic effects or affecting cell viability. Since we have determined that K562 cells have undetectable levels of endogenous lipid peroxidation, all these effects can be assigned to the exogenous HNE treatment. After a 1-h treatment with 1 microM HNE, c-myc mRNA levels decrease transiently during the first 4 h, rebounding later to higher levels, and normalizing to basal expression after 4 days. Run-on experiments show a transient transcriptional block 20 min after HNE treatment and subsequent posttranscriptional regulation. According to S1 mapping, mRNA changes are exerted on c-myc transcripts initiated from both the principal constitutive start sites (P1 and P2). gamma-Globin mRNA levels concomitantly increase 3- to 4-fold, but no significant changes of housekeeping gene expression are observed. On the basis of these results it appears that the restoration in human erythroleukemic K562 cells of HNE concentrations closer to the level in normal cells can modulate the expression of specific genes.

Vitamin E dietary supplementation inhibits transforming growth factor beta 1 gene expression in the rat liver

Overexpression of transforming growth factor beta 1 (TGF beta 1) and increased transcription of pro-collagen type I, are known to represent major events implicated in the development of liver fibrosis under either experimental or clinical conditions. Here we report that long-term dietary vitamin E supplementation in animals undergoing an experimental model of liver fibrosis (induced by chronic treatment of rats with carbon tetrachloride) results in a net inhibition of both hepatic TGF beta 1 and alpha 2 (I) procollagen mRNA levels. Moreover, of striking interest is the observation that vitamin E supplementation per so down-modulates basal levels of TGF beta 1 mRNA in the liver of untreated animals, suggesting that a dietary regimen rich in vitamin E may potentially interfere with both the initiation and progression of the fibrosclerotic processes.