Cholesterol induced autophagy via IRE1/JNK pathway promotes autophagic cell death in heart tissue

Sozen E, Yazgan B, Tok OE, Demirel T, Ercan F, Proto JD, Ozer NK

Metabolism. 2020 Mar 14;106:154205. doi: 10.1016/j.metabol.2020.154205. [Epub ahead of print]

Abstract

BACKGROUND:

Cardiovascular diseases (CVDs), with highest mortality and morbidity rates, are the major cause of death in the world. Due to the limited information on heart tissue changes, mediated by hypercholesterolemia, we planned to investigate molecular mechanisms of endoplasmic reticulum (ER) stress and related cell death in high cholesterol fed rabbit model and possible beneficial effects of α-tocopherol.

METHODS:

Molecular changes in rabbit heart tissue and cultured cardiomyocytes (H9c2 cells) were measured by western blotting, qRT-PCR, immunflouresence and flow cytometry experiments. Histological modifications were assessed by light and electron microscopes, while degradation of mitochondria was quantified through confocal microscope.

RESULTS:

Feeding rabbits 2% cholesterol diet for 8 weeks and treatment of cultured cardiomyocytes with 10 μg/mL cholesterol for 3 h induced excessive autophagic activity via IRE1/JNK pathway. While no change in ER-associated degradation (ERAD) and apoptotic cell death were determined, electron and confocal microscopy analyses in cholesterol supplemented rabbits revealed significant parameters of autophagic cell death, including cytoplasmic autophagosomes, autolysosomes and organelle loss in juxtanuclear area as well as mitochondria engulfment by autophagosome. Either inhibition of ER stress or JNK in cultured cardiomyocytes or α-tocopherol supplementation in rabbits could counteract the effects of cholesterol.

CONCLUSION:

Our findings underline the essential role of hypercholesterolemia in stimulating IRE1/JNK branch of ER stress response which then leads to autophagic cell death in heart tissue. Results also showed α-tocopherol as a promising regulator of autophagic cell death in cardiomyocytes.

Hosny KM, Rizg WY, Khallaf RA

Pharmaceutics. 2020 Mar 13;12(3). pii: E263. doi: 10.3390/pharmaceutics12030263.

Abstract

The objective of this study was to develop an optimized sustained-release nanotransfersomes (NTS) based in situ gel formulation of rosuvastatin (RO) combined with ellagic acid (EA) antioxidant, to enhance cytotoxic and anti-proliferative activity against tongue carcinoma. The concentrations of lecithin, Tween 80, and d-tocopherol polyethylene glycol succinate (TPGS) were considered as independent variables. Particle size, entrapment, and stability were selected as dependent variables. The obtained formulation containing 25% lecithin, 20% Tween 80, and TPGS 15% fulfilled the prerequisites of the optimum formulation. RO-NTS loaded in situ gel was prepared and optimized for concentrations of Poloxamer 407, and Carbopol, using statistical design. Drug release from in situ gel showed a sustained release profile. The RO IC50 was decreased by half for the in situ gel in comparison to plain RO and RO-EA-NTS. A significant amount of caspase-3 was detected in all the formulation treatments. The studies indicated that EA’s synergistic anti-oxidant effect owing to a high affinity to the PGP efflux transporter and higher penetration in the RO-NTS formulation led to a higher inhibition against human chondrosarcome-3 cancer cell lines. RO-EA NTS-loaded in situ gel had a sustained release that could be significant in localized therapy as an alternative to surgery in the treatment of aggressive tongue carcinoma.

Li Y, Ye C, Cai C, Zhao M, Han N, Liu Z, Zhai J, Yin J

Pharm Res. 2020 Mar 12;37(3):66. doi: 10.1007/s11095-020-02789-w.

Abstract

PURPOSE:

TXA9, a novel cardiac glycoside, has a potent anti-proliferative effect against A549 human lung cancer cells, however, possesses a poor water-solubility and a rapid metabolic rate in vivo which limited the further development of TXA9. To overcome the shortcomings of TXA9, four polymer prodrugs of TXA9 were designed and synthesized.

METHODS:

Poly (ethylene glycol) monomethyl ether (mPEG) and α-tocopherol polyethylene glycol succinate (TPGS) were applied to modify TXA9 via carbonate ester and glycine linkers respectively to obtain four polymer prodrugs. The water-solubility and stability of prodrugs were studied in vitro while their pharmacokinetic behaviors and antitumor activity were investigated in vivo.

RESULTS:

The water-solubility of TXA9 was obviously increased and prodrugs with glycine linkers showed a better stability in rat plasma. Their pharmacokinetic investigation found that the t_1/2 and AUC_0-∞ of TPGS-Gly-TXA9 was increased by 80- and 9.6-fold compared with that of TXA9, which was more superior than the other three prodrugs. More importantly, the tumor inhibition rate of TPGS-Gly-TXA9 (43.81%) on A549 xenograft nude mice was significantly increased compared with that of TXA9 (25.26%).

CONCLUSION:

The above results suggested that TPGS-Gly-TXA9 possessed better antitumor efficiency than TXA9 and could be further investigated as an anti-cancer agent.

Hemilä H

J Nutr Sci. 2020 Mar 11;9:e11. doi: 10.1017/jns.2020.3.

Abstract

A previous analysis of the Alpha-Tocopherol Beta-Carotene (ATBC) Study on male smokers found that β-carotene supplementation increased the risk of pneumonia 4-fold in those who started smoking at the age of ≥21 years and smoked ≥21 cigarettes/d (a subgroup of 7 % of the study population). The present study hypothesised that β-carotene increases mortality in the same subgroup. The ATBC Study (1985-1993) recruited 29 133 Finnish male smokers (≥5 cigarettes/d) aged 50-69 years. Cox regression models were constructed to estimate the effect of β-carotene supplementation in subgroups. β-Carotene increased mortality (risk ratio 1·56; 95 % CI 1·06, 2·3) in those who started to smoke at ≥21 years and smoked ≥21 cigarettes/d. Within this subgroup, there was strong evidence of further heterogeneity. The effect of β-carotene supplementation was further modified by dietary vitamin C intake, fruit and vegetable intake (P = 0·0004), and by vitamin E supplementation (P = 0·011). Thus, harm from β-carotene was not uniform within the study population. Interactions between β-carotene and vitamins C and E were seen only within a subgroup of 7 % of the ATBC participants, and therefore should not be extrapolated to the general population. Heterogeneity of the β-carotene effect on mortality challenges the validity of previous meta-analyses that have pooled many diverse antioxidants for one single estimate of effect using the assumption that a single estimate equally applies to all antioxidants and all people.

Aryaie A, Tinsley G, Lee J, Watkins BA, Moore L, Alhaj-Saleh A, Shankar K, Wood SR, Wang R, Shen CL

BMJ Open. 2020 Mar 8;10(3):e034338. doi: 10.1136/bmjopen-2019-034338.

Abstract

INTRODUCTION:

Obesity is a major health concern in postmenopausal women, and chronic low-grade inflammation contributes to the development of obesity. Cellular studies and high-fat-diet-induced obese mouse model mimicking obesity show the antiobesity effect of annatto-extracted tocotrienols (TT) with antioxidant capability. We aim to assess the safety and efficacy of TT consumption for lipid-related parameters in obese postmenopausal women.

METHODS AND ANALYSIS:

Eligible obese postmenopausal women will be randomly assigned to placebo group (430 mg olive oil) and TT group (DeltaGold Tocotrienol 70%) for 24 weeks. In the present study, the primary outcome is total/regional fat mass and visceral adipose tissue. The secondary outcomes include lipid profile in serum, mRNA expression of fatty acid synthase and carnitine palmitoyltransferase 1A in fat tissue, oxylipins and endocannabinoids in plasma and adipose tissue, abundance and composition of intestinal microbiome in faeces, high-sensitivity C-reactive protein (hs-CRP) in serum and leptin in serum. Every participant will be evaluated at 0 (prior to starting intervention) and 24 weeks of intervention, except for serum lipid profile and hs-CRP at 0, 12 and 24 weeks. ‘Intent-to-treat‘ principle is employed for data analysis. Hierarchical linear modelling is used to estimate the effects of dietary TT supplementation while properly accounting for dependency of data and identified covariates. To our knowledge, this is the first randomised, placebo-controlled, double-blinded study to determine dietary TT supplementation on an obese population. If successful, this study will guide the future efficacy TT interventions and TT can be implemented as an alternative for obese population in antiobesity management.

ETHICS AND DISSEMINATION:

This study has been approved by the Bioethics Committee of the Texas Tech University Health Sciences Center, Lubbock. An informed consent form will be signed by a participant before enrolling in the study. The results from this trial will be actively disseminated through academic conference presentation and peer-reviewed journals.

Pirhadi-Tavandashti N, Imani H, Ebrahimpour-Koujan S, Samavat S, Hakemi MS

J Stroke Cerebrovasc Dis. 2020 Mar 6:104747. doi: 10.1016/j.jstrokecerebrovasdis.2020.104747. [Epub ahead of print]

Abstract

OBJECTIVES:

Up to 41% of intracerebral hemorrhages (ICH) are considered cryptogenic despite a thorough investigation to determine etiology. Certain over-the-counter supplements may increase proclivity to bleeding, and we hypothesize that specifically vitamin E may have an association with ICH and acutely elevated serum levels of α-tocopherol. Our aim is to report 3 cases of recently admitted patients with hypervitaminosis E and otherwise cryptogenic ICH.

METHODS:

At our institution between January and December 2018, 179 patients were admitted with ICH with 73 imputed to be “cryptogenic” (without clear etiology as per Structural vascular lesions, Medication, Amyloid angiopathy, Systemic disease, Hypertension, or Undetermined and Hypertension, Amyloid angiopathy, Tumor, Oral anticoagulants, vascular Malformation, Infrequent causes, and Cryptogenic criteria). Of these, we found 3 (4.1%) clearly admitted to consistent use of vitamin E supplementation for which α-tocopherol levels were checked. We describe the clinical presentation and course of these patients and their etiologic and diagnostic evaluations including neuroimaging and α-tocopherol laboratory data.

RESULTS:

All patients in this series were consistently consuming higher than recommended doses of vitamin E and developed acute ICH. The first 2 patients both had subcortical (thalamic) intraparenchymal hemorrhages while the third had an intraventricular hemorrhage. Serum α-tocopherol levels in patient A, B, and C were elevated at 30.8, 46.7, and 23.3 mg/L, respectively (normal range 5.7-19.9 mg/L) with a mean of 33.6 mg/L. No clear alternate etiologies to their ICH could be conclusively determined despite thorough workups.

CONCLUSIONS:

In patients with cryptogenic ICH, clinicians should consider hypervitaminosis E and check serum α-tocopherol level during admission. Reviewing the patient’s pharmacologic history, including over-the-counter supplements such as vitamin E, may help identify its association, and its avoidance in the future may mitigate risk. With its known vitamin K antagonism, hypo-prothrombinemic effect, cytochrome p-450 interaction, and antiplatelet activity, vitamin E may not be as benign as presumed. Its consumption in nonrecommended doses may increase ICH risk, which may be underestimated and under-reported.

Liu J, Zhan S, Jia Y, Li Y, Liu Y, Dong Y, Tang G, Li L, Zhai Y, Cao Z

Matern Child Nutr. 2020 Mar 5:e12975. doi: 10.1111/mcn.12975. [Epub ahead of print]

Abstract

Profound physiological changes during pregnancy may affect the requirement of retinol and tocopherol, which are essential micronutrients for the maintenance of maternal health and foetal development. However, the current reference intervals (RIs) of retinol and tocopherol are based on non-pregnant population. In the present study, a liquid chromatography-tandem mass spectrometry quantitation method for serum retinol and α-tocopherol was established and validated. In addition, we established trimester-specific RIs of retinol and α-tocopherol using the data from paired screening test for 31,301 outpatients who participated in the prenatal vitamins A/E evaluation program at our hospital using the Hoffmann method, which is a simple indirect RI estimation method that does not require the recruitment of healthy subjects. Further, to explore the associations between the levels of retinol and α-tocopherol and the parameters of complete blood count (CBC), the results of retinol, α-tocopherol, and CBC of 1,977 pregnant outpatients in the third trimester were analysed. The testing interval between the levels of vitamins and CBC was no more than 7 days. Although no significant changes were noticed in the levels of retinol, the α-tocopherol levels continuously increased with normal physiological changes throughout pregnancy. Lower retinol levels were associated with the higher incidence of anaemia, whereas higher levels of retinol and lower levels of α-tocopherol were associated with higher platelet count.

Fadda LM, Alhusaini AM, Al-Qahtani QH, Ali HM, Hasan IH

J Biochem Mol Toxicol. 2020 Mar 5:e22481. doi: 10.1002/jbt.22481. [Epub ahead of print]

Abstract

The present work was aimed to evaluate the protective effects of alpha-tocopherol (α-toco) and/or Lactobacillus plantarum (LCB) against testicular atrophy induced by mercuric chloride (MCH). Rats were injected with 5 mg/kg MCH for 5 days consecutively, then treated with 100 mg/kg α-toco and 6 × 10¹⁰ CFU 1.8701/kg LCB alone or together for 3 weeks. The MCH elevated serum TNF-α, IL- 6, caspase-3, and testicular malondialdehyde. However, serum testosterone, dehydroepiandrosterone, testicular messenger RNA of a steroidogenic acute regulatory protein, 17-β-hydroxysteroid dehydrogenase, 3β-hydroxysteroid dehydrogenase, glutathione level, and superoxide dismutase activity were decreased. Protein expression of Nrf2 was downregulated whereas that of Bax and DNA fragmentation was upregulated in the testicular tissues. Treatment with α-toco and LCB ameliorated the deviated biochemical parameters and improved tissue injury. It was concluded that the combination of LCB and α-toco achieved promising results in the amelioration of MCH-induced testicular atrophy. Nrf2, Bax expressions, and DNA fragmentation are involved in the testicular atrophy induced by MCH.

Cortés-Jofré M, Rueda JR, Asenjo-Lobos C, Madrid E, Bonfill Cosp X

Cochrane Database Syst Rev. 2020 Mar 4;3:CD002141. doi: 10.1002/14651858.CD002141.pub3.

Abstract

BACKGROUND:

This is the second update of this Cochrane Review. Some studies have suggested a protective effect of antioxidant nutrients and higher dietary levels of fruits and vegetables on lung cancer.

OBJECTIVES:

To determine whether vitamins and minerals and other potential agents, alone or in combination, reduce lung cancer incidence and lung cancer mortality in healthy populations.

SEARCH METHODS:

We searched CENTRAL, MEDLINE and Embase from 1974 to May 2019 and screened references included in published studies and reviews.

SELECTION CRITERIA:

We included randomised controlled trials (RCTs) comparing vitamins or mineral supplements with placebo, administered to healthy people with the aim of preventing lung cancer.

DATA COLLECTION AND ANALYSIS:

Four review authors independently selected the trials to be included in the review, assessed their methodological quality and extracted data. For dichotomous outcomes we calculated risk ratios (RRs) and 95% confidence intervals (CIs) and pooled results using the random-effects model. We assessed the risk of bias using Cochrane’s ‘Risk of bias’ assessment tool and certainty of evidence using the GRADE approach.

MAIN RESULTS:

In this update, we identified three new trials for a total of 12 studies. Six analysed vitamin A, three vitamin C, three combined vitamin D3 + calcium, four vitamin E combined with other products, one selenium supplements and nine studied combinations of two or more products. Four studies included only men and five only women. Vitamin A results in little to no difference in lung cancer incidence (RR 1.09, 95% CI 1.00 to 1.19; 5 RCTs, 212314 participants; high-certainty evidence) and lung cancer mortality (RR 1.06, 95% CI 0.81 to 1.38; 3 RCTs, 190118 participants; high-certainty evidence). But in smokers or asbestos workers vitamin A increases the risk of lung cancer incidence (RR 1.10, 95% CI 1.01 to 1.20; 3 RCTs, 43995 participants; high-certainty evidence), lung cancer mortality (RR 1.18, 95% CI 1.01 to 1.38; 2 RCTs, 29426 participants; high-certainty evidence) and all-cause mortality (RR 1.09, 95% CI 1.05 to 1.13; 2 RCTs, 32883 participants; high-certainty evidence). Vitamin A increases the risk of minor side effects, such as yellowing of the skin and minor gastrointestinal symptoms (high-certainty evidence). Vitamin C likely results in little to no difference in lung cancer incidence (RR 1.29, 95% CI 0.67 to 2.49; 2 RCTs, 14953 participants; moderate-certainty evidence). In women, vitamin C increases the risk of lung cancer incidence (RR 1.84, 95% CI 1.14 to 2.95; 1 RCT, 7627 participants; high-certainty evidence). In men, vitamin C results in little to no difference in mortality for lung cancer (RR 0.81, 95% CI 0.53 to 1.23; 1 RCT, 7326 participants; high-certainty evidence). Vitamin D + calcium may result in little to no difference in lung cancer incidence in postmenopausal women (RR 0.90, 95% CI 0.39 to 2.08; 3 RCTs, 37601 women; low-certainty evidence). Vitamin E results in little to no difference in lung cancer incidence (RR 1.01, 95% CI 0.90 to 1.14; 3 RCTs, 36841 participants; high-certainty evidence) or to lung cancer mortality (RR 0.96, 95% CI 0.77 to 1.18; 2 RCTs, 29214 participants; high-certainty evidence), but increases the risk of haemorrhagic strokes (hazard ratio (HR), 1.74, 95% CI 1.04 to 2.91; 1 RCT, 14641 participants; high-certainty evidence). Calcium results in little to no difference in lung cancer incidence in postmenopausal women (RR 0.65, 95% CI 0.13 to 3.18; 1 RCT, 733 participants) or in risk of renal calculi (RR 1.94, 95% CI 0.20 to 18.57; 1 RCT, 733 participants; low-certainty evidence). Selenium in men results in little to no difference in lung cancer incidence (RR 1.11, 95% CI 0.80 to 1.54; 1 RCT, 17448 participants; high-certainty evidence) and lung cancer mortality (RR 1.09, 95% CI 0.72 to 1.66; 1 RCT, 17448 participants; high-certainty evidence) and increases the risk for grade 1 to 2 dermatitis (RR 1.16, 95% CI 1.04 to 1.31; 1 RCT, 17448 participants; high-certainty evidence) and for alopecia (RR 1.28, 95% CI 1.07 to 1.53; 1 RCT, 17448 participants; high-certainty evidence). The combination of vitamins A, C, E + selenium + zinc results in little to no difference in lung cancer incidence (RR 0.64, 95% CI 0.28 to 1.48; 1 RCT, 12741 participants; high-certainty evidence).

AUTHORS’ CONCLUSIONS:

Well-designed RCTs have shown no beneficial effect of supplements for the prevention of lung cancer and lung cancer mortality in healthy people. Vitamin A supplements increase lung cancer incidence and mortality in smokers or persons exposed to asbestos. Vitamin C increases lung cancer incidence in women. Vitamin E increases the risk of haemorrhagic strokes.

Maeta M, Miura N, Tanaka H2 Nakamura T, Kawanishi R, Nishikawa Y, Asano K, Tanaka M, Tamagawa S, Nakai Y, Tange K, Yoshioka H, Harashima H, Akita H

Mol Pharm. 2020 Mar 4. doi: 10.1021/acs.molpharmaceut.9b01262. [Epub ahead of print]

Abstract

DNA vaccinations are promising strategies for treating diseases that require cellular immunity (i.e., cancer and protozoan infection). Here, we report on the use of a liposomal nanocarrier (lipid nanoparticles (LNPs)) composed of an SS-cleavable and pH-activated lipidlike material (ssPalm) as an in vivo DNA vaccine. After subcutaneous administration, the LNPs containing an ssPalmE, an ssPalm with vitamin E scaffolds, elicited a higher gene expression activity in comparison with the other LNPs composed of the ssPalms with different hydrophobic scaffolds. Immunization with the ssPalmE-LNPs encapsulating plasmid DNA that encodes ovalbumin (OVA, a model tumor antigen) or profilin (TgPF, a potent antigen of Toxoplasma gondii) induced substantial antitumor or antiprotozoan effects, respectively. Flow cytometry analysis of the cells that had taken up the LNPs in draining lymph nodes (dLNs) showed that the ssPalmE-LNPs were largely taken up by macrophages and a small number of dendritic cells. We found that the transient deletion of CD169⁺ macrophages, a subpopulation of macrophages that play a key role in cancer immunity, unexpectedly enhanced the activity of the DNA vaccine. These data suggest that the ssPalmE-LNPs are effective DNA vaccine carriers, and a strategy for avoiding their being trapped by CD169⁺ macrophages will be a promising approach for developing next-generation DNA vaccines.