Still-face effect in domestic dogs: comparing untrained with trained and animal assisted interventions dogs

The still-face effect has been extensively studied in human infants and comprises the reduction in affiliative behaviors and increased stress that occurs after a sudden interruption of social interaction with a caregiver. Domestic dogs (Canis familiaris) are model candidates for showing this effect, as they form deep bonds with their owners and interspecific social interaction is reinforcing to them. The aim of these studies was to assess if companion dogs exhibit the still-face effect and whether prior experiences during ontogeny modulate this effect. To this end, Study 1 compared dogs with different levels of training (untrained, intermediate, and advanced), while Study 2 assessed dogs that participated in Animal Assisted Interventions (AAIs) and companion dogs (CDs). The procedure was carried out virtually and comprised three phases lasting 1 min: interaction, still-face (the owner turned suddenly indifferent), and reunion (the interaction was resumed). Dogs exhibited a decrease in proximity to and contact with the owner, as well as an increase in begging and stress behaviors during the still-face phase. Moreover, this was not observed in a control condition in which the interaction continued in the same way during all three phases, discarding alternative explanations for these changes. These results show that dogs experience a still-face effect in a similar way to infants, highlighting the value interspecific social interaction has for dogs. Nevertheless, the absence of differences according to their training level or participation in AAIs suggests this is a robust phenomenon, which appears to be less susceptible to the influences of ontogenetic experiences.

Low-dose curcuminoid-loaded in dextran nanobubbles can prevent metastatic spreading in prostate cancer cells

Preventing recurrences and metastasis of prostate cancer after prostatectomy by administering adjuvant therapies is quite a controversial issue. In addition to effectiveness, absence of side effects and long term toxicity are mandatory. Curcuminoids (Curc) extracted with innovative techniques and effectively loaded by polymeric nanobubbles (Curc-NBs) satisfy such requirements. Curc-NBs showed stable over 30 d, were effectively internalized by tumor cells and were able to slowly release Curc in a sustained way. Significant biological effects were detected in PC-3 and DU-145 cell lines where Curc-NBs were able to inhibit adhesion and migration, to promote cell apoptosis and to affect cell viability and colony-forming capacity in a dose-dependent manner. Since the favourable effects are already detectable at very low doses, which can be reached at a clinical level, the actual drug concentration can be visualized and monitored by US or MRI, Curc-NBs can be proposed as an effective adjuvant theranostic tool.

Magnetization switching in high-density magnetic nanodots by a fine-tune sputtering process on a large-area diblock copolymer mask

Ordered magnetic nanodot arrays with extremely high density provide unique properties to the growing field of nanotechnology. To overcome the size limitations of conventional lithography, a fine-tuned sputtering deposition process on mesoporous polymeric template fabricated by diblock copolymer self-assembly is herein proposed to fabricate uniform and densely spaced nanometer-scale magnetic dot arrays. This process was successfully exploited to pattern, over a large area, sputtered Ni₈₀Fe₂₀ and Co thin films with thicknesses of 10 and 13 nm, respectively. Carefully tuned sputter-etching at a suitable glancing angle was performed to selectively remove the magnetic material deposited on top of the polymeric template, producing nanodot arrays (dot diameter about 17 nm). A detailed study of magnetization reversal at room temperature as a function of sputter-etching time, together with morphology investigations, was performed to confirm the synthesis of long-range ordered arrays displaying functional magnetic properties. Magnetic hysteresis loops of the obtained nanodot arrays were measured at different temperatures and interpreted via micromagnetic simulations to explore the role of dipole-dipole magnetostatic interactions between dots and the effect of magnetocrystalline anisotropy. The agreement between measurements and numerical modelling results indicates the use of the proposed synthesis technique as an innovative process in the design of large-area nanoscale arrays of functional magnetic elements.

Is previous experience important for inhibitory control? A comparison between shelter and pet dogs in A-not-B and cylinder tasks

This study compares the performance of two groups of dogs with different levels of social interaction with humans, shelter and pet dogs, in two inhibitory control tasks. (1) In the A-not-B task, dogs were required to resist searching for food in a previously rewarded location, and (2) in the cylinder task, dogs were required to resist approaching visible food directly in favor of a detour reaching response. Our first aim was to evaluate the importance of learning and ontogeny in performing inhibitory tasks. Also, we assessed whether there is a correlation between the two tasks by comparing performance in the same subjects. Results showed significant differences between shelter and pet dogs in the A-not-B task, with poorer performance in shelter dogs. However, no differences were found in the cylinder task. The poorer performance of shelter dogs might be related to their infrequent interaction with humans, which reduces the chances to learn to inhibit certain behaviors. This result would highlight the importance of ontogeny in developing that ability. On the other hand, no correlations were found between the two tasks, which contributes information to the debate about the context specificity of inhibitory control in dogs.

Premature loss of muscle mass and function in type 2 diabetes

INTRODUCTION

Muscle mass and function are among the most relevant factors that contribute to an optimal quality of life, and are strong predictors of mortality in the elderly. Loss of lean tissues and deterioration of muscle function have been described as one of the many complications of type 2 diabetes mellitus (DM2), but most studies do not isolate age as an intervening factor.

AIM

To study whether adult DM2 patients up to 60years of age have decreased muscle mass and function compared with healthy non-diabetic (ND) subjects of similar age.

METHODOLOGY

Appendicular fat-free mass (ApFFM) by dual X-ray absorptiometry (DEXA), handgrip strength (HS), quadriceps strength (QS), 12 min walking capacity (12MW) and the Timed Up and Go test (TUG) were measured in 100 DM2 patients and 39 ND controls. Muscle quality, or the ratio between lean mass and muscle strength of upper and lower limbs, and the functional limitations associated with pain and stiffness assessed according to the Western Ontario and McMaster Universities Arthrosis Index (WOMAC) were also recorded. Specific tests were performed to rule out microvascular diabetic complications (retinal and peripheral nerves), metabolic control, kidney function and vitamin D status and examine their association with ApFFM and function.

RESULTS

ApFFM was significantly higher among DM2 female patients and lower among diabetic men. However opposite results were obtained when individual values were corrected for body mass index (BMI), specifically among women, who were more likely to be obese. As for muscle strength and global functionality tests, significantly better performances in TUG, 12MW, QS and HS were observed among ND subjects of both sexes. These differences prevailed even after excluding diabetic patients with microvascular complications as well as those with more than 10years of diabetes. Muscle quality was also significantly better among ND women. Higher scores of pain and stiffness in the WOMAC scale correlated with 12MW and TUG in both groups but did not correlate with ApFFM.

CONCLUSIONS

We found a clear deterioration of lean mass and muscle functions among adult DM2 patients of up to 60years old, independent of length of disease, metabolic control, vitamin D status and presence of microvascular complications and pain.

Tolerance to delayed reward tasks in social and non-social contexts

Domestic dogs have demonstrated striking social skills towards humans, however, there are few studies investigating impulsivity with delay-choice tasks in communicative contexts. In Study 1 we introduced a novel social delay-choice task in which subjects had to choose between one human cueing an immediate, low quality reward and another human signaling a delayed, high quality reward. In Study 2 we evaluated the tolerance to increasing delays using social and non-social cues. We also explored if more self-controlled dogs show any distinct behaviours during delays. Finally, we correlated all results with the Dog Impulsivity Assessment Scale (Wright et al., 2011). In Study 1 dogs reached an average maximum delay of 11.55s. In Study 2 that average was 52.14s with social cues and 40.2s with non-social, but differences were not significant. Tolerance to delays showed high interindividual variation. Dogs remained mostly standing and near the delayed experimenter in the social tasks although we could not to find any distinct coping strategies. No significant correlations were found between the delay reached and behaviours, neither with the scale. These results show the relevance of the parameters and methods used to investigate tolerance to delay of reinforcements. More investigations are required, especially an assessment of the same subjects performing the same tasks using different contexts.

YAP activation protects urothelial cell carcinoma from treatment-induced DNA damage

Current standard of care for muscle-invasive urothelial cell carcinoma (UCC) is surgery along with perioperative platinum-based chemotherapy. UCC is sensitive to cisplatin-based regimens, but acquired resistance eventually occurs, and a subset of tumors is intrinsically resistant. Thus, there is an unmet need for new therapeutic approaches to target chemotherapy-resistant UCC. Yes-associated protein (YAP) is a transcriptional co-activator that has been associated with bladder cancer progression and cisplatin resistance in ovarian cancer. In contrast, YAP has been shown to induce DNA damage associated apoptosis in non-small cell lung carcinoma. However, no data have been reported on the YAP role in UCC chemo-resistance. Thus, we have investigated the potential dichotomous role of YAP in UCC response to chemotherapy utilizing two patient-derived xenograft models recently established. Constitutive expression and activation of YAP inversely correlated with in vitro and in vivo cisplatin sensitivity. YAP overexpression protected while YAP knock-down sensitized UCC cells to chemotherapy and radiation effects via increased accumulation of DNA damage and apoptosis. Furthermore, pharmacological YAP inhibition with verteporfin inhibited tumor cell proliferation and restored sensitivity to cisplatin. In addition, nuclear YAP expression was associated with poor outcome in UCC patients who received perioperative chemotherapy. In conclusion, these results suggest that YAP activation exerts a protective role and represents a pharmacological target to enhance the anti-tumor effects of DNA damaging modalities in the treatment of UCC.

Skeletal muscle ceramide species in men with abdominal obesity

BACKGROUND

Obesity is a risk factor for diabetes and its consequences, including accelerated ageing and mortality. The underlying factor could be accumulation of certain lipid moieties, such as ceramides (CER) and diacylgycerol (DAG) within muscle tissue, which are known to promote insulin resistance (IR), induce inflammation and oxidative injury, ultimately altering muscle function.

AIM

First, to study the relationship between body composition and age (independent variables) with skeletal muscle accumulation of lipid species, oxidative injury and strength. Second, to analyze the relationship between muscle tissue metabolites and insulin resistance, inflammation and lymphocyte telomere length, the latter as an indicator of ageing.

METHODOLOGY

The sample included 56 healthy sedentary males, scheduled for inguinal hernia surgery, aged 27 to 80 y. Each individual was subject to anthropometric measurements, body composition assessment through radiologic densitometry (DEXA), measurement of handgrip and quadriceps strength, serum biochemical parameters (lipoproteins, creatinine, high sensitivity C reactive protein [hsCRP], fasting and post glucose insulin and glucose concentrations for calculation of IR through the Matsuda and HOMA-IR indexes), and extraction of peripheral leukocytes for measurement of telomere length. During the surgical procedure, a sample of muscle tissue was obtained (anterior abdominal oblique) in order to measure CER and DAG (and sub species according to chain length and saturation) by mass spectrometry, 4 hydroxy-2-nonenal adducts (4-HNE) using electron microscopy immunohistochemistry, and carboxymethyl-lisine (CML) by immunohistochemistry, the latter as indicators of oxidative stress (OS).

RESULTS

Body mass index (BMI) of twenty six individuals was > 25 k/m2, while BMI of 7 was > 30 k/m2. Overweight/obese individuals, did not exhibit differences in skeletal muscle lipid metabolites, however total CER and specific long chain CER sub-species (20 and 22 carbon) increased significantly among individuals with a central fat distribution (n = 14) as well as in glucose intolerant subjects (n =23). A negative association was found between mononuclear leukocyte telomere length and 20 and 22 carbon CER (rho = - 0.4 and -0.5 0 p < 0.05). Muscle strength was not associated with any of the measured muscle metabolites or markers of OS. A multiple regression analysis accepted central abdominal fat and telomere length as significant predictors of CER (R2 = 0.28).

CONCLUSIONS

An association was found between accumulation of specific ceramide species in muscle tissue and abdominal obesity, glucose intolerance and shortening of leukocyte telomeres, although not with muscle oxidative injury or dysfunction.

Solid lipid nanoparticles of cholesteryl butyrate inhibit the proliferation of cancer cells in vitro and in vivo models

BACKGROUND AND PURPOSE

Solid lipid nanoparticles containing cholesteryl butyrate (cholbut SLN) can be a delivery system for the anti-cancer drug butyrate. These nanoparticles inhibit adhesion of polymorphonuclear and tumour cells to endothelial cells and migration of tumour cells, suggesting that they may act as anti-inflammatory and anti-tumour agents. Here we have evaluated the effects of cholbut SLN on tumour cell growth using in vitro and in vivo models.

EXPERIMENTAL APPROACH

Cholbut SLNs were incubated with cultures of four tumour cell lines, and cell growth was analysed by assessing viability, clonogenic capacity and cell cycle. Effects on intracellular signalling was assessed by Western blot analysis of Akt expression. The in vivo anti-tumour activity was measured in two models of PC-3 cell xenografts in SCID/Beige mice.

KEY RESULTS

Cholbut SLN inhibited tumour cell line viability, clonogenic activity, Akt phosphorylation and cell cycle progression. In mice injected i.v. with PC3-Luc cells and treated with cholbut SLN, . in vivo optical imaging and histological analysis showed no metastases in the lungs of the treated mice. In another set of mice injected s.c. with PC-3 cells and treated with cholbut SLN when the tumour diameter reached 2 mm, analysis of the tumour dimensions showed that treatment with cholbut SLN substantially delayed tumour growth.

CONCLUSION AND IMPLICATIONS

Cholbut SLN were effective in inhibiting tumour growth in vitro and in vivo. These effects may involve, in part, inhibition of Akt phosphorylation, which adds another mechanism to the activity of this multipotent drug.

Dietary intake increases serum levels of carboxymethil-lysine (CML) in diabetic patients

INTRODUCTION

Advanced glycation end products are produced endogenously, in association with hyperglycemia and oxidative stress. They can also be generated during cooking or food processing and, once absorbed, alter protein function and promote inflammation.

METHODS

We selected 40 healthy male subjects, 17 patients with type 2 diabetes of both sexes and 15 patients with type 1 diabetes of both sexes. Each participant underwent both a food frequency questionnaire (FFQ) and 24-hour dietary recall specially adapted for measuring CML intake, anthropometry, measurement of blood pressure and biochemical parameters in blood and urine.

RESULTS

Serum CML levels were significantly higher in patients with diabetes compared to healthy subjects (p 0.04), showing a direct relationship between dietary intake and serum levels of CML in T2D patients (r 0.53 p 0.03). sCML levels correlated positively with length of diabetes mellitus, and inversely with body mass index (BMI). The most important dietary factor contributing to raise CML levels in these patients with diabetes was the consumption of milk powder.

CONCLUSION

Serum levels of CML were found to be higher among diabetic subjects, associated to length of diabetes as expected, but also with the ingestion of foods containing higher amounts of ML. The consumption of milk powder in this group is a major determinant of increased serum levels.

Cholesteryl butyrate solid lipid nanoparticles inhibit the adhesion and migration of colon cancer cells

BACKGROUND AND PURPOSE Cholesteryl butyrate solid lipid nanoparticles (cholbut SLN) provide a delivery system for the anti-cancer drug butyrate. These SLN inhibit the adhesion of polymorphonuclear cells to the endothelium and may act as anti-inflammatory agents. As cancer cell adhesion to endothelium is crucial for metastasis dissemination, here we have evaluated the effect of cholbut SLN on adhesion and migration of cancer cells. EXPERIMENTAL APPROACH Cholbut SLN was incubated with a number of cancer cell lines or human umbilical vein endothelial cells (HUVEC) and adhesion was quantified by a computerized micro-imaging system. Migration was detected by the scratch 'wound-healing' assay and the Boyden chamber invasion assay. Expression of ERK and p38 MAPK was analysed by Western blot. Expression of the mRNA for E-cadherin and claudin-1 was measured by RT-PCR. KEY RESULTS Cholbut SLN inhibited HUVEC adhesiveness to cancer cell lines derived from human colon-rectum, breast, prostate cancers and melanoma. The effect was concentration and time-dependent and exerted on both cancer cells and HUVEC. Moreover, these SLN inhibited migration of cancer cells and substantially down-modulated ERK and p38 phosphorylation. The anti-adhesive effect was additive to that induced by the triggering of B7h, which is another stimulus inhibiting both ERK and p38 phosphorylation, and cell adhesiveness. Furthermore, cholbut SLN induced E-cadherin and inhibited claudin-1 expression in HUVEC. CONCLUSION AND IMPLICATIONS These results suggest that cholbut SLN could act as an anti-metastastic agent and they add a new mechanism to the anti-tumour activity of this multifaceted preparation of butyrate.

High fever following postpartum administration of sublingual misoprostol

Objective

To explore what triggers an elevated body temperature of ≥40.0°C in some women given misoprostol, a prostaglandin E1 analogue, for postpartum haemorrhage (PPH).

Design

Post hoc analysis.

Setting

One tertiary-level hospital in Quito, Ecuador.

Population

A cohort of 58 women with a fever of above 40°C following treatment with sublingual misoprostol (800 micrograms) for PPH.

Methods

Side effects were documented for 163 Ecuadorian women given sublingual misoprostol to treat their PPH. Women’s body temperatures were measured, and if they had a fever of ≥40.0°C, measurements were taken hourly until the fever subsided. Temperature trends were analysed, and the possible physiological mechanisms by which postpartum misoprostol produces a high fever were explored.

Main outcome measures

The onset, duration, peak temperatures, and treatments administered for cases with a high fever.

Results

Fifty-eight of 163 women (35.6%) treated with misoprostol experienced a fever of ≥40.0°C. High fevers followed a predictable pattern, often preceded by moderate/severe shivering within 20 minutes of treatment. Body temperatures peaked 1–2 hours post-treatment, and gradually declined over 3 hours. Fevers were transient and did not lead to any hospitalisation. Baseline characteristics were comparable among women who did and did not develop a high fever, except for known previous PPH and time to placental expulsion.

Conclusions

An unexpectedly high rate of elevated body temperature of ≥40.0°C was documented in Ecuador following sublingually administered misoprostol. It is unclear why temperatures ≥40.0°C occurred with a greater frequency in Ecuador than in other study populations using similar treatment regimens for PPH. Pharmacogenetic studies may shed further light on variations in individuals’ responses to misoprostol.

Lean and fat mass as determinants of muscle strength and insulin sensitivity in Chilean elderly subjects

PURPOSE

To report the association of lean body mass with nutritional, social and economic factors and its functional consequences in free living healthy elderly subjects.

MATERIAL AND METHODS

Healthy elderly subjects of low socioeconomic level were studied. Monthly income, marital status, anthropometric measures and fall risk were assessed. Mini Nutritional Assessment score was calculated. Body composition and bone mineral density were measured by double beam X ray absorptiomentry. Fasting serum lipids, fasting and postprandial insulin and glucose levels were measured. Hand grip, quadriceps and biceps strengths and maximal inspiratory and expiratory pressures were measured.

RESULTS

One hundred and nine subjects (56 women), aged 75 +/- 4 years old were studied. Lean body mass was 34.1 +/- 4 and 49.2 +/- 5.4 kg in women and men respectively (p < 0.001), fat mass was 22.8 +/- 7.1 and 20.7 +/- 6.4 kg in women and men respectively (p= NS). Lean body mass correlated with hand grip, quadriceps and biceps muscle strengths in men and with quadriceps and biceps strength in women. Men that exercised regularly had higher quadriceps strength and maximal expiratory pressure. Total body fat correlated positively with fasting and postprandial serum insulin levels.

CONCLUSIONS

In this sample, lean body mass is directly related to muscle strength mostly in men. On the other hand, total fat mass is related to serum insulin levels.

Effects of nutritional supplementation and resistance training on muscle strength in free living elders. Results of one year follow

PURPOSE

To assess the effects of a one year nutritional supplementation and resistance training program on muscle strength and walking capacity in the elderly.

MATERIAL AND METHODS

Elderly subjects from two outpatient clinics received a nutritional supplement, that provided 400 Kcal, 15 g/protein and 50% of vitamin DRVs per day. Half the subjects receiving and not receiving the supplement were randomly assigned to a resistance exercise training program with two sessions per week. Every six months, body composition using DEXA, limb muscle strength, maximal inspiratory and expiratory pressures and walking capacity were assessed.

RESULTS

One hundred forty nine subjects were considered eligible and 101 (31 supplemented and trained, 28 supplemented, 16 trained and 26 without supplementation nor training) completed the year of follow up. Overall compliance with the supplement was 48 22 % and trained subjects attended 56 21% of programmed sessions. No changes in fat free mass were observed in any of the groups, but fat mass increased from 22.5 7.3 to 23.2 7.3 kg in all groups (p < 0.001). Upper and lower limb strength and walking capacity increased significantly in trained subjects whether supplemented or not. Maximal inspiratory pressure and right hand grip strength increased only in the supplemented and trained group.

CONCLUSIONS

Resistance training improved muscle strength and walking capacity.

[Biological, familial and metabolic characteristics of infantile and juvenile obesity]

BACKGROUND

Obesity is the most prevalent nutritional disease in people of less than 20 years old.

AIM

To report biological, familial and metabolic characteristics in obese children.

PATIENTS AND METHODS

A retrospective review of 187 children seen at obesity clinics and that had a complete metabolic study.

RESULTS

Ninety five prepuberal and 92 puberal children, aged 8.7 +/- 2.2 and 12.6 +/- 2.2 years old respectively, were studied. Body mass index was over 4 standard deviations in 48.4% of prepuberal children and in 39.1% of puberal children. Paternal obesity was twice more prevalent (30.2%) than in the general population. The daily caloric intake and basal metabolic rate (BMR) were within the normal range; nevertheless there was a positive caloric balance due to minimal physical activity. The mean daily fat intake was normal (26.4 +/- 8.5 and 25.3 +/- 9.1% of total calories in prepuberal and puberal children respectively). The daily fiber intake was under 70% of recommendation. The total cholesterol was over 200 mg/dl in 26.6 and 23.9% of prepuberal and puberal children. LDL cholesterol was over 130 mg/dl in 27.3 and 26.6% and triacylglycerol was over 150 mg/dl in 16.9 and 25% of prepuberal and puberal children respectively. Basal serum insulin was over 20 uIU/ml in 27.7 and 42.2% of prepuberal and puberal children, respectively. Post glucose serum insulin was over 60 uIU/ml in 40 and 63% of prepuberal and puberal children, respectively.

CONCLUSIONS

Infantile and juvenile obesity is a chronic disease with a high incidence of metabolic alterations.

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.