Reversible conduction block of peroneal nerve associated with SARS-CoV-2.

BACKGROUND: The ongoing SARS-CoV-2 pandemic, which is dramatically spreading worldwide, is well known for its respiratory sequelae. Besides cases of Guillain-Barré Syndrome, encephalitis, hyposmia, the whole range of neurological complications due to SARSCoV-2 is still not well known. METHODS AND FINDINGS: Herein, we report a new case of COVID-19, associated with mononeuropathy with reversible conduction block (CB). After SARS-CoV-2 infection, the patient developed acute weakness of left peroneal muscles. He underwent an endovenous immunoglobulin treatment, and symptoms improved. Two electroneurographic exam (before and after treatment), showed a reversible CB on left peroneal nerve. Dosage of serum antiganglioside antibodies showed anti-GM1 IgM positivity. CONCLUSIONS: The present case gives new informations about reversible CB neuropathy as an acute presentation of SARS-CoV-2. Besides, antiganglioside antibodies evaluation could be useful to understand etiology of the increasing number of neurological manifestations related to SARS-CoV-2.

Identification of a tumor-promoter cholesterol metabolite in human breast cancers acting through the glucocorticoid receptor.

Breast cancer (BC) remains the primary cause of death from cancer among women worldwide. Cholesterol-5,6-epoxide (5,6-EC) metabolism is deregulated in BC but the molecular origin of this is unknown. Here, we have identified an oncometabolism downstream of 5,6-EC that promotes BC progression independently of estrogen receptor α expression. We show that cholesterol epoxide hydrolase (ChEH) metabolizes 5,6-EC into cholestane-3ß,5α,6ß-triol, which is transformed into the oncometabolite 6-oxo-cholestan-3ß,5α-diol (OCDO) by 11ß-hydroxysteroid-dehydrogenase-type-2 (11ßHSD2). 11ßHSD2 is known to regulate glucocorticoid metabolism by converting active cortisol into inactive cortisone. ChEH inhibition and 11ßHSD2 silencing inhibited OCDO production and tumor growth. Patient BC samples showed significant increased OCDO levels and greater ChEH and 11ßHSD2 protein expression compared with normal tissues. The analysis of several human BC mRNA databases indicated that 11ßHSD2 and ChEH overexpression correlated with a higher risk of patient death, highlighting that the biosynthetic pathway producing OCDO is of major importance to BC pathology. OCDO stimulates BC cell growth by binding to the glucocorticoid receptor (GR), the nuclear receptor of endogenous cortisol. Interestingly, high GR expression or activation correlates with poor therapeutic response or prognosis in many solid tumors, including BC. Targeting the enzymes involved in cholesterol epoxide and glucocorticoid metabolism or GR may be novel strategies to prevent and treat BC.

Alpha- and gamma-tocopherol levels in human semen and their potential functional implications.

Vitamin E is a potent antioxidant that has been considered involved in fertility, but studies have mostly focused on α-tocopherol. Our study aimed at measuring, by an isotope dilution gas chromatography-mass spectrometry method, α- and γ-tocopherol concentration in human semen in a large and well-characterised population (134 men with different semen parameters and in varicocele patients), as well as their potential role in male fertility. We carried out freeze/thaw experiments in 15 samples with the two isomers in the cryoprotective medium. Moreover, our study included 10 subjects supplemented in vivo with α-tocopherol for 90 days. In seminal plasma, γ-tocopherol concentration was significantly lower in the varicocele group than in the normozoospermic group. We observed that γ-tocopherol, supplemented to cryopreservation medium, induced a higher post-thaw human sperm viability and motility than α-tocopherol. The results of in vivo α-tocopherol supplementation showed a decrease in γ-tocopherol concentration with increasing α-tocopherol level in blood. This is the first report related to γ-tocopherol distribution in human semen analysed by gas chromatography-mass spectrometry. γ-tocopherol would not seem to be related to semen parameters but to cellular oxidative condition. This tocopherol may contribute to human health in a yet unexplored way.

Quantitative charge-tags for sterol and oxysterol analysis.

BACKGROUND: Global sterol analysis is challenging owing to the extreme diversity of sterol natural products, the tendency of cholesterol to dominate in abundance over all other sterols, and the structural lack of a strong chromophore or readily ionized functional group. We developed a method to overcome these challenges by using different isotope-labeled versions of the Girard P reagent (GP) as quantitative charge-tags for the LC-MS analysis of sterols including oxysterols. METHODS: Sterols/oxysterols in plasma were extracted in ethanol containing deuterated internal standards, separated by C18 solid-phase extraction, and derivatized with GP, with or without prior oxidation of 3ß-hydroxy to 3-oxo groups. RESULTS: By use of different isotope-labeled GPs, it was possible to analyze in a single LC-MS analysis both sterols/oxysterols that naturally possess a 3-oxo group and those with a 3ß-hydroxy group. Intra- and interassay CVs were <15%, and recoveries for representative oxysterols and cholestenoic acids were 85%-108%. By adopting a multiplex approach to isotope labeling, we analyzed up to 4 different samples in a single run. Using plasma samples, we could demonstrate the diagnosis of inborn errors of metabolism and also the export of oxysterols from brain via the jugular vein. CONCLUSIONS: This method allows the profiling of the widest range of sterols/oxysterols in a single analytical run and can be used to identify inborn errors of cholesterol synthesis and metabolism.

Implications of cholesterol autoxidation products in the pathogenesis of inflammatory diseases.

There is rising interest in non-enzymatic cholesterol oxidation because the resulting oxysterols have biological activity and can be used as non-invasive markers of oxidative stress in vivo. The preferential site of oxidation of cholesterol by highly reactive species is at C7 having a relatively weak carbon-hydrogen bond. Cholesterol autoxidation is known to proceed via two distinct pathways, a free radical pathway driven by a chain reaction mechanism (type I autoxidation) and a non-free radical pathway (type II autoxidation). Oxysterols arising from type II autoxidation of cholesterol have no enzymatic correlates, and singlet oxygen ((1)ΔgO2) and ozone (O3) are the non-radical molecules involved in the mechanism. Four primary derivatives are possible in the reaction of cholesterol with singlet oxygen via ene addition and the formation of 5α-, 5ß-, 6α- and 6ß-hydroxycholesterol preceded by their respective hydroperoxyde intermediates. The reaction of ozone with cholesterol is very fast and gives rise to a complex array of oxysterols. The site of the initial ozone reaction is at the Δ5,6 -double bond and yields 1,2,3-trioxolane, a compound that rapidly decomposes into a series of unstable intermediates and end products. The downstream product 3ß-hydroxy-5-oxo-5,6-secocholestan-6-al (sec-A, also called 5,6-secosterol), resulting from cleavage of the B ring, and its aldolization product (sec-B) have been proposed as a specific marker of ozone-associated tissue damage and ozone production in vivo. The relevance of specific ozone-modified cholesterol products is, however, hampered by the fact sec-A and sec-B can also arise from singlet oxygen via Hock cleavage of 5α-hydroperoxycholesterol or via a dioxietane intermediate. Whatever the mechanism may be, sec-A and sec-B have no enzymatic route of production in vivo and are reportedly bioactive, rendering them attractive biomarkers to elucidate oxidative stress-associated pathophysiological pathways and to develop pharmacological agents.

Oxidative stress and antioxidant therapy in cystic fibrosis.

Cystic fibrosis is a lethal autosomal recessive condition caused by a defect of the transmembrane conductance regulator gene that has a key role in cell homeostasis. A dysfunctional cystic fibrosis transmembrane conductance regulator impairs the efflux of cell anions such as chloride and bicarbonate, and also that of other solutes such as reduced glutathione. This defect produces an increased viscosity of secretions together with other metabolic defects of epithelia that ultimately promote the obstruction and fibrosis of organs. Recurrent pulmonary infections and respiratory dysfunction are main clinical consequences of these pathogenetic events, followed by pancreatic and liver insufficiency, diabetes, protein-energy malnutrition, etc. This complex comorbidity is associated with the extensive injury of different biomolecular targets by reactive oxygen species, which is the biochemical hallmark of oxidative stress. These biological lesions are particularly pronounced in the lung, in which the extent of oxidative markers parallels that of inflammatory markers between chronic events and acute exacerbations along the progression of the disease. Herein, an abnormal flux of reactive oxygen species is present by the sustained activation of neutrophils and other cystic fibrosis-derived defects in the homeostatic processes of pulmonary epithelia and lining fluids. A sub-optimal antioxidant protection is believed to represent a main contributor to oxidative stress and to the poor control of immuno-inflammatory pathways in these patients. Observed defects include an impaired reduced glutathione metabolism and lowered intake and absorption of fat-soluble antioxidants (vitamin E, carotenoids, coenzyme Q-10, some polyunsaturated fatty acids, etc.) and oligoelements (such as Se, Cu and Zn) that are involved in reactive oxygen species detoxification by means of enzymatic defenses. Oral supplements and aerosolized formulations of thiols have been used in the antioxidant therapy of this inherited disease with the main aim of reducing the extent of oxidative lesions and the rate of lung deterioration. Despite positive effects on laboratory end points, poor evidence was obtained on the side of clinical outcome so far. These aspects examined in this critical review of the literature clearly suggest that further and more rigorous trials are needed together with new generations of pharmacological tools to a more effective antioxidant and anti-inflammatory therapy of cystic fibrosis patients. This article is part of a Special Issue entitled: Antioxidants and Antioxidant Treatment in Disease.

Global Neurocognitive and Frontal Functions Analysis and Precision Intrathecal Pressure Measurement to Settle the Diagnostic Dilemma of the Normal Pressure Hydrocephalus: A Preliminary Experience.

INTRODUCTION: Normal-pressure hydrocephalus (NPH) is a common condition associated with a cognitive deterioration and possibly involving up to 9%-14% of all nursing home residents older than 65 years old. The purpose of the present paper is to introduce an inclusive study protocol aimed at increasing the diagnostic precision and follow-up accuracy. METHODS: A total of 28 patients were operated on for NPH in our institution in the period ranging between January 2015 and December 2019. All the patients underwent magnetic resonance imaging of the brain with standard sequences, calculation of the Evans index and corpus callosum angle, and evaluations by means of Montreal Cognitive Assessment (MOCA), Mini-Mental State Examination, and Frontal Assessment Battery (FAB) neuropsychological tests preoperatively and at 1 and 6 months. A preoperative lumbar test infusion (LIT) with fine measurement of the intrathecal pressures at the beginning and at the end of the procedures was performed. RESULTS: MOCA and FAB proved an overall improvement of the neurocognitive conditions at 1 month postoperatively. The mean pressure at the beginning of the LIT, was negatively associated with the neuropsychological outcome variables (Mini-Mental State Examination, FAB, and MOCA) in the 3 different evaluations, with FAB and MOCA at 6 months. We found a strong positive correlation between the Evans index as measured on the first magnetic resonance imaging scan both with the diastolic and systolic pressure at the beginning of the test. CONCLUSIONS: Neuropsychological assessment, combined with LIT with intrathecal pressure managements aids the diagnostic process in patients affected by NPH. It allows standardizing in a rigorous fashion the follow-up evaluation of patients undergoing surgery for a ventriculoperitoneal shunt.

3ß-Hydroxy-5ß-hydroxy-B-norcholestane-6ß-carboxaldehyde (SEC-B) Induces Proinflammatory Activation of Human Endothelial Cells Associated with Nitric Oxide Production and Endothelial Nitric Oxide Synthase/Caveolin-1 Dysregulation.

Oxysterols are a family of 27-carbon cholesterol oxidation derivatives found in low-density lipoproteins (LDLs) and atherosclerotic plaques where they trigger several biological responses involved in the initiation and progression of atherosclerosis. Several pieces of evidence suggest that oxysterols contribute to endothelial dysfunction (ED) due to their ability to alter membrane fluidity and cell permeability leading to inflammation, oxidative stress and apoptosis. The present study aimed to investigate the molecular events occurring in human microvascular endothelial cells (HMEC-1) in response to autoxidation-generated 3ß-hydroxy-5ß-hydroxy-B-norcholestane-6ß-carboxaldehyde (SEC-B) exposure. Our results highlight that SEC-B rapidly activates HMEC-1 by inducing oxidative stress, nitric oxide (NO) production and pro-inflammatory cytokine release. Exposure to SEC-B up to 24 h results in persistent accumulation of the vasodilator NO paralleled by an upregulation of the endothelial nitric oxide synthase (eNOS) enzyme and downregulation of Caveolin-1 (Cav-1) protein levels. Moreover, reduced expression and extracellular release of the vasoconstrictor factor endothelin-1 (ET-1) are observed. Furthermore, SEC-B stimulates the expression of the cytokines interleukin-6 (IL-6) and tumor necrosis factor-like weak inducer of apoptosis (TWEAK). This proinflammatory state leads to increased monocyte recruitment on activated HMEC-1 cells. Our findings add new knowledge on the role of SEC-B in ED and further support its potential implication in atherosclerosis.

Assessment of the genetic effects of polymorphisms in the osteoprotegerin gene, TNFRSF11B, on serum osteoprotegerin levels and carotid plaque vulnerability.

BACKGROUND AND PURPOSE: Osteoprotegerin (OPG) is a secretory glycoprotein which belongs to the tumor necrosis factor receptor family. Various mechanisms have been suggested by which calcification might alter atherosclerotic plaque stability, but the significance of this intimal calcification is controversial. High concentrations of OPG have been associated with the presence of vascular and cardiovascular diseases. This study was designed to assess the association between gene polymorphisms of the OPG gene (TNFRSF11B), the serum OPG level, and plaque stability in patients with carotid atherosclerosis. METHODS: We studied 177 patients with internal carotid artery stenosis who underwent carotid endarterectomy and also 303 controls. Carotid endarterectomy samples removed from patients were assessed by immunohistochemistry. Concentrations of OPG were measured and gene polymorphisms were examined by polymerase chain reaction and restriction enzyme analysis and were compared, initially between patients with carotid atherosclerosis and controls, and subsequently between stable and unstable carotid plaques. RESULTS: We found that the GG genotype of the T245G polymorphism, the CC genotype of the T950C polymorphism, and the CC genotype of the G1181C polymorphism were significantly higher in patients with carotid plaque than in controls (21.5% versus 10.9% , P<0.01; 15.8% versus 7.6%, P<0.01; and 20.3% versus 10.9%, P<0.01, respectively) and that these polymorphisms were associated with high serum OPG levels (4.02 [3.07] versus 2.94 [1.81] pmol/L; P<0.01), which were significantly higher in patients with unstable atherosclerotic plaques (5.86 [4.02] versus 3.53 [1.87] pmol/L; P<0.01). CONCLUSIONS: The TNFRSF11B gene polymorphisms studied are associated with high serum OPG levels and might be potential markers for plaque instability.

Rheumatoid Arthritis with Generalized Lymphadenopathy Mimicking Lymphoma on Positron Emission Tomography/Computed Tomography with 18F-Fluorodeoxyglucose.

A 42-year-old male presented with weight loss and progressively increasing pain and swelling in joints over the past 3 months. Contrast-enhanced computed tomography (CT) demonstrated pleuropulmonary opacities and supra/infradiaphragmatic lymph nodes enlargement. Positron emission tomography (PET/CT) with 18F-fluorodeoxyglucose showed intensely increased tracer uptake in joints, in pulmonary opacities, as well as in thoracic, iliac, and inguinal nodes. On suspicion of lymphoma with synovial involvement, he was submitted to lymph node and synovial biopsy, which revealed reactive follicular lymphadenopathy and synovium inflammatory changes, respectively. Rheumatoid factor resulted increased, and thus, diagnosis of rheumatoid arthritis with related lung and lymph node involvement was made.

LDL receptors, caveolae and cholesterol in endothelial dysfunction: oxLDLs accomplices or victims?

Oxidized LDLs (oxLDLs) and oxysterols play a key role in endothelial dysfunction and the development of atherosclerosis. The loss of vascular endothelium function negatively impacts vasomotion, cell growth, adhesiveness and barrier functions. While for some of these disturbances, a reasonable explanation can be provided from a mechanistic standpoint, for many others, the molecular mediators that are involved are unknown. Caveolae, specific plasma membrane domains, have recently emerged as targets and mediators of oxLDL-induced endothelial dysfunction. Caveolae and their associated protein caveolin-1 (Cav-1) are involved in oxLDLs/LDLs transcytosis, mainly through the scavenger receptor class B type 1 (SR-B1 or SCARB1). In contrast, oxLDLs endocytosis is mediated by the lectin-like oxidized LDL receptor 1 (LOX-1), whose activity depends on an intact caveolae system. In addition, LOX-1 regulates the expression of Cav-1 and vice versa. On the other hand, oxLDLs may affect cholesterol plasma membrane content/distribution thus influencing caveolae architecture, Cav-1 localization and the associated signalling. Overall, the evidence indicate that caveolae have both active and passive roles in oxLDL-induced endothelial cell dysfunction. First, as mediators of lipid uptake and transfer in the subendothelial space and, later, as targets of changes in composition/dynamics of plasma membrane lipids resulting from increased levels of circulating oxLDLs. Gaining a better understanding of how oxLDLs interact with endothelial cells and modulate caveolae-mediated signalling pathways, leading to endothelial dysfunction, is crucial to find new targets for intervention to tackle atherosclerosis and the related clinical entities. LINKED ARTICLES: This article is part of a themed issue on Oxysterols, Lifelong Health and Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.16/issuetoc.

7-ketocholesterol and 5,6-secosterol modulate differently the stress-activated mitogen-activated protein kinases (MAPKs) in liver cells.

Enhanced oxidative stress is a common feature of liver diseases and contributes to chronic liver disease (CLD) progression by inducing fibrogenesis during liver regeneration. Peroxidation products of cholesterol metabolism, named oxysterols, are new and reliable markers of oxidative stress in vivo. Patients affected by CLDs present high plasma levels of oxysterols, raising the question of the origin and biological relevance of these compounds in the pathophysiology of chronic liver damage. The aim of this study was to examine the molecular basis of the biological effects of oxysterols on liver-derived cells, HepG2 and Huh7. Cells were treated with different concentrations (10(-9) to 10(-5) M) of 7-ketocholesterol used as a reference, and 5,6-secosterol, a recently discovered oxysterol. FACS investigations, caspase-3 activation, and Sytox Green immunofluorescent assay showed that pathological concentrations of oxysterols induced necrosis (30-50%) after 48 h of treatment. The two analyzed compounds displayed a similar, but not identical, behavior. In fact, 5,6-secosterol, but not 7-ketocholesterol, induced cell senescence. Notably, low concentrations of 5,6-secosterol caused a sustained activation of ERK1/2, inducing cell proliferation, this unexpected behavior should be better characterized by further studies. Since enhanced oxidative stress is known to worsen liver chronic hepatitis and frequently results in overall decreased cellular survival, our data suggest the important and different role oxysterols may have in interfering with physiological liver tissue regeneration in injured human liver. Antioxidant treatment may provide a highly specific and effective mean to counteract the common consequences of oxidative stress on chronic hepatitis, such as fibrosis/cirrhosis and liver failure.

Extra virgin olive oil improves synaptic activity, short-term plasticity, memory, and neuropathology in a tauopathy model.

In recent years, increasing evidence has accumulated supporting the health benefits of extra virgin olive oil (EVOO). Previous studies showed that EVOO supplementation improves Alzheimer's disease (AD)-like amyloidotic phenotype of transgenic mice. However, while much attention has been focused on EVOO-mediated modulation of Aß processing, its direct influence on tau metabolism in vivo and synaptic function is still poorly characterized. In this study, we investigated the effect of chronic supplementation of EVOO on the phenotype of a relevant mouse model of tauopathy, human transgenic tau mice (hTau). Starting at 6 months of age, hTau mice were fed chow diet supplemented with EVOO or vehicle for additional 6 months, and then the effect on their phenotype was assessed. At the end of the treatment, compared with control mice receiving EVOO displayed improved memory and cognition which was associated with increased basal synaptic activity and short-term plasticity. This effect was accompanied by an upregulation of complexin 1, a key presynaptic protein. Moreover, EVOO treatment resulted in a significant reduction of tau oligomers and phosphorylated tau at specific epitopes. Our findings demonstrate that EVOO directly improves synaptic activity, short-term plasticity, and memory while decreasing tau neuropathology in the hTau mice. These results strengthen the healthy benefits of EVOO and further support the therapeutic potential of this natural product not only for AD but also for primary tauopathies.

Malignant Insulinoma with Multiple Liver Metastases and Hypercalcitoninemia in a Patient with Type 2 Diabetes Mellitus Presenting as Recurrent Episodes of Diaphoresis due to Severe Hypoglycemia.

Insulinoma is an insulin-producing pancreatic neuroendocrine tumor that can be malignant in about 10% of cases. Locoregional invasion, lymph node metastases, or remote metastases are the main criteria of malignant insulinoma. Its incidence in patients with pre-existing diabetes mellitus (DM) is exceptionally rare. In this report, we describe a 66-year-old man with long-standing type 2 DM who presented with recurrent episodes of diaphoresis due to severe hypoglycemia despite the withdrawal of insulin therapy, hypercalcitoninemia, and biochemical and radiological findings suggestive of metastatic malignant insulinoma. Unfortunately, after few days of diazoxide treatment, edema, hypotension, oliguria, and water retention were observed, patient's clinical status deteriorated rapidly, and he died in our department from acute renal failure.

Pioglitazone enhances collateral blood flow in ischemic hindlimb of diabetic mice through an Akt-dependent VEGF-mediated mechanism, regardless of PPARgamma stimulation.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is commonly associated with both microvascular and macrovascular complications and a strong correlation exists between glycaemic control and the incidence and progression of vascular complications. Pioglitazone, a Peroxisome proliferator-activated receptor-gamma (PPARgamma) ligand indicated for therapy of type T2DM, induces vascular effects that seem to occur independently of glucose lowering. METHODS: By using a hindlimb ischemia murine model, in this study we have found that pioglitazone restores the blood flow recovery and capillary density in ischemic muscle of diabetic mice and that this process is associated with increased expression of Vascular Endothelial Growth Factor (VEGF). Importantly, these beneficial effects are abrogated when endogenous Akt is inhibited; furthermore, the direct activation of PPARgamma, with its selective agonist GW1929, does not restore blood flow recovery and capillary density. Finally, an important collateral vessel growth is obtained with combined treatment with pioglitazone and selective PPARgamma inhibitor GW9662. CONCLUSION: These data demonstrate that Akt-VEGF pathway is essential for ischemia-induced angiogenic effect of pioglitazone and that pioglitazone exerts this effect via a PPARgamma independent manner.

Imaging coronary and extracoronary atherosclerosis: feasibility and impact of whole-body computed tomography angiography.

A comprehensive whole-body approach to noninvasive evaluation of coronary and extracoronary vasculature is currently not available. The objective of our study was to assess the potential of 64-slice computed tomography angiography (64-CTA) for whole-body evaluation of atherosclerosis burden. Seventy-eight patients referred for coronary imaging underwent whole-body 64-CTA using an adjusted strategy for the administration of contrast medium with dose-saving algorithms involving ECG modulation and reduced tube voltage. Arterial segments (15 coronary, 32 systemic) were evaluated for significant (> or =50%) steno-occlusive disease while arterovenous density was evaluated at seven extracoronary locations. Homogeneous attenuation (mean 321 +/- 20 HU) was obtained throughout the systemic vasculature. Atherosclerosis was observed in 238/995 (24%) coronary and 368/2441 (15%) systemic segments. Significant stenoses/occlusions were present in 214 (21%)/24 (2.5%) coronary segments while asymptomatic clinically relevant stenoses were present in 49 systemic segments. Sensitivity, specificity, positive and negative predictive values of coronary 64-CTA among 52 patients who also underwent quantitative coronary angiography were 92%, 95%, 81% and 98%, respectively. ECG modulation decreased radiation exposure to 14.1-15.4 mSv per patient. Comprehensive, noninvasive assessment of atherosclerosis can be performed by whole-body 64-CTA and may have a positive impact on secondary prevention.

Adverse reactions of Amiodarone.

Adverse drug reaction is defined by the World Health Organization as any response to a drug that is noxious and unintended and occurs at a dose normally used in man. Older people are at elevated risk of adverse drug reactions-because of changes in pharmacodynamics, concurrent use of multiple medications and the related drug interactions. However, adverse drug reactions are significantly underestimated in the elderly population that is also exposed to inappropriate drugs. Amiodarone is an antiarrhythmic drug used commonly for the treatment of atrial fibrillation and is increasingly prescribed in older people. While amiodarone is an efficient drug for rhythm control, it's a carrier of different adverse reactions, and pro and cons must be carefully evaluated before its use especially in older people.

Secosterol-B affects endoplasmic reticulum structure in endothelial cells.

Oxysterols, oxidized derivatives of cholesterol found in LDL and atherosclerotic plaques, trigger several biological responses involved in the initiation and progression of atherosclerosis. Endothelial dysfunction, which occurs when vascular homeostasis is altered, plays a key role in the pathogenesis of several metabolic diseases. The contribution of endoplasmic reticulum (ER) stress to endothelial disfunction is a relatively recent area of investigation. There is a well-established link between LDL oxidation and ER stress but the role played by specific products of lipid oxidation into this interaction is still to be defined. The present study shows that secosterol-B (SEC-B), 3ß-hydroxy-5ß-hydroxy-B-norcholestane-6ßcarboxaldehyde, a cholesterol autoxidation product recently identified in the atherosclerotic plaque, is able to induce ER stress in HUVEC cells, as revealed by significant expansion and change of structure. At low doses, i.e. 1 and 5 µM, cells try to cope with this stress by activating autophagy and the ubiquitin proteasome system in the attempt to restore ER function. However, at higher doses, i.e. 20 µM, cell apoptosis occurs in a pathway that involves early phosphorylation of eIF2α and NF-kB activation, suggesting that the adaptive program fails and the cell activates the apoptotic program. These findings provide additional insight about the role of oxysterols in endothelial dysfunction and its potential involvement in atherosclerotic pathophysiology.