scholarly journals Krüppel-like factor 4 is a radioprotective factor for the intestine following γ-radiation-induced gut injury in mice

2015 ◽  
Vol 308 (2) ◽  
pp. G121-G138 ◽  
Author(s):  
Daniel Talmasov ◽  
Xinjun Zhang ◽  
Bing Yu ◽  
Mandayam O. Nandan ◽  
Agnieszka B. Bialkowska ◽  
...  
Keyword(s):  
Intestinal Epithelium ◽  
Morphological Changes ◽  
Γ Irradiation ◽  
Γ Radiation ◽  
Proliferative Zone ◽  
Acute Response ◽  
Radiation Induced ◽  
Total Body

Gut radiation-induced injury is a concern during treatment of patients with cancer. Krüppel-like factor 4 (KLF4) is expressed in differentiated villous epithelial cells of the small intestine. We previously showed that KLF4 protects cells from apoptosis following γ-irradiation in vitro. We sought to determine whether KLF4 mediates the small intestinal response to γ-irradiation in vivo. Mice with intestinal epithelium-specific deletion of Klf4 ( Klf4 ΔIS) and control ( Klf4 fl/fl) mice were irradiated with total-body γ-radiation. Following irradiation, the Klf4 ΔIS mice had significantly increased mortality compared with irradiated Klf4 fl/fl mice. Immunohistochemistry and immunofluorescence staining were used to assess the morphological changes, levels of proliferation, and apoptosis in the intestinal epithelium. At 96 h following irradiation, there was a regenerative response manifested by an expansion of the proliferative zone in both mouse groups, with the control mice having a higher proliferative activity than the Klf4 ΔIS group. In addition, there was a significant increase in the number of Klf4/Ki67-copositive cells in the irradiated control mice compared with unirradiated mice. Also, the irradiated Klf4 ΔIS mice had a significantly higher number of crypt cells positive for apoptosis, p53, and p21 compared with irradiated Klf4 fl/fl mice. Taken together, our data suggest that Klf4 may function as a radioprotective factor against gastrointestinal syndrome in mice following γ-irradiation by inhibiting apoptosis in the acute response to irradiation and contributing to crypt regeneration.

scholarly journals The sialyltransferase ST6GAL1 protects against radiation-induced gastrointestinal damage

Glycobiology ◽  
2020 ◽  
Vol 30 (7) ◽  
pp. 446-453 ◽  
Author(s):  
Patrick R Punch ◽  
Eric E Irons ◽  
Charles T Manhardt ◽  
Himangi Marathe ◽  
Joseph T Y Lau
Keyword(s):  
Bone Marrow ◽  
Marrow Transplant ◽  
High Dose ◽  
Wild Type ◽  
Γ Irradiation ◽  
Risk Of Death ◽  
Radiation Induced ◽  
Total Body

Abstract High-dose irradiation poses extreme risk of mortality from acute damage to the hematopoietic compartment and gastrointestinal tract. While bone marrow transplantation can reestablish the hematopoietic compartment, a more imminent risk of death is posed by gastrointestinal acute radiation syndrome (GI-ARS), for which there are no FDA-approved medical countermeasures. Although the mechanisms dictating the severity of GI-ARS remain incompletely understood, sialylation by ST6GAL1 has been shown to protect against radiation-induced apoptosis in vitro. Here, we used a C57BL/6 St6gal1-KO mouse model to investigate the contribution of ST6GAL1 to susceptibility to total body irradiation in vivo. Twelve gray total body ionizing γ-irradiation (TBI) followed by bone marrow transplant is not lethal to wild-type mice, but St6gal1-KO counterparts succumbed within 7 d. Both St6gal1-KO and wild-type animals exhibited damage to the GI epithelium, diarrhea and weight loss, but these symptoms became progressively more severe in the St6gal1-KO animals while wild-type counterparts showed signs of recovery by 120 h after TBI. Increased apoptosis in the GI tracts of St6gal1-KO mice and the absence of regenerative crypts were also observed. Together, these observations highlight an important role for ST6GAL1 in protection and recovery from GI-ARS in vivo.

scholarly journals Polymyxin B Attenuates LPS-Induced Death but Aggravates Radiation-Induced Death via TLR4-Myd88-IL-6 Pathway

2017 ◽  
Vol 42 (3) ◽  
pp. 1120-1126 ◽  
Author(s):  
Ying Cheng ◽  
Jicong Du ◽  
Jiaqi Han ◽  
Weimin Sun ◽  
Fu Gao ◽  
...  
Keyword(s):  
Polymyxin B ◽  
Protection Factor ◽  
Knock Out ◽  
Endotoxin Contamination ◽  
Radiation Induced ◽  
Total Body ◽  
Α Level

Background/Aims: Polymyxin B (PMB) is a cyclic cationic polypeptide antibiotic widely used to counteract the effects of endotoxin contamination, both in vitro and in vivo. Lipopolysaccharide (LPS) is an endotoxin that acts as a radiation protection factor. In this study, we focus on the role of PMB in LPS-induced and radiation-induced mortality in mice. Methods: Mice received total-body radiation or were pretreated by LPS or PMB, and the survival of mice was recorded. Elisa were used to detect the cytokines levels. Results: PMB decreased LPS-induced, but increased radiation-induced mortality in mice. Moreover, PMB could block the LPS-induced radioprotective effect. The ELISA and gene knock-out experiments indicated that PMB reduces TNF-α level to block LPS-induced mortality in mice, and inhibits IL-6, G-CSF and IL-10 to increase radiation-induced mortality via the TLR4-Myd88-IL-6 pathway. Conclusions: Our study revealed a role of PMB in LPS-induced endotoxemia and radiation exposure. We infer that the TLR4-Myd88-IL-6 pathway may play a crucial role in the process.

scholarly journals Rapamycin Promotes ROS-Mediated Cell Death via Functional Inhibition of xCT Expression in Melanoma Under γ-Irradiation

2021 ◽  
Vol 11 ◽  
Author(s):  
Yunseo Woo ◽  
Hyo-Ji Lee ◽  
Jeongyeon Kim ◽  
Seung Goo Kang ◽  
Sungjin Moon ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Cells ◽  
Mtor Signaling ◽  
Γ Irradiation ◽  
Γ Radiation ◽  
Hypoxic Conditions ◽  
Tumor Tissues ◽  
Γ Rays

Although many cancer patients are administered radiotherapy for their treatment, the interaction between tumor cells and macrophages in the tumor microenvironment attenuates the curative effects of radiotherapy. The enhanced activation of mTOR signaling in the tumors promotes tumor radioresistance. In this study, the effects of rapamycin on the interaction between tumor cells and macrophages were investigated. Rapamycin and 3BDO were used to regulate the mTOR pathway. In vitro, tumor cells cocultured with macrophages in the presence of each drug under normoxic or hypoxic conditions were irradiated with γ–rays. In vivo, mice were irradiated with γ–radiation after injection with DMSO, rapamycin and 3BDO into tumoral regions. Rapamycin reduced the secretion of IL-4 in tumor cells as well as YM1 in macrophages. Mouse recombinant YM1 decreased the enhanced level of ROS and the colocalized proportion of both xCT and EEA1 in irradiated tumor cells. Human recombinant YKL39 also induced results similar to those of YM1. Moreover, the colocalized proportion of both xCT and LC3 in tumor tissues was elevated by the injection of rapamycin into tumoral regions. Overall, the suppression of mTOR signaling in the tumor microenvironment might be useful for the improvement of tumor radioresistance.

Polyamine depletion inhibits irradiation-induced apoptosis in intestinal epithelia

2005 ◽  
Vol 289 (3) ◽  
pp. G599-G606 ◽  
Author(s):  
Wenlin Deng ◽  
Mary Jane Viar ◽  
Leonard R. Johnson
Keyword(s):  
Structural Damage ◽  
Caspase 3 ◽  
Intestinal Epithelial ◽  
Γ Irradiation ◽  
Intestinal Epithelia ◽  
Proapoptotic Protein ◽  
Radiation Induced ◽  
Induced Apoptosis

Our group has previously shown that polyamine depletion delays apoptosis in rat intestinal epithelial (IEC-6) cells (Ray RM, Viar MJ, Yuan Q, and Johnson LR , Am J Physiol Cell Physiol 278: C480–C489, 2000). Here, we demonstrate that polyamine depletion inhibits γ-irradiation-induced apoptosis in vitro and in vivo. Pretreatment of IEC-6 cells with 5 mM α-difluoromethylornithine (DFMO) for 4 days significantly reduced radiation-induced caspase-3 activity and DNA fragmentation. This protective effect was prevented by the addition of 10 μM exogenous putrescine. Radiation exposure to mice resulted in a high frequency of apoptosis over cells positioned fourth to seventh in crypt-villus units. Pretreatment of mice with 2% DFMO in drinking water significantly reduced apoptotic cells from ∼2.75 to 1.61 per crypt-villus unit, accompanied by significant decreases in caspase-3 levels. Further examination showed that DFMO pretreatment inhibited the radiation-induced increase in the proapoptotic protein Bax. Moreover, DFMO pretreatment significantly enhanced the intestinal crypt survival rate by 2.1-fold subsequent to radiation and ameliorated mucosal structural damage. We conclude that polyamine depletion by DFMO inhibits γ-irradiation-induced apoptosis of intestinal epithelial cells both in vitro and in vivo through inhibition of Bax and caspase-3 activity, which leads to attenuation of radiation-inflicted intestinal injury. These data indicate that DFMO may be therapeutically useful to counteract the gastrointestinal toxicity caused by chemoradiotherapy. This is the first demonstration that polyamines are required for apoptosis in vivo.

The Anti-tumor Activity and Mechanisms of rLj-RGD3 on Human Laryngeal Squamous Carcinoma Hep2 Cells

2020 ◽  
Vol 19 (17) ◽  
pp. 2108-2119
Author(s):  
Yang Jin ◽  
Li Lv ◽  
Shu-Xiang Ning ◽  
Ji-Hong Wang ◽  
Rong Xiao
Keyword(s):  
Wound Healing ◽  
Western Blot ◽  
Morphological Changes ◽  
In Vivo Studies ◽  
Migration And Invasion ◽  
Tunel Staining ◽  
Dna Ladder ◽  
Western Blot Assay

Background: Laryngeal Squamous Cell Carcinoma (LSCC) is a malignant epithelial tumor with poor prognosis and its incidence rate increased recently. rLj-RGD3, a recombinant protein cloned from the buccal gland of Lampetra japonica, contains three RGD motifs that could bind to integrins on the tumor cells. Methods: MTT assay was used to detect the inhibitory rate of viability. Giemsa’s staining assay was used to observe the morphological changes of cells. Hoechst 33258 and TUNEL staining assay, DNA ladder assay were used to examine the apoptotic. Western blot assay was applied to detect the change of the integrin signal pathway. Wound-healing assay, migration, and invasion assay were used to detect the mobility of Hep2 cells. H&E staining assay was used to show the arrangement of the Hep2 cells in the solid tumor tissues. Results: In the present study, rLj-RGD3 was shown to inhibit the viability of LSCC Hep2 cells in vitro by inducing apoptosis with an IC50 of 1.23µM. Western blot showed that the apoptosis of Hep2 cells induced by rLj- RGD3 was dependent on the integrin-FAK-Akt pathway. Wound healing, transwells, and western blot assays in vitro showed that rLj-RGD3 suppressed the migration and invasion of Hep2 cells by integrin-FAKpaxillin/ PLC pathway which could also affect the cytoskeleton arrangement in Hep2 cells. In in vivo studies, rLj-RGD3 inhibited the growth, tumor volume, and weight, as well as disturbed the tissue structure of the solid tumors in xenograft models of BALB/c nude mice without reducing their body weights. Conclusion: hese results suggested that rLj-RGD3 is an effective and safe suppressor on the growth and metastasis of LSCC Hep2 cells from both in vitro and in vivo experiments. rLj-RGD3 might be expected to become a novel anti-tumor drug to treat LSCC patients in the near future.

scholarly journals The Radiation-Induced Regenerative Response of Adult Tissue-Specific Stem Cells: Models and Signaling Pathways

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 855
Author(s):  
Paola Serrano Martinez ◽  
Lorena Giuranno ◽  
Marc Vooijs ◽  
Robert P. Coppes
Keyword(s):  
Signaling Pathways ◽  
Progenitor Cells ◽  
Tissue Regeneration ◽  
Normal Tissue ◽  
Cellular Response ◽  
Adult Tissue ◽  
Tissue Specific ◽  
Radiation Induced

Radiotherapy is involved in the treatment of many cancers, but damage induced to the surrounding normal tissue is often inevitable. Evidence suggests that the maintenance of homeostasis and regeneration of the normal tissue is driven by specific adult tissue stem/progenitor cells. These tasks involve the input from several signaling pathways. Irradiation also targets these stem/progenitor cells, triggering a cellular response aimed at achieving tissue regeneration. Here we discuss the currently used in vitro and in vivo models and the involved specific tissue stem/progenitor cell signaling pathways to study the response to irradiation. The combination of the use of complex in vitro models that offer high in vivo resemblance and lineage tracing models, which address organ complexity constitute potential tools for the study of the stem/progenitor cellular response post-irradiation. The Notch, Wnt, Hippo, Hedgehog, and autophagy signaling pathways have been found as crucial for driving stem/progenitor radiation-induced tissue regeneration. We review how these signaling pathways drive the response of solid tissue-specific stem/progenitor cells to radiotherapy and the used models to address this.

scholarly journals Reduced High-Dose Radiation-Induced Residual Genotoxic Damage by Induction of Radioadaptive Response and Prophylactic Mild Dietary Restriction in Mice

Dose-Response ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 155932582098216
Author(s):  
Bing Wang ◽  
Kaoru Tanaka ◽  
Takanori Katsube ◽  
Kouichi Maruyama ◽  
Yasuharu Ninomiya ◽  
...  
Keyword(s):  
Dietary Restriction ◽  
High Dose ◽  
Cancer Treatments ◽  
Hematopoietic Stem ◽  
Beneficial Effects ◽  
Radiation Induced ◽  
Potential Strategy ◽  
Higher Doses

Radioadaptive response (RAR) describes a phenomenon in a variety of in vitro and in vivo systems that a low-dose of priming ionizing radiation (IR) reduces detrimental effects of a subsequent challenge IR at higher doses. Among in vivo investigations, studies using the mouse RAR model (Yonezawa Effect) showed that RAR could significantly extenuate high-dose IR-induced detrimental effects such as decrease of hematopoietic stem cells and progenitor cells, acute radiation hematopoietic syndrome, genotoxicity and genomic instability. Meanwhile, it has been demonstrated that diet intervention has a great impact on health, and dietary restriction shows beneficial effects on numerous diseases in animal models. In this work, by using the mouse RAR model and mild dietary restriction (MDR), we confirmed that combination of RAR and MDR could more efficiently reduce radiogenotoxic damage without significant change of the RAR phenotype. These findings suggested that MDR may share some common pathways with RAR to activate mechanisms consequently resulting in suppression of genotoxicity. As MDR could also increase resistance to chemotherapy and radiotherapy in normal cells, we propose that combination of MDR, RAR, and other cancer treatments (i.e., chemotherapy and radiotherapy) represent a potential strategy to increase the treatment efficacy and prevent IR risk in humans.

scholarly journals Protein kinase D promotes plasticity-induced F-actin stabilization in dendritic spines and regulates memory formation

2015 ◽  
Vol 210 (5) ◽  
pp. 771-783 ◽  
Author(s):  
Norbert Bencsik ◽  
Zsófia Szíber ◽  
Hanna Liliom ◽  
Krisztián Tárnok ◽  
Sándor Borbély ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Protein Kinase ◽  
Dendritic Spines ◽  
Morphological Changes ◽  
Long Term Potentiation ◽  
Memory Formation ◽  
Protein Kinase D

Actin turnover in dendritic spines influences spine development, morphology, and plasticity, with functional consequences on learning and memory formation. In nonneuronal cells, protein kinase D (PKD) has an important role in stabilizing F-actin via multiple molecular pathways. Using in vitro models of neuronal plasticity, such as glycine-induced chemical long-term potentiation (LTP), known to evoke synaptic plasticity, or long-term depolarization block by KCl, leading to homeostatic morphological changes, we show that actin stabilization needed for the enlargement of dendritic spines is dependent on PKD activity. Consequently, impaired PKD functions attenuate activity-dependent changes in hippocampal dendritic spines, including LTP formation, cause morphological alterations in vivo, and have deleterious consequences on spatial memory formation. We thus provide compelling evidence that PKD controls synaptic plasticity and learning by regulating actin stability in dendritic spines.

scholarly journals The hormonal induction of cervical remodeling in the common marmoset monkey (Callithrix jacchus)

Reproduction ◽  
2009 ◽  
Vol 137 (3) ◽  
pp. 517-525 ◽  
Author(s):  
Christina Simon ◽  
Almuth Einspanier
Keyword(s):  
Morphological Changes ◽  
Common Marmoset ◽  
Cervical Ripening ◽  
Cervical Tissue ◽  
Ecm Remodeling ◽  
Marmoset Monkey ◽  
Gene And Protein Expression ◽  
The Common

Controversy still exists regarding the involvement of relaxin (RLX) in cervical reorganization throughout parturition in the human, despite its well-known role in facilitating extensive extracellular matrix (ECM) remodeling in diverse organs. Therefore, the aim of the present study was to examine the influence of RLX and estrogen (E2) on the cervical tissue of the common marmoset monkey. Two experimental designs were used: 1)in vivoanalysis of the intracervical diameter under locally applied RLX and 2) ovariectomized (ov) marmosets were treated systemically with either recombinant human (rh) RLX, E2 or rhRLX+E2 to examine their action on the cervix.In vivo-locally applied rhRLX induced a distinct and significant widening of the cervix (before: 4.8±1.1 mm versus after: 5.7±0.9 mm in diameter;P<0.030, MV±s.e.m.). This widening effect was most pronounced in animals without previous pregnancies.In vitroinvestigation of cervical tissue showed significantly increased wet weights after all three hormone treatments (E2: 0.27±0.07 g, RLX: 0.25±0.04 g, E2+RLX: 0.30±0.11 g; allP<0.05; MV±s.e.m.) versus controls (0.10±0.04 g). Furthermore, morphological changes such as loosening of the connective tissue structure and decline in collagen content, an increase in the number of eosinophils, increased the expression of matrix metalloproteinases (MMP1) and MMP2, as well as gene and protein expression of the RLX receptor RXFP1 could be detected in the cervical tissue after all hormone treatments, compared with controls. In summary, RLX has a potent widening effect on the cervix of the common marmoset monkey. Although E2 is not required for this RLX effect, a combined application of E2 and RLX induced the most prominent cervical ripening.

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