Gene deletion of Interleukin-1α reduces ER stress-induced CHOP expression in macrophages and attenuates the progression of atherosclerosis in apoE-deficient mice

The pathophysiology of atherosclerosis initiation and progression involves many inflammatory cytokines, one of them is interleukin (IL)-1α that has been shown to be secreted by activated macrophages. We have previously shown that IL-1α from bone marrow-derived cells is critical for early atherosclerosis development in mice. It is known that endoplasmic reticulum (ER) stress in macrophages is involved in progression to more advanced atherosclerosis, but it is still unknown whether this effect is mediated through cytokine activation or secretion. We previously demonstrated that IL-1α is required in ER stress-induced activation of inflammatory cytokines in hepatocytes and in the associated induction of steatohepatitis. In the current study, we aimed to examine the potential role of IL-1α in ER stress-induced activation of macrophages, which is relevant to progression of atherosclerosis. First, we demonstrated that IL-1α is required for atherosclerosis development and progression in the apoE knockout (KO) mouse model of atherosclerosis. Next, we showed that ER stress in mouse macrophages results in the protein production and secretion of IL-1α in a dose-dependent manner, and that IL-1α is required in ER stress-induced production of the C/EBP homologous protein (CHOP), a critical step in ER stress-mediated apoptosis. We further demonstrated that IL-1α-dependent CHOP production in macrophages is specifically mediated through the PERK-ATF4 signaling pathway. Altogether, these findings highlight IL-1α as a potential target for prevention and treatment of atherosclerotic cardiovascular disease.

The effect of α-linolenic acid enrichment in perinatal diets in preventing high fat diet-induced SCD1 increased activity and lipid disarray in adult offspring of low density lipoprotein receptor knockout (LDLRKO) mice

The present study examined the effects of maternal perinatal dietary ALA enrichment on the high fat diet (HFD)-induced lipid disarray in the adult offspring of low density lipoprotein receptor knock-out (LDLRKO) mice. Female LDLRKO mice received, during pregnancy and lactation, isocaloric diets with either corn oil, RD, or flax oil, ALA. The weaning offspring was given a regular chow diet for a washout period of eight weeks, which was followed by HFD for eight weeks. Plasma and liver lipids and SCD1 activity were then analyzed. The HFD-fed RD adult offspring had substantially higher plasma cholesterol levels than the HFD-fed ALA offspring (15.7 versus 9.7 mmole/l, p<0.00001) and non-alcoholic fatty liver disease (NAFLD) (65.0 versus 23.9 mg/g lipids, p<0.00001). Liver lipids oleic acid (OA) content and monounsaturated to saturated fatty acids (MUFA/SAT) ratio, were two times lower in RD compared to ALA (p<0.0001). The threefold HFD-induced SCD1 raised activity (p<0.00001), and OA produced from SA, observed in RD adult offspring were prevented by perinatal ALA. In conclusion, the resilience of SCD1 to HFD- induced increased activity may account for the beneficial effects of perinatal ALA dietary enrichment in preventing NAFLD and hypercholesterolemia from occurring in adult LDLRKO offspring mice.

β-Carotene from the Alga Dunaliella bardawil Decreases Gene Expression of Adipose Tissue Macrophage Recruitment Markers and Plasma Lipid Concentrations in Mice Fed a High-Fat Diet

Vitamin A and provitamin A carotenoids are involved in the regulation of adipose tissue metabolism and inflammation. We examined the effect of dietary supplementation using all-trans and 9-cis β-carotene-rich Dunaliella bardawil alga as the sole source of vitamin A on obesity-associated comorbidities and adipose tissue dysfunction in a diet-induced obesity mouse model. Three-week-old male mice (C57BL/6) were randomly allocated into two groups and fed a high-fat, vitamin A-deficient diet supplemented with either vitamin A (HFD) or β-carotene (BC) (HFD-BC). Vitamin A levels in the liver, WATs, and BAT of the HFD-BC group were 1.5–2.4-fold higher than of the HFD group. BC concentrations were 5–6-fold greater in BAT compared to WAT in the HFD-BC group. The eWAT mRNA levels of the Mcp-1 and Cd68 were 1.6- and 2.1-fold lower, respectively, and the plasma cholesterol and triglyceride concentrations were 30% and 28% lower in the HFD-BC group compared with the HFD group. Dietary BC can be the exclusive vitamin A source in mice fed a high-fat diet, as shown by the vitamin A concentration in the plasma and tissues. Feeding BC rather than vitamin A reduces adipose tissue macrophage recruitment markers and plasma lipid concentrations.

Blood fatty acid analysis reveals similar n-3 fatty acid composition in non-pregnant and pregnant women and their neonates in an Israeli pilot study

Maternal docosahexaenoic acid (DHA) is required during pregnancy to supply for normal fetal growth and development. This pilot study aimed to assess the unknown fatty acid (FA) composition in a cohort of non-pregnant and pregnant Israeli women at term and their offspring on a normal diet without n-3 FA supplementation. The fatty acid profile, analyzed using gas chromatography, showed significantly higher plasma monounsaturated (MUFA) and lower n-6 FA percent distribution with similar n-3 index, in pregnant compared to non-pregnant women. RBC exhibited significantly higher MUFA with similar n-3 index, in pregnant compared to non-pregnant women. N-3 FA significantly correlated between neonates' plasma, with higher n-3 index, and pregnant women's DHA. Conclusion: DHA levels in non-pregnant and pregnant Israeli women at term were comparable and the DHA in pregnant women's plasma positively correlated with their neonate's level, suggesting an efficient mother-fetus FA transfer and/or fetal fatty acid metabolism to longer FA products.

Dietary alpha linolenic acid in pregnant mice and during weaning increases brain docosahexaenoic acid and improves recognition memory in the offspring

Docosahexaenoic acid (DHA) is critical for normal brain development and function. DHA is in danger of being significantly reduced in the human food supply, and the question of whether its metabolic precursor, the essential n-3 alpha linolenic acid (ALA) during pregnancy, can support fetal brain DHA levels for optimal neurodevelopment, is fundamental. Female mice were fed either ALA-enriched or Control diet during pregnancy and lactation. The direct effect of maternal dietary ALA on lipids was analyzed in liver, red blood cells, brain and brain vasculature, together with genes of fatty acid metabolism and transport in three-week-old offspring. The long-term effect of maternal dietary ALA on brain fatty acids and memory was studied in 19-week-old offspring. Three-week-old ALA offspring showed higher levels of n-3 fatty acids in liver, red blood cell, blood-brain barrier (BBB) vasculature and brain parenchyma, DHA enrichment in brain phospholipids and higher gene and protein expression of the DHA transporter, major facilitator superfamily domain containing 2a, compared to Controls. 19-week-old ALA offspring showed higher brain DHA levels and better memory performance than Controls. The increased brain DHA levels induced by maternal dietary ALA during pregnancy-lactation, together with the up-regulated levels of major facilitator superfamily domain containing 2a, may indicate a mode for greater DHA uptake with long-term impact on better memory in ALA offspring.

[UPDATED ISRAELI GUIDELINES FOR THE TREATMENT OF DYSLIPIDEMIA 2020]

Despite the impressive decline in mortality from atherosclerotic cardiovascular diseases (ASCVD), these diseases still account for a large proportion of the overall morbidity and mortality worldwide. A vast amount of research has demonstrated the key role played by circulating lipoproteins, and especially low-density lipoprotein (LDL), in the etiology of atherosclerosis, and numerous studies have proven the efficacy of interventions that lower the atherogenic lipoproteins in reducing morbidity and mortality from ASCVD. While previous guidelines placed an emphasis on the use HMG-CoA reductase inhibitors (statins) for the treatment of dyslipidemia, recent studies have shown that other LDL cholesterol lowering drugs, including ezetimibe and the PCSK9 inhibitors, can provide additional benefit when used in combination with (and in certain cases instead of) statins. These studies have also shown that blood LDL cholesterol levels lower than previously recommended targets provide additional benefit, without evidence of a threshold beyond which the benefit ceases and without excess adverse effects. The updated guidelines were formulated by a committee that consisted of representatives from the Israeli Society for the Research, Prevention and Treatment of Atherosclerosis, the Israel Society of Internal Medicine, the Israeli Heart Association, the Israeli Neurology Association and the Israel Association of Family Medicine. They provide recommendations for revised risk stratification of patients, novel target goals, and the use of evidence-based treatment and follow-up strategies with reference to specific patient sub-groups.

Dietary β-Carotene Rescues Vitamin A Deficiency and Inhibits Atherogenesis in Apolipoprotein E-Deficient Mice

Vitamin A deficiency (VAD) is a major health problem, especially in developing countries. In this study, we investigated the effect of VAD from weaning to adulthood in apoE^−/− mice. Three-week-old male mice were allocated into four diet groups: I. VAD II. VAD+vitamin A (VA), 1500 IU retinyl-palmitate; III. VAD+β-carotene (BC), 6 g/kg feed, containing 50% all-trans and 50% 9-cis BC. IV. VAD with BC and VA (BC+VA). After 13 weeks, we assessed the size of atherosclerotic plaques and measured VA in tissues and BC in plasma and tissues. VAD resulted in diminished hepatic VA levels and undetectable brain VA levels compared to the other groups. BC completely replenished VA levels in the liver, and BC+VA led to a two-fold elevation of hepatic VA accumulation. In adipose tissue, mice fed BC+VA accumulated only 13% BC compared to mice fed BC alone. Atherosclerotic lesion area of BC group was 73% lower compared to VAD group (p < 0.05). These results suggest that BC can be a sole source for VA and inhibits atherogenesis.

Addition of fish oil to atherogenic high fat diet inhibited atherogenesis while olive oil did not, in LDL receptor KO mice

BACKGROUND AND AIMS

Mediterranean diet has been associated with decreased cardiovascular morbidity and mortality. Both fish and olive oil are key components of this diet. Therefore, we compared their effects on nonalcoholic fatty liver disease (NAFLD) and atherogenesis in a mouse model, fed a high fat diet.

METHODS AND RESULTS

Forty nine, female LDL receptor knockout (LDLR KO) mice were allocated into 3 groups and fed an atherogenic high fat (HF) diet for 9 weeks. The HF group was fed a high fat diet alone. A HF + OO group was fed a HF diet with added olive oil (60 ml/kg feed), and the third group (HF + FO) was fed a HF diet with added fish oil (60 ml/kg feed). Both additions of fish and olive oil, significantly decreased plasma cholesterol elevation compared to HF diet. Nevertheless, only fish oil addition reduced significantly atherosclerotic lesion area by 51% compared to HF group. Liver levels of eicosapentenoic (EPA) and docosahexaenoic (DHA) acids were several folds higher in HF + FO group than in HF and HF + OO groups. Liver levels of oleic acid were higher in HF + OO compared to the other groups. Moreover, Fish oil addition significantly decreased NAFLD scores related to steatosis and inflammation and lowered the expression of the inflammatory genes interleukin 6 (IL6) and monocyte chemoattractant protein 1 (MCP1).

CONCLUSION

These results suggest that fish oil addition on top of an atherogenic, HF diet, is beneficial, while olive oil is not, in its effect on plaque formation and NAFLD in LDLR KO mice.

Specific overexpression of 15-lipoxygenase in endothelial cells promotes cancer cell death in an in vivo Lewis lung carcinoma mouse model

PURPOSE

Lipoxygenases (LOX) have been implicated in carcinogenesis, however both pro- and anti-carcinogenic effects have been reported in different cancer models. Using transgenic mice, which specifically overexpress human 15-lipoxygenase (ALOX15) in endothelial cells (EC), we previously demonstrated significant inhibition of tumor development. In the Lewis lung carcinoma (LLC) model, the primary tumor developed similarly in both wild type (WT) and ALOX15 overexpressing mice. However, metastases development was significantly inhibited in the transgenic mice. Here, we explored the molecular basis for the anti-metastatic effect of endothelial cell specific ALOX15 overexpression.

MATERIALS/METHODS

We used ALOX15 overexpressing mice, and in-vitro cell model to evaluate the molecular effect of ALOX15 on EC and LLC cells.

RESULTS

When LLC cells were injected in WT and ALOX15 overexpressing mice, we observed a higher degree of apoptosis and necrosis in primary and metastatic tumors of ALOX15 overexpressing animals. These anti-carcinogenic and anti-metastatic effects were paralleled by augmented expression of cyclin-dependent kinase inhibitor 1A (CDKN1A; p21) and of the peroxisome proliferators-activated receptor (PPAR)γ and by downregulation of the steady state concentrations of connexin26 mRNA. Consistent with these in vivo effects, ALOX15 overexpression in LLC and HeLa cancer cells in vitro significantly reduced cell viability in culture. In contrast, similar treatment of non-cancerous B2B epithelial cells did not impact cell viability.

CONCLUSIONS

Taken together, our data suggests that endothelial cell specific overexpression of ALOX15 promotes apoptosis and necrosis in primary and metastatic tumors in mice, by upregulation of P21 and PPARγ expression in adjacent cancer cells.

Interleukin-1α deficiency reduces adiposity, glucose intolerance and hepatic de-novo lipogenesis in diet-induced obese mice

OBJECTIVE

While extensive research revealed that interleukin (IL)-1β contributes to insulin resistance (IR) development, the role of IL-1α in obesity and IR was scarcely studied. Using control, whole body IL-1α knockout (KO) or myeloid-cell-specific IL-1α-deficient mice, we tested the hypothesis that IL-1α deficiency would protect against high-fat diet (HFD)-induced obesity and its metabolic consequences.

RESEARCH DESIGN AND METHODS

To induce obesity and IR, control and IL-1α KO mice were given either chow or HFD for 16 weeks. Glucose tolerance test was performed at 10 and 15 weeks, representing early and progressive stages of glucose intolerance, respectively. Liver and epididymal white adipose tissue (eWAT) samples were analyzed for general morphology and adipocyte size. Plasma levels of adiponectin, insulin, total cholesterol and triglyceride (TG), lipoprotein profile as well as hepatic lipids were analyzed. Expression of lipid and inflammation-related genes in liver and eWAT was analyzed. Primary mouse hepatocytes isolated from control mice were treated either with dimethyl sulfoxide (DMSO) (control) or 20 ng/mL recombinant IL-1α for 24 hours and subjected to gene expression analysis.

RESULTS

Although total body weight gain was similar, IL-1α KO mice showed reduced adiposity and were completely protected from HFD-induced glucose intolerance. In addition, plasma total cholesterol and TG levels were lower and HFD-induced accumulation of liver TGs was completely inhibited in IL-1α KO compared with control mice. Expression of stearoyl-CoA desaturase1 (SCD1), fatty acid synthase (FASN), elongation of long-chain fatty acids family member 6 (ELOVL6), acetyl-CoA carboxylase (ACC), key enzymes that promote de-novo lipogenesis, was lower in livers of IL-1α KO mice. Treatment with recombinant IL-1α elevated the expression of ELOVL6 and FASN in mouse primary hepatocytes. Finally, mice with myeloid-cell-specific deletion of IL-1α did not show reduced adiposity and improved glucose tolerance.

CONCLUSIONS

We demonstrate a novel role of IL-1α in promoting adiposity, obesity-induced glucose intolerance and liver TG accumulation and suggest that IL-1α blockade could be used for treatment of obesity and its metabolic consequences.

Voriconazole-induced QT prolongation among hemato-oncologic patients: clinical characteristics and risk factors

PURPOSE

The purpose of this study is to determine the rate of QTcP and associated risk factors in patients treated with voriconazole.

METHODS

We conducted a retrospective chart review of all patients treated with voriconazole in a large tertiary center between 2009 and 2015, using paired comparison of QTc intervals on and off voriconazole treatment, adjusted for comorbidities, electrolyte abnormalities, and concurrent medications.

RESULTS

Fifty-four patients were included, of whom 53 were diagnosed with oncologic/hemato-oncologic disease. Mean QTc during voriconazole therapy (448.0 ± 52.9 msec) was significantly longer compared to QTc off voriconazole (421.8 ± 42.2 msec; p = 0.002). QTcP ≥30 msec and ≥60 msec was demonstrated in 43% (23 patients) and 28% (15 patients), respectively. Multivariate analysis showed that QTcP was significantly associated with baseline QTc ≥ 450 msec (upper QTc quartile) (p < 0.01) and low serum potassium levels (p < 0.01). Contrarily, no significant association was found between mean voriconazole daily and cumulative dose and QTcP.

CONCLUSION

Our findings indicate that hemato-oncologic patients treated with voriconazole are at increased risk for QTcP, especially in the presence of baseline QTc ≥ 450 msec and low serum potassium levels.

Interleukin 1-alpha deficiency increases the expression of Follicle-stimulating hormone receptors in granulosa cells

Follicle-stimulating hormone receptor (FSHR) is a pivotal regulator of ovarian response to hormonal stimulation. Inflammatory conditions have been linked to lower FSHR expression in granulosa cells (GCs) as well as an attenuated response to hormonal stimulation. The current study aimed to reveal if deficiency and/or blockage of the pro-inflammatory cytokine interleukin 1-alpha (IL1A) increased Fshr expression in rodent GCs. We found elevated Fshr transcript abundance, as assessed by quantitative PCR, in primary GCs isolated from Il1a-knockout compared to wild-type mice, and that the expression of FSHR is significantly higher in Il1a-knockout compared to wild-type ovaries. Supplementing GC cultures with recombinant IL1A significantly lowered Fshr expression in these cells. In accordance with the Fshr expression pattern, proliferation of GCs was higher in follicles from Il1a-knockout mice compared to wild-type mice, as indicated by the MKI67 immunohistochemical staining. Furthermore, treating wild-type mice with anakinra, an IL1 receptor 1 antagonist, significantly increased the expression of Fshr in primary GCs from treated compared to control mice. These data highlight an important interdependency between the potent pro-inflammatory cytokine IL1A and Fshr expression.

Nifedipine Treatment for Hypertension is Associated with Enhanced Lipolytic Activity and Accelerated Clearance of Postprandial Lipemia

Hypertension, advanced age, postprandial hyperlipidemia, and insulin resistance are major risk factors for atherosclerosis. The calcium channel blocker nifedipine is reported to ameliorate insulin resistance possibly by activating PPARγ. This is expected to become accentuated in elderly individuals due to age-related insulin resistance. Insulin resistance modulates lipoprotein metabolism. Therefore, we reasoned that nifedipne offers the potential for improving postprandial lipemia in association with increasing age. We studied the effect of nifedipine on fasting lipids, postprandial lipemia, insulin sensitivity, and plasma lipolytic activity in 24 and 15 hypertensive subjects aged 70-75 years and 40-45 years, respectively. As expected, nifedipine significantly lowered systolic and diastolic blood pressure. Nifedipine decreased fasting triglyceride level (23%) and increased HDL-C (15%) in the elderly group. At baseline, postprandial triglyceride levels were remarkably elevated in elderly compared to younger patients (1 288±798 vs. 501±260 mg·dl(-1)·h, p<0.05), as was retinyl palmitate (surrogate marker for intestinally-derived cholesterol) in the chylomicrons (45.0±26.5 vs. 23.4±10.6 mg·l(-1)·h, p<0.05) and chylomicron remnant (15.2±5.4 vs. 11.7±4.7 mg·l(-1)·h, p<0.05) fractions. Importantly, while the level of chylomicron remnants in the group of younger subjects remained unchanged after treatment, nifedipine was associated with a significantly decreased chylomicron remnants retinyl palmitate in the elderly group, which dropped to levels, observed in younger subjects. This was accompanied by enhanced insulin sensitivity and augmented plasma lipolytic activity. The present work suggests that nifedipine has favorable metabolic effects that are beyond the known enhancement of insulin sensitivity. The improvement in postprandial lipidemia by nifedipine may add to its anti-atherogenic effects in hypertensive patients.

The Effect of Klotho Treatment on Atherogenesis, Blood Pressure, and Metabolic Parameters in Experimental Rodent Models

Klotho is a transmembrane protein, expressed mainly in the kidneys and the choroid plexus. The extracellular domain of klotho is composed of 2 internal repeats, KL1 and KL2, which can be cleaved and act as hormones. Klotho-deficient mice develop a phenotype resembling human aging. Laboratory and clinical data suggest a favorable effect of klotho on atherosclerosis, high blood pressure, and metabolic syndrome. Therefore, we aimed to study the effect of klotho treatment on atherogenesis, blood pressure, and metabolic parameters in experimental rodent models. Fructose-fed Sprague-Dawley rats (metabolic syndrome model) and apolipoprotein E (apoE -/-) knock-out mice (atherosclerosis model) were treated with either klotho or its active domain KL1. In apoE -/- mice, klotho unexpectedly elevated plasma cholesterol and triglyceride levels compared to the control group. Yet, it did not increase the aortic sinus atherosclerotic lesion area. In fructose-fed Sprague-Dawley rats, klotho treatment did not lower blood pressure or plasma triglyceride levels. Although KL1 treatment did not lower blood pressure or plasma insulin levels, it significantly reduced the elevation of total plasma triglyceride levels (from 2.3-fold to 1.6-fold, p<0.05) due to lower triglyceride-rich VLDL levels. Klotho did not show any beneficial effects on atherosclerosis and components of the metabolic syndrome and was associated with increased plasma cholesterol levels. On the other hand, treatment with KL1 may lower plasma triglyceride levels independent of insulin. Additional studies are required in order to decipher the complex role of klotho and its active domains in the regulation of plasma lipid levels.

Interleukin-1α deficiency attenuates endoplasmic reticulum stress-induced liver damage and CHOP expression in mice

BACKGROUND & AIMS

ER stress promotes liver fat accumulation and induction of inflammatory cytokines, which contribute to the development of steatohepatitis. Unresolved ER stress upregulates the pro-apoptotic CHOP. IL-1α is localized to the nucleus in apoptotic cells, but is released when these cells become necrotic and induce sterile inflammation. We investigated whether IL-1α is involved in ER stress-induced apoptosis and steatohepatitis.

METHODS

We employed WT and IL-1α-deficient mice to study the role of IL-1α in ER stress-induced steatohepatitis.

RESULTS

Liver CHOP mRNA was induced in a time dependent fashion in the atherogenic diet-induced steatohepatitis model, and was twofold lower in IL-1α deficient compared to WT mice. In the ER stress-driven steatohepatitis model, IL-1α deficiency decreased the elevation in serum ALT levels, the number of apoptotic cells (measured as caspase-3-positive hepatocytes), and the expression of IL-1β, IL-6, TNFα, and CHOP, with no effect on the degree of fatty liver formation. IL-1α was upregulated in ER-stressed-macrophages and the protein was localized to the nucleus. IL-1β mRNA and CHOP mRNA and protein levels were lower in ER-stressed-macrophages from IL-1α deficient compared to WT mice. ER stress induced the expression of IL-1α and IL-1β also in mouse primary hepatocytes. Recombinant IL-1α treatment in hepatocytes did not affect CHOP expression but upregulated both IL-1α and IL-1β mRNA levels.

CONCLUSION

We show that IL-1α is upregulated in response to ER stress and IL-1α deficiency reduces ER stress-induced CHOP expression, apoptosis and steatohepatitis. As a dual function cytokine, IL-1α may contribute to the induction of CHOP intracellularly, while IL-1α released from necrotic cells accelerates steatohepatitis via induction of inflammatory cytokines by neighboring cells.

9-cis β-carotene Inhibits Atherosclerosis Development in Female LDLR-/- Mice

Background: Several epidemiological studies have shown that diets rich in carotenoids are associated with a reduced risk of cardiovascular disease. However, administration of synthetic all-trans b-carotene was reported to have no effect on cardiovascular disease. We previously showed that the 9-cis b-carotene-rich powder of the alga Dunaliella bardawil inhibits atherogenesis and reduces plasma non-HDL cholesterol levels in mice.Context and purpose of this study: We sought to study whether isolated 9-cis b-carotene inhibits atherogenesis in a murine model of atherosclerosis.Results: Twelve-week-old female LDL receptor knockout mice (LDLR-/-) were pretreated for  2 weeks with regular chow diet fortified with the alga Dunaliella powder, 9-cis β-carotene isomer, all-trans β-carotene isomer, or 9-cis retinoic acid, followed by 10 weeks of a high-fat diet with the same fortifications. In contrast to Dunaliella, 9-cis β-carotene did not inhibit the high fat diet-induced elevation of plasma cholesterol. In addition, diet fortification with Dunaliella powder, β-carotene isomers, or 9-cis retinoic acid did not change the plasma retinol or retinoic acid levels. Nevertheless, 9-cis β-carotene significantly inhibited atherogenesis compared to the control mice (39% reduction).Conclusions: The results suggest that 9-cis β-carotene should be considered as an anti-atherogenic agent in the human diet.Key words: Atherosclerosis, Dunaliella, 9CBC, LDLR-/- mice

Lack of interleukin-1α in Kupffer cells attenuates liver inflammation and expression of inflammatory cytokines in hypercholesterolaemic mice

BACKGROUND

The role of Kupffer cell interleukin (IL)-1 in non-alcoholic steatohepatitis development remains unclear.

AIMS

To evaluate the role of Kupffer cell IL-1α, IL-1β or IL-1 receptor type-1 (IL-1R1) in steatohepatitis.

METHODS

C57BL/6 mice were irradiated and transplanted with bone marrow-derived cells from WT, IL-1α-/-, IL-1β-/- or IL-1R1-/- mice combined with Kupffer cell ablation with Gadolinium Chloride, and fed atherogenic diet. Plasma and liver triglycerides and cholesterol, serum alanine aminotransferase (ALT), liver histology and expression levels of inflammatory genes were assessed.

RESULTS

The ablation and replacement of Kupffer cells with bone marrow-derived cells was confirmed. The atherogenic diet elevated plasma and liver cholesterol, reduced plasma and liver triglycerides and increased serum ALT levels in all groups. Steatosis and steatohepatitis were induced, but without liver fibrosis. A reduction in the severity of portal inflammation was observed only in mice with Kupffer cell deficiency of IL-1α. Accordingly, liver mRNA levels of inflammatory genes encoding for IL-1α, IL-1β, TNFα, SAA1 and IL-6 were significantly lower in mice with Kupffer cell deficiency of IL-1α compared to WT mice.

CONCLUSION

Selective deficiency of IL-1α in Kupffer cells reduces liver inflammation and expression of inflammatory cytokines, which may implicate Kupffer cell-derived IL-1α in steatohepatitis development.

[Phytosterols: another way to reduce LDL cholesterol levels]

Phytosterols are sterols found naturally in various oils from plants. Phytosterols compete with cholesterol for a place in the mixed micelles, needed for cholesterol absorption by the small intestine. As a result, cholesterol absorption, either from food or from bile salts is lowered by about 50%, leading to a towering of about 10% of blood cholesterol level, despite an increase in hepatic cholesterol synthesis. This reduction is achieved when phytosterols are given both as monotherapy, and in addition to statin therapy. The average Western diet contains about 400-800 mg of phytosterols per day, while the dose needed for lowering the blood cholesterol level is about 2-3 grams per day. Therefore, for the purpose of reducing blood cholesterol, they should be given either as phytosterol-enriched food or as supplements. The reduction in the level of LDL-choLesterol achieved with phytosterols may reduce the risk of coronary disease by about 25%. Hence, the American Heart Association recommended the consumption of phytosterols, as part of a balanced diet, for towering blood cholesterol levels.

Normal adiponectin levels in kidney transplant patients with hypertension

BACKGROUND

Kidney transplant patients are a unique population where despite correction of their kidney function they are still considered to be at high cardiovascular (CV) risk. Adiponectin, an adipokine secreted from adipocytes, has protective CV properties. Patients with essential hypertension (HTN) have low adiponectin levels that are associated with a high CV risk. The aim of this study was to assess adiponectin levels in hypertensive renal transplant recipients.

MATERIALS AND METHODS

Fasting blood adiponectin levels were measured in hypertensive kidney transplant patients (n = 18), patients with essential HTN (n = 17) and healthy subjects (n = 14). Patients with diabetes mellitus and renal failure were excluded from the study. Anthropomorphic and metabolic parameters were also measured.

RESULTS

Patients with essential HTN had lower adiponectin levels than healthy controls (6 ± 0.7 μg/mL vs. 11 ± 0.9 μg/mL, p < 0.001), whereas hypertensive kidney transplant patients had adiponectin levels that were similar to adiponectin levels found in normal controls (11 ± 1.1 μg/mL). Adiponectin levels in healthy subjects were inversely correlated with plasma triglycerides (r = -0.876, p < 0.001) and with body weight (r = -0.7, p < 0.001). There was no such a correlation in patients with HTN.

CONCLUSION

Adiponectin in hypertensive kidney transplant recipients is not an appropriate CV risk marker as it does not adequately distinguish these patients from normal controls.

Apolipoprotein A-V modulates multiple atherogenic mechanisms in a mouse model of disturbed clearance of triglyceride-rich lipoproteins

OBJECTIVE

Apolipoprotein A-V plays an important role in reducing plasma triglyceride levels. We hypothesized that expression of apoA-V would inhibit atherogenesis in apoE(-/-) mice fed chow diet which is a known model of hypercholesterolemia. Our aim was to study this protective effect and to explore possible mechanisms.

METHODS AND RESULTS

ApoA-V(+/+)ApoE(-/-) mice expressing human apolipoprotein A-V (hapoA-V) were generated and compared to apoE(-/-) mice. Atherosclerotic aortic sinus lesion area was 70% smaller in hapoA-V(+/+)apoE(-/-). This was accompanied by a 58% reduction in lesion macrophage content. Furthermore, advanced atherosclerotic lesions in hapoA-V(+/+)apoE(-/-) mice showed features of a more stable plaque, manifested by 59% and 37% higher collagen and α-actin content, respectively. Plasma triglyceride and cholesterol levels in hapoA-V(+/+)apoE(-/-) mice were 47% and 33% lower, respectively. These were associated with a 33% reduction in very low density lipoprotein triglyceride production and 2-fold acceleration in triglyceride-rich lipoprotein clearance in hapoA-V(+/+)apoE(-/-) mice. In addition, hapoA-V(+/+)apoE(-/-) mice showed enhanced insulin sensitivity (25% and 15% improvement in glucose tolerance and insulin responsiveness, respectively). Finally, hapoA-V(+/+)apoE(-/-) displayed a milder systemic inflammatory response compared to apoE(-/-) mice, manifested by 22%, 65% and 15% lower plasma levels of TNFα, IL-1β and IL-6, respectively.

CONCLUSIONS

We showed that human apolipoprotein A-V is a potent modulator of atherosclerosis in mice through multiple modes of action. These findings may identify apoA-V as a potential therapeutic target for treatment of atherosclerosis.

Low-dose calcitriol decreases aortic renin, blood pressure, and atherosclerosis in apoe-null mice

AIMS

To determine whether low-dose calcitriol attenuates atherosclerosis in apoE-null mice and, if so, through which predominant mechanism.

METHODS

Starting at the age of 6 weeks, mice received intraperitoneal injections of either 0.25 ng/g body weight of calcitriol or the vehicle, every other day for 8 weeks.

RESULTS

Calcitriol treatment resulted in 35% reduction of atherosclerosis at the aortic sinus, and in a significant decrease in blood pressure. These effects were possibly mediated by downregulation of the renin-angiotensin system (RAS), as there was a 64% decrease in the aortic level of renin mRNA. None of the other components of the RAS or the prorenin receptor were affected by treatment. Low-dose calcitriol treatment did not modify the plasma level of monocyte chemoattractant protein-1, interferon γ, interleukin-4 and interleukin-10, which were similar in control and treated mice. Likewise, there was no difference in the percentage of splenic Foxp3+ regulatory T cells. Calcitriol treatment resulted in an unfavorable metabolic profile (glucose and lipids), as determined after a limited fast, a difference that disappeared after food was withheld for a longer time.

CONCLUSIONS

At a relatively low dosage, calcitriol attenuates the development of atherosclerosis in apoE-null mice, most probably by down regulation of RAS, and not through immunomodulation; however, even at this low dose, calcitriol appears to elevate calcium and to have potentially adverse metabolic effects. Exploring the potential antiatherogenic effects of non-calcemic and safer analogues is therefore warranted.

Lack of interleukin-1α or interleukin-1β inhibits transformation of steatosis to steatohepatitis and liver fibrosis in hypercholesterolemic mice

BACKGROUND & AIMS

The identification of the cellular and molecular pathways that mediate the development of non-alcoholic steatohepatitis is of crucial importance. Cytokines produced by liver-resident and infiltrating inflammatory cells, play a pivotal role in liver inflammation. The role of the proinflammatory cytokines IL-1α and IL-1β in steatohepatitis remains elusive.

METHODS

We employed IL-1α and IL-1β-deficient mice and transplanted marrow cells to study the role of liver-resident and bone marrow-derived IL-1 in steatosis and its progression to steatohepatitis.

RESULTS

Atherogenic diet-induced steatohepatitis in wild-type mice was associated with 16 and 4.6 fold-elevations in mRNA levels of hepatic IL-1α and IL-1β, respectively. In mice deficient in either IL-1α or IL-1β the transformation of steatosis to steatohepatitis and liver fibrosis was markedly reduced. This protective effect in IL-1α-deficient mice was noted despite increased liver cholesterol levels. Deficiency of IL-1α markedly reduced plasma serum amyloid A and steady-state levels of mRNA coding for inflammatory genes (P-selectin, CXCL1, IL-6, and TNFα) as well as pro-fibrotic genes (MMP-9 and Collagen) and particularly a 50% decrease in TGFβ levels (p = 0.004). IL-1α mRNA levels were two-folds lower in IL-1β-deficient mice, and IL-1β transcripts were three-folds lower in IL-1α-deficient compared to wild-type mice. Hepatic cell derived IL-1α rather than from recruited bone marrow-derived cells was required for steatohepatitis development.

CONCLUSIONS

These data demonstrate the critical role of IL-1α and IL-1β in the transformation of steatosis to steatohepatitis and liver fibrosis in hypercholesterolemic mice. Therefore, the potential of neutralizing IL-1α and/or IL-1β to inhibit the development of steatohepatitis should be explored.

The effect of chronic hyperinsulinemia on plasma adiponectin levels in Sprague-Dawley rats

Adiponectin is an important vascular protective substance whose levels are reduced in states of insulin resistance. The relationships between plasma insulin levels and adiponectin are not fully understood, and it is not known whether it is the elevated circulating levels of insulin or insulin resistance that directly affects adiponectin levels. The present study evaluates the direct effect of chronic hyperinsulinemia on plasma adiponectin levels. Male Sprague-Dawley rats were treated with insulin (n=15) administered by a sustained-release implant or were given a sham implantation (n=10) as a control group. Body weight, systolic blood pressure, plasma glucose, triglycerides, insulin, and adiponectin were measured at baseline and after 20 and 40 d of treatment. Insulin-treated rats and controls showed a similar increase in body weight. The insulin-treated group had a significant increase in plasma insulin levels and a decrease in plasma glucose levels compared with the sham group, with no change in blood pressure or triglyceride levels. Adiponectin levels remained unchanged despite the significant increase in insulin levels. High circulating insulin levels do not affect plasma adiponectin levels. These results support the concept that the primary defect that results in insulin resistance and hyperinsulinemia is responsible for the altered plasma adiponectin levels in the metabolic syndrome and type 2 diabetes.

A 9-cis beta-carotene-enriched diet inhibits atherogenesis and fatty liver formation in LDL receptor knockout mice

Our aim was to study the effect of 9-cis beta-carotene-rich powder of the alga Dunaliella bardawil on lipid profile, atherogenesis, and liver steatosis in high-fat diet-fed LDL receptor knockout mice. In 4 sets of experiments, mice were distributed into the following groups: control, fed an unfortified diet; Dunaliella 50, fed a diet composed of 50% 9-cis and 50% all-trans beta-carotene; Dunaliella 25, fed a diet containing 25% 9-cis and 75% all-trans beta-carotene; beta-carotene-deficient Dunaliella, fed beta-carotene-deficient Dunaliella powder; and all-trans beta-carotene, fed a synthetic all-trans beta-carotene. All fortified diets contained 0.6% total beta-carotene. Algal 9-cis beta-carotene was absorbed by the mice and accumulated in the liver. Synthetic all-trans beta-carotene was not converted to 9-cis beta-carotene. Dunaliella 50 inhibited high-fat diet-induced plasma cholesterol elevation by 40-63% and reduced cholesterol concentrations in the atherogenic VLDL and LDL. Atherosclerotic lesion area in mice treated with Dunaliella 50 was 60-83% lower compared with mice fed the high-fat diet alone. beta-Carotene-deficient Dunaliella did not influence plasma cholesterol and atherogenesis, suggesting that beta-carotene is essential for a Dunaliella protective effect. Moreover, by administrating Dunaliella powder containing different levels of 9-cis and all-trans beta-carotene isomers, we found that the effect on plasma cholesterol concentration and atherogenesis is 9-cis-dependent. Dunaliella 50 also inhibited fat accumulation and inflammation in the livers of mice fed a high-fat diet, which was accompanied by reduced mRNA levels of inflammatory genes. These results in mice suggest that 9-cis beta-carotene may have the potential to inhibit atherogenesis in humans.

Metabolic syndrome: comparison of the two commonly used animal models

BACKGROUND

The etiology of the metabolic syndrome (MS) includes both genetic and environmental factors. The two most commonly studied animal models of the MS are the high-sucrose diet given to spontaneously hypertensive rats (SHRs) and high-fructose diet given to Sprague Dawley rats (SDRs). This study compares between these two models.

METHODS

The two rat strains were examined; within each group, the rats were assigned to either the high-sugar diet (SDRs with fructose-enriched diet and SHRs with sucrose-enriched diet) or standard rat chow (control group). The rats were followed for 7 weeks. The main MS components (obesity, hypertension, impaired glucose tolerance, hyperinsulinemia, hypertriglyceridemia, and hypercholesterolemia) were measured.

RESULTS

At baseline systolic blood pressure (SBP), fasting blood levels of triglycerides and insulin, as well as glucose intolerance, were significantly higher among the SHRs compared to SDRs. Following fructose enrichment, SDRs became hyperinsulinemic, hypertriglyceridemic, hypercholesterolemic, hypertensive, and insulin resistant, whereas SHRs responded to sucrose supplementation by a significant elevation in blood pressure and mild worsening of insulin resistance. Endpoint results revealed superiority of sucrose--SHR model in terms of hypertension and superiority of fructose--SDR model in terms of hyperinsulinemia, hypertriglyceridemia, and hypercholesterolemia. Both models showed similar postintervention degree of glucose tolerance.

CONCLUSIONS

The fructose-fed SDR model represents a predominantly environmentally acquired MS, whereas the SHR model is less affected by dietary intervention and better displays the predominantly genetic spontaneous appearance of the syndrome. This fundamental difference should be taken into consideration when choosing an animal model to study the MS.

A carotenoid algal preparation containing phytoene and phytofluene inhibited LDL oxidation in vitro

The antioxidative effect of the carotenoids phytoene and phytofluene in biological systems has not yet been studied. We therefore sought to investigate the effect of these carotenoids, isolated from the alga Dunaliella bardawil, in a biological system and used the in vitro low density lipoprotein (LDL) oxidation method to assay their antioxidative effects. We found that similar to beta-carotene and alpha-tocopherol, a carotenoid algal preparation containing phytoene and phytofluene inhibited LDL oxidation. These findings and the presence of phytoene and phytofluene in human tissues suggest that they can be part of the defense system against oxidative stress.

Characterisation of atherosclerotic lesions with scanning electron microscopy (SEM) of wet tissue

Atherosclerotic cardiovascular disease (CVD) is the universal leading cause of mortality and a major cause of morbidity. Additionally, the global epidemic of diabetes is associated with considerable cardiovascular mortality risk due to accelerated premature atherosclerosis. Development of effective therapies for atherosclerosis is dependent upon improved tools to assess atherosclerotic lesion progression in animal models. We present a novel technique that utilises scanning electron microscopy (SEM) for imaging wet biological specimens, thus enabling rapid and high-resolution imaging of atherosclerotic lesions. This wet SEM technique was used in an apoE-deficient mice model for morphological characterisation of early and advanced atherosclerotic lesions. Further demonstration of lipid-rich atherosclerotic lesions was carried out with osmium tetroxide staining for cholesterol. Gold immunolabelling of specific epitopes was applied in identification of the cellular and molecular components within the atherosclerotic lesions, namely foam cells, smooth muscle cells and collagen. The wet SEM technique demonstrates an accurate and detailed structural evaluation of the pathological process of atherosclerosis. Understanding the mechanisms that precipitate the atherosclerotic process, utilising this novel technique, may assist in the development of innovative therapeutic interventions for CVD management and prevention in the general population and in those with diabetes.

Metabolic stress with a high carbohydrate diet increases adiponectin levels

BACKGROUND

Adiponectin is an adipose tissue-specific protein, which possesses anti-atherogenic and antidiabetic properties, yet its plasma levels are decreased in subjects with metabolic syndrome. Although high fat diet has been linked to hypoadiponectinemia, the effect of high-carbohydrate diet on adiponectin levels is not known. Therefore, we studied the effect of high-carbohydrate diet on adiponectin levels in the rat models of hypertension and insulin resistance.

METHODS

Rats were randomly assigned to the high carbohydrate diet [Sprague-Dawley rats with fructose enriched diet (SDR-F) and spontaneously hypertensive rats with sucrose enriched diet (SHR-S model)] or chow diet (Control group). Rats were followed for 6 weeks (SDR-F model) and 8 weeks (SHR-S model). Body weight, systolic blood pressure, plasma levels of glucose, insulin, triglycerides and adiponectin, were recorded.

RESULTS

Both models were associated with features of the metabolic syndrome, namely, high insulin levels, increased blood pressure and triglyceride levels. Plasma adiponectin levels did not change in the control groups. In contrast, adiponectin levels increased by 39 and 30% compared to baseline following four and six weeks of fructose enriched diet in SDR (from 3.3+/-0.2 to 4.5+/-0.4 and 4.3+/-0.2 microg/ml, respectively, p<0.05). Likewise, five and eight weeks of sucrose enriched diet in SHR, induced a 54 and 81% increase in adiponectin levels compared to baseline (from 4.2+/-0.3 to 6.3+/-0.3 and 7.3+/-0.5 microg/ml, respectively, p<0.01).

CONCLUSION

Metabolic stress with a high-carbohydrate diet increases plasma levels of adiponectin. Further studies will elucidate whether this is a transitory compensatory mechanism or a sign of target organ resistance to adiponectin.

Effect of PPAR-gamma agonist on adiponectin levels in the metabolic syndrome: lessons from the high fructose fed rat model

BACKGROUND

The health hazard of the metabolic syndrome (MS) is increasing, yet there is no effective pharmacologic treatment to this entity as a whole. Recently, hypoadiponectinemia was found to play an important role in the development of MS. We studied the effect of the PPAR-gamma agonist rosiglitazone on adiponectin and the metabolic profile in the fructose-induced hypertensive, hyperinsulinemic, hypertriglyceridemic rat model.

METHODS

Thirty male Sprague-Dawley rats were divided into three groups. Ten were fed standard rat chow for 5 weeks, 10, a fructose-enriched diet for 5 weeks, and 10, a fructose-enriched diet for 5 weeks, with rosiglitazone 10 mg/kg/d added during the last 2 weeks. Blood pressure (BP), oral glucose tolerance test (OGTT), plasma insulin, triglycerides, and adiponectin were recorded, as well as mRNA levels of the adiponectin gene in visceral adipose tissue.

RESULTS

Fructose-fed rats developed MS as manifested by the increase in systolic BP (from 139 +/- 3 to 158 +/- 4 mm Hg, P < .05), insulin (from 26 +/- 1.6 to 40 +/- 2.5 muU/mL, P < .05), triglycerides (from 91 +/- 9 to 304 +/- 24 mg/dL, P < .05), and impaired OGTT (area under the curve from 13,894 +/- 246 to 17,725 +/- 700 mg/dL/min). Treatment with rosiglitazone reversed these effects and reduced BP to 133 +/- 7 mm Hg, insulin levels to 30 +/- 2.8 muU/mL, triglycerides to 116 +/- 9 mg/dL, and the OGTT to 15,415 +/- 372 mg/dL/min (P < .05 for all variables). In addition, rosiglitazone increased plasma levels of adiponectin fourfold from 4.3 +/- 0.1 to 18.4 +/- 0.6 mug/mL (P < .05). This increase was coupled with 3.8-fold increase in adiponectin mRNA in visceral adipose tissue.

CONCLUSIONS

This study shows for the first time that in an animal model of MS, the insulin sensitizer, rosiglitazone, improves the metabolic profile and increases plasma levels of adiponectin and its gene expression. It is possible therefore that rosiglitazone exerts its beneficial effects by increasing the levels of adiponectin.

Differential role and tissue specificity of interleukin-1alpha gene expression in atherogenesis and lipid metabolism

OBJECTIVE

We examined the role of IL-1alpha and IL-1beta expressed by bone marrow-derived cells in atherogenesis and lipid metabolism.

METHODS AND RESULTS

We first studied the effect of atherogenic diet on wild-type C57BL/6 IL-1alpha or IL-1beta deficient mice. IL-1alpha KO resulted in a comparatively higher total cholesterol levels, compared to WT and IL-1beta KO mice (398+/-10; 266+/-19; 223+/-13 mg/dl, respectively, p<0.001), due to higher non-HDL cholesterol. Nevertheless, aortic sinus lesion area was 56% lower in IL-1alpha KO (p<0.05) and 50% lower in IL-1beta KO (p=0.08), compared to WT mice. Likewise, SAA levels in IL-1alpha KO mice were markedly lower compared to WT and IL-1beta KO mice (31+/-14; 220+/-33 and 106+/-39 microg/ml, respectively, p<0.001). To study the specific role of bone marrow-derived IL-1, irradiated C57BL/6 mice were transplanted with either IL-1+/+, IL-1alpha-/- or IL-1beta-/- bone marrow cells. Despite similar lipoprotein levels, aortic sinus lesion area was 59% lower in IL-1alpha-/- transplanted (p<0.05) compared to IL-1+/+ transplanted mice. Lesion area in IL-1beta-/- was 33% lower than in IL-1+/+ recipient mice, but it was not statistically significant.

CONCLUSION

We demonstrated that early lesion formation is accelerated specifically by bone marrow-derived IL-1alpha. Furthermore, we showed that the expression of IL-1alpha in cells other than the bone marrow plays a significant role in non-HDL cholesterol metabolism.

Melatonin reduces night blood pressure in patients with nocturnal hypertension

PURPOSE

Nocturnal hypertension is associated with a high risk of morbidity and mortality. A blunted nocturnal surge in melatonin excretion has been described in nondipping hypertensive patients. We therefore studied the potency of melatonin to reduce nighttime blood pressure (BP) in treated hypertensive patients with nocturnal hypertension.

PATIENTS AND METHODS

Thirty-eight treated hypertensive patients (22 males, mean age 64+/-11 years) with confirmed nocturnal hypertension (mean nighttime systolic BP >125 mm Hg), according to repeated 24-hour ambulatory blood pressure monitoring (ABPM), were randomized in a double-blind fashion to receive either controlled release (CR)-melatonin 2 mg or placebo 2 hours before bedtime for 4 weeks. A 24-hour ABPM was then performed.

RESULTS

Melatonin treatment reduced nocturnal systolic BP significantly from 136+/-9 to 130+/-10 mm Hg (P=.011), and diastolic BP from 72+/-11 to 69+/-9 mm Hg (P=.002), whereas placebo had no effect on nocturnal BP. The reduction in nocturnal systolic BP was significantly greater with melatonin than with placebo (P=.01), and was most prominent between 2:00 AM and 5:00 AM (P=.002).

CONCLUSIONS

Evening CR-melatonin 2 mg treatment for 4 weeks significantly reduced nocturnal systolic BP in patients with nocturnal hypertension. Thus, an addition of melatonin 2 mg at night to stable antihypertensive treatment may improve nocturnal BP control in treated patients with nocturnal hypertension.

Adiponectin: linking the metabolic syndrome to its cardiovascular consequences

Obesity and its related disorders, glucose intolerance, hypertension and hyperlipidemia, collectively named the metabolic syndrome, result in substantial cardiovascular morbidity and mortality. Recent data point to several underlying regulatory mechanisms through which obesity links these various outcomes. Adipose tissue is now understood to function not merely as a passive energy storage depot but as an active endocrine organ, producing a variety of bioactive substances termed adipocytokines. Adiponectin, an adipocytokine first described as the most abundant protein produced by adipocytes, appears to serve as a central regulatory protein in many of the physiologic pathways controlling lipid and carbohydrate metabolism, and to mediate various vascular processes. Adiponectin displays both anti-inflammatory and antiatherogenic properties. Unlike other adipocytokines, its levels are paradoxically decreased in obesity and insulin-resistance states including metabolic syndrome and diabetes, as well as hypertension and coronary artery disease. This review will detail the relationship of adiponectin to various features of obesity and insulin-resistance syndromes, as well as its relationship to the cardiovascular complications of these disorders.

Circulating adiponectin concentrations in patients with congestive heart failure

OBJECTIVES

To determine concentrations of adiponectin and its predictive value on outcome in a cohort of patients with congestive heart failure (CHF).

METHODS

Serum and clinical data were obtained for outpatients with clinically controlled CHF (n = 175). Serum concentrations of adiponectin, C reactive protein, N-terminal pro-brain natriuretic peptide (NT-proBNP), interleukin (IL) -1beta, IL-6, IL-8, IL-10, IL-12, tumour necrosis factor alpha and CD-40 ligand were determined. The association of adiponectin with the clinical severity of CHF was sought as well as the predictive value of this adipokine on mortality, CHF hospitalisations or the occurrence of each of these end points.

RESULTS

Concentrations of adiponectin were significantly increased in patients with CHF. Patients with higher New York Heart Association class had significantly higher serum concentrations of adiponectin. Adiponectin serum concentrations were lower in patients with diabetes and CHF as well as in patients with ischaemic cardiomyopathy. Serum adiponectin concentration was positively associated with age and NT-proBNP but was negatively correlated with C reactive protein concentrations. Serum adiponectin above the 75th centile was found to be an independent predictor of total mortality, CHF hospitalisations or a composite of these end points over a two-year prospective follow up.

CONCLUSION

Adiponectin is increased in CHF patients and predicts mortality and morbidity.

Apolipoprotein A-V Deficiency Results in Marked Hypertriglyceridemia Attributable to Decreased Lipolysis of Triglyceride-Rich Lipoproteins and Removal of Their Remnants

OBJECTIVE

ApoAV, a newly discovered apoprotein, affects plasma triglyceride level. To determine how this occurs, we studied triglyceride-rich lipoprotein (TRL) metabolism in mice deficient in apoAV.

METHODS AND RESULTS

No significant difference in triglyceride production rate was found between apoa5(-/-) mice and controls. The presence or absence of apoAV affected TRL catabolism. After the injection of 14C-palmitate and 3H-cholesterol labeled chylomicrons and (125)I-labeled chylomicron remnants, the disappearance of 14C, 3H, and (125)I was significantly slower in apoa5(-/-) mice relative to controls. This was because of diminished lipolysis of TRL and the reduced rate of uptake of their remnants in apoa5(-/-) mice. Observed elevated cholesterol level was caused by increased high-density lipoprotein (HDL) cholesterol in apoa5(-/-) mice. VLDL from apoa5(-/-) mice were poor substrate for lipoprotein lipase, and did not bind to the low-density lipoprotein (LDL) receptor as well as normal very-low-density lipoprotein (VLDL). LDL receptor levels were slightly elevated in apoa5(-/-) mice consistent with lower remnant uptake rates. These alterations may be the result of the lower apoE-to-apoC ratio found in VLDL isolated from apoa5(-/-) mice.

CONCLUSIONS

These results support the hypothesis that the absence of apoAV slows lipolysis of TRL and the removal of their remnants by regulating their apoproteins content after secretion.

Peripartum hypertension from pheochromocytoma: a rare and challenging entity

BACKGROUND

Pheochromocytoma, a rare and usually curable cause of hypertension, is characterized by symptoms and signs related to increased catecholamine secretion. Pregnancy can elicit clinical manifestations of otherwise unrecognized pheochromocytoma.

METHODS AND RESULTS

Four women, ranging in age from 27 to 37 years, were referred to the hypertension clinic with the following presentations: 1) a 35-year-old woman, diagnosed with gestational hypertension and headaches during the third trimester of her pregnancy and 5 months after delivery, was hospitalized with pulmonary edema. Echocardiography revealed severe dilated left ventricular (LV) dysfunction. Cardiac function was normalized after surgical resection of a pheochromocytoma from her left adrenal; 2) a 37-year-old woman suffered from preeclampsia, persistent hypertension and orthostatic hypotension after a cesarean section. A diagnostic work-up revealed a catecholamine-secreting paraganglioma in the retroperitoneum. The patient underwent a laparosopic resection of the tumor; 3) a 27-year-old woman suffered from hypertension and episodes of palpitations, sweating, and dyspnea in the first trimester of her pregnancy. An ultrasound revealed a 5-cm mass in the left adrenal. She underwent a left adrenalectomy at the 17th week of pregnancy, which confirmed the diagnosis of pheochromocytoma; 4) a 34-year-old woman, at the 26th week of pregnancy, presented with an acute loss of vision and blood pressure of 230/140 mm Hg. Fundoscopy showed papilledema with soft exudates in both eyes. Chemical studies were positive and imaging revealed a left adrenal pheochromocytoma. Despite aggressive medical treatment, fetal distress mandated a laparotomy at the end of the 28th week of pregnancy. A healthy newborn was delivered and resection of the adrenal tumor confirmed the diagnosis of pheochromocytoma.

CONCLUSIONS

Although rare, pheochromocytoma can cause severe peripartum hypertension. Screening for pheochromocytoma, ideally with plasma-free metanephrines, should be considered in cases of peripartum hypertension.

Diuretic induced hyponatraemia in elderly hypertensive women

Diuretics are recommended as first-line antihypertensive treatment in elderly patients. Although attention is usually paid to prevent hypokalaemia with diuretic therapy, risk of hyponatraemia is often ignored. We performed this study to characterise hypertensive patients at increased risk to develop hyponatraemia. We reviewed charts of hypertensive patients hospitalised in Chaim Sheba Medical Center for hyponatraemia from 1990 to 1997. Patients with other causes of hyponatraemia were excluded. The General Practice Maccabi database was used to estimate age and sex distribution of patients prescribed diuretics for hypertension. We identified 180 hypertensive patients (149 F, 31 M; mean age 76.4 +/- 9.2 years) hospitalised because of hyponatraemia. Across all age groups, odds ratio (OR) to develop hyponatraemia was three times higher for women vs men (OR 3.10, 95% confidence interval (CI): 2.07-4.67). One hundred and sixty-two patients (90%) were older than 65 years. Patients of both sexes older than 65 years were 10 times (and if they were older than 75 years 16 times) more likely to develop hyponatraemia than those younger than 65 years (OR 9.87, 95%, CI: 5.93-16.64). Most patients (74.5%) used a thiazide-based diuretic; only 10% used a low dose (<25 mg/day). In 37% of patients diuretics were used for more than 1 year before hyponatraemia developed. Diuretic-induced hyponatraemia may be insidious and appear even after prolonged diuretics use. Elderly women seem to be at particularly high risk. In this population diuretic use should be associated with close monitoring of sodium and potassium levels.