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The most widely used cancer therapy is radiation therapy, but radiation damage to healthy tissues, particularly the gastrointestinal (GI) system, frequently reduces its effectiveness. This study investigates whether etoricoxib-loaded nanostructured lipid carriers (Et-NLC) could help shield the rat jejunum from radiation damage. Gamma irradiation (6 Gy) was used to damage the jejunum of Wistar albino rats, and then Et or Et-NLC (10 mg/kg b.w.) was administered orally for 14 days. It was found that the amounts of glutathione S-transferase (GST), superoxide dismutase (SOD), and nitric oxide (NO) decreased after irradiation but increased after Et-NLC therapy. Molecular analysis showed radiation-induced expression of microRNA-34a (miR34a), which may be involved in cellular stress response. Et-NLC treatments modulated the expression of miR34a, suggesting possible regulatory roles. Western blot analysis revealed changes in P53, interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and cyclooxygenase-2 (COX-2) levels. Et-NLC treatments decreased TNF-α, IL-6, IL-10, and COX-2 levels, indicating anti-inflammatory actions. DNA fragmentation analysis revealed a decrease in apoptotic activity after Et-NLC treatments. A histopathological examination confirmed that Et-NLC treatments had attenuated radiation damage, which had improved vascularization and reduced inflammation. The findings show that Et-NLC is more effective than Et-alone at reducing damage to the jejunum caused by radiation by controlling inflammation, oxidative stress, and apoptotic activity., (© 2024. The Author(s).)

Radiation injury to the intestine is one of the most common complications in patients undergoing abdominal or pelvic cavity radiotherapy. In this study, we investigated the potential protective effect of Lactobacillus rhamnosus GG (LGG) on radiation-induced intestinal injury and its underlying mechanisms. Mice were assigned to a control group, a 10 Gy total abdominal irradiation (TAI) group, or a group pretreated with 10 8 CFU LGG for three days before TAI. Small intestine and gut microbiota were analyzed 3.5 days post-exposure. LGG intervention improved intestinal structure, reduced jejunal DNA damage, and inhibited the inflammatory cGAS/STING pathway. Furthermore, LGG reduced M1 proinflammatory macrophage and CD8+ T cell infiltration, restoring the balance between Th17 and Treg cells in the inflamed jejunum. LGG also partially restored the gut microbiota. These findings suggest the possible therapeutic radioprotective effect of probiotics LGG in alleviating radiation-induced intestinal injury by maintaining immune homeostasis and reshaping gut microbiota., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Background/aim: The aim of this study was to develop an enhanced intestinal toxicity assay with three outputs assessing proliferation, villi morphology and DNA damage after irradiation., Materials and Methods: Whole 5 cm jejunal lengths were collected from mice following total body x-ray irradiation (0-15 Gy) at 0-84 h. Tissues were wrapped into swirls for cryopreservation and immunohistochemically stained for EdU, CD31, and γH2AX. A semi-automated image analysis was developed for the proliferation, villi morphology, and DNA damage models., Results: Proliferation assessed via EdU staining varied with cycles of damage repair, hyperproliferation, and homeostasis after radiation, with the time to onset of each cycle variable based on radiation dose. An analysis model evaluating the amount of proliferation per unit length of jejunum analyzed was developed, with a dose-response curve identified at 48 h post treatment. The villi length model measured the length of intact and healthy CD31-stained capillary beds between the crypts and villi tips at 3.5 days post treatment within a 0-10 Gy dose range. The DNA damage model evaluated the intensity of γH2AX staining within cellular nuclei, with a useful dose-response identified at 1 h post-radiation treatment., Conclusion: This assay demonstrates flexibility for assessing radiation-induced damage, with analysis of proliferation, villi length, or direct DNA damage achievable at defined time points and within useful radiation dose curves. The software-assisted image analysis allows for rapid, comprehensive, and objective data generation with an assay turnover time of days instead of weeks on samples that are representative of most of the treated jejunum., (Copyright © 2024 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Purpose: Ultrahigh-dose-rate (FLASH) irradiation has been reported to reduce normal tissue damage compared with conventional dose rate (CONV) irradiation without compromising tumor control. This proof-of-concept study aims to develop a deep learning (DL) approach to quantify the FLASH isoeffective dose (dose of CONV that would be required to produce the same effect as the given physical FLASH dose) with postirradiation mouse intestinal histology images., Methods and Materials: Eighty-four healthy C57BL/6J female mice underwent 16 MeV electron CONV (0.12 Gy/s; n = 41) or FLASH (200 Gy/s; n = 43) single fraction whole abdominal irradiation. Physical dose ranged from 12 to 16 Gy for FLASH and 11 to 15 Gy for CONV in 1 Gy increments. Four days after irradiation, 9 jejunum cross-sections from each mouse were hematoxylin and eosin stained and digitized for histological analysis. CONV data set was randomly split into training (n = 33) and testing (n = 8) data sets. ResNet101-based DL models were retrained using the CONV training data set to estimate the dose based on histological features. The classical manual crypt counting (CC) approach was implemented for model comparison. Cross-section-wise mean squared error was computed to evaluate the dose estimation accuracy of both approaches. The validated DL model was applied to the FLASH data set to map the physical FLASH dose into the isoeffective dose., Results: The DL model achieved a cross-section-wise mean squared error of 0.20 Gy 2 on the CONV testing data set compared with 0.40 Gy 2 of the CC approach. Isoeffective doses estimated by the DL model for FLASH doses of 12, 13, 14, 15, and 16 Gy were 12.19 ± 0.46, 12.54 ± 0.37, 12.69 ± 0.26, 12.84 ± 0.26, and 13.03 ± 0.28 Gy, respectively., Conclusions: Our proposed DL model achieved accurate CONV dose estimation. The DL model results indicate that in the physical dose range of 13 to 16 Gy, the biologic dose response of small intestinal tissue to FLASH irradiation is represented by a lower isoeffective dose compared with the physical dose. Our DL approach can be a tool for studying isoeffective doses of other radiation dose modifying interventions., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Although there are several types of radiation exposure, it is debated whether low‑dose‑rate (LDR) irradiation (IR) affects the body. Since the small intestine is a radiation‑sensitive organ, the present study aimed to evaluate how it changes when exposed to LDR IR and identify the genes sensitive to these doses. After undergoing LDR (6.0 mGy/h) γ radiation exposure, intestinal RNA from BALB/c mice was extracted 1 and 24 h later. Mouse whole genome microarrays were used to explore radiation‑induced transcriptional alterations. Reverse transcription‑quantitative (RT‑q) PCR was used to examine time‑ and dose‑dependent radiation responses. The histopathological status of the jejunum in the radiated mouse was not changed by 10 mGy of LDR IR; however, 23 genes were upregulated in response to LDR IR of the jejunum in mice after 1 and 24 h of exposure. Upregulated genes were selected to validate the results of the RNA sequencing analysis for RT‑qPCR detection and results showed that only Na + /K + transporting subunit α4, glucose‑6‑phosphatase catalytic subunit 2 (G6PC2), mucin 6 (MUC6) and transient receptor potential cation channel subfamily V member 6 levels significantly increased after 24 h of LDR IR. Furthermore, G6PC2 and MUC6 were notable genes induced by LDR IR exposure according to protein expression via western blot analysis. The mRNA levels of G6PC2 and MUC6 were significantly elevated within 24 h under three conditions: i) Exposure to LDR IR, ii) repeated exposure to LDR IR and iii) exposure to LDR IR in the presence of inflammatory bowel disease. These results could contribute to an improved understanding of immediate radiation reactions and biomarker development to identify radiation‑susceptible individuals before histopathological changes become noticeable. However, further investigation into the specific mechanisms involving G6PC2 and MUC6 is required to accomplish this.

The purpose of this investigation was to characterize the natural history of a murine total-abdominal-irradiation exposure model to measure gastrointestinal acute radiation injury. Male CD2F1 mice at 12 to 15 weeks old received total-abdominal irradiation using 4-MV linear accelerator X-rays doses of 0, 11, 13.5, 15, 15.75 and 16.5 Gy (2.75 Gy/min). Daily cage-side (i.e., in the animal housing room) observations of clinical signs and symptoms including body weights on all animals were measured up to 10 days after exposure. Jejunum tissues from cohorts of mice were collected at 1, 3, 7 and 10 days after exposure and radiation injury was assessed by histopathological analyses. Results showed time- and dose-dependent loss of body weight [for example at 7 days: 0.66 (±0.80) % loss for 0 Gy, 6.40 (±0.76) % loss at 11 Gy, 9.43 (±2.06) % loss at 13.5 Gy, 23.53 (± 1.91) % loss at 15 Gy, 29.97 (±1.16) % loss at 15.75 Gy, and 31.79 (±0.76) % loss at 16.5 Gy]. Negligible clinical signs and symptoms, except body weight changes, of radiation injury were observed up to 10 days after irradiation with doses of 11 to 15 Gy. Progressive increases in the severity of clinical signs and symptoms were found after irradiation with doses >15 Gy. Jejunum histology showed a progressive dose-dependent increase in injury. For example, at 7 days postirradiation, the percent of crypts, compared to controls, decreased to 82.3 (±9.5), 69.2 (±12.3), 45.4 (±11.9), 18.0 (±3.4), and 11.5 (± 1.8) with increases in doses from 11 to 16.5 Gy. A mucosal injury scoring system was used that mainly focused on changes in villus morphology damage (i.e., subepithelial spaces near the tips of the villi with capillary congestion, significant epithelial lifting along the length of the villi with a few denuded villus tips). Peak levels of total-abdominal irradiation induced effects on the mucosal injury score were seen 7 days after irradiation for doses ≥15 Gy, with a trend to show a decline after 7 days. A murine multiple-parameter gastrointestinal acute-radiation syndrome severity-scoring system was established based on clinical signs and symptoms that included measures of appearance (i.e., hunched and/or fluffed fur), respiratory rate, general (i.e., decreased mobility) and provoked behavior (i.e., subdued response to stimulation), weight loss, and feces/diarrhea score combined with jejunum mucosal-injury grade score. In summary, the natural-history radio-response for murine partial-body irradiation exposures is important for establishing a well-characterized radiation model system; here we established a multiple-parameter gastrointestinal acute-radiation syndrome severity-scoring system that provides a radiation injury gastrointestinal tissue-based assessment utility., (©2024 by Radiation Research Society. All rights of reproduction in any form reserved.)

In the event of a radiological attack or accident, it is more likely that the absorbed radiation dose will be heterogeneous, rather than uniformly distributed throughout the body. This type of uneven dose distribution is known as partial-body irradiation (PBI). Partial exposure of the vital organs, specifically the highly radiosensitive intestines, may cause death, if the injury is significant and the post-exposure recovery is considerably compromised. Here we investigated the recovery rate and extent of recovery from PBI-induced intestinal damage in large animals. Rhesus macaques (Macaca mulatta) were randomly divided into four groups: sham-irradiated (0 Gy), 8 Gy PBI, 11 Gy PBI and 14 Gy PBI. A single dose of ionizing radiation was delivered in the abdominal region using a uniform bilateral anteroposterior and posteroanterior technique. Irradiated animals were scheduled for euthanasia on days 10, 28 or 60 postirradiation, and sham-irradiated animals on day 60. Intestinal structural injuries were assessed via crypt depth, villus height, and mucosal surface length in the four different intestinal regions (duodenum, proximal jejunum, distal jejunum and ileum) using H&E staining. Higher radiation doses corresponded with more injury at 10 days post-PBI and a faster recovery rate. However, at 60 days post-PBI, damage was still evident in all regions of the intestine. The proximal and distal ends (duodenum and ileum, respectively) sustained less damage and recovered more fully than the jejunum., (©2021 by Radiation Research Society. All rights of reproduction in any form reserved.)

Ionizing radiation causes dramatic change in the transport and barrier functions of the intestine. The degree of radiation damage rate depends primarily on the absorbed dose and post-irradiation time. Variety of experimental protocols providing different time points and doses exist, with the lack of a common approach. In this study, to develop a unified convenient experimental scheme, dose and time dependence of barrier and transport properties of rat jejunum following ionizing radiation exposure were examined. Male Wistar rats were exposed to total body X-ray irradiation (2, 5, or 10 Gy). The control group was subjected to sham irradiation procedure. Samples of rat jejunum were obtained at 24, 48, or 72 h post-irradiation. Transepithelial resistance, short circuit current (I sc ), and paracellular permeability for sodium fluorescein of jejunum samples were measured in an Ussing chamber; a histological examination was also performed. These parameters were significantly disturbed only 72 h after irradiation at a dose of 10 Gy, which was accompanied by loss of crypt and villi, inflammatory infiltrations, and disintegration of enterocytes. This suggests that found experimental point (72 h after 10 Gy exposure) is the most appropriate for future study using rat jejunum as a model., (© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society.)

Amifostine has been the only small molecule radio-protector approved by FDA for decades; however, the serious adverse effects limit its clinical use. To address the toxicity issues and maintain the good potency, a series of modified small polycysteine peptides had been prepared. Among them, compound 5 exhibited the highest radio-protective efficacy, the same as amifostine, but much better safety profile. To confirm the correlation between the radiation-protective efficacy and the DNA binding capability, each of the enantiomers of the polycysteine peptides had been prepared. As a result, the L-configuration compounds had obviously higher efficacy than the corresponding D-configuration enantiomers; among them, compound 5 showed the highest DNA binding capability and radiation-protective efficacy. To our knowledge, this is the first study that has proved their correlations using direct comparison. Further exploration of the mechanism revealed that the ionizing radiation (IR) triggered ferroptosis inhibition by compound 5 could be one of the pathways for the protection effect, which was different from amifostine. In summary, the preliminary result showed that compound 5, a polycysteine as a new type of radio-protector, had been developed with good efficacy and safety profile. Further study of the compound for potential use is ongoing.

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.

Purpose: Gastrointestinal (GI) injuries post ionizing radiation (IR) becomes a crucial factor in survival. Thus, the current study was aimed to explore the molecular mechanisms behind IR produced GI proteome alterations and their amelioration by a safe radioprotective formulation candidate, G-003M (podophyllotoxin+rutin). Materials and method: C57BL/6 mice were administered with G-003M 1 h before 9 Gy whole body γ irradiation. 2DE-MS analysis was conducted to identify differential expression of jejunum proteins with fold change >1.5 ( p  < .05) at various time-points. Results: G-003M pre-administration decreased total number of differential proteins. It mediated protection to cytoskeleton, modulated stress, apoptosis and inflammatory proteins. Direct effect on eukaryotic translation initiation factor 4H (Eif4h), thioredoxin domain-containing protein 17 (Txndc17) and interferon-induced protein 35 (Ifi35) was observed. Bioinformatics depicted transcription factor-MYC, was also positively modulated by G-003M. Further, it also enhanced level of citrulline (ELISA analysis), and restored crypts and villi lengths (histological analysis) against severe damage caused by lethal irradiation. Conclusion: Current findings reveal that G-003M may be an efficient candidate in protecting key proteins of metabolic and biochemical pathways assisting in the rapid recovery of GI proteome. This fairly improved the chances of animal survival exposed to lethal doses of whole body radiation.

Aim: In this study, we aimed to determine possible mitigation of radiationinduced toxicities in the duodenum, jejunum and colon using post-exposure treatment with resveratrol and alpha-lipoic acid., Background: After the bone marrow, gastrointestinal system toxicity is the second critical cause of death following whole-body exposure to radiation. Its side effects reduce the quality of life of patients who have undergone radiotherapy. Resveratrol has an antioxidant effect and stimulates DNA damage responses (DDRs). Alpha-lipoic acid neutralizes free radicals via the recycling of ascorbic acid and alpha-tocopherol., Objective: This study is a pilot investigation of the mitigation of enteritis using resveratrol and alpha-lipoic acid following histopathological study., Methods: 60 male mice were randomly assigned to six groups; control, resveratrol treatment, alpha-lipoic acid treatment, whole-body irradiation, irradiation plus resveratrol, and irradiation plus alpha-lipoic acid. The mice were irradiated with a single dose of 7 Gy from a cobalt-60 gamma-ray source. Treatment with resveratrol or alpha-lipoic acid started 24 h after irradiation and continued for 4 weeks. All mice were sacrificed after 30 days for histopathological evaluation of radiation-induced toxicities in the duodenum, jejunum and colon., Results and Discussion: Exposure to radiation caused mild to severe damages to vessels, goblet cells and villous. It also led to significant infiltration of macrophages and leukocytes, especially in the colon. Both resveratrol and alpha-lipoic acid were able to mitigate morphological changes. However, they could not mitigate vascular injury., Conclusion: Resveratrol and alpha-lipoic acid could mitigate radiation-induced injuries in the small and large intestine. A comparison between these agents showed that resveratrol may be a more effective mitigator compared to alpha-lipoic acid., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Although multiple radioprotectors are currently being investigated preclinically for efficacy and safety, few studies have investigated concomitant metabolic changes. This study examines the effects of amifostine on the metabolic profiles in tissues of mice exposed to cobalt-60 total-body gamma-radiation. Global metabolomic and lipidomic changes were analyzed using ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight mass spectrometry (QTOF-MS) in bone marrow, jejunum, and lung samples of amifostine-treated and saline-treated control mice. Results demonstrate that radiation exposure leads to tissue specific metabolic responses that were corrected in part by treatment with amifostine in a drug-dose dependent manner. Bone marrow exhibited robust responses to radiation and was also highly responsive to protective effects of amifostine, while jejunum and lung showed only modest changes. Treatment with amifostine at 200 mg/kg prior to irradiation seemed to impart maximum survival benefit, while the lower dose of 50 mg/kg offered only limited survival benefit. These findings show that the administration of amifostine causes metabolic shifts that would provide an overall benefit to radiation injury and underscore the utility of metabolomics and lipidomics to determine the underlying physiological mechanisms involved in the radioprotective efficacy of amifostine. This approach may be helpful in identifying biomarkers for radioprotective efficacy of amifostine and other countermeasures under development.

Background/aim: The significance of the anatomical variations of proximal jejunal vein [the so-called 1st jejunal vein (J1v)] has been reported from a technical standpoint. The aim of this study was to retrospectively investigate the prognostic impact of the anatomical variations of J1v in the surgical treatment of resectable pancreatic cancer (PC)., Patients and Methods: A total of 49 patients with resectable PC located in the uncinate process were included in this study. The J1v converging pattern was divided into 2 groups in terms of its relation to the SMA (i.e., the J1v status): i) group D: the J1v travels posterior to the SMA; ii) group V: the J1v travels anterior to the SMA. The associations between the J1v status and surgical outcome were assessed., Results: The 5-year survival rate after resection in group V (35%) was significantly lower than that in group D (70%) (p=0.029), and the J1v status of group V was the only independent negative prognostic factor (HR=5.49; 95% CI=1.69-19.3; p=0.005)., Conclusion: The J1v converging pattern is a significant prognostic variable in patients with PC located in the uncinate process: the J1v status of group V was significantly associated with impaired survival., (Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Acute radiation enteritis (ARE), a common complication of intestinal caused by abdominal and pelvic radiation therapy. Rheinic acid is a major active ingredient derived from Rhubarb. Rhubarb could suppress inflammation, tumor, fibrosis oxidative damage. However, RA as the main active component and extract monomer of Rhubarb, the pharmacological activity and the underlying molecular mechanism on various diseases has not yet been revealed., Objective: To determine the potential role of rheinic acid (RA) in ameliorating inflammation of rats with acute radiation enteritis (ARE), and explore the underlying mechanism., Methods: ARE rat model was established by irradiated with single-dose 10 Gy X-rays at a rate of 0.62 Gy/min to the abdomen. The rats were executed after orally administered with Rheinic acid 7 days and used in the subsequent experiments. Body weight, fecal characteristics and bloody of rats were used to assess the disease activity index. Histological analysis of the jejunum and colon were evaluated using H&E staining. The pro-inflammatory cytokines levels were measured by immunohistochemistry and ELISA. The levels of nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) were also determined. The mRNA and protein expression were examined by real-time polymerase chain reaction (qRT-PCR) and western blot, respectively., Results: Rheinic acid promoted intestinal functional recovery, and ameliorated intestinal damage and bloody stool in ARE rats. Rheinic acid strongly decreased the levels of tumor necrosis factor-α, interleukin-1, interleukin-6, NO, and MDA, whereas increased levels of anti-oxidants, SOD and GSH. Moreover, the expression of apoptosis-related proteins, cleaved caspase-3 and cleaved poly (ADP-ribose) polymerase (PARP), were decreased with RA treatment. Further study indicated that PPAR-γ was activated and thereby NF-κB and p38 MAPK signaling pathway were suppressed after rheinic acid treatment., Conclusion: Rheinic acid could ameliorate acute radiation enteritis and the underlying molecular mechanism is, at least partially, through PPAR-γ/NF-κB and p38 MAPK/JNK pathways.

When radiotherapy is applied to the abdomen or pelvis, normal tissue toxicity in the gastrointestinal (GI) tract is considered a major dose-limiting factor. Proton beam therapy has a specific advantage in terms of reduced doses to normal tissues. This study investigated the fundamental differences between proton- and X-ray-induced intestinal injuries in mouse models. C57BL/6J mice were irradiated with 6-MV X-rays or 230-MeV protons and were sacrificed after 84 h. The number of surviving crypts per circumference of the jejunum was identified using Hematoxylin and Eosin staining. Diverse intestinal stem cell (ISC) populations and apoptotic cells were analyzed using immunohistochemistry (IHC) and a terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) assay, respectively. The crypt microcolony assay revealed a radiation-dose-dependent decrease in the number of regenerative crypts in the mouse jejunum; proton irradiation was more effective than X-ray irradiation with a relative biological effectiveness of 1.14. The jejunum is the most sensitive to radiations, followed by the ileum and the colon. Both types of radiation therapy decreased the number of radiosensitive, active cycling ISC populations. However, a higher number of radioresistant, reserve ISC populations and Paneth cells were eradicated by proton irradiation than X-ray irradiation, as shown in the IHC analyses. The TUNEL assay revealed that proton irradiation was more effective in enhancing apoptotic cell death than X-ray irradiation. This study conducted a detailed analysis on the effects of proton irradiation versus X-ray irradiation on intestinal crypt regeneration in mouse models. Our findings revealed that proton irradiation has a direct effect on ISC populations, which may result in an increase in the risk of GI toxicity during proton beam therapy.

The acute radiation syndrome of the gastrointestinal tract has been histologically characterized, but the molecular and functional mechanisms that lead to these cellular alterations remain enigmatic. Mass spectrometry imaging is the only technique that enables the simultaneous detection and cellular or regional localization of hundreds of biomolecules in a single experiment. This current study utilized matrix-assisted laser desorption/ionization mass spectrometry imaging for the molecular characterization of the first natural history study of gastrointestinal acute radiation syndrome in the nonhuman primate. Jejunum samples were collected at days 4, 8, 11, 15, and 21 following 12-Gy partial-body irradiation with 2.5% bone marrow sparing. Mass spectrometry imaging investigations identified alterations in lipid species that further understanding of the functional alterations that occur over time in the different cellular regions of the jejunum following exposure to high doses of irradiation. Alterations in phosphatidylinositol species informed on dysfunctional epithelial cell differentiation and maturation. Differences in glycosphingolipids of the villi epithelium that would influence the absorptive capacity and functional structure of the brush border membrane were detected. Dichotomous alterations in cardiolipins indicated altered structural and functional integrity of mitochondria. Phosphatidylglycerol species, known regulators of toll-like receptors, were detected and localized to regions in the lamina propria that contained distinct immune cell populations. These results provide molecular insight that can inform on injury mechanism in a nonhuman primate model of the acute radiation syndrome of the gastrointestinal tract. Findings may contribute to the identification of therapeutic targets and the development of new medical countermeasures.

High-throughput, targeted metabolomics was used to identify early time-point small intestine and plasma metabolite markers of gastrointestinal acute radiation syndrome. The small intestine metabolite markers were cross correlated to plasma metabolites in order to identify minimally invasive circulating markers. The radiation exposure covered lethal and sublethal gastrointestinal acute radiation syndrome. The small intestine and plasma metabolite profiles were generated at 1 and 3 d postexposure following total-body irradiation. The small intestine and plasma metabolite profiles for mice receiving radiation at day 1 and 3 postexposure were significantly different from sham-irradiated mice. There were 14 metabolite markers identified at day 1 and 18 metabolite markers at day 3 that were small-intestine-specific plasma markers of gastrointestinal acute radiation syndrome. A number of the identified metabolites at day 1 were amino acids. Dysregulation of amino acid metabolism at 24 h post-total-body irradiation provides potential insight into the initial inflammatory response during gastrointestinal acute radiation syndrome.

Male rhesus macaques were subjected to partial-body irradiation at 10, 11, or 12 Gy with 5% bone marrow protection. Animals were euthanized when dictated by prospectively determined clinical parameters or at approximately 180 d following irradiation. Histological sections of jejunum, colon, and mesenteric lymph node were stained with hematoxylin and eosin as well as a battery of histochemical and immunohistochemical stains. The immediate postirradiation histopathological alterations in the jejunum and colon were based primarily on injury to rapidly proliferating crypt epithelial cells, though there was evidence of additional radiation-induced fibrogenic responses. There was substantial resolution of the radiation-related mucosal injury through the observation period, but microscopically visible defects in mucosal structure persisted to the end of the observation period. In the later stages of the observation period, the jejunum and colon had overt fibrosis that was most commonly located in the submucosa and serosa, with less microscopically discernible involvement of the mucosa. Mesenteric lymph nodes had an immediate postirradiation reduction in cellularity due to the known effects of irradiation on lymphoid cell populations. In later stages of the observation period the lymph nodes also developed fibrotic changes, possibly related to transmigration of immunomodulatory cells and/or signaling molecules from the radiation-damaged intestine.

LncRNAs have been reported to play an important role in various diseases. However, their role in the radiation-induced intestinal injury is unknown. The goal of the present study was to analyse the potential mechanistic role of lncRNAs in the radiation-induced intestinal injury. Mice were divided into two groups: Control (non-irradiated) and irradiated. Irradiated mice were administered 14 Gy of abdominal irradiation (ABI) and were assessed 3.5 days after irradiation. Changes to the jejuna of ABI mice were analysed using RNA-Seq for alterations to both lncRNA and mRNA. These results were validated using qRT-PCR. LncRNAs targets were predicted based on analysis of lncRNAs-miRNAs-mRNAs interaction. 29 007 lncRNAs and 17 142 mRNAs were detected in the two groups. At 3.5 days post-irradiation, 91 lncRNAs and 57 lncRNAs were significantly up- and downregulated respectively. Similarly, 752 mRNAs and 400 mRNAs were significantly up- and downregulated respectively. qRT-PCR was used to verify the altered expression of four lncRNAs (ENSMUST00000173070, AK157361, AK083183, AK038898) and four mRNAs (Mboat1, Nek10, Ccl24, Cyp2c55). Gene ontology and KEGG pathway analyses indicated the predicted genes were mainly involved in the VEGF signalling pathway. This study reveals that the expression of lncRNAs was altered in the jejuna of mice post-irradiation. Moreover, it provides a resource for the study of lncRNAs in the radiation-induced intestinal injury., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Purpose: Amifostine (AMF), a radioprotectant, is FDA-approved for intravenous administration in cancer patients receiving radiation therapy (XRT). Unfortunately, it remains clinically underutilized due to adverse side effects. The purpose of this study is to define the pharmacokinetic profile of an oral AMF formulation potentially capable of reducing side effects and increasing clinical feasibility., Methods: Calvarial osteoblasts were radiated under three conditions: no drug, AMF, and WR-1065 (active metabolite). Osteogenic potential of cells was measured using alkaline phosphatase staining. Next, rats were given AMF intravenously or directly into the jejunum, and pharmacokinetic profiles were evaluated. Finally, rats were given AMF orally or subcutaneously, and blood samples were analyzed for pharmacokinetics., Results: WR-1065 preserved osteogenic potential of calvarial osteoblasts after XRT to a greater degree than AMF. Direct jejunal AMF administration incurred a systemic bioavailability of 61.5%. Subcutaneously administrated AMF yielded higher systemic levels, a more rapid peak exposure (0.438 vs. 0.875 h), and greater total systemic exposure of WR-1065 (116,756 vs. 16,874 ng*hr/ml) compared to orally administered AMF., Conclusions: Orally administered AMF achieves a similar systemic bioavailability and decreased peak plasma level of WR-1065 compared to intravenously administered AMF, suggesting oral AMF formulations maintain radioprotective efficacy without causing onerous side effects, and are clinically feasible.

Aim: To investigate the discordance in the programmed cell death-ligand 1 (PD-L1) expression between primary and metastatic tumors and analyze the association between the discordance and the clinical factors in non-small cell lung cancer (NSCLC) patients., Patients and Methods: Twenty-one NSCLC patients who underwent surgery or biopsy for paired primary and metastatic lesions at our Institution from 2005 to 2016 were analyzed. Lesions with the PD-L1 expression being ≥5% were considered PD-L1-positive., Results: The metastatic sites included the brain (n=16), adrenal gland (n=3), spleen (n=1) and jejunum (n=1). Negative conversion of the primary PD-L1-positive NSCLC and positive conversion of the primary PD-L1-negative NSCLC were observed in 3 (14%) and 2 (10%) cases, respectively. Radiotherapy for the metastatic brain lesion before its resection showed a significant relationship with the positive conversion of the primary PD-L1-negative NSCLC (p=0.048)., Conclusion: Radiotherapy-derived effects may contribute to the positive conversion of the primary PD-L1-negative NSCLC., (Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

The aim of this study was to explore the protective effect of emodin, a plant-derived anthraquinone, against gamma radiation-induced mortality and intestinal injury in mice, and to investigate the radioprotective molecular mechanism. C57BL/6 male mice were pre-treated with emodin for 7days via oral gavage before gamma radiation. We found that pretreatment with emodin prolonged mice survival time after 9Gy total body irradiation (TBI). Mice were sacrificed at 1 week after 7Gy TBI, we found that emodin attenuated intestinal morphological changes and increased villus height, crypt numbers, and reduced villus and crypt apoptosis as well as inhibited the expression of p53. MTT assay, flow cytometry, Hoechst 33258 staining, real-time PCR, and Western blotting indicated that emodin pretreatment can effectively increase human umbilical venous endothelial cells (HUVECs) viability and attenuate cell apoptosis; it also inhibited the expression of p53, Bax, and Caspase3 in HUVECs after irradiation. In summary, these results suggest the potential of emodin as an effective radioprotectant against radiation-induced intestinal injury., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The main focus of this study is evaluation of radioprotective efficacy of silymarin, a flavonolignan, against γ-radiation-induced damage to hematological, vital organs (liver and intestine), and immune system. Survival studies revealed that silymarin (administered orally for 3 days) provided maximum protection (67%) at 70 mg/kg body weight (b.wt.) against lethal 9 Gy γ-irradiation (dose reduction factor = 1.27). The study revealed significant (p < 0.05) changes in levels of catalase (12.57 ± 2.58 to 30.24 ± 4.89 units), glutathione peroxidase (6.23 ± 2.95 to 13.26 ± 1.36 µg of reduced glutathione consumed/min/mg protein), glutathione reductase (0.25 ± 5.6 to 11.65 ± 2.83 pM NADPH consumed/min/mg protein), and superoxide dismutase (11.74 ± 0.2 to 16.09 ± 3.47 SOD U/mg of protein) activity at 30th day. Silymarin pretreated irradiated group exhibited increased proliferation in erythrocyte count (1.76 ± 0.41 × 10(6) to 9.25 ± 0.24 × 10(6) ), hemoglobin (2.15 ± 0.48g/dL to 14.77 ± 0.25g/dL), hematocrit (4.55 ± 0.24% to 37.22 ± 0.21%), and total leucocyte count (1.4 ± 0.15 × 10(6) to 8.31 ± 0.47 × 10(6) ) as compared with radiation control group on 15th day. An increase in CD4:CD8 ratio was witnessed (0.2-1%) at 30th day time interval using flow cytometry. Silymarin also countered radiation-induced decrease (p < 0.05) in regulatory T-cells (Tregs ) (11.23% in radiation group at 7th day versus 0.1% in pretreated silymarin irradiated group at 15th day). The results of this study indicate that flavonolignan-silymarin protects enzymatic, hematological, and immune system against γ-radiation-induced toxicity and might prove useful in management of nuclear and radiological emergencies. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 641-654, 2016., (© 2014 Wiley Periodicals, Inc.)

Introduction: The aim of this study was to compare the efficacy of Nigella sativa in protection of jejunal mucosa against harmful effects of gamma radiation., Methods: Radiotherapy group received abdominal gamma radiation of 15Gy in addition to physiological saline. Radiotherapy+Nigella sativa treatment group received abdominal gamma radiation of 15Gy in addition to Nigella sativa treatment in the amount of 400mg/kg. Radiotherapy and treatment groups were sacrificed 3 days after the exposure to irradiation. Then, jejunum samples were harvested for biochemical and histological assessment of mucosal injury., Results: Nigella sativa treatment was found to significantly lower elevated tissue malondialdehyde (MDA) levels and, to raise reduced glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activity in intestinal tissues samples. Single dose 15Gy gamma-irradiation was noted to result in a marked jejunal mucosal injury. Three days after exposure to irradiation, the villi and Lieberkühn crypts were observed as denuded, and villous height diminished. Concomitantly with inflammatory cell invasion, capillary congestion and ulceration were observed in the atrophic mucosa. Nigella sativa treatment significantly attenuated the radiation induced morphological changes in the irradiated rat jejunal mucosa., Conclusion: Nigella sativa has protective effects against radiation-induced damage, suggesting that clinical transfer is feasible., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

Excess exposure to ionizing radiation generates reactive oxygen species and increases the cellular inflammatory response by modifying various metabolic pathways. However, an investigation of metabolic perturbations and organ-specific responses based on the amount of radiation during the acute phase has not been conducted. In this study, high-resolution magic-angle-spinning (HR-MAS) NMR and solution NMR-based metabolic profiling were used to investigate dose-dependent metabolic changes in multiple organs and tissues--including the jejunum, spleen, liver, and plasma--of rats exposed to X-ray radiation. The organs, tissues, and blood samples were obtained 24, 48, and 72 h after exposure to low-dose (2 Gy) and high-dose (6 Gy) X-ray radiation and subjected to metabolite profiling and multivariate analyses. The results showed the time course of the metabolic responses, and many significant changes were detected in the high-dose compared with the low-dose group. Metabolites with antioxidant properties showed acute responses in the jejunum and spleen after radiation exposure. The levels of metabolites related to lipid and protein metabolism were decreased in the jejunum. In addition, amino acid levels increased consistently at all post-irradiation time points as a consequence of activated protein breakdown. Consistent with these changes, plasma levels of tricarboxylic acid cycle intermediate metabolites decreased. The liver did not appear to undergo remarkable metabolic changes after radiation exposure. These results may provide insight into the major metabolic perturbations and mechanisms of the biological systems in response to pathophysiological damage caused by X-ray radiation., (Copyright © 2016 John Wiley & Sons, Ltd.)

Dysfunction of the intestinal epithelial barrier and leakage of luminal antigens and bacteria across the barrier have been linked to various human diseases. Intestinal permeability is regulated by intercellular structures, termed "tight junction" (Tj), which are disrupted after total-body irradiation (TBI). In this study, we investigated radiation-induced alterations in Tj-related proteins in the jejunum, ileum and colon of a non-human primate (NHP) model. NHPs were total-body irradiated with 6.7 and 7.4 Gy and intestines were procured at day 4, 7 and 12. Radiation exposure was found to induce significant increases in claudin-10 mRNA early (day 4) in all three gut segments and claudin-4 mRNA levels were repressed through day 12. TNF-alpha was highly induced in the jejunum and colon at early time points, but little induction was found in the ileum. Claudin-1 was induced only in the colon on day 4 postirradiation. Unlike the colon and jejunum, the ileum levels of claudin-7 were significantly downregulated through day 12 postirradiation. Western blot analysis revealed increased levels of claudin-2 on day 4 and of JAM-1 on day 7 postirradiation in all three gut segments. E-cadherin was downregulated on day 4 postirradiation in all segments, but remained reduced in the jejunum only until day 12. Taken together, these data suggest that exposure to radiation causes segment-specific alterations in the expression of Tj-related proteins. Interruption of Tjs may be a key factor contributing to injury to the intestinal mucosal barrier and increased intestinal permeability.

Results of numerous researches have revealed that most sensitive to electromagnetic radiations are the nervous, endocrine and cardiovascular systems of an organism, however, the analysis of literary data confirms also the direct involvement of organs of the intestinal system in physiological, and not seldom, and the pathological program of the response of an organism to the action of extreme factors. In the experiment executed on white laboratory male rats by ourselves there was studied the grade of the radiosensitivity of morphoenzymological structural elements of jejunum mucous membrane after 5, 7 and 10 months of chronic influence of electromagnetic fields impulses with a density of induced currents 0.37; 0.7; 0.8; 2.7 kA/m and frequency of impulses 50, 100 and 500 in a week irrespective of their divisibility of ultrashort duration of 15 a 40 ns. Scientific value and novelty of results is concluded in revealed multiple linear relationships between indices of electromagneticfields (duration of the impact, density of induced currents, periodicity of impulses and the dynamics of the studied indices of a morphofunctional condition of a jejunum mucous membrane). Besides that, there was found the critical population to indices of electromagneticfields impulses parameters - the jejunum mast cells differing in hypersensitivity and dependence on duration of influence and density of induced currents revealed, at that their bioeffects were unidirectional.

With an aim to devise a prophylactic and/or therapeutic approach for preventing internalization of radiothallium (201Tl), and more importantly by implication, its chemical analogue radiocesium (137Cs) during any nuclear emergency, different ex vivo and in vivo animal models were created to determine the role ofpH in absorption of 201Tl across jejunum/muscle tissue and whole body retention of 201Tl respectively. Movement of Tl+ under simulated pH conditions proved that pH had direct influence on its absorption. Oral intake of acidified water or parenteral administration of lactic acid was able to reduce the body burden of 201Tl by up to 12 and 50% respectively. The results indicate that acidification of gut, within physiological range may be used as an option for decorporation/inhibition of incorporation of radiothallium and radiocesium, particularly in cases of mass casualty.

The goal of this study was to elucidate the action of the CD28 mimetic peptide p2TA (AB103) that attenuates an excessive inflammatory response in mitigating radiation-induced inflammatory injuries. BALB/c and A/J mice were divided into four groups: Control (C), Peptide (P; 5 mg/kg of p2TA peptide), Radiation (R; total body irradiation with 8 Gy γ-rays), and Radiation + Peptide (RP; irradiation followed by p2TA peptide 24 h later). Gastrointestinal tissue damage was evaluated by analysis of jejunum histopathology and immunohistochemistry for cell proliferation (Cyclin D1) and inflammation (COX-2) markers, as well as the presence of macrophages (F4/80). Pro-inflammatory cytokines IL-6 and KC as well as fibrinogen were quantified in plasma samples obtained from the same mice. Our results demonstrated that administration of p2TA peptide significantly reduced the irradiation-induced increase of IL-6 and fibrinogen in plasma 7 days after exposure. Seven days after total body irradiation with 8 Gy of gamma rays numbers of intestinal crypt cells were reduced and villi were shorter in irradiated animals compared to the controls. The p2TA peptide delivery 24 h after irradiation led to improved morphology of villi and crypts, increased Cyclin D1 expression, decreased COX-2 staining and decreased numbers of macrophages in small intestine of irradiated mice. Our study suggests that attenuation of CD28 signaling is a promising therapeutic approach for mitigation of radiation-induced tissue injury.

GL2011 is a naturally occurring thiol compound and a series of thiol compounds have been proposed as radioprotectors. Radioprotective efficacy of a triple intraperitoneal dose of GL2011 of 100 mg/kg body weight of Wistar rats, 30 min prior to and 3 and 6 h following irradiation (6.7 Gy) was evaluated. Four groups of animals were used, vehicle-treated non-irradiated (VN), GL2011-treated and irradiated (GI), GL2011-treated and non-irradiated (GN) and vehicle-treated and irradiated (VI) (n = 30 per group). The radioprotective efficacy of GL2011 was determined by measuring 28-day survival and intestinal crypt cell survival. Neuroprotection in terms of behaviour was evaluated using the behavioural observational battery, open field test and elevated plus maze paradigm. An RNA microarray was carried out in order to show differences at the RNA level between VI and VN groups. Brain protein changes were identified using a gel-based proteomics method and major brain receptor complex levels were determined by blue-native gels followed by immunoblotting. 28-Day survival rate in VI was 30 %, in GI survival was 93 %, survival of VN and GN was 100 %. Jejunal crypt cell survival was significantly enhanced in GI. Protein-level changes of peroxiredoxin-5, Mn-superoxide dismutase 2, voltage-dependent anion-selective channel protein 1, septin 5 and dopamine D2 receptor complex levels were paralleling radiation damage and protection. Taken together, the findings demonstrate that GL2011 improves survival rates and jejunal crypt survival, provides partial neuroprotection at the behavioural level and modulates proteins known to be involved in protection against oxidative stress-mediated cell damage.

High levels of anthropogenic impact on the environment requires a detailed study of the features of the influence of heavy metals and ionizing radiation on living organisms, and provides for the development and use of effective means of protecting the body from its negative influence. The purpose of the work was to study the characteristics of the exchange of bile pigments of rats under the action of ecopathogenic factors (ionizing radiation and cadmium) on the organism and the corrective properties of liposomes on the basis of milk phospholipids. An analysis of the chromatographic studies of bilirubin and derivatives (nonconjugated bilirubin, bilirubin sulfate, billirubin glucuronide, urobilin and stercobilin) in the whole blood, liver, jejunum contents and feces under the action on the animal organism of ecopathogenic factors (ionizing radiation and cadmium) indicate material violation of the exchange bile pigments that may be due to the destabilization of the structural and functional hot hepatocytes. Correction of the liposomal form of biologically active additive (BAA) FLP-MD is recommended; the latter is a mixture of phospholipids isolated from milk, with a mixture of unsaturated fatty acids (oleic, linoleic, linolenic) and antioxidants (alpha-tocopherol and retinol acetate). The additive components exhibit the reparative effect of the action in respect of the damaged membrane structures with simultaneous improving of cholepoietic and billiation liver function, and therefore contribute to the normalization of exchange og bile pigments in terms of action on the body ecopathogenic factors.

Owing to its susceptibility to radiation, the small intestine of mice is valuable for studying radioprotective effects. When exposed to radiation, intestinal crypt cells immediately go through apoptosis, which impairs swift differentiation necessary for the regeneration of intestinal villi. Our previous studies have elucidated that acidic polysaccharide of Panax ginseng (APG) protects the mouse small intestine from radiation-induced damage by lengthening villi with proliferation and repopulation of crypt cells. In the present study, we identified the molecular mechanism involved. C57BL/6 mice were irradiated with gamma-rays with or without APG and the expression levels of apoptosis-related molecules in the jejunum were investigated using immunohistochemistry. APG pretreatment strongly decreased the radiation-induced apoptosis in the jejunum. It increased the expression levels of anti-apoptotic proteins (Bcl-2 and Bcl-XS/L) and dramatically reduced the expression levels of pro-apoptotic proteins (p53, BAX, cytochrome c and caspase-3). Therefore, APG attenuated the apoptosis through the intrinsic pathway, which is controlled by p53 and Bcl-2 family members. Results presented in this study suggest that APG protects the mouse small intestine from irradiation-induced apoptosis through inhibition of the p53-dependent pathway and the mitochondria/caspase pathway. Thus, APG may be a potential agent for preventing radiation induced injuries in intestinal cells during radio-therapy such as in cancer treatment., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

Bone marrow transplantation (BMT) substantially improves 10-day survival after total body irradiation (TBI), consistent with an effect on intestinal radiation death. Total body irradiation, in addition to injuring the intestinal epithelium, also perturbs the mucosal immune system, the largest immune system in the body. This study focused on how transplanted bone marrow cells (BMCs) help restore mucosal immune cell populations after sublethal TBI (8.0 Gy). We further evaluated whether transplanted BMCs: (a) home to sites of radiation injury using green fluorescent protein labeled bone marrow; and (b) contribute to restoring the mucosal barrier in vivo. As expected, BMT accelerated recovery of peripheral blood (PB) cells. In the intestine, BMT was associated with significant early recovery of mucosal granulocytes (P = 0.005). Bone marrow transplantation did not affect mucosal macrophages or lymphocyte populations at early time points, but enhanced the recovery of these cells from day 14 onward (P = 0.03). Bone marrow transplantation also attenuated radiation-induced increase of intestinal CXCL1 and restored IL-10 levels (P = 0.001). Most importantly, BMT inhibited the post-radiation increase in intestinal permeability after 10 Gy TBI (P = 0.02) and modulated the expression of tight junction proteins (P = 0.01-0.05). Green fluorescent protein-positive leukocytes were observed both in intestinal tissue and in PB. These findings strongly suggest that BMT, in addition to enhancing general hematopoietic and immune system recovery, helps restore the intestinal immune system and enhances intestinal mucosal barrier function. These findings may be important in the development and understanding of strategies to alleviate or treat intestinal radiation toxicity.

Purpose: Several fibroblast growth factors (FGFs) were shown to inhibit radiation-induced tissue damage through FGF receptor (FGFR) signaling; however, this signaling was also found to be involved in the pathogenesis of several malignant tumors. In contrast, FGF12 cannot activate any FGFRs. Instead, FGF12 can be internalized readily into cells using 2 cell-penetrating peptide domains (CPP-M, CPP-C). Therefore, this study focused on clarifying the role of FGF12 internalization in protection against radiation-induced intestinal injury., Methods and Materials: Each FGF or peptide was administered intraperitoneally to BALB/c mice in the absence of heparin 24 hours before or after total body irradiation with γ rays at 9 to 12 Gy. Several radioprotective effects were examined in the jejunum., Results: Administration of FGF12 after radiation exposure was as effective as pretreatment in significantly promoting intestinal regeneration, proliferation of crypt cells, and epithelial differentiation. Two domains, comprising amino acid residues 80 to 109 and 140 to 169 of FGF12B, were identified as being responsible for the radioprotective activity, so that deletion of both domains from FGF12B resulted in a reduction in activity. Interestingly, these regions included the CPP-M and CPP-C domains, respectively; however, CPP-C by itself did not show an antiapoptotic effect. In addition, FGF1, prototypic FGF, possesses a domain corresponding to CPP-M, whereas it lacks CPP-C, so the fusion of FGF1 with CPP-C (FGF1/CPP-C) enhanced cellular internalization and increased radioprotective activity. However, FGF1/CPP-C reduced in vitro mitogenic activity through FGFRs compared with FGF1, implying that FGFR signaling might not be essential for promoting the radioprotective effect of FGF1/CPP-C. In addition, internalized FGF12 suppressed the activation of p38α after irradiation, resulting in reduced radiation-induced apoptosis., Conclusions: These findings indicate that FGF12 can protect the intestine against radiation-induced injury through its internalization, independently of FGFRs, suggesting that cellular uptake of FGF12 is an alternative signaling pathway useful for cancer radiation therapy., (Copyright © 2014 Elsevier Inc. All rights reserved.)

We recently demonstrated that natural delta-tocotrienol (DT3) significantly enhanced survival in total-body irradiated (TBI) mice, and protected mouse bone marrow cells from radiation-induced damage through Erk activation-associated mTOR survival pathways. Here, we further evaluated the effects and mechanisms of DT3 on survival of radiation-induced mouse acute gastrointestinal syndrome. DT3 (75-100 mg/kg) or vehicle was administered as a single subcutaneous injection to CD2F1 mice 24 h before 10-12 Gy (60)Co total-body irradiation at a dose rate of 0.6 Gy/min and survival was monitored. In a separate group of mice, jejunum sections were stained with hematoxylin and eosin and the surviving crypts in irradiated mice were counted. Apoptosis in intestinal epithelial cells was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) staining and bacterial translocation from gut to heart, spleen and liver in irradiated mice were evaluated. DT3 (75 mg/kg) significantly enhanced survival in mice that received 10, 10.5, 11 or 12 Gy TBI. Administration of DT3 protected intestinal tissue, decreased apoptotic cells in jejunum and inhibited gut bacterial translocation in irradiated mice. Furthermore, DT3 significantly inhibited radiation-induced production of pro-inflammatory factors interleukin-1β and -6 and suppressed expression of protein tyrosine kinase 6 (PTK6), a stress-induced kinase that promotes apoptosis in mouse intestinal cells. Our data demonstrate that administration of DT3 protected mice from radiation-induced gastrointestinal system damage.

Gamma ray irradiation triggers DNA damage and apoptosis of proliferating stem cells and peripheral immune cells, resulting in the destruction of intestinal crypts and lymphoid system. Geraniin is a natural compound extracts from an aquatic plant Nymphaea tetragona and possesses good antioxidant property. In this study, we demonstrate that geraniin rescues radiosensitive splenocytes and jejunal crypt cells from radiation-induced DNA damage and apoptosis. Isolated splenocytes from C57BL/6 mice treated with geraniin were protected against radiation injury of 2 Gy irradiation through the enhancement of the proliferation and attenuation of DNA damage. Also, geraniin inhibited apoptosis in radiosensitive splenocytes by reducing the expression level and immunoreactivity of proapoptotic p53 and Bax and increasing those of anti-apoptotic Bcl-2. In mice exposed to radiation, geraniin treatment protected splenocytes and intestinal crypt cells from radiation-induced cell death. Our results suggest that geraniin presents radioprotective effects by regulating DNA damage on splenocytes, exerting immunostimulatory capacities and inhibiting apoptosis of radiosensitive immune cells and jejunal crypt cells. Therefore, geraniin can be a radioprotective agent against γ-irradiation exposure., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: Radiation therapy is the most widely used treatment for cancer, but it causes the side effect of mucositis due to intestinal damage. We examined the protective effect of genistein in tumor-bearing mice after abdominal irradiation by evaluation of apoptosis and intestinal morphological changes., Methods: Mouse colon cancer CT26 cells were subcutaneously injected at the flank of BALB/c mice to generate tumors. The tumor-bearing mice were treated with abdominal radiation at 5 and 10 Gy, and with genistein at 200 mg/kg body weight per day for 1 d before radiation. The changes in intestinal histology were evaluated 12 h and 3.5 d after irradiation. To assess the effect of the combination treatment on the cancer growth, the tumor volume was determined at sacrifice before tumor overgrowth occurred., Results: Genistein significantly decreased the number of apoptotic nuclei compared with that in the irradiation group 12 h after 5 Gy irradiation. Evaluation of histological changes showed that genistein ameliorated intestinal morphological changes such as decreased crypt survival, villus shortening, and increased length of the basal lamina 3.5 d after 10 Gy irradiation. Moreover, the genistein-treated group exhibited more Ki-67-positive proliferating cells in the jejunum than the irradiated control group, and crypt depths were greater in the genistein-treated group than in the irradiated control group. The mean weight of the CT26 tumors was reduced in the group treated with genistein and radiation compared with the control group., Conclusion: Genistein had a protective effect on intestinal damage induced by irradiation and delayed tumor growth. These results suggest that genistein is a useful candidate for preventing radiotherapy-induced intestinal damage in cancer patients.

Purpose: The objective of this study was to elucidate the action of α-tocopherol succinate (TS)- and AMD3100-mobilized progenitors in mitigating radiation-induced injuries., Material and Methods: CD2F1 mice were exposed to a high dose of radiation and then transfused intravenously with 5 million peripheral blood mononuclear cells (PBMC) from TS- and AMD3100-injected mice after irradiation. Intestinal and splenic tissues were harvested after irradiation and cells of those tissues were analyzed for markers of apoptosis and mitosis. Bacterial translocation from gut to heart, spleen, and liver in TS-treated and irradiated mice was evaluated by bacterial culture., Results: We observed that the infusion of PBMC from TS- and AMD3100-injected mice significantly inhibited apoptosis, increased cell proliferation in the analyzed tissues of recipient mice, and inhibited bacterial translocation to various organs compared to mice receiving cells from vehicle-mobilized cells. This study further supports our contention that the infusion of TS-mobilized progenitor-containing PBMC acts as a bridging therapy by inhibiting radiation-induced apoptosis, enhancing cell proliferation, and inhibiting bacterial translocation in irradiated mice., Conclusions: We suggest that this novel bridging therapeutic approach that involves the infusion of TS-mobilized hematopoietic progenitors following acute radiation injury might be applicable to humans as well.

Purpose: Human fibroblast growth factor-1 (FGF1) has radioprotective effects on the intestine, although its structural instability limits its potential for practical use. Several stable FGF1 mutants were created increasing stability in the order, wild-type FGF1, single mutants (Q40P, S47I, and H93G), Q40P/S47I, and Q40P/S47I/H93G. This study evaluated the contribution of the structural stability of FGF1 to its radioprotective effect., Methods and Materials: Each FGF1 mutant was administered intraperitoneally to BALB/c mice in the absence of heparin 24 h before or after total body irradiation (TBI) with γ-rays at 8-12 Gy. Several radioprotective effects were examined in the jejunum., Results: Q40P/S47I/H93G could activate all subtypes of FGF receptors in vitro much more strongly than the wild-type without endogenous or exogenous heparin. Preirradiation treatment with Q40P/S47I/H93G significantly increased crypt survival more than wild-type FGF1 after TBI at 10 or 12 Gy, and postirradiation treatment with Q40P/S47I/H93G was effective in promoting crypt survival after TBI at 10, 11, or 12 Gy. In addition, crypt cell proliferation, crypt depth, and epithelial differentiation were significantly promoted by postirradiation treatment with Q40P/S47I/H93G. The level of stability of FGF1 mutants correlated with their mitogenic activities in vitro in the absence of heparin; however, preirradiation treatment with the mutants increased the crypt number to almost the same level as Q40P/S47I/H93G. When given 24 h after TBI at 10 Gy, all FGF1 mutants increased crypt survival more than wild-type FGF1, and Q40P/S47I/H93G had the strongest mitogenic effects in intestinal epithelial cells after radiation damage. Moreover, Q40P/S47I/H93G prolonged mouse survival after TBI because of the repair of intestinal damage., Conclusion: These findings suggest that the structural stability of FGF1 can contribute to the enhancement of protective effects against radiation-induced intestinal damage. Therefore, Q40P/S47I/H93G is pharmacologically one of the most promising candidates for clinical applications for radiation-induced gastrointestinal syndrome., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Ionizing irradiation induces severe damage to the intestinal crypt cells which are responsible for renovation and maintenance of the intestinal cellular architecture. Therefore, protection of intestinal cells and tissue against lethal irradiation using a semiquinone glucoside derivative (SQGD) isolated from radioresistant bacterium Bacillus sp. INM-1 is the prime focus of the present investigation. BALB/c mice were administered by SQGD (50 mg/kg.b.wt. i.p.) 2 h before whole body irradiation (10 Gy), and histological analysis of the jejunum section was carried out and compared to the irradiated mice. Significant (p < 0.0001) increase in villus length, number of cells per villus, crypts numbers per villus section, total cells counts and mitotic cell counts per crypt and low goblet cells per villus section, and low apoptotic index per crypt section were observed in the irradiated mice pre-treated by SQGD at 48-168 h. Significant induction in NF-kβ at 24 h and Bcl-2/Bax ratio was observed in irradiated mice pre-treated by SQGD compared to only irradiated animals. SQGD pre-treatment before irradiation was found instrumental to reverse the radiation-induced degenerative changes by replenishment of the damaged cells by enhancing mitotic, proliferating, pro-survival, and apoptosis inhibitory activities probably through modulation of cell cycle arrest in G(1)/S phase in the intestinal cellular milieu.

Background & Aims: Adult stem cells have been proposed to be quiescent and radiation resistant, repairing DNA double-strand breaks by nonhomologous end joining. However, the population of putative small intestinal stem cells (ISCs) at position +4 from the crypt base contradicts this model, in that they are highly radiosensitive. Cycling crypt base columnar cells (CBCs) at crypt positions +1-3 recently were defined as an alternative population of ISCs. Little is known about the sensitivity of this stem cell population to radiation., Methods: Radiation-induced lethality of CBCs was quantified kinetically in Lgr5-lacZ transgenic mice. γ-H2AX, BRCA1, RAD51, and DNA-PKcs foci were used as DNA repair surrogates to investigate the inherent ability of CBCs to recognize and repair double-strand breaks. 5-ethynyl-2'-deoxyuridine and 5-bromo-2'-deoxyuridine incorporation assays were used to study patterns of CBC growth arrest and re-initiation of cell cycling. Apoptosis was evaluated by caspase-3 staining., Results: CBCs are relatively radioresistant, repairing DNA by homologous recombination significantly more efficiently than transit amplifying progenitors or villus cells. CBCs undergo apoptosis less than 24 hours after irradiation (32% ± 2% of total lethality) or mitotic death at 24-48 hours. Survival of CBCs at 2 days predicts crypt regeneration at 3.5 days and lethality from gastrointestinal syndrome. Crypt repopulation originates from CBCs that survive irradiation., Conclusions: Adult ISCs in mice can cycle rapidly yet still be radioresistant. Importantly, homologous recombination can protect adult stem cell populations from genotoxic stress. These findings broaden and refine concepts of the phenotype of adult stem cells., (Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background and Objective: To investigate the effects of low-level laser therapy applied to the serosal surface of the rat jejunum following ischemia and reperfusion., Materials and Methods: Ninety-six male Sprague-Dawley rats were assigned to 15 groups and anesthetized. Small intestinal ischemia was induced by clamping the superior mesenteric artery for 60 minutes. A laser diode (70 mW, 650 nm) was applied to the serosal surface of the jejunum at a dose of 0.5 J/cm(2) either immediately before or following initiation of reperfusion. Animals were maintained under anesthesia and sacrificed at 0, 1, and 6 hours following reperfusion. Intestinal, lung, and liver samples were evaluated histologically., Results: Intestinal injury was significantly worse (P < 0.0001) in animals treated with laser and no ischemia-reperfusion injury (IRI) compared to sham. Intestinal injury was significantly worse in animals that underwent IRI and laser treatment at all time points compared to sham (P < 0.001). In animals that underwent IRI, those treated with laser had significantly worse intestinal injury compared to those that did not have laser treatment at 0 (P = 0.0104) and 1 (P = 0.0015) hour of reperfusion. After 6 hours of reperfusion there was no significant difference in injury between these two groups. Lung injury was significantly decreased following IRI in laser-treatment groups (P < 0.001)., Conclusions: At the dose and parameters used, low-level laser did not protect against intestinal IRI in the acute phase of injury. However, laser did provide protection against distant organ injury. Failure to observe a therapeutic response in the intestine may be due to inappropriate dosing parameters. Furthermore, the model was designed to detect the histologic response within the first 6 hours of injury, whereas the beneficial effects of laser, if they occur, may not be observed until the later phases of healing. The finding of secondary organ protection is important, as lung injury following IRI is a significant source of morbidity and mortality., (Copyright © 2012 Wiley Periodicals, Inc.)

Gastrointestinal injury is a major cause of death following exposure to high levels of radiation, and no effective treatments are currently available. In this study, we examined the capacity of granulocyte colony-stimulating factor (G-CSF) to mitigate intestinal injury in, and improve survival of, C3H/HeN mice given a lethal dose (12 Gy) of radiation to the abdomen. G-CSF (100 μg/kg body weight) was injected subcutaneously daily for 3 days after irradiation and shown to improve survival and intestinal morphology at 3.5 days compared with saline-injected controls. The morphological features improved by G-CSF included crypt number and depth, villous length, and the length of basal lamina of 10 enterocytes. G-CSF also normalized the levels of circulating tumor necrosis factor alpha and attenuated the loss of peripheral neutrophils, caused by radiation-induced myelosuppression. In conclusion, our results suggest that G-CSF enhanced the survival of irradiated mice and minimized the effects of radiation on gastrointestinal injury., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Recent identification of intestinal epithelial stem cell (ISC) markers and development of ISC reporter mice permit visualization and isolation of regenerating ISCs after radiation to define their functional and molecular phenotypes. Previous studies in uninjured intestine of Sox9-EGFP reporter mice demonstrate that ISCs express low levels of Sox9-EGFP (Sox9-EGFP Low), whereas enteroendocrine cells (EEC) express high levels of Sox9-EGFP (Sox9-EGFP High). We hypothesized that Sox9-EGFP Low ISCs would expand after radiation, exhibit enhanced proliferative capacities, and adopt a distinct gene expression profile associated with rapid proliferation. Sox9-EGFP mice were given 14 Gy abdominal radiation and studied between days 3 and 9 postradiation. Radiation-induced changes in number, growth, and transcriptome of the different Sox9-EGFP cell populations were determined by histology, flow cytometry, in vitro culture assays, and microarray. Microarray confirmed that nonirradiated Sox9-EGFP Low cells are enriched for Lgr5 mRNA and mRNAs enriched in Lgr5-ISCs and identified additional putative ISC markers. Sox9-EGFP High cells were enriched for EEC markers, as well as Bmi1 and Hopx, which are putative markers of quiescent ISCs. Irradiation caused complete crypt loss, followed by expansion and hyperproliferation of Sox9-EGFP Low cells. From nonirradiated intestine, only Sox9-EGFP Low cells exhibited ISC characteristics of forming organoids in culture, whereas during regeneration both Sox9-EGFP Low and High cells formed organoids. Microarray demonstrated that regenerating Sox9-EGFP High cells exhibited transcriptomic changes linked to p53-signaling and ISC-like functions including DNA repair and reduced oxidative metabolism. These findings support a model in which Sox9-EGFP Low cells represent active ISCs, Sox9-EGFP High cells contain radiation-activatable cells with ISC characteristics, and both participate in crypt regeneration.

The goal of this study was to elucidate the role of α-tocopherol succinate (TS)- and AMD3100-mobilized progenitors in mitigating the ionizing-radiation-induced gastrointestinal syndrome in mice. We demonstrate the efficacy of a bridging therapy that will allow the lymphohematopoietic system of severely immunocompromised victims exposed to ionizing radiation to recover from high doses of radiation. CD2F1 mice were irradiated with a high dose of radiation causing gastrointestinal syndrome (11 Gy, cobalt-60 γ-radiation) and then transfused intravenously (retro-orbital sinus) with whole blood or peripheral blood mononuclear cells (PBMC) from TS- and AMD3100-injected mice 2, 24, or 48 hours post irradiation and monitored for 30-day survival. Jejunum sections were analyzed for tissue area, surviving crypts, villi, mitotic figures, and basal lamina enterocytes. Our results demonstrate that infusion of whole blood or PBMC from TS- and AMD3100-injected mice significantly improved survival of mice receiving a high dose of radiation. Histopathology and immunostaining of jejunum from irradiated and TS- and AMD3100-mobilized PBMC-transfused mice reveal significant protection of gastrointestinal tissue from radiation injury. We demonstrate that TS and AMD3100 mobilize progenitors into peripheral circulation and that the infusion of mobilized progenitor-containing blood or PBMC acts as a bridging therapy for immune-system recovery in mice exposed to high, potentially fatal, doses of ionizing radiation., (Published by Elsevier Inc.)

The intestinal epithelium is sensitive to radiation injury. Damage to the intestinal epithelium is dose limiting in radiation therapy of abdominal cancers. There is a need for agents that can be given before radiation therapy to protect the intestinal epithelium. C57BL6 mice were subjected to 12 Gy of total body radiation. Some mice received intraperitoneal hyaluronic acid (HA) before radiation. Mice were killed 6 h after radiation to assess radiation-induced apoptosis in the intestine; other mice were killed at 84 h to assess crypt survival. Total body radiation (12 Gy) resulted in increased expression of HA synthases and HA in the intestine and increased plasma HA (5-fold). Intraperitoneal injection of HA (30 mg/kg) before radiation resulted in a 1.8-fold increase in intestinal crypt survival and a decrease in radiation-induced apoptosis. The radioprotective effects of HA were not seen in Toll-like receptor 4 (TLR4)- or cyclooxygenase-2 (COX-2)-deficient mice. Intraperitoneal injection of HA induced a 1.5-fold increase in intestinal COX-2 expression, a 1.5-fold increase in intestinal PGE₂, and the migration of COX-2-expressing mesenchymal stem cells from the lamina propria in the villi to the lamina propria near the crypt. We conclude that 1) radiation induces increased HA expression through inducing HA synthases, 2) intraperitoneal HA given before radiation reduces radiation-induced apoptosis and increases crypt survival, and 3) these radioprotective effects are mediated through TLR4, COX-2, and the migration of COX-2-expressing mesenchymal stem cells.

Rapid advances have been made in the understanding of how the highly proliferative gastrointestinal tract epithelium is regulated under homeostasis and disease. The identification of putative intestinal stem cell (ISC) genes and the ability to culture ISC capable of generating all four lineages plus the architecture of small intestinal (SI) crypts has been transformative. Here, we show that transcription factor Myb governs ISC gene expression, particularly Lgr5. Lgr5 is associated with cells that have the capacity to generate all cell lineages in SI organoid cultures and colorectal cancer cells, which overexpress Myb. Furthermore, Wnt signaling and Myb cooperate in maximal Lgr5 promoter activation while hypomorphic Myb (plt4/plt4) mice have decreased Lgr5 expression. After ionizing radiation (IR), ISC genes are elevated; but in plt4/plt4 mice, this response is substantially subdued. ISC genes bmi-1 and olfm4 are expressed at subnormal levels in plt4/plt4 mice, and bmi-1 is induced with IR to half the level in mutant mice. dcamkl-1 and olfm4 failed to recover after IR in both wild-type (wt) and mutant mice. Although not considered as an ISC gene, cyclinE1 is nevertheless used to assist cells in the emergence from a quiescent state (an expectation of ISC following IR) and is overexpressed after IR in wt mice but does not change from a very low base in plt4/plt4 mice. Self-renewal assays using organoid cultures and inducible Myb knockout studies further highlighted the dependence of ISC on Myb consistent with role in other stem cell-containing tissues., (Copyright © 2011 AlphaMed Press.)