Tocol Prophylaxis for Total-body Irradiation: A Proteomic Analysis in Murine Model.

Rosen E, Fatanmi OO, Wise SY, Rao VA, Singh VK

Health Phys. 2020 Mar 20. doi: 10.1097/HP.0000000000001221. [Epub ahead of print]

Abstract

The aim of this study was to analyze the changes in mouse jejunum protein expression in response to prophylactic administration of two promising tocols, γ-tocotrienol (GT3) and α-tocopherol succinate (TS), as radiation countermeasures before irradiation to elucidate the molecular mechanism(s) of their radioprotective efficacy. Mice were administered GT3 or TS (200 mg kg) subcutaneously 24 h prior to exposure to 11 Gy Co γ-radiation, a supralethal dose for mice. Jejunum was harvested 24 h post-irradiation. Results of the two-dimensional differential in-gel electrophoresis (2D-DIGE), coupled with mass spectrometry, and advanced bioinformatics tools suggest that the tocols have a corresponding impact on expression of 13 proteins as identified by mass spectrometry. Ingenuity Pathway Analysis (IPA) reveals a network of associated proteins involved in inflammatory response, organismal injury and abnormalities, and cellular development. Relevant signaling pathways including actin cytoskeleton signaling, RhoA signaling, and Rho family GTPase were identified. This study reveals the major proteins, pathways, and networks involved in preventing the radiation-induced injury in gut that may be contributing to enhanced survival.

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Beneficial effects of vitamin E on radioiodine induced gastrointestinal damage: an experimental and pathomorphological study.

Yumusak N, Sadic M, Akbulut A, Aydinbelge FN, Koca G, Korkmaz M

Bratisl Lek Listy. 2019;120(4):263-269. doi: 10.4149/BLL_2019_048.

Abstract

OBJECTIVES:

The aim of the present study was to investigate the radioprotective effect of vitamin E in the prevention of radioiodine (RAI) induced gastrointestinal damage.

METHOD:

Twenty-four rats were randomly divided into three groups as follows: Group-1 was untreated control group, Group-2 was orally administered single dose of 111 MBq RAI, and Group-3 was orally administered 111 MBq RAI and 1 mL of oral vitamin EVitamin E was started two days before RAI administration and was continued for five days once daily after RAI. Pathomorphological parameters of gastrointestinal tissues (stomach, small intestines and bowels) were measured using Hematoxylin-Eosin and Masson’s trichrome staining.

RESULTS:

Varying degrees of inflammation, edema, ulcer, mucosal degeneration, necrosis and fibrosis were seen in the stomach, small intestine and bowel tissues of the rats in both study groups and not in the control group. The differences were statistically significant between these groups for all parameters (p < 0.05). The histopathological damage in the vitamin E treated group was significantly less than the damage in the RAI only group (p < 0.05 for all pathomorphological parameters).

CONCLUSION:

The results of this study showed that vitamin E has a radioprotective property with antiinflammatory and antifibrotic effects protecting against gastrointestinal damage caused by radioiodine.

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Gamma radiation-induced crosslinked composite membranes based on polyvinyl alcohol/chitosan/AgNO3/vitamin E for biomedical applications

Nasef SM, Khozemy EE, Kamoun EA, El-Gendi H

Int J Biol Macromol. 2019 Jul 5;137:878-885. doi: 10.1016/j.ijbiomac.2019.07.033. [Epub ahead of print]

Abstract

Crosslinked hydrogel composite membranes based on polyvinyl alcohol (PVA) and chitosan-loaded AgNO3 and vitamin E were prepared using gamma irradiation. Chitosan has been used as antimicrobial blend materials to provide further biocompatibility for the prepared composite hydrogel membranes. The crosslinking reaction between PVA and chitosan owing to gamma irradiation was verified and characterized by FTIR analysis, while the morphology of hydrogel composite membranes was investigated by SEM. Important parameters affecting on hydrogel membranes formation, such as copolymer concentration, irradiation dose, AgNO3 concentration, plasticizer, and vitamin E of PVA/chitosan membranes were evaluated and discussed in details. In addition, the mechanical and thermal properties of hydrogel composite membranes were examined to evaluate the possibility of its application for wound dressings. The results revealed that the gelation (%) of hydrogel membranes increased dramatically with PVA composition, irradiation dose and glycerol content up to 20%; however, it decreased with AgNP incorporation due to the viscosity of copolymer composition is hyper-increased. The swelling ratio of composed hydrogel membranes decreased notably with increasing the radiation dose and incorporation of AgNP, due to reducing of the crosslinking degree of formed hydrogel membranes. PVA-Cs-Ag composed hydrogel membranes showed significant antimicrobial activity in particular against Streptococcus mutans due to the presence of AgNP in membranes, compared to other bacteria and fungi microbes. Thus, the PVA/chitosan/AgNO3-Vit.E hydrogel composite membranes showed satisfactory properties for use as wound dressing materials.

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Beneficial effects of vitamin E on radioiodine induced gastrointestinal damage: an experimental and pathomorphological study

Yumusak N, Sadic M, Akbulut A, Aydinbelge FN, Koca G, Korkmaz M

Bratisl Lek Listy. 2019;120(4):263-269. doi: 10.4149/BLL_2019_048.

Abstract

OBJECTIVES:

The aim of the present study was to investigate the radioprotective effect of vitamin E in the prevention of radioiodine (RAI) induced gastrointestinal damage.

METHOD:

Twenty-four rats were randomly divided into three groups as follows: Group-1 was untreated control group, Group-2 was orally administered single dose of 111 MBq RAI, and Group-3 was orally administered 111 MBq RAI and 1 mL of oral vitamin EVitamin E was started two days before RAI administration and was continued for five days once daily after RAI. Pathomorphological parameters of gastrointestinal tissues (stomach, small intestines and bowels) were measured using Hematoxylin-Eosin and Masson’s trichrome staining.

RESULTS:

Varying degrees of inflammation, edema, ulcer, mucosal degeneration, necrosis and fibrosis were seen in the stomach, small intestine and bowel tissues of the rats in both study groups and not in the control group. The differences were statistically significant between these groups for all parameters (p < 0.05). The histopathological damage in the vitamin E treated group was significantly less than the damage in the RAI only group (p < 0.05 for all pathomorphological parameters).

CONCLUSION:

The results of this study showed that vitamin E has a radioprotective property with antiinflammatory and antifibrotic effects protecting against gastrointestinal damage caused by radioiodine.

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Gamma-Tocotrienol Protects the Intestine from Radiation Potentially by Accelerating Mesenchymal Immune Cell Recovery

Garg S, Sadhukhan R, Banerjee S, Savenka AV, Basnakian AG, McHargue V, Wang J, Pawar SA, Ghosh SP, Ware J, Hauer-Jensen M, Pathak R

Antioxidants (Basel). 2019 Mar 6;8(3). pii: E57. doi: 10.3390/antiox8030057.

Abstract

Natural antioxidant gamma-tocotrienol (GT3), a vitamin E family member, provides intestinal radiation protection. We seek to understand whether this protection is mediated via mucosal epithelial stem cells or sub-mucosal mesenchymal immune cells. Vehicle- or GT3-treated male CD2F1 mice were exposed to total body irradiation (TBI). Cell death was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Villus height and crypt depth were measured with computer-assisted software in tissue sections. Functional activity was determined with an intestinal permeability assay. Immune cell recovery was measured with immunohistochemistry and Western blot, and the regeneration of intestinal crypts was assessed with ex vivo organoid culture. A single dose of GT3 (200 mg/kg body weight (bwt)) administered 24 h before TBI suppressed cell death, prevented a decrease in villus height, increased crypt depth, attenuated intestinal permeability, and upregulated occludin level in the intestine compared to the vehicle treated group. GT3 accelerated mesenchymal immune cell recovery after irradiation, but it did not promote ex vivo organoid formation and failed to enhance the expression of stem cell markers. Finally, GT3 significantly upregulated protein kinase B or AKT phosphorylation after TBI. Pretreatment with GT3 attenuates TBI-induced structural and functional damage to the intestine, potentially by facilitating intestinal immune cell recovery. Thus, GT3 could be used as an intestinal radioprotector.

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Enhanced Survival in Mice Exposed to Ionizing Radiation by Combination of Gamma-Tocotrienol and Simvastatin

Pathak R, Kumar VP, Hauer-Jensen M, Ghosh SP

Mil Med. 2019 Mar 1;184(Supplement_1):644-651. doi: 10.1093/milmed/usy408.

Abstract

Ionizing radiation exposure is a major concern for active military service members, as well as civilian population. Considering that the exposure is not predictable, it is imperative that strategies to counteract radiation damage must be discovered. Recent in vitro studies performed in our laboratory demonstrated that the vitamin E analog gamma-tocotrienol (GT3) in combination with cholesterol-lowering drugs (Statins), synergistically induced endothelial thrombomodulin, an anticoagulant with radio-protective efficacy. It was hypothesized that the combination of treatment with both GT3 along with Statins would provide better radiation protection in vivo than each drug individually. CD2F1 mice were injected subcutaneously with either vehicle or single dose of GT3 (200 mg/kg body weight) 24 hours before irradiation followed by oral or subcutaneous administration of various doses of simvastatin (25, 50, and 100 mg/kg body weight) before exposure to lethal doses (11.5 and 12 Gy) of Cobalt-60 (60Co) gamma-irradiation. The combined treatment group exhibited enhanced radiation lethality protection substantially, accelerated white blood cell recovery, and augmented restoration of bone marrow cellularity when compared to the animals treated with either drug exclusively. This information clearly suggests that combined treatment could be used as a safeguard for military personnel from exposure to harmful ionizing radiation.

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Utilization of Vitamin E Analogs to Protect Normal Tissues While Enhancing Antitumor Effects

Aykin-Burns N, Pathak R, Boerma M, Kim T, Hauer-Jensen M

Semin Radiat Oncol. 2019 Jan;29(1):55-61. doi: 10.1016/j.semradonc.2018.10.008.

Abstract

Despite advances in radiation delivery techniques, side effects of radiation therapy due to radiation exposure of normal tissues are common and can limit the deliverable dose to tumors. Significant interests lie in pharmacologic modifiers that may protect against normal tissue toxicity from cancer treatment while simultaneously enhancing the tumor response to therapy. While no such treatments are available in the clinic, this is an area of active preclinical and clinical research. This review summarizes research studies that provide evidence to indicate that tocotrienols, natural forms of vitamin E, are potent radiation protectors and may also have antitumor effects. Hence, several current clinical trials test tocotrienols as concomitant treatment in cancer therapies.

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Proteomic Changes in Mouse Spleen after Radiation-Induced Injury and its Modulation by Gamma-Tocotrienol

Cheema AK, Byrum SD, Sharma NK, Altadill T, Kumar VP, Biswas S, Balgley BM, Hauer-Jensen M, Tackett AJ, Ghosh SP

Radiat Res. 2018 Aug 2. doi: 10.1667/RR15008.1. [Epub ahead of print]

Abstract

Gamma-tocotrienol (GT3), a naturally occurring vitamin E isomer, a promising radioprotector, has been shown to protect mice against radiation-induced hematopoietic and gastrointestinal injuries. We analyzed changes in protein expression profiles of spleen tissue after GT3 treatment in mice exposed to gamma radiation to gain insights into the molecular mechanism of radioprotective efficacy. Male CD2F1 mice, 12-to-14 weeks old, were treated with either vehicle or GT3 at 24 h prior to 7 Gy total-body irradiation. Nonirradiated vehicle, nonirradiated GT3 and age-matched naïve animals were used as controls. Blood and tissues were harvested on days 0, 1, 2, 4, 7, 10 and 14 postirradiation. High-resolution mass-spectrometry-based radioproteomics was used to identify differentially expressed proteins in spleen tissue with or without drug treatment. Subsequent bioinformatic analyses helped delineate molecular markers of biological pathways and networks regulating the cellular radiation responses in spleen. Our results show a robust alteration in spleen proteomic profiles including upregulation of the Wnt signaling pathway and actin-cytoskeleton linked proteins in mediating the radiation injury response in spleen. Furthermore, we show that 24 h pretreatment with GT3 attenuates radiation-induced hematopoietic injury in the spleen by modulating various cell signaling proteins. Taken together, our results show that the radioprotective effects of GT3 are mediated, via alleviation of radiation-induced alterations in biochemical pathways, with wide implications on overall hematopoietic injury.

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Cebpd Is Essential for Gamma-Tocotrienol Mediated Protection against Radiation-Induced Hematopoietic and Intestinal Injury

Banerjee S, Shah SK, Melnyk SB, Pathak R, Hauer-Jensen M, Pawar SA.

Antioxidants (Basel). 2018 Apr 6;7(4). pii: E55. doi: 10.3390/antiox7040055.

Abstract

Gamma-tocotrienol (GT3) confers protection against ionizing radiation (IR)-induced injury. However, the molecular targets that underlie the protective functions of GT3 are not yet known. We have reported that mice lacking CCAAT enhancer binding protein delta (Cebpd-/-) display increased mortality to IR due to injury to the hematopoietic and intestinal tissues and that Cebpd protects from IR-induced oxidative stress and cell death. The purpose of this study was to investigate whether Cebpd mediates the radio protective functions of GT3. We found that GT3-treated Cebpd-/- mice showed partial recovery of white blood cells compared to GT3-treated Cebpd⁺/+ mice at 2 weeks post-IR. GT3-treated Cebpd-/- mice showed an increased loss of intestinal crypt colonies, which correlated with increased expression of inflammatory cytokines and chemokines, increased levels of oxidized glutathione (GSSG), S-nitrosoglutathione (GSNO) and 3-nitrotyrosine (3-NT) after exposure to IR compared to GT3-treated Cebpd+/+ mice. Cebpd is induced by IR as well as a combination of IR and GT3 in the intestine. Studies have shown that granulocyte-colony stimulating factor (G-CSF), mediates the radioprotective functions of GT3. Interestingly, we found that IR alone as well as the combination of IR and GT3 caused robust augmentation of plasma G-CSF in both Cebpd⁺/+ and Cebpd-/- mice. These results identify a novel role for Cebpd in GT3-mediated protection against IR-induced injury, in part via modulation of IR-induced inflammation and oxidative/nitrosative stress, which is independent of G-CSF.

KEYWORDS:

Cebpd; GSH; GSNO; gamma tocotrienol; granulocyte-colony stimulating factor; hematopoietic injury; intestinal injury; ionizing radiation

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Ionization of tocopherols and tocotrienols in APCI

Bartosińska E, Borsuk-De Moor A, Siluk D, Markuszewski MJ, Wiczling P.

Rapid Commun Mass Spectrom. 2018 Mar 26. doi: 10.1002/rcm.8124

Abstract

RATIONALE:

Tocopherols and tocotrienols are chemical compounds insusceptible to the ionization process under atmospheric pressure conditions. Therefore, the selection of the optimal ion source settings for their quantification requires special attention. The aim of this study was to analyse the influence of the APCI source parameters on the response of tocochromanols and two related compounds.

METHODS:

Standard solutions of target compounds were injected on the HPLC-APCI-MS/MS system separately and analysed in 30 randomly selected ion source settings. The obtained responses were modelled by multivariate linear regression with least absolute shrinkage and selection operator. The developed models were used for choosing best APCI conditions.

RESULTS:

Multivariate linear models were built for eight tocochromanols, trolox and BHT. The APCI settings derived from the models did not increase the peak areas obtained for T and T3 during ionization process. Ionization conditions based on models for trolox and BHT improved analytical responses for 12-36% and 4-32%, respectively. The application of the ion source settings optimal for trolox and BHT to tocochromanols did not result in better analytical responses.

CONCLUSIONS:

The ionization pattern of tocochromanols in APCI source is problematic and should be further investigated. Modelling methodology for response improvement presented in this study can be applied in similar studies.

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