Genetically Engineered Probiotic Limosilactobacillus reuteri Releasing IL-22 (LR-IL-22) Modifies the Tumor Microenvironment, Enabling Irradiation in Ovarian Cancer.

Despite recent advances in cancer therapy, ovarian cancer remains the most lethal gynecological cancer worldwide, making it crucial and of the utmost importance to establish novel therapeutic strategies. Adjuvant radiotherapy has been assessed historically, but its use was limited by intestinal toxicity. We recently established the role of Limosilactobacillus reuteri in releasing IL-22 (LR-IL-22) as an effective radiation mitigator, and we have now assessed its effect in an ovarian cancer mouse model. We hypothesized that an LR-IL-22 gavage would enable intestinal radioprotection by modifying the tumor microenvironment and, subsequently, improving overall survival in female C57BL/6MUC-1 mice with widespread abdominal syngeneic 2F8cis ovarian cancer. Herein, we report that the LR-IL-22 gavage not only improved overall survival in mice when combined with a PD-L1 inhibitor by inducing differential gene expression in irradiated stem cells but also induced PD-L1 protein expression in ovarian cancer cells and mobilized CD8+ T cells in whole abdomen irradiated mice. The addition of LR-IL-22 to a combined treatment modality with fractionated whole abdomen radiation (WAI) and systemic chemotherapy and immunotherapy regimens can facilitate a safe and effective protocol to reduce tumor burden, increase survival, and improve the quality of life of a locally advanced ovarian cancer patient.

Chemical Carcinogen (Dimethyl-benzanthracene) Induced Transplantable Cancer in Fanconi Anemia (Fanca-/-) Mice.

BACKGROUND/AIM: Patients with radiation sensitive Fanconi anemia (FA) are presenting with cancers of the oral cavity, oropharynx, and other anatomic locations. MATERIALS AND METHODS: Animal models for cancer in FA mice used orthotopic tumors from wild type mice. We derived a cancer cell line from Fanca-/- mice by topical application of the chemical carcinogen dimethyl benzanthracene (DMBA). RESULTS: A Fanca-/- mouse rhabdomyosarcoma was derived from a Fanca-/- (129/Sv) mouse. The in vitro clonogenic survival of the Fanca-/- clone 6 cancer cell line was consistent with the FA genotype. Transplanted tumors demonstrated hypoxic centers surrounded by senescent cells. CONCLUSION: This Fanca-/- mouse syngeneic cancer should provide a valuable resource for discovery and development of new normal tissue radioprotectors for patients with FA and cancer.

Inhibition of tyrosine kinase Fgr prevents radiation-induced pulmonary fibrosis (RIPF).

Cellular senescence is involved in the development of pulmonary fibrosis as well as in lung tissue repair and regeneration. Therefore, a strategy of removal of senescent cells by senolytic drugs may not produce the desired therapeutic result. Previously we reported that tyrosine kinase Fgr is upregulated in ionizing irradiation-induced senescent cells. Inhibition of Fgr reduces the production of profibrotic proteins by radiation-induced senescent cells in vitro; however, a mechanistic relationship between senescent cells and radiation-induced pulmonary fibrosis (RIPF) has not been established. We now report that senescent cells from the lungs of mice with RIPF, release profibrotic proteins for target cells and secrete chemotactic proteins for marrow cells. The Fgr inhibitor TL02-59, reduces this release of profibrotic chemokines from the lungs of RIPF mice, without reducing numbers of senescent cells. In vitro studies demonstrated that TL02-59 abrogates the upregulation of profibrotic genes in target cells in transwell cultures. Also, protein arrays using lung fibroblasts demonstrated that TL02-59 inhibits the production of chemokines involved in the migration of macrophages to the lung. In thoracic-irradiated mice, TL02-59 prevents RIPF, significantly reduces levels of expression of fibrotic gene products, and significantly reduces the recruitment of CD11b+ macrophages to the lungs. Bronchoalveolar lavage (BAL) cells from RIPF mice show increased Fgr and other senescent cell markers including p16. In human idiopathic pulmonary fibrosis (IPF) and in RIPF, Fgr, and other senescent cell biomarkers are increased. In both mouse and human RIPF, there is an accumulation of Fgr-positive proinflammatory CD11b+ macrophages in the lungs. Thus, elevated levels of Fgr in lung senescent cells upregulate profibrotic gene products, and chemokines that might be responsible for macrophage infiltration into lungs. The detection of Fgr in senescent cells that are obtained from BAL during the development of RIPF may help predict the onset and facilitate the delivery of medical countermeasures.

Release of Interferon-ß (IFN-ß) from Probiotic Limosilactobacillus reuteri-IFN-ß (LR-IFN-ß) Mitigates Gastrointestinal Acute Radiation Syndrome (GI-ARS) following Whole Abdominal Irradiation.

Irradiation can be an effective treatment for ovarian cancer, but its use is limited by intestinal toxicity. Thus, strategies to mitigate toxicity are important and can revitalize the current standard of care. We previously established that LR-IL-22 protects the intestine from WAI. We now hypothesize that LR-IFN-ß is an effective radiation protector and mitigator and is rapidly cleared from the digestive tract, making it an option for intestinal radioprotection. We report that the gavage of LR-IFN-ß during WAI provides improved intestinal barrier integrity and significantly preserves the numbers of Lgr5+GFP+ intestinal stem cells, improving survival. The rapid clearance of the genetically engineered probiotic from the digestive tract renders it a safe and feasible radiation mitigator. Therefore, the above genetically engineered probiotic is both a feasible and effective radiation mitigator that could potentially revolutionize the management of OC patients. Furthermore, the subsequent addition of platinum/taxane-based chemotherapy to the combination of WAI and LR-IFN-ß should reduce tumor volume while protecting the intestine and should improve the overall survival in OC patients.

Carcinogen 4-Nitroquinoline Oxide (4-NQO) Induces Oncostatin-M (OSM) in Esophageal Cells.

BACKGROUND/AIM: The earliest cellular and molecular biologic changes in the esophagus that lead to esophageal cancer were evaluated in a mouse model. We correlated numbers of senescent cells with the levels of expression of potentially carcinogenic genes in sorted side population (SP) cells containing esophageal stem cells and non-stem cells in the non-side population cells in the 4-nitroquinolone oxide (NQO)-treated esophagus. MATERIALS AND METHODS: We compared stem cells with non-stem cells from the esophagus of mice treated with the chemical carcinogen 4-NQO (100 µg/ml) in drinking water. We also compared gene expression in human esophagus samples treated with 4-NQO (100 µg/ml media) to non-treated samples. We separated and quantitated the relative levels of expression of RNA using RNAseq analysis. We identified senescent cells by luciferase imaging of p16+/LUC mice and senescent cells in excised esophagus from tdTOMp16+ mice. RESULTS: A significant increase in the levels of RNA for oncostatin-M was found in senescent cells of the esophagus from 4-NQO-treated mice and human esophagus in vitro. CONCLUSION: Induction of OSM in chemically-induced esophageal cancer in mice correlates with the appearance of senescent cells.

Practitioners' Views on Enabling People With Dementia to Remain in Their Homes During and After Crisis.

One way of supporting people living with dementia is assisting them to live in their homes (as opposed to being admitted to hospital or other facility) and providing them with a specialist service that responds to crises. This makes it important to understand how best to organize such crisis response services. This study examines practitioners' actions to reduce inpatient admissions among this population. Through interviews with healthcare practitioners, we find that practitioners negotiate a complex intersection between (1) what constitutes a crisis in relation to the patient and/or the carer, (2) the demands of building a working relationship with both the patient and their family carers, and (3) ensuring effective communications with social services responsible for long-term community support. Findings suggest that policies aimed at reducing admissions should be based on a model of care that more closely maps practitioners' relational and bio-medical work in these services.

Intestinal Radiation Protection and Mitigation by Second-Generation Probiotic Lactobacillus-reuteri Engineered to Deliver Interleukin-22.

(1) Background: The systemic administration of therapeutic agents to the intestine including cytokines, such as Interleukin-22 (IL-22), is compromised by damage to the microvasculature 24 hrs after total body irradiation (TBI). At that time, there is significant death of intestinal microvascular endothelial cells and destruction of the lamina propria, which limits drug delivery through the circulation, thus reducing the capacity of therapeutics to stabilize the numbers of Lgr5+ intestinal crypt stem cells and their progeny, and improve survival. By its direct action on intestinal stem cells and their villus regeneration capacity, IL-22 is both an ionizing irradiation protector and mitigator. (2) Methods: To improve delivery of IL-22 to the irradiated intestine, we gavaged Lactobacillus-reuteri as a platform for the second-generation probiotic Lactobacillus-reuteri-Interleukin-22 (LR-IL-22). (3) Results: There was effective radiation mitigation by gavage of LR-IL-22 at 24 h after intestinal irradiation. Multiple biomarkers of radiation damage to the intestine, immune system and bone marrow were improved by LR-IL-22 compared to the gavage of control LR or intraperitoneal injection of IL-22 protein. (4) Conclusions: Oral administration of LR-IL-22 is an effective protector and mitigator of intestinal irradiation damage.

Lactobacillus reuteri Releasing IL-22 (LR-IL-22) Facilitates Intestinal Radioprotection for Whole-Abdomen Irradiation (WAI) of Ovarian Cancer.

Oral administration (gavage) of a second-generation probiotic, Lactobacillus reuteri (L. reuteri), that releases interleukin-22 (LR-IL-22) at 24 h after total-body irradiation (TBI) mitigates damage to the intestine. We determined that LR-IL-22 also mitigates partial-body irradiation (PBI) and whole-abdomen irradiation (WAI). Irradiation can be an effective treatment for ovarian cancer, but its use is limited by intestinal toxicity. Strategies to mitigate toxicity are important and can revitalize this modality to treat ovarian cancer. In the present studies, we evaluated whether LR-IL-22 facilitates fractionated WAI in female C57BL/6 mice with disseminated ovarian cancer given a single fraction of either 15.75 Gy or 19.75 Gy or 4 daily fractions of 6 Gy or 6.5 Gy. Mice receiving single or multiple administrations of LR-IL-22 during WAI showed improved intestinal barrier integrity (P = 0.0167), reduced levels of radiation-induced intestinal cytokines including KC/CXCL1 (P = 0.002) and IFN-γ (P = 0.0024), and reduced levels of plasma, Eotaxin/CCL11 (P = 0.0088). LR-IL-22 significantly preserved the numbers of Lgr5+GFP+ intestinal stem cells (P = 0.0010) and improved survival (P < 0.0343). Female C57BL/6MUC-1 mice with widespread abdominal syngeneic 2F8cis ovarian cancer that received LR-IL-22 during 6.5 Gy WAI in 4 fractions had reduced tumor burden, less intestinal toxicity, and improved 30-day survival. Furthermore, LR-IL-22 facilitated WAI when added to Paclitaxel and Carboplatin chemotherapy and further increased survival. Oral administration (gavage) of LR-IL-22 is a potentially valuable intestinal radioprotector, which can facilitate therapeutic WAI for widespread intra-abdominal ovarian cancer.

Achieving Quality and Effectiveness in Dementia Using Crisis Teams (AQUEDUCT): a study protocol for a randomised controlled trial of a Resource Kit.

BACKGROUND: Improving care at home for people with dementia is a core policy goal in the dementia strategies of many European countries. A challenge to effective home support is the occurrence of crises in the care of people with dementia which arise from changes in their health and social circumstances. Improving the management of these crises may prevent hospital admissions and facilitate better and longer care at home. This trial is part of a National Institute for Health Research funded programme, AQUEDUCT, which aims to improve the quality and effectiveness of teams working to manage crises in dementia. METHODS/DESIGN: It is a pragmatic randomised controlled trial of an online Resource Kit to enhance practice in teams managing crises in dementia care. Thirty teams managing mental health crises in dementia in community settings will be randomised between the Resource Kit intervention and treatment as usual. The primary outcome measure is psychiatric admissions to hospital for people with dementia in the teams' catchment area recorded 6 months after randomisation. Other outcomes include quality of life measures for people with dementia and their carers, practitioner impact measures, acute hospital admissions and costs. To enhance understanding of the Resource Kit intervention, qualitative work will explore staff, patient and carers' experience. DISCUSSION: The Resource Kit intervention reflects current policy to enable home-based care for people with dementia by addressing the management of crises which threaten the viability of care at home. It is based upon a model of best practice for managing crises in dementia designed to enhance the quality of care, developed in partnership with people with dementia, carers and practitioners. If the Resource Kit is shown to be clinically and cost-effective in this study, this will enhance the probability of its incorporation into mainstream practice. TRIAL REGISTRATION: ISRCTN 42855694 ; Registered on 04/03/2021; Protocol number: 127686/2020v9; Research Ethics Committee, 09/03/2021, Ref 21/WM/0004; IRAS ID: 289982.

Ionizing irradiation-induced Fgr in senescent cells mediates fibrosis.

The role of cellular senescence in radiation-induced pulmonary fibrosis (RIPF) and the underlying mechanisms are unknown. We isolated radiation-induced senescent tdTOMp16 positive mesenchymal stem cells, established their absence of cell division, then measured levels of irradiation-induced expression of biomarkers of senescence by RNA-seq analysis. We identified a Log2 6.17-fold upregulation of tyrosine kinase Fgr, which was a potent inducer of biomarkers of fibrosis in target cells in non-contact co-cultures. Inhibition of Fgr by shRNA knockdown did not block radiation-induced senescence in vitro; however, both shRNA knockdown, or addition of a specific small-molecule inhibitor of Fgr, TL02-59, abrogated senescent cell induction of profibrotic genes in transwell-separated target cells. Single-cell RNA-seq (scRNAseq) analysis of mouse lungs at day 150 after 20 Gy thoracic irradiation revealed upregulation of Fgr in senescent neutrophils, and macrophages before detection of lung fibrosis. Thus, upregulated Fgr in radiation-induced senescent cells mediates RIPF and is a potential therapeutic target for the prevention of this radiation late effect.

Silica Induced Lung Fibrosis Is Associated With Senescence, Fgr, and Recruitment of Bone Marrow Monocyte/Macrophages.

BACKGROUND/AIM: The role of senescence and bone marrow-derived cells in silica-induced pulmonary fibrosis is unknown. MATERIALS AND METHODS: C57BL/6HNsd, p16+/LUC, and tdTOMp16+ mice were intratracheally injected with 200 mg/kg crystalline silica or irradiated (20 Gy) to the thoracic cavity and followed for the development of lung fibrosis. RESULTS: The p16+/LUC mice demonstrated senescence by day 7 after silica exposure. C57BL/6 mice exposed to silica demonstrated upregulation of p16, p21, and tyrosine kinase Fgr by day 7, whereas thoracic irradiation induced p21 and Fgr by day 50 and p16 by day 110. Silica exposed GFP+ bone marrow chimeric C57BL/6 mice demonstrated senescent cells and gfp+/Fgr+ monocyte/macrophages in the lungs on day 21. The Fgr inhibitor TL02-59 abrogated monocyte/macrophages recruitment in in vitro transwell experiments. CONCLUSION: Both silica and radiation exposure induce senescence and upregulate tyrosine kinase Fgr for the recruitment of bone marrow-derived monocyte/macrophages and the development of pulmonary fibrosis.

Radiation-Induced Senescence in p16+/LUC Mouse Lung Compared to Bone Marrow Multilineage Hematopoietic Progenitor Cells.

We defined the time course of ionizing radiation-induced senescence in lung compared to bone marrow of p16+/LUC mice in which the senescence-induced biomarker (p16) is linked to a luciferase reporter gene. Periodic in situ imaging revealed increased luciferase activity in the lungs of 20 Gy thoracic irradiated, but not 8 Gy total-body irradiated (TBI) mice beginning at day 75 and increasing to day 170. In serial sections of explanted lungs, senescent cells appeared in the same areas as did fibrosis in the 20 Gy thoracic irradiated, but not the 8 Gy TBI group. Lungs from 8 Gy TBI mice at one year did show increased RNA levels for p16, p21, p19 and TGF-ß. Individual senescent cells in 20 Gy irradiated mouse lung included those with epithelial, endothelial, fibroblast and hematopoietic cell biomarkers. Rare senescent cells in the lungs of 8 Gy TBI mice at one year were of endothelial phenotype. Long-term bone marrow cultures (LTBMCs) were established at either day 60 or one year after 8 Gy TBI. In freshly removed marrow at both times after irradiation, there were increased senescent cells. In LTBMCs, there were increased senescent cells in both weekly harvested single cells and in colonies of multilineage hematopoietic progenitor cells producing CFU-GEMM (colony forming unit-granulocyte, erythrocyte, monocyte/macrophage, mega-karyocyte) that were formed in secondary cultures when these single cells were plated in semisolid media. LTBMCs from TBI mice produced fewer CFU-GEMM; however, the relative percentage of senescent cell-containing colonies was increased as measured by both p16-luciferase and ß-galactosidase. Therefore, 20 Gy thoracic radiation, as well as 8 Gy TBI, induces senescent cells in the lungs. With bone marrow, 8 Gy TBI induced senescence in both hematopoietic cells and in colony-forming progenitors. The p16+/LUC mouse strain provides a valuable system in which to compare the kinetics of radiation-induced senescence between organs in vivo, and to evaluate the potential role of senescent cells in irradiation pulmonary fibrosis.

Development of an Evidence-Based Best Practice Model for Teams Managing Crisis in Dementia: Protocol for a Qualitative Study.

BACKGROUND: Teams working in the community to manage crisis in dementia currently exist, but with widely varying models of practice, it is difficult to determine the effectiveness of such teams. OBJECTIVE: The aim of this study is to develop a "best practice model" for dementia services managing crisis, as well as a set of resources to help teams implement this model to measure and improve practice delivery. These will be the best practice tool and toolkit to be utilized by teams to improve the effectiveness of crisis teams working with older people with dementia and their caregivers. This paper describes the protocol for a prospective study using qualitative methods to establish an understanding of the current practice to develop a "best practice model." METHODS: Participants (people with dementia, caregivers, staff members, and stakeholders) from a variety of geographical areas, with a broad experience of crisis and noncrisis work, will be purposively selected to participate in qualitative approaches including interviews, focus groups, a consensus workshop, and development and field testing of both the best practice tool and toolkit. RESULTS: Data were collected between October 2016 and August 2018. Thematic analysis will be utilized to establish the current working of teams managing crisis in dementia in order to draw together elements of the best practice. CONCLUSIONS: This is the first study to systematically explore the requirements needed to fulfill effective and appropriate home management for people with dementia and their caregivers at the time of mental health crisis, as delivered by teams managing crisis in dementia. This systematic approach to development will support greater acceptability and validity of the best practice tool and toolkit and lay the foundation for a large scale trial with teams managing crisis in dementia across England to investigate the effects on practice and impact on service provision, as well as the associated experiences of people with dementia and their caregivers. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR1-10.2196/14781.

AQUEDUCT Intervention for Crisis Team Quality and Effectiveness in Dementia: Protocol for a Feasibility Study.

BACKGROUND: Specialist community teams often support people with dementia who experience crisis. These teams may vary in composition and models of practice, which presents challenges when evaluating their effectiveness. A best practice model for dementia crisis services could be used by teams to improve the quality and effectiveness of the care they deliver. OBJECTIVE: The aim of this study is to examine the feasibility of conducting a large-scale randomized controlled trial comparing the AQUEDUCT (Achieving Quality and Effectiveness in Dementia Using Crisis Teams) Resource Kit intervention to treatment as usual. METHODS: This is a multisite feasibility study in preparation for a future randomized controlled trial. Up to 54 people with dementia (and their carers) and 40 practitioners will be recruited from 4 geographically widespread teams managing crisis in dementia. Quantitative outcomes will be recorded at baseline and at discharge. This study will also involve a nested health economic substudy and qualitative research to examine participant experiences of the intervention and acceptability of research procedures. RESULTS: Ethical approval for this study was granted in July 2019. Participant recruitment began in September 2019, and as of September 2020, all data collection has been completed. Results of this study will establish the acceptability of the intervention, recruitment rates, and will assess the feasibility and appropriateness of the outcome measures in preparation for a large-scale randomized controlled trial. CONCLUSIONS: There is a need to evaluate the effectiveness of crisis intervention teams for older people with dementia. This is the first study to test the feasibility of an evidence-based best practice model for teams managing crisis in dementia. The results of this study will assist in the planning and delivery of a large-scale randomized controlled trial. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/18971.

Developing a model of best practice for teams managing crisis in people with dementia: a consensus approach.

BACKGROUND: Teams delivering crisis resolution services for people with dementia and their carers provide short-term interventions to prevent admission to acute care settings. There is great variation in these services across the UK. This article reports on a consensus process undertaken to devise a Best Practice Model and evaluation Tool for use with teams managing crisis in dementia. METHODS: The Best Practice Model and Tool were developed over a three stage process: (i) Evidence gathering and generation of candidate standards (systematic review and scoping survey, interviews and focus groups); (ii) Prioritisation and selection of standards (consultation groups, a consensus conference and modified Delphi process); (iii) Refining and operationalising standards (consultation group and field-testing). RESULTS: One hundred sixty-five candidate standards arose from the evidence gathering stage; were refined and reduced to 90 through a consultation group exercise; and then reduced to 50 during the consensus conference and weighted using a modified Delphi process. Standards were then operationalised through a clinical consultation group and field-tested with 11 crisis teams and 5 non-crisis teams. Scores ranged from 48 to 92/100. The median score for the crisis teams was 74.5 (range 67-92), and the median score for non-crisis teams was 60 (range 48-72). CONCLUSIONS: With further psychometric testing, this Best Practice Model and Tool will be ideal for the planning, improvement and national benchmarking of teams managing dementia crises in the future.

Involving the Person with Dementia in Crisis Planning: Focus Groups with Crisis Intervention Teams.

Dementia leads to progressive critical situations that can escalate to a crisis episode if not adequately managed. A crisis may also resolve spontaneously, or not resolve after receiving professional support. Because of the intensity of the crisis, the extent to which the person engages in decision making for their own care is often decreased. In UK mental health services, 'crisis teams' work to avert the breakdown of support arrangements and to avoid admissions to hospital or long-term care where possible. This study aimed to explore the views of crisis teams about promoting the involvement of the person with dementia in decision-making at all points in the care pathway, here defined as co-production. The staff of crisis teams from three NHS Trusts in the UK were interviewed through focus groups. Data were analysed using framework analysis. Three focus groups were run with 22 staff members. Data clustered around strategies used to promote the active involvement of the person with dementia, and the challenges experienced when delivering the care. Staff members reported that achieving a therapeutic relationship was fundamental to successful co-production. Miscommunication and/or lack of proper contact between the team and the individuals and carers receiving support adversely affected the quality of care. Making service users aware of the support provided by crisis teams before they need this may help promote a positive therapeutic relationship and effective care management.

Conceptualizing Dementia Crisis and Preferences for Resolution: A Public Perspective.

Background: Crisis intervention services for people with dementia in the United Kingdom are poorly defined with no standardized model of working. This may be due to the lack of a clear conceptualization of dementia crisis, resulting in variation in national service delivery. Methods: This study employed a novel public engagement questionnaire data collection technique with 57 participants to gain an updated perspective on the concept of health-related crisis from the point of view of the public. Results: Analysis revealed crisis as a transformational moment that may arrive unexpectedly but could also be the culmination of a sequence of events. Crisis resolution requires external and expert help, and associated feelings of panic and despair can engender the task of resolution by oneself insurmountable. Conclusions: Participants had clear expectations of crisis intervention services, with initial practical and emotional support to reduce risks, and a person-centered approach with family involvement.

Anti-Ferroptosis Drug Enhances Total-Body Irradiation Mitigation by Drugs that Block Apoptosis and Necroptosis.

Mitigation of total-body irradiation (TBI) in C57BL/6 mice by two drugs, which target apoptosis and necroptosis respectively, increases survival compared to one drug alone. Here we investigated whether the biomarker (signature)directed addition of a third anti-ferroptosis drug further mitigated TBI effects. C57BL/6NTac female mice (30-33 g) received 9.25 Gy TBI, and 24 h or later received JP4-039 (20 mg/kg), necrostatin-1 (1.65 mg/kg) and/or lipoxygenase-15 inhibitor (baicalein) (50 mg/kg) in single-, dual- or three-drug regimens. Some animals were sacrificed at days 0, 1, 2, 3, 4 or 7 postirradiation, while the majority in each group were maintained beyond 30 days. For those mice sacrificed at the early time points, femur bone marrow, intestine (ileum), lung and blood plasma were collected and analyzed for radiation-induced and mitigator-modified levels of 33 pro-inflammatory and stress response proteins. Each single mitigator administered [JP4-039 (24 h), necrostatin-1 (48 h) or baicalein (24 h)] improved survival at day 30 after TBI to 25% (P = 0.0432, 0.2816 or 0.1120, respectively) compared to 5% survival of 9.25 Gy TBI controls. Mice were administered the drug individually based on weight (mg/kg). Drug vehicles comprised 30% cyclodextrin for JP4-039 and baicalein, and 10% Cremphor-EL/10% ethanol/80% water for necrostatin-1; thus, dual-vehicle controls were also tested. The dual-drug combinations further enhanced survival: necrostatin-1 (delayed to 72 h) with baicalein 40% (P = 0.0359); JP4-039 with necrostatin-1 50% (P = 0.0062); and JP4-039 with baicalein 60% (P = 0.0064). The three-drug regimen, timed to signature directed evidence of onset after TBI of each death pathway in marrow and intestine, further increased the 30-day survival to 75% (P = 0.0002), and there was optimal normalization to preirradiation levels of inflammatory cytokine and stress response protein levels in plasma, intestine and marrow. In contrast, lung protein levels were minimally altered by 9.25 Gy TBI or mitigators over 7 days. Significantly, elevated intestinal proteins at day 7 after TBI were reduced by necrostatin-1-containing regimens; however, normalization of plasma protein levels at day 7 required the addition of JP4-039 and baicalein. These findings indicate that mitigator targeting to three distinct cell death pathways increases survival after TBI.

Fanconi Anemia Mouse Genotype-specific Mitigation of Total Body Irradiation by GS-Nitroxide JP4-039.

BACKGROUND/AIM: Radiation mitigator, GS-nitroxide, JP4-039, was evaluated for mitigation of total body irradiation (TBI) in Fanconi anemia (FA) Fancd2-/- (129/Sv), Fancg-/- (B6), and Fanca-/- (129/Sv) mice. MATERIALS AND METHODS: JP4-039 dissolved in 30% 2-hydroxypropyl-ß-cyclodextrin was injected intramuscularly 24 h after total body irradiation (9.25 Gy) into Fanca-/-, Fancd2-/- and Fancg-/- mice. Irradiation survival curves were performed in vitro using bone marrow stromal cell lines derived from Fanca-/-, Fancd2-/- and Fancg-/- mice. RESULTS: FA mice demonstrate genotype specific differences in TBI mitigation by JP4-039. Radiation effects in derived bone marrow stromal cell lines in vitro were mitigated by drugs that block apoptosis, but not necroptosis or ferroptosis. CONCLUSION: FA mouse models are valuable for elucidating DNA repair pathways in cell and tissue responses to TBI, and the role of drugs that target distinct cell death pathways.

Second-generation Probiotics Producing IL-22 Increase Survival of Mice After Total Body Irradiation.

BACKGROUND/AIM: Intestinal damage induced by total body irradiation (TBI) reduces leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5)-expressing stem cells, goblet, and Paneth cells, breaching the epithelial lining, and facilitating bacterial translocation, sepsis, and death. MATERIALS AND METHODS: Survival was measured after TBI in animals that received wild-type or recombinant bacteria producing interleukin-22 (IL-22). Changes in survival due to microbially delivered IL-22 were measured. Lactobacillus reuteri producing IL-22, or Escherichia coli-IL-22 were compared to determine which delivery system is better. RESULTS: C57BL/6 mice receiving IL-22 probiotics at 24 h after 9.25 Gy TBI, demonstrated green fluorescent protein-positive bacteria in the intestine, doubled the number of Lgr5+ intestinal stem cells, and increased 30-day survival. Bacteria were localized to the jejunum, ileum, and colon. CONCLUSION: Second-generation probiotics appear to be valuable for mitigation of TBI, and radiation protection during therapeutic total abdominal irradiation.