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Effective therapies for cognitive impairments induced by brain irradiation are currently lacking. This study investigated the therapeutic potential of hyperbaric oxygen therapy (HBOT) for radiation-induced brain injury in a randomized controlled experimental model using adult male Wistar rats. Adult male Wistar rats were divided into four experimental groups: 0 Gy whole brain radiotherapy (WBRT) with normal baric air (NBA) treatment, 0 Gy WBRT with HBOT, 10 Gy WBRT with NBA, and 10 Gy WBRT with HBOT. Behavioral tests and histochemical analyses were conducted four weeks post-WBRT to assess cognitive function, hippocampal microgliosis, apoptosis, and lipid peroxidation. Compared with the rats with 0 Gy WBRT on 28 days, the rats with 10 Gy WBRT on 28 days had significantly higher severity of spatial learning and memory dysfunction and hippocampal microgliosis, newborn neuronal apoptosis, and lipid peroxidation. HBOT significantly prevented and reversed WBRT-induced cognitive deficits, hippocampal microgliosis, newborn neuronal apoptosis, and lipid peroxidation. In addition, HBOT prevented and reversed the increased apoptosis among newborn neural stem cells and neuroblasts caused by 10 Gy WBRT on 7 days. The findings suggest that WBRT disrupts neurogenesis and enhance microgliosis, apoptosis of neuronal progenitors, and lipid peroxidation in the dentate gyrus, potentially leading to cognitive deficits and neuronal death. HBOT may offer a protective effect against these cognitive impairments and their underlying mechanisms in adult male rats following WBRT., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Background: Stromal vascular fraction (SVF) treatment promoted the regeneration of the intestinal epithelium, limiting lethality in a mouse model of radiation-induced gastrointestinal syndrome (GIS). The SVF has a heterogeneous cell composition; the effects between SVF and the host intestinal immunity are still unknown. The specific role of the different cells contained in the SVF needs to be clarified. Monocytes-macrophages have a crucial role in repair and monocyte recruitment and activation are orchestrated by the chemokine receptors CX3CR1 and CCR2., Methods: Mice exposed to abdominal radiation (18 Gy) received a single intravenous injection of SVF (2.5 × 10 6 cells), obtained by enzymatic digestion of inguinal fat tissue, on the day of irradiation. Intestinal immunity and regeneration were evaluated by flow cytometry, RT-PCR and histological analyses., Results: Using flow cytometry, we showed that SVF treatment modulated intestinal monocyte differentiation at 7 days post-irradiation by very early increasing the CD11b + Ly6C + CCR2 + population in the intestine ileal mucosa and accelerating the phenotype modification to acquire CX3CR1 in order to finally restore the F4/80 + CX3CR1 +  macrophage population. In CX3CR1-depleted mice, SVF treatment fails to mature the Ly6C - MCHII + CX3CR1 + population, leading to a macrophage population deficit associated with proinflammatory environment maintenance and defective intestinal repair; this impaired SVF efficiency on survival. Consistent with a CD11b + being involved in SVF-induced intestinal repair, we showed that SVF-depleted CD11b + treatment impaired F4/80 + CX3CR1 + macrophage pool restoration and caused loss of anti-inflammatory properties, abrogating stem cell compartment repair and survival., Conclusions: These data showed that SVF treatment mitigates the GIS-involving immunomodulatory effect. Cooperation between the monocyte in SVF and the host monocyte defining the therapeutic properties of the SVF is necessary to guarantee the effective action of the SVF on the GIS., (© 2023. The Author(s).)

Purpose: To clarify the preventive and therapeutic effects of repetitive transcranial magnetic stimulation (rTMS) on brain injury induced by X-ray cranial irradiation, preliminarily identify the mechanism and provide a novel clinical approach for the prevention and treatment of radiation-induced brain injury (RBI)., Materials and Methods: Male C57BL/6 mice were randomly divided into the sham group, large fractionated dose (5 Gy × 4 d) group, large fractionated dose + rTMS (5 Gy × 4 d + rTMS) group, conventional fractionated dose (2 Gy × 10 d) group and conventional fractionated dose + rTMS (2 Gy × 10 d + rTMS) group. After cranial irradiation and rTMS, behavioral experiments, morphological staining and molecular biology experiments were performed. We further determined the mechanism of rTMS on the prevention and treatment of RBI, including changes in hippocampal neuronal apoptosis, neural stem cell (NSC) proliferation and differentiation, and neuronal synaptic plasticity., Results: rTMS alleviated the negative effects of cranial radiation on the general health of mice and promoted their recovery. rTMS ameliorated the impairment of spatial learning and memory induced by cranial radiation, and this beneficial effect was more robust in the conventional fractionated dose group than the large fractionated dose group. Moreover, rTMS alleviated the alterations in hippocampal structure and neuronal death and had preventive and therapeutic effects against RBI. In addition, rTMS reduced hippocampal cell apoptosis, promoted NSC proliferation and differentiation in the hippocampus after cranial irradiation, and enhanced neuronal synaptic plasticity in the hippocampus. Subsequent studies showed that rTMS upregulated the expression of learning- and memory-related proteins., Conclusion: rTMS could alleviate learning and memory impairment caused by RBI, and the preventive and therapeutic effects of rTMS were better for the conventional fraction radiation paradigms.

We studied the possibility of using sodium deoxyribonucleate (Derinat) for improving the efficiency of co-transplantation of mesenchymal (MSC) and hematopoietic stem cells (HSC) to female F1(CBA×C57BL/6) mice with bone marrow aplasia caused by exposure to γ-radiation. It was found that immunomodulator Derinat enhanced the effect of co-transplantation, in particular, triple post-irradiation administration of Derinat accelerated hematopoiesis recovery judging from the parameters of peripheral blood, total cellularity of the bone marrow and spleen, and animal survival. Single or double administration of Derinat prior to irradiation was ineffective. The optimal result was obtained when the following scheme was applied: MSC→HSC with an interval of 48 h starting during the first hours after irradiation and triple administration of Derinat (in 10-15 min, 3 and 7 days after irradiation) in a dose of 3 mg/mouse., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

Advancements in telecommunication sector result in increasing exposure to electromagnetic (EM) radiation, which has been correlated with incidence of male infertility. Therefore, the present study focused on analyzing the consequence of EM radiation (2115 MHz) exposure on the reproductive system of male Wistar rats. Besides, the antioxidant protective effect of Punica granatum juice was also evaluated. For experimental analysis, rats were divided into five groups (control, sham exposed, exposed, herbal plus exposed, and herbal only). Individual group consisted of 6 rats which were exposed to radiation for 45 days (2 h/day). The herbal-treated groups were given 1 ml of Punica granatum extract orally. Various parameters such as organ to body ratio, sperm count, motility, viability, and testis histopathology were studied. Furthermore, oxidative stress parameters and free radical generation were analyzed. The exposed group showed changes in sperm parameters along with decrease in seminiferous tubule diameter. On the contrary, herbal-exposed group showed enhanced sperm count, increased motility, and viability in comparison to exposed group. Histopathology studies also revealed the protective role of herbal juice. Significant alteration in oxidative parameters along with an enhanced free radical generation in exposed group and reduction in herbal groups was observed. The results thus indicate that continuous exposure to EM radiation can lead to oxidative stress which induces biochemical changes in rat sperms. However, Punica granatum extract has a protective role against oxidative damage induced by EM radiation., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The USA has experienced one large-scale nuclear incident in its history. Lessons learned during the Three-Mile Island nuclear accident provided government planners with insight into property damage resulting from a low-level release of radiation, and an awareness concerning how to prepare for future occurrences. However, if there is an incident resulting from detonation of an improvised nuclear device or state-sponsored device/weapon, resulting casualties and the need for medical treatment could overwhelm the nation's public health system. After the Cold War ended, government investments in radiation preparedness declined; however, the attacks on 9/11 led to re-establishment of research programs to plan for the possibility of a nuclear incident. Funding began in earnest in 2004, to address unmet research needs for radiation biomarkers, devices and products to triage and treat potentially large numbers of injured civilians. There are many biodosimetry approaches and medical countermeasures (MCMs) under study and in advanced development, including those to address radiation-induced injuries to organ systems including bone marrow, the gastrointestinal (GI) tract, lungs, skin, vasculature and kidneys. Biomarkers of interest in determining level of radiation exposure and susceptibility of injury include cytogenetic changes, 'omics' technologies and other approaches. Four drugs have been approved by the US Food and Drug Administration (FDA) for the treatment of acute radiation syndrome (ARS), with other licensures being sought; however, there are still no cleared devices to identify radiation-exposed individuals in need of treatment. Although many breakthroughs have been made in the efforts to expand availability of medical products, there is still work to be done., (Published by Oxford University Press on behalf of The Japanese Radiation Research Society and Japanese Society for Radiation Oncology 2021.)

Survival from partial-body irradiation (PBI) may be limited by the development of the late lung injury response of pneumonitis. Herein we investigated the hypothesis that acute hematopoietic depletion alters the onset and severity of lung disease in a mouse model. To establish depletion, C3H/HeJ mice received 8 Gy PBI with shielding of only the tibiae, ankles and feet. One week after irradiation, blood lymphocyte and neutrophil counts were each significantly reduced (P < 0.04) in these mice compared to levels in untreated controls or in mice receiving 16 Gy to the whole thorax only. All 8 Gy PBI mice survived to the experimental end point of 16 weeks postirradiation. To determine whether the hematopoietic depletion affects lung disease, groups of mice received 8 Gy PBI plus 8 Gy whole-thorax irradiation (total lung dose of 16 Gy) or 16 Gy whole-thorax irradiation only. The weight loss, survival to onset of respiratory distress (P = 0.17) and pneumonitis score (P = 0.96) of mice that received 8 Gy PBI plus 8 Gy whole-thorax irradiation were not significantly different from those of mice receiving 16 Gy whole-thorax irradiation only. Mice in respiratory distress from PBI plus whole-thorax irradiation had significantly reduced (P = 0.02) blood monocyte counts compared to levels in distressed, whole-thorax irradiated mice, and symptomatic pneumonitis was associated with increased blood neutrophil counts (P = 0.04) relative to measures from irradiated, non-distressed mice. In conclusion, survivable acute hematopoietic depletion by partial-body irradiation did not alter the onset or severity of lethal pneumonitis in the C3H/HeJ mouse model., (©2021 by Radiation Research Society. All rights of reproduction in any form reserved.)

Background: Cancer treatment of prepubertal patients impacts future fertility due to the abolition of spermatogonial stem cells (SSCs). In macaques, spermatogenesis could be regenerated by intratesticular transplantation of SSCs, but no studies have involved cytotoxic treatment before puberty and transplantation after puberty, which would be the most likely clinical scenario., Objectives: To evaluate donor-derived functional sperm production after SSC transplantation to adult monkeys that had received testicular irradiation during the prepubertal period., Materials and Methods: We obtained prepubertal testis tissue by unilaterally castrating six prepubertal monkeys and 2 weeks later irradiated the remaining testes with 6.9 Gy. However, because spermatogenic recovery was observed, we irradiated them again 14 months later with 7 Gy. Three of the monkeys were treated with GnRH-antagonist (GnRH-ant) for 8 weeks. The cryopreserved testis cells from the castrated testes were then allogeneically transplanted into the intact testes of all monkeys. Tissues were harvested 10 months later for analyses., Results: In three of the six monkeys, 61%, 38%, and 11% of the epididymal sperm DNA were of the donor genotype. The ability to recover donor-derived sperm production was not enhanced by the GnRH-ant pretreatment. However, the extent of filling seminiferous tubules during the transplantation procedure was correlated with the eventual production of donor spermatozoa. The donor epididymal spermatozoa from the recipient with 61% donor contribution were capable of fertilizing rhesus eggs and forming embryos. Although the transplantation was done into the rete testis, two GnRH-ant-treated monkeys, which did not produce donor-derived epididymal spermatozoa, displayed irregular tubular cords in the interstitium containing testicular spermatozoa derived from the transplanted donor cells., Discussion and Conclusion: The results further support that sperm production can be restored in non-human primates from tissues cryopreserved prior to prepubertal and post-pubertal gonadotoxic treatment by transplantation of these testicular cells after puberty into seminiferous tubules., (© 2021 American Society of Andrology and European Academy of Andrology.)

Severe radiation-induced skin injury is a complication of tumor radiotherapy and nuclear accidents. Cell therapy is a potential treatment for radiation-induced skin injury. The stromal vascular fraction (SVF) is a newer material in stem cell therapy that is made up of stem cells harvested from adipose tissue, which has been shown to promote the healing of refractory wounds of different causes. In this study, SVF was isolated from patients with radiation-induced skin injury. Adipose-derived stem cells (ADSCs) accounted for approximately 10% of the SVF by flow cytometry. Compared with the control group of rats, administration with SVF attenuated the skin injury induced by electron beam radiation. The effect of SVF on the human skin fibroblast microenvironment was determined by proteomic profiling of secreted proteins in SVF-co-cultured human skin fibroblast WS1 cells. Results revealed 293 upregulated and 1,481 downregulated proteins in the supernatant of SVF-co-cultured WS1 cells. WS1 co-culture with SVF induced secretion of multiple proteins including collagen and MMP-1. In the clinic, five patients with radiation-induced skin injury were recruited to receive SVF transfer-based therapy, either alone or combined with flap transplantation. Autogenous SVF was isolated and introduced into a multi-needle precision electronic injection device, which automatically and aseptically distributed the SVF to the exact layer of the wound in an accurate amount. After SVF transfer, wound healing clearly improved and pain was significantly relieved. The patients' skin showed satisfactory texture and shape with no further wound recurrence. Our findings suggest that transplantation of SVF could be an effective countermeasure against severe radiation-induced skin injury., (©2021 by Radiation Research Society. All rights of reproduction in any form reserved.)

Radiation-induced multiple organ injury, including γ-radiation nephropathy, is the most common. Even with dose fractionation strategy, residual late side effects are inevitable. Bone marrow-derived mesenchymal stem cells (BM-MSCs) transplantation and erythropoietin (EPO) have shown to be effective in treating chronic kidney disease and associated anemia. This study aimed to evaluate the effect of BM-MSCs and/or EPO in fractionated γ-irradiation induced kidney damage in rats. Adult male Wistar rats were randomized into 2 groups; normal and 8 Gy (fractionated dose of 2 Gy for 4 days) γ-irradiated rats. Animal from both groups were subdivided to receive the following treatments: BM-MSCs (1 × 10 6 cells/rat, i.v - once), EPO (100 IU/kg, i.p - every other day for 30 days) or their combined treatment (BM-MSCs and EPO). γ-Irradiated rats showed a noticeable elevation in serum urea and creatinine, kidney malondialdehyde (MDA) and caspase 3 activity. They also revealed significant drop in kidney glutathione (GSH) and Bcl2 protein contents. Conspicuously, they revealed down-regulation of renal EPO signaling (EPO, EPOR, pJAK2, pPI3K and pAkt). Conversely, groups treated with BM-MSCs and/or EPO revealed significant modulation in most tested parameters and appeared to be effective in minimizing the hazard effects of radiation. In conclusion, BM-MSCs and/or EPO exhibited therapeutic potentials against nephrotoxicity induced by fractionated dose of γ-irradiation. An effect mediated by antioxidant and non-hematopoietic EPO downstream anti-apoptotic signaling (PI3K/Akt) pathway. EPO potentiate the repair capabilities of BM-MSCs making this combined treatment a promising therapeutic strategy to overcome radiotherapy-induced kidney damage., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Radiotherapy is one of the three main treatments for tumors. Almost 70% of tumor patients undergo radiotherapy at different periods. Although radiotherapy can enhance the local control rate of tumors and patients' quality of life, normal tissues often show radiation damage following radiotherapy. In recent years, several studies have shown that exosomes could be biomarkers for diseases and be involved in the treatment of radiation damage. Exosomes are nanoscale vesicles containing complex miRNAs and proteins. They can regulate the inflammatory response, enhance the regeneration effect of damaged tissue, and promote the repair of damaged tissues and cells, extending their survival time. In addition, their functions are achieved by paracrine signaling. In this review, we discuss the potential of exosomes as biomarkers and introduce the impact of exosomes on radiation damage in different organs and the hematopoietic system in detail., (Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Fibrosis is a leading cause of death in occidental states. The increasing number of patients with fibrosis requires innovative approaches. Despite the proven beneficial effects of mesenchymal stem cell (MSC) therapy on fibrosis, there is little evidence of their anti-fibrotic effects in colorectal fibrosis. The ability of MSCs to reduce radiation-induced colorectal fibrosis has been studied in vivo in Sprague-Dawley rats. After local radiation exposure, rats were injected with MSCs before an initiation of fibrosis. MSCs mediated a downregulation of fibrogenesis by a control of extra cellular matrix (ECM) turnover. For a better understanding of the mechanisms, we used an in vitro model of irradiated cocultured colorectal fibrosis in the presence of human MSCs. Pro-fibrotic cells in the colon are mainly intestinal fibroblasts and smooth muscle cells. Intestinal fibroblasts and smooth muscle cells were irradiated and cocultured in the presence of unirradiated MSCs. MSCs mediated a decrease in profibrotic gene expression and proteins secretion. Silencing hepatocyte growth factor (HGF) and tumor necrosis factor-stimulated gene 6 (TSG-6) in MSCs confirmed the complementary effects of these two genes. HGF and TSG-6 limited the progression of fibrosis by reducing activation of the smooth muscle cells and myofibroblast. To settle in vivo the contribution of HGF and TSG-6 in MSC-antifibrotic effects, rats were treated with MSCs silenced for HGF or TSG-6. HGF and TSG-6 silencing in transplanted MSCs resulted in a significant increase in ECM deposition in colon. These results emphasize the potential of MSCs to influence the pathophysiology of fibrosis-related diseases, which represent a challenging area for innovative treatments.

In the event of a high-dose radiation exposure accident, adipose-derived stem cell (ADSC) transplantation might be used as an emergency medical treatment to compensate for bone marrow failure. To investigate the possible course of that treatment, we examined whether transplantation of ADSCs into whole-body X-ray irradiated mice would provide resistance to radiation damage. ADSCs were obtained from a primary culture of adipocytes from adipose tissue of syngeneic mice. The ADSCs were transplanted via an intravenous (i.v.) route after whole-body irradiation (6 Gy, X-rays) of the ICR mice. Fifty days after transplantation, the survival rate of the transplanted group was 40% higher than the control group, and the difference in survival rates was maintained in the following 200 days. After 400 days, however, the difference in survival rates became smaller and disappeared after 650 days. The results indicate that ADSC transplantation may reduce lethality from acute radiation bone marrow injury for several hundred days.

Objective: To determine in experiment the quality of healing of skin radiation ulcers infected with Staphylococcusaureus (S. aureus) under the photodynamic therapy (PDT) administration and the use of platelet-rich plasma (PRP)., Materials and Methods: The experiment was performed on 95 male WAG rats of 6 months of age, which were divided into three groups. Group 1 included animals in whom a skin radiation ulcers in the thigh area was simulated, followed by application of a 0.2 ml suspension of reference strain of S. aureus to its surface on the 7th day after irradiation. Group 2 included animals with S. aureus-infected skin radiation ulcers, in whom the PET was administered aday after infection contamination. Group 3 included animals with S. aureus-infected skin radiation ulcers, in whomthe PDT was administered a day after infection in the morning, and the PRP was manifold injected in periwound areain the afternoon. The skin with underlying soft tissues from the area of radiation damage were the material for morphological examination. The hematoxylin and eosin, picrofuxin according to van Gizon, Mallory staining wereapplied to micropreparations. A morphometric study was conducted., Results: In animals with skin radiation ulcers, in whom the PDT was administered upon infection with S. aureus(group 2), compared with animals with simulated infected skin radiation ulcers without treatment (group 1), Theactivation (i.e. accelerating) of the healing occurred for the period from the 14th to the 52nd day of experiment dueto the active processes of wound cleansing from necrotized tissues, less pronounced inflammatory changes in thelesion, and active of appearance and maturation of granulation tissue, less pronounced hemodynamic, ischemic andalternative disorders in the dermis, hypodermis, muscle tissue surrounding the wound cavity, activation of proliferative processes in epithelial layer localized in the marginal parts of the wound. Formation of pathological (hypertrophic or keloid) scar of the skin was the result of healing of skin radiation ulcer infected with S. aureus. In animalswith radiation ulcers infected with S. aureus, in the case of PDT and PRP (group 3) the regenerative process wasdirected not only at accelerating the rate of healing, but also on restoration of original structure of the lost parts ofthe skin compared with only PDT administration (group 2). Acceleration of the healing of the infected skin radiation ulcer in animals of groups 2 and 3 was due to similar processes., Conclusions: Photodynamic therapy activates and accelerates the healing process of skin radiation ulcers infectedwith S. aureus and leads to formation of a pathological scar (hypertrophic or keloid). Healing of the infected S. aureusradiation ulcers occurs more actively upon the photodynamic therapy administration in combination with multipleperiwound injections of the platelet-enriched plasma, compared with only photodynamic therapy administration,and finishes with an organotypic regeneration and almost complete skin recovery., (M. V. Krasnoselsky, O. S. Pushkar, L. I. Simonova, M. S. Myroshnychenko.)

Mesenchymal stem cells are mechano-sensitive cells with the potential to restore the function of damaged tissues. Low-intensity ultrasound has been increasingly considered as a bioactive therapeutic apparatus. Optimizing transplantation conditions is a critical aim for radiation-induced skin tissue injury. Therefore, the therapeutic function of adipose-derived mesenchymal stem cells to ultrasound stimulus was examined based on the mechanical index (MI). Mesenchymal stem cells were isolated from the adipose tissues of mature guinea pigs. An ultrasound system (US) was constructed with a 40 kHz frequency. The radiation-induced skin injury model was produced on the abdominal skin of guinea pigs by 60 Gy of radiation. Then, they were divided to 7 groups (n = 42): control, sham, US (MI = 0.7), AdMSCs injection, US AdMSCs (AdMSCs, under US with MI = 0.2), AdMSCs + US (AdMSCs transplantation and US with MI = 0.7) and US AdMSCs + US (combining the last two groups). The homing of stem cells was verified with fluorescence imaging. The groups were followed with serial photography, ultrasound imaging, tensiometry, and histology. The thickness of the skin was analyzed. Functional changes in skin tissue were evaluated with Young's modulus (kPa). One-way ANOVA tests were performed to analyze differences between treatment protocols (p < 0.05). The results of Kumar's score showed that radiation injury was significantly lower in the treatment groups of US AdMSCs and US AdMSCs + US than other groups after 14 days (p < 0.05). There was a significant difference in skin thickness between treatment groups with control, sham, and US groups after 60 Gy radiation and were closer to the thickness of healthy skin. Young's modulus in US AdMSCs + US, US AdMSCs, and AdMSCs + US groups demonstrated a significant difference with the other groups (p < 0.05). Young's modulus in US AdMSCs + US and US AdMSCs treatment groups were closer to Young's modulus of the healthy skin. The histological results confirmed the improvement of acute radiation damage in the combined treatment method, especially in US AdMSCs + US and US AdMSCs groups with increasing the epithelialization and formation of collagen. An ultrasonic treatment plan based on a mechanical index of the target medium could be used to enhance stem cell therapy.

The aim of this study was to explore the therapeutic effects of fat grafting on radiation-induced hind limb contracture. Radiation therapy (RT) is used to palliate and/or cure a range of malignancies but causes inevitable and progressive fibrosis of surrounding soft tissue. Pathological fibrosis may lead to painful contractures which limit movement and negatively impact quality of life. Fat grafting is able to reduce and/or reverse radiation-induced soft tissue fibrosis. We explored whether fat grafting could improve extensibility in irradiated and contracted hind limbs of mice. Right hind limbs of female 60-day-old CD-1 nude mice were irradiated. Chronic skin fibrosis and limb contracture developed. After 4 weeks, irradiated hind limbs were then injected with (a) fat enriched with stromal vascular cells (SVCs), (b) fat only, (c) saline, or (d) nothing (n = 10/group). Limb extension was measured at baseline and every 2 weeks for 12 weeks. Hind limb skin then underwent histological analysis and biomechanical strength testing. Irradiation significantly reduced limb extension but was progressively rescued by fat grafting. Fat grafting also reduced skin stiffness and reversed the radiation-induced histological changes in the skin. The greatest benefits were found in mice injected with fat enriched with SVCs. Hind limb radiation induces contracture in our mouse model which can be improved with fat grafting. Enriching fat with SVCs enhances these beneficial effects. These results underscore an attractive approach to address challenging soft tissue fibrosis in patients following RT., (©AlphaMed Press 2019.)

In the setting of radiation-induced trauma, exposure to high levels of radiation can cause an acute radiation syndrome (ARS) causing bone marrow (BM) failure, leading to life-threatening infections, anemia, and thrombocytopenia. We have previously shown that human macrophages educated with human mesenchymal stem cells (MSCs) by coculture can significantly enhance survival of mice exposed to lethal irradiation. In this study, we investigated whether exosomes isolated from MSCs could replace direct coculture with MSCs to generate exosome educated macrophages (EEMs). Functionally unique phenotypes were observed by educating macrophages with exosomes from MSCs (EEMs) primed with bacterial lipopolysaccharide (LPS) at different concentrations (LPS-low EEMs or LPS-high EEMs). LPS-high EEMs were significantly more effective than uneducated macrophages, MSCs, EEMs, or LPS-low EEMs in extending survival after lethal ARS in vivo. Moreover, LPS-high EEMs significantly reduced clinical signs of radiation injury and restored hematopoietic tissue in the BM and spleen as determined by complete blood counts and histology. LPS-high EEMs showed significant increases in gene expression of STAT3, secretion of cytokines like IL-10 and IL-15, and production of growth factors like FLT-3L. LPS-EEMs also showed increased phagocytic activity, which may aid with tissue remodeling. LPS-high EEMs have the potential to be an effective cellular therapy for the management of ARS., (Copyright © 2019 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

After radioiodine (RI) therapy, patients with thyroid cancer frequently suffer from painful salivary gland (SG) swelling, xerostomia, taste alterations, and oral infections. This study was aimed to determine whether adipose-derived mesenchymal stem cells (AdMSCs) might restore RI-induced SG dysfunction in a murine model. Forty -five mice were divided into three groups; a PBS sham group, a RI+ PBS sham group (0.01 mCi/g mouse, orally), and an RI+AdMSCs (1 × 10 5 cells/150 uL, intraglandular injection on experimental day 28) treated group. At 16 weeks after RI treatment, body weights, SG weight, salivary flow rates (SFRs), and salivary lag times were measured. Morphologic and histologic examinations and immunohistochemistry (IHC) were performed and the activities of amylase and EGF in saliva were also measured. Changes in salivary 99m Tc pertechnetate excretion were followed by SPECT and TUNEL assays were performed. The body and SG weights were similar in the AdMSCs and sham groups. Hematoxylin and eosin staining revealed the AdMSCs group had more mucin-containing acini than the RI group. Furthermore, AdMSCs treatment resulted in tissue remodeling and elevated expressions of epithelial (AQP5) and endothelial (CD31) markers, and increased SFRs. The activities of amylase and EGF were higher in the AdMSCs group than in the RI treated group. 99m Tc pertechnetate excretions were similar in the AdMSCs and sham group. Also, TUNEL positive apoptotic cell numbers were less in the AdMSCs group than in the RI group. Local delivery of AdMSCs might regenerate SG damage induced by RI.

Nowadays, ionizing radiations have numerous applications, especially in medicine for diagnosis and therapy. Pharmacological radioprotection aims at increasing detoxification of free radicals. Radiomitigation aims at improving survival and proliferation of damaged cells. Both strategies are essential research area, as non-contained radiation can lead to harmful effects. Some advances allowing the comprehension of normal tissue injury mechanisms, and the discovery of related predictive biomarkers, have led to developing several highly promising radioprotector or radiomitigator drugs. Next to these drugs, a growing interest does exist for biotherapy in this field, including gene therapy and cell therapy through mesenchymal stem cells. In this review article, we provide an overview of the management of radiation damages to healthy tissues via gene or cell therapy in the context of radiotherapy. The early management aims at preventing the occurrence of these damages before exposure or just after exposure. The late management offers promises in the reversion of constituted late damages following irradiation., (Copyright © 2019. Published by Elsevier Masson SAS.)

Radiation therapy to anatomic regions, including the head and neck, chest wall, and extremities, can produce radiation-induced fibrosis (RIF). To elucidate the cellular and molecular mechanism(s) involved in RIF, female C57BL/6J mice were irradiated to the right flank to 35 Gy in single fraction using 6 Mv electrons. Radiation fibrosis was detected by day 14, was increased by day 28, and confirmed by Masson's trichrome histological staining for collagen. Biopsied tissue at day 14 showed an increase in expression of fibrosis-related genes including transforming growth factor-β (TGF-β) and collagens 1-6. A single adipose-derived stem cell (ASC) injection on day 28 at the irradiated site decreased by day 40: epithelial thickness, collagen deposition, and significantly improved limb excursion compared with irradiated controls. Noncontact transwell coculture of ASCs above a monolayer of irradiated human foreskin fibroblasts downregulated fibrosis-related genes TGF-β, connective tissue growth factor, interleukin-1, NF-kB, tumor necrosis factor, and collagens 1-6. Hepatocyte growth factor (HGF) secreted by ASCs was identified as a novel mechanism by which ASCs exert antifibrotic effects by downregulating fibrotic gene expression in irradiated cells and recruiting bone marrow cells to the irradiated site. In conclusion, these data indicate a mechanistic role of HGF secreted by ASCs in reducing RIF. Stem Cells 2019;37:791-802., (©AlphaMed Press 2019.)

Objective: In this study, we evaluated changes in bone remodeling in an irradiated rat calvarial defect model according to duration of hyperbaric oxygen therapy., Materials and Methods: The 28 rats were divided into four groups. Radiation of 12 Gy was applied to the skull, and 5-mm critical size defects were formed on both sides of the skull. Bone grafts were applied to one side of formed defects. From the day after surgery, HBO was applied for 0, 1, and 3 weeks. At 6 weeks after bone graft, experimental sites were removed and analyzed for radiography, histology, and histomorphometry., Results: Micro-CT analysis showed a significant increase in new bone volume in the HBO-3 group, with or without bone graft. When bone grafting was performed, BV, BS, and BS/TV all significantly increased. Histomorphometric analysis showed significant increases in %NBA and %BVN in the HBO-1 and HBO-3 groups, regardless of bone graft., Conclusion: Hyperbaric oxygen therapy was effective for bone regeneration with only 1 week of treatment.

Radiation vasculitis is one of the most common detrimental effects of radiotherapy for malignant tumors. This is developed at the vasculature of adjacent organs. Animal experiments have showed that transplantation of mesenchymal stem cells (MSCs) restores vascular function after irradiation. But the population of MSCs being engrafted into irradiated vessels is too low in the conventional models to make assessment of therapeutic effect difficult. This is presumably because circulating MSCs are dispersed in adjacent tissues being irradiated simultaneously. Based on the assumption, a rat model, namely, RT (radiation) plus TX (transplantation), was established to promote MSC homing by sequestering irradiated vessels. In this model, a 1.5 cm long segment of rat abdominal aorta was irradiated by 160kV X-ray at a single dose of 35Gy before being procured and grafted to the healthy counterpart. F344 inbred rats served as both donors and recipients to exclude the possibility of immune rejection. A lead shield was used to confine X-ray delivery to a 3 cm×3 cm square-shaped field covering central abdominal region. The abdominal viscera especially small bowel and colon were protected from irradiation by being pushed off the central abdominal cavity. Typical radiation-induced vasculopathy was present on the 90 th day after irradiation. The recruitment of intravenously injected MSCs to irradiated aorta was significantly improved by using the RT-plus-TX model as compared to the model with irradiation only. Generally, the RT-plus-Tx model promotes MSC recruitment to irradiated aorta by separating irradiated vascular segment from adjacent tissue. Thus, the model is preferred in the study of MSC-based therapy for radiation vasculitis when the evaluation of MSC homing is demanding.

Mucosal healing occurs through migration and proliferation of cells within injured epithelium, yet these processes may be inadequate for mucosal healing after significant injury where the mucosa is denuded. We hypothesize that extra-intestinal cells can contribute to mucosal healing after injury to the small and large intestine. We generated parabiotic pairs between wild-type and tdTomato mice, which were then subjected to radiation-induced enteritis and 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis. We now show that as compared with singleton mice, mice with a parabiotic partner were protected against intestinal damage as revealed by significantly reduced weight loss, reduced expression of pro-inflammatory cytokines, reduced enterocyte apoptosis, and improved crypt proliferation. Donor cells expressed CD45 - , Sca-1 + , c-kit + , and CXCR4 + and accumulated around the injured crypts but did not transdifferentiate into epithelia, suggesting that extra-intestinal cells play a paracrine role in the healing response, while parabiotic pairings with Rag1 -/- mice showed improved healing, indicating that adaptive immune cells were dispensable for mucosal healing. Strikingly, ablation of the bone marrow of the donor parabionts removed the protective effects. These findings reveal that the recruitment of extra-intestinal, bone marrow-derived cells into the injured intestinal mucosa can promote mucosal healing, suggesting novel therapeutic approaches for severe intestinal disease.

Objective: We investigate the protective and therapeutic effects of ozone therapy (OT) in radiotherapy (RT)-induced testicular damage., Methods: Thirty healthy adult male Wistar rats divided into five groups consisting of six animals each as follows: (1) Control (C), (2) RT, (3) OT, (4) OT + RT, and (5) RT + OT group. Histopathological findings, Johnsen scores, thiobarbituric acid-reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx) levels were evaluated., Results: RT caused a significant decrease in testicular weight and Johnsen score compared to the control group. In addition, TBARS level was significantly higher, whereas GSH, SOD, catalase, and GPx levels were significantly lower in the RT group when compared to the control group. Pre and postRT OT significantly increased GSH, SOD, catalase, and GPx levels and decreased TBARS level. Furthermore, testicular weight and Johnsen score were increased with OT., Conclusions: The present study showed that OT is protective and therapeutic in radiation-induced testicular damage. OT may be beneficial to the patients who underwent RT., Competing Interests: None

Aims: As a source of growth factors and with its cytoprotective properties, platelet-rich plasma (PRP) received considerable attention in regenerative medicine. Thus, this study was designed to evaluate the protective efficacy of PRP against γ-radiation-induced nephrotoxicity., Main Methods: Forty male rats were distributed in four groups: 1) control, 2) PRP, 3) Radiation, and 4) PRP + radiation. Nephrotoxicity was examined in rats after a whole body γ-irradiation at a single dose of 8 Gy. Activated PRP (0.5 ml/kg BW) was injected subcutaneously twice weekly for three successive weeks prior to γ-irradiation. At the end of the experiment, creatinine, urea, albumin, and neutrophil gelatinase-associated lipocalin (NGAL) serum levels, as well as renal relative gene expression level of kidney injury molecule-1 (KIM-1) were estimated. Further, malondialdehyde level, nitric oxide content and reduced glutathione content in addition to superoxide dismutase and catalase activities were measured. Moreover, the expression levels of B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X (Bax), and caspase-3 proteins were assayed., Key Findings: PRP pre-treatment significantly reduced the radiation-induced abnormalities in kidney histology and attenuated the induced cell injury. Furthermore, PRP notably ameliorated the state of oxidative stress and appeared to inhibit the induced apoptosis., Significance: This study lends a probable protective role of PRP against γ-radiation-induced nephrotoxicity which can highlight the possibilities of its application as a complementary procedure during radiotherapy., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Clinical expression of gastrointestinal radiation toxicity on non-cancerous tissue could be very life threatening and clinicians must deal increasingly with the management of late side effects of radiotherapy. Cell therapy, in particular mesenchymal stromal cell (MSC) therapy, has shown promising results in numerous preclinical animal studies and thus has emerged as a new hope for patient refractory to current treatments. However, many stem cell clinical trials do not confer any beneficial effect suggesting a real need to accelerate research towards the successful clinical application of stem cell therapy. In this study, we propose a new concept to improve the procedure of MSC-based treatment for greater efficacy and clinical translatability. We demonstrated that heparan sulfate mimetic (HS-m) injections that restore the extracellular matrix network and enhance the biological activity of growth factors, associated with local injection of MSC protected in a hydrogel, that increase cell engraftment and cell survival, improve the therapeutic benefit of MSC treatment in two animal models relevant of the human pathology. For the first time, a decrease of the injury score in the ulcerated area was observed with this combined treatment. We also demonstrated that the combined treatment favored the epithelial regenerative process. In this study, we identified a new way, clinically applicable, to optimize stem-cell therapy and could be proposed to patients suffering from severe colonic defect after radiotherapy.

Ionizing radiation-induced skin injury is a common and severe side effect of radiotherapy suffered by cancer patients. Although the therapy using stem cells has been demonstrated to be effective, fully grasping their role in the repair of radiation-induced skin damage remains challenging owing to the lack of highly reliable cell trackers. Herein, we report the design and synthesis of a highly near-infrared emissive organic nanodots with aggregation-induced emission (AIE) characteristic, which give excellent performance in seeing the fate and regenerative mechanism of adipose-derived stem cells (ADSCs) in treatment of radiation-induced skin injury. The resultant AIE dots show a rather high quantum yield of 33% in aqueous media, prominent retention ability in ADSCs without leakage, good biocompatibility during the ADSC differentiation and proliferation as well as excellent injury relief capability on radiation-induced endothelial cells injury. In vivo studies reveal that the AIE dots are capable of serving as an effective fluorescent cell tracker to precisely trace the behavior of the transplanted ADSCs in radiation-induced skin injury-bearing mice and help to understand the ADSCs therapeutic mechanism for at least one month. This study will provide new materials and insights into the stem cell therapy of radiation-induced injury., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Because of the potential regenerative and cytoprotective effects of its content of numerous bioactive growth factors and cytokines, platelet-rich plasma (PRP) became an attractive biomaterial for therapeutic purposes. Therefore, the current study was designed to investigate the potential therapeutic effect of PRP against lead nitrate- and/or γ-radiation-induced hepatotoxicity. To do so, hepatotoxicity was induced in rats by intraperitoneal administration of lead nitrate (7.5 mg/kg) thrice weekly for two consecutive weeks and/or a whole-body γ-irradiation at a single dose of 6 Gy. Activated PRP (0.5 ml/kg) was injected subcutaneously 24 h after the last dose of lead nitrate and/or γ-irradiation and continued twice weekly for three successive weeks. Lead nitrate intoxication and/or γ-irradiation resulted in a significant elevation of serum alanine transaminase and aspartate transaminase activities accompanied with a significant decrease in serum levels of total protein and albumin. Further, a significant increase in malondialdehyde level and nitric oxide content accompanied with a significant decrease in the reduced glutathione content and the enzyme activities of glutathione-S-transferase, superoxide dismutase, and catalase were observed. Additionally, hepatic extracellular signal-regulated kinase (ERK) and Akt signaling pathways were stimulated. PRP treatment notably ameliorated the induced cell injury, reduced the intracellular oxidative and interestingly increased the upregulation of phosphorylated ERK1/2 and Akt. Moreover, PRP treatment relieved lead nitrate and/or γ-radiation-induced hepatic histological damages. In conclusion, this study sheds the light on a probable therapeutic role of PRP against lead nitrate- and/or γ-radiation-induced hepatotoxicity which might attribute to its ability to activate ERK and Akt signaling pathways.

Basic fibroblast growth factor (bFGF) can protect the lung against radiation-induced pulmonary vascular endothelial apoptosis and subsequent radiation-induced lung injury (RILI). However, guiding bFGF to pulmonary vascular endothelial cells is a key determinant for the success of bFGF therapy. To improve the lung-targeting ability of bFGF, a lung endothelial cell-targeting peptide was fused to bFGF (LET-bFGF). An in vitro biological activity assay indicated that fusion of LET did not affect the bioactivity of bFGF. In addition, the fused protein showed superior lung-targeting ability following intravenous injection. Upon injecting LET-bFGF intravenously after thorax radiation, LET-bFGF could better protect against pulmonary vascular endothelial cell apoptosis as early as 4 h post-radiation. Compared with native bFGF, enhanced therapeutic effects of LET-bFGF were also observed in terms of decreased vascular abnormalities, disorganized lung structure, inflammatory cell migration, and lung density at 2 months post-radiation. Therefore, lung endothelial cell-targeted bFGF may represent a promising remedy for RILI., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The ability to repair damaged urinary bladders through the application of bone marrow-derived cells is in the earliest stages of development. We investigated the application of bone marrow-derived cells to repair radiation-injured bladders. We used a three-dimensional bioprinting robot system to biofabricate bone marrow-derived cell structures. We then determined if the biofabricated structures could restore the tissues and functions of radiation-injured bladders. The bladders of female 10-week-old Sprague-Dawley (SD) rats were irradiated with 2-Gy once a week for 5 weeks. Adherent and proliferating bone marrow-derived cells harvested from the femurs of male 17-week-old green fluorescence protein-transfected Tg-SD rats were cultured in collagen-coated flasks. Bone marrow-derived cell spheroids were formed in 96-well plates. Three layers of spheroids were assembled by the bioprinter onto a 9 × 9 microneedle array. The assembled spheroids were perfusion cultured for 7 days, and then the microneedle array was removed. Two weeks after the last radiation treatment, the biofabricated structures were transplanted into an incision on the anterior wall of the bladders (n = 10). Control rats received the same surgery but without the biofabricated structures (sham-structure, n = 12). At 2 and 4 weeks after surgery, the sham-structure control bladder tissues exhibited disorganized smooth muscle layers, decreased nerve cells, and significant fibrosis with increased presence of fibrosis-marker P4HB-positive cells and hypoxia-marker hypoxia-induced factor 1α (HIF1α)-positive cells. The transplanted structures survived within the recipient tissues, and blood vessels extended within them from the recipient tissues. The bone marrow-derived cells in the structures differentiated into smooth muscle cells and formed smooth muscle clusters. The recipient tissues near the transplanted structures had distinct smooth muscle layers and reconstructed nerve cells, and only minimal fibrosis with decreased presence of P4HB- and HIF1α-positive cells. At 4 weeks after surgery, the sham-structure control rats exhibited significant urinary frequency symptoms with irregular and short voiding intervals, and low micturition volumes. In contrast, the structure-transplanted rats had regular micturition with longer voiding intervals and higher micturition volumes compared with the control rats. Furthermore, the residual volume of the structure-transplanted rats was lower than for the controls. Therefore, transplantation of biofabricated bone marrow-derived cell structures reconstructed functional bladders.

Purpose: To investigate the effect of human umbilical cord-derived mesenchymal stem cell (MSC) transplantation on canine radiation-induced lung injury., Methods and Materials: Beagle dogs received localized 15-Gy x-ray radiation to the right lower lung to establish the model of radiation-induced lung injury. After 180 days, dogs were divided into 2 groups (4 per group). The MSC group received intratracheal MSC transplantation, and the saline group received the same volume of normal saline by lavage. The effect of MSC transplantation on lung injury was then evaluated 180 days after transplantation., Results: At 180 days after 15-Gy radiation, canine arterial blood oxygen partial pressure was significantly decreased, and the levels of hydroxyproline and transforming growth factor (TGF)-β in peripheral blood were significantly increased, whereas that of TGF-α was significantly decreased. Computed tomography evaluation revealed visible honeycomb shadows in the right middle and lower pulmonary pleurae. Blood oxygen partial pressure of the MSC group gradually increased over time, whereas the levels of hydroxyproline and TGF-β in the peripheral blood showed a decreasing trend; TGF-α levels gradually increased, which differed significantly from the results observed in the saline group. In addition, computed tomography and pathologic examination showed that the degree of lung injury in the MSC group was milder. The MSC group also showed significantly increased pulmonary superoxide dismutase levels and significantly decreased tumor necrosis factor-α, Interleukein-1, and hyaluronic acid levels. Further study confirmed that MSC transplantation inhibited the activation of TGF-β-Smad2/3 in lung tissues, and in vitro experiments showed that medium conditioned with MSCs effectively inhibited the increase in Smad2 and 3 levels induced by TGF-β1., Conclusion: Canine radiation-induced lung injury could be observed at 180 days after radiation at 15 Gy. MSC transplantation can reduce oxidative stress, inflammatory reactions, and TGF-β-Smad2/3 pathway activation, thereby reducing lung injury., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Syzygium aromaticum L., commonly named clove, is widely used in the food industry due to its antioxidant and antibacterial capabilities. However, little information is available regarding its role in resisting skin photoaging. This study investigated 50% ethanol extract of Syzygium aromaticum L. (SA) and eugenol (EO) for anti-aging effects in UVB-irradiated normal human dermal fibroblasts (NHDFs) and hairless mice. In vitro, SA and EO suppressed matrix metalloproteinase-1, 3 (MMP-1 and MMP-3) secretion as well as the activator protein 1 (AP-1) phosphorylation. SA and EO also activated nuclear erythroid 2-related factor/antioxidant-response element (Nrf2/ARE) signaling which improves the antioxidant activity and inhibited nuclear factor-κB (NF-κB) and interleukin-6 (IL-6) expression, pro-inflammatory factors. Furthermore, SA and EO suppressed the nuclear factor of activated T cells c1 (NFATc1) which is a known activator of MMPs, cooperator transforming growth factor beta (TGF-β) and NF-κB in Ca2+/calcineurin-regulated transcription. In vivo, SA significantly improved the levels of procollagen type I and elastin through TGF/Smad signaling. The histopathological studies found that SA reduced wrinkles. SA also increased filament aggregating protein (filaggrin), which repairs the skin barrier function and improved the skin's hydration. Altogether, SA effectively ameliorated UVB-induced photoaging. It is expected to become a promising natural product.

Distinct subsets of resident tissue macrophages are important in hematopoietic stem cell niche homeostasis and erythropoiesis. We used a myeloid reporter gene ( Csf1r -eGFP) to dissect the persistence of bone marrow and splenic macrophage subsets following lethal irradiation and autologous hematopoietic stem cell transplantation in a mouse model. Multiple recipient bone marrow and splenic macrophage subsets survived after autologous hematopoietic stem cell transplantation with organ-specific persistence kinetics. Short-term persistence (5 weeks) of recipient resident macrophages in spleen paralleled the duration of extramedullary hematopoiesis. In bone marrow, radiation-resistant recipient CD169 + resident macrophages and erythroid-island macrophages self-repopulated long-term after transplantation via autonomous cell division. Posttransplant peak expansion of recipient CD169 + resident macrophage number in bone marrow aligned with the persistent engraftment of phenotypic long-term reconstituting hematopoietic stem cells within bone marrow. Selective depletion of recipient CD169 + macrophages significantly compromised the engraftment of phenotypic long-term reconstituting hematopoietic stem cells and consequently impaired hematopoietic reconstitution. Recipient bone marrow resident macrophages are essential for optimal hematopoietic stem cell transplantation outcomes and could be an important consideration in the development of pretransplant conditioning therapies and/or chemoresistance approaches., (© 2018 by The American Society of Hematology.)

Human amniotic epithelial cells (hAECs), derived from the innermost layer of the term placenta closest to the fetus, have been shown to be potential seed cells for allogeneic cell therapy. Previous studies have shown a certain therapeutic effect of hAECs. However, no appropriate isolation and culture system for hAECs has been developed for clinical applications. In the present study, we established a serum-free protocol for hAEC isolation and cultivation, in which better cell growth was observed compared with that in a traditional culture system with serum. In addition to specific expression of cell surface markers (CD29, CD166 and CD90), characterization of the biological features of hAECs revealed expression of the pluripotent markers SSEA4, OCT4 and NANOG, which was greater than that in human mesenchymal stem cells, whereas very low levels of HLA-DR and HLA-DQ were detected, suggesting the weak immunogenicity of hAECs. Intriguingly, CD90+ hAECs were identified as a unique population with a powerful immunoregulatory capacity. In a systemic safety evaluation, intravenous administration of hAEC did not result in hemolytic, allergy, toxicity issues or, more importantly, tumorigenicity. Finally, the therapeutic effect of hAECs was demonstrated in mice with radiation-induced damage. The results revealed a novel function of hAECs in systemic injury recovery. Therefore, the current study provides an applicable and safe strategy for hAEC cell therapy administration in the clinical setting.

Background: Clinical sequelae of irradiation result in tissue devitalization (e.g., ischemia, fibrosis, and atrophy) where wound healing capacity is impaired. Fat-derived products may work to treat such pathology., Methods: Nonlethal irradiation at various doses (5, 10, and 15 Gy) and frequencies (one to three times on sequential days) was delivered to dorsal skin of nude mice, and subsequent gross and microscopic changes were evaluated for up to 4 weeks. Cutaneous punch wounds were then created to compare wound healing in irradiated and nonirradiated states. Wounds were also locally injected with vehicle, cultured adipose-derived stem cells, centrifuged fat tissue, or micronized cellular adipose matrix, and the therapeutic impact was monitored for up to 15 days., Results: Nude mice given total doses greater than 15 Gy spontaneously developed skin ulcers, and radiation damage was dose-dependent; however, a fractionated irradiation protocol was able to reduce the damage. Histologic assessment revealed dose-dependent dermal fibrosis/thickening and subcutaneous atrophy. Dose-dependent (5 to 15 Gy) impairment of wound healing was also evident. At the highest dosage (15 Gy three times), open wounds persisted on day 15. However, wounds injected with cultured adipose-derived stem cells were nearly healed on day 12, and those treated with injection of centrifuged fat or micronized tissue healed faster than untreated controls (p < 0.05). There was no significant differences between treated groups., Conclusions: Tissue devitalization by irradiation was dose-dependent, although fractionated protocols helped to reduce it. Adipose-derived stem cells and other fat-derived products harboring adipose-derived stem cells successfully revitalized irradiated tissues and accelerated wound healing.

Purpose: To evaluate the therapeutic effects of decorin (DCN)-modified mesenchymal stem cells (MSCs) on radiation-induced lung injuries (RILIs) and to clarify the underlying mechanisms., Methods and Materials: Umbilical cord-derived mesenchymal stem cells (MSCs) were modified with Ad(E1-).DCN to generate DCN-expressing MSCs (DCN-modified MSCs [MSCs.DCN]). In an experimental mouse model of RILI, MSCs.DCN and MSCs.Null [MSCs modified with Ad(E1-).Null] were intravenously engrafted at 6 hours or 28 days after irradiation. The therapeutic effects on lung inflammation and fibrosis were evaluated by histopathologic analysis at 28 days and 3 months after irradiation. Inflammatory cytokines and chemokines were analyzed in both sera and lung tissues, and subtypes of T lymphocytes including regulatory T cells (Tregs) were analyzed in the peripheral blood and spleen., Results: Both MSC treatments could alleviate histopathologic injuries by reducing lymphocyte infiltration, decreasing apoptosis, increasing proliferation of epithelial cells, and inhibiting fibrosis in the later phase. However, treatment with MSCs.DCN resulted in much more impressive therapeutic effects. Moreover, we discovered that MSC treatment reduced the expression of chemokines and inflammatory cytokines and increased the expression of anti-inflammatory cytokines in both the peripheral blood and local pulmonary tissues. An important finding was that MSCs.DCN were much more effective in inducing interferon-γ expression, inhibiting collagen type III α1 expression in pulmonary tissues, and decreasing the proportion of Tregs. Furthermore, our data suggested that treatment during the acute phase (6 hours) after irradiation evoked much stronger responses both in attenuating inflammation and in inhibiting fibrosis than in the later phase (28 days)., Conclusions: MSCs.DCN could attenuate acute inflammation after irradiation and significantly inhibit later fibrosis. Likewise, DCN enhanced the functions of MSCs by targeting profibrotic factors and Tregs., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Photobiomodulation (PBM) with 670 nm light has been shown to accelerate wound healing in soft tissue injuries, and also to protect neuronal tissues. However, little data exist on its effects on the non-neuronal components of the retina, such as Müller cells (MCs), which are the principal macroglia of the retina that play a role in maintaining retinal homeostasis. The aim of this study was to explore the effects of 670 nm light on activated MCs using in vivo and in vitro stress models. Adult Sprague-Dawley rats were exposed to photo-oxidative damage (PD) for 24 h and treated with 670 nm light at 0, 3 and 14 days after PD. Tissue was collected at 30 days post-PD for analysis. Using the in vitro scratch model with a human MC line (MIO-M1), area coverage and cellular stress were analysed following treatment with 670 nm light. We showed that early treatment with 670 nm light after PD reduced MC activation, lowering the retinal expression of GFAP and FGF-2. 670 nm light treatment mitigated the production of MC-related pro-inflammatory cytokines (including IL-1β), and reduced microglia/macrophage (MG/MΦ) recruitment into the outer retina following PD. This subsequently decreased photoreceptor loss, slowing the progression of retinal degeneration. In vitro, we showed that 670 nm light directly modulated MC activation, reducing rates of area coverage by suppressing cellular proliferation and spreading. This study indicates that 670 nm light treatment post-injury may have therapeutic benefit when administered shortly after retinal damage, and could be useful for retinal degenerations where MC gliosis is a feature of disease progression., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Three-dimensional (3D) cultures recapitulate the microenvironment of tissue-resident stem cells and enable them to modulate their properties. We determined whether salivary gland-resident stem cells (SGSCs) are primed by a 3D spheroid culture prior to treating irradiation-induced salivary hypofunction using in-vitro coculture and in-vivo transplant models., Methods: 3D spheroid-derived SGSCs (SGSCs 3D ) were obtained from 3D culture in microwells consisting of a nanofiber bottom and cell-repellent hydrogel walls, and were examined for salivary stem or epithelial gene/protein expression, differentiation potential, and paracrine secretory function compared with monolayer-cultured SGSCs (SGSCs 2D ) in vitro and in vivo., Results: SGSCs 3D expressed increased salivary stem cell markers (LGR5 and THY1) and pluripotency markers (POU5F1 and NANOG) compared with SGSCs 2D . Also, SGSCs 3D exhibited enhanced potential to differentiate into salivary epithelial cells upon differentiation induction and increased paracrine secretion as compared to SGSCs 2D . Wnt signaling was activated by 3D spheroid formation in the microwells and suppression of the Wnt/β-catenin pathway led to reduced stemness of SGSCs 3D . Enhanced radioprotective properties of SGSCs 3D against radiation-induced salivary hypofunction was confirmed by an organotypic 3D coculture and in-vivo transplantation experiments., Conclusion: The 3D spheroid culture of SGSCs in nanofibrous microwells promotes stem cell properties via activation of Wnt signaling. This may contribute to SGSC priming prior to regenerative therapy to restore salivary hypofunction after radiotherapy.

Unwanted radiological or nuclear exposure remains a public health risk for which effective therapeutic countermeasures are lacking. Here, we evaluated the efficacy of fibroblast growth factor-2 (FGF2) in treating radiation-induced gastrointestinal syndrome (RIGS) incurred by lethal whole-body irradiation (WBI) when administered in conjunction with bone marrow transplantation (BMT). In vitro experiments indicated FGF2 treatment increased proliferation, reduced apoptosis, and upregulated AKT-GSK3β/β-catenin signaling in irradiated IEC-6 cells. We next established and analyzed mice cohorts consisting of sham irradiation (Group Sh); 12 Gy WBI (Group A); WBI with BMT (Group B); WBI with FGF2 treatment (Group F); and WBI with BMT and FGF2 treatment (Group BF). At 2 weeks post-irradiation, Group BF showed a dramatic increase in survival over all other groups. Intestinal epithelium of Group BF, but not Group B or F, showed augmented proliferation, decreased apoptosis, and preserved crypt numbers and morphology. Furthermore, Group BF maintained intestinal barrier function with minimal inflammatory disturbances in a manner comparable to Group Sh. In accordance, transcriptomic analyses showed significant upregulation of intestinal barrier and stem cell markers in Group BF relative to Groups A and B. Taken together, parenteral FGF2 synergizes with BMT to confer potent mitigation against RIGS.

Nervous system injury is a frequent result of cancer therapy involving cranial irradiation, leaving patients with marked memory and other neurobehavioral disabilities. Here, we report an unanticipated link between bone marrow and brain in the setting of radiation injury. Specifically, we demonstrate that bone marrow-derived monocytes and macrophages are essential for structural and functional repair mechanisms, including regeneration of cerebral white matter and improvement in neurocognitive function. Using a granulocyte-colony stimulating factor (G-CSF) receptor knockout mouse model in combination with bone marrow cell transplantation, MRI, and neurocognitive functional assessments, we demonstrate that bone marrow-derived G-CSF-responsive cells home to the injured brain and are critical for altering neural progenitor cells and brain repair. Additionally, compared with untreated animals, animals that received G-CSF following radiation injury exhibited enhanced functional brain repair. Together, these results demonstrate that, in addition to its known role in defense and debris removal, the hematopoietic system provides critical regenerative drive to the brain that can be modulated by clinically available agents.

Blackcurrants (Ribes nigrum L.) have various benefits for human health. In particular, a polysaccharide derived from blackcurrant was found to be an immunostimulating food ingredient in a mouse model. We named a polysaccharide derived from blackcurrant cassis polysaccharide (CAPS). In a previous clinical study, we reported that CAPS affects skin dehydration, demonstrating its effectiveness against skin inflammation was related to atopic dermatitis; skin inflammation caused skin dehydration. However, there are no studies regarding CAPS effectiveness against skin dehydration. The current study aimed to investigate CAPS effectiveness against skin dehydration. We further demonstrate the effect of oral administration of CAPS on skin dehydration caused by ultraviolet (UV) irradiation-induced inflammation in mice. We found that CAPS administration suppresses skin dehydration caused by UV irradiation. We also found that CAPS decreases interleukin-6 and matrix metalloproteinase transcription levels in the mouse skin. These results show that CAPS improves skin hydration in UV-irradiated mice.

The development of medical countermeasures against acute and delayed multi-organ injury requires animal models predictive of the human response to radiation and its treatment. Late chronic injury is a well-known feature of radiation nephropathy, but acute kidney injury has not been reported in an appropriate animal model. We have established a single-fraction partial-body irradiation model with minimal marrow sparing in non-human primates. Subject-based medical management was used including parenteral fluids according to prospective morbidity criteria. We show herein that 10 or 11 Gy exposures caused both acute and chronic kidney injury. Acute and chronic kidney injury appear to be dose-independent between 10 and 11 Gy. Acute kidney injury was identified during the first 50 days postirradiation and appeared to resolve before the occurrence of chronic kidney injury, which was progressively more severe up to 180 days postirradiation, which was the end of the study. These findings show that mitigation of the acute radiation syndrome by medical management will unmask delayed late effects that occur months after partial-body irradiation. They further emphasize that both acute and chronic changes in kidney function must be taken into account in the use and timing of mitigators and medical management for acute radiation syndrome and delayed effects of acute radiation exposure (DEARE).

Background: Although tissue-resident mesenchymal stromal cells (MSCs) in the larynx have been described, their distinct characteristics and roles have not been thoroughly explored. Therefore, we investigated stem cell characteristics and regenerative potentials of single clonal populations isolated from rat epiglottic mucosa (EM), lamina propria (LP), and macula flava (MF) to determine whether they comprised laryngeal tissue-resident stem cells., Methods: Single clonal laryngeal cells were isolated following microdissection of the EM, LP, and MF from the rat larynx. Several clonal populations from the three laryngeal subsites were selected and expanded in vitro. We compared the stem cell characteristics of self-renewal and differentiation potential, as well as the cell surface phenotypes and gene expression profiles, of laryngeal MSC-like cells to that of bone marrow MSCs (BM-MSCs). We also investigated the regenerative potential of the laryngeal cells in a radiation-induced laryngeal injury animal model., Results: Self-renewing, clonal cell populations were obtained from rat EM, LP, and MF. EM-derived and LP-derived clonal cells had fibroblast-like features, while MF-resident clonal cells had stellate cell morphology and lipid droplets containing vitamin A. All laryngeal clonal cell populations had MSC-like cell surface marker expression (CD29, CD44, CD73, and CD90) and the potential to differentiate into bone and cartilage cell lineages; EM-derived and MF-derived cells, but not LP-derived cells, were also able to differentiate into adipocytes. Clonal cells isolated from the laryngeal subsites exhibited differential extracellular matrix-related gene expression. We found that the mesenchymal and stellate cell-related genes desmin and nestin were enriched in laryngeal MSC-like cells relative to BM-MSCs (P < 0.001). Growth differentiation factor 3 (GDF3) and glial fibrillary acidic protein (GFAP) transcript and protein levels were higher in MF-derived cells than in other laryngeal populations (P < 0.001). At 4 weeks after transplantation, laryngeal MF-derived and EM-derived cells contributed to laryngeal epithelial and/or glandular regeneration in response to radiation injury., Conclusions: These results suggest that cell populations with MSC characteristics reside in the EM, LP, and MF of the larynx. Laryngeal MSC-like cells contribute to regeneration of the larynx following injury; further investigation is needed to clarify the differential roles of the populations in laryngeal tissue regeneration, as well as the clinical implications for the treatment of laryngeal disease.

Background Aims: Mesenchymal stromal cells (MSCs) are a promising agent for treating impaired wound healing, and their therapeutic potential may be enhanced by employing extracellular matrix scaffolds as cell culture scaffolds or transplant cell carriers. Here, we evaluated the effect of human umbilical cord blood-derived (hUCB)-MSCs and a porcine small intestinal submucosa (SIS)-derived extracellular matrix scaffold in a combined radiation-wound mouse model of impaired wound healing., Methods: hUCB-MSCs and SIS hydrogel composite was applied to the excisional wound of whole-body irradiated mice. Assessment of wound closing and histological evaluation were performed in vivo. We also cultured hUCB-MSCs on SIS gel and examined the angiogenic effect of conditioned medium on irradiated human umbilical vein endothelial cells (HUVECs) in vitro., Results: hUCB-MSCs and SIS hydrogel composite treatment enhanced wound healing and angiogenesis in the wound site of mice. Conditioned medium from hUCB-MSCs cultured on SIS hydrogel promoted the chemotaxis of irradiated HUVECs more than their proliferation. The secretion of angiogenic growth factors hepatocyte growth factor, vascular endothelial growth factor-A and angiopoietin-1 from hUCB-MSCs was significantly increased by SIS hydrogel, with HGF being the predominant angiogenic factor of irradiated HUVECs., Conclusions: Our results suggest that the wound healing effect of hUCB-MSCs is enhanced by SIS hydrogel via a paracrine factor-mediated recruitment of vascular endothelial cells in a combined radiation-wound mouse model., (Copyright © 2017 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Radiation-induced intestinal injury (RIII) commonly occurs in patients who received radiotherapy for pelvic or abdominal cancer, or who suffered from whole-body irradiation during a nuclear accident. RIII can lead to intestinal disorders and even death given its integrity damage that results from intestinal stem cell (ISC) loss. Recovery from RIII relies on the intensity of supportive treatment, which can attenuate lethal infection and give surviving stem cells an opportunity to regenerate. It has been reported that RSPO1 is a cytokine with potent and specific proliferative effects on intestinal crypt cells. MSCs have multiple RIII-healing effects, including anti-inflammatory and anti-irradiation injury properties, due to its negative immune regulation and its homing ability to the damaged intestinal epithelia. To combine the comprehensive anti-injury potential of MSCs, and the potent ability of RSPO1 as a mitogenic factor for ISCs, we constructed RSPO1-modified C3H10 T1/2 cells and expected that RSPO1, the ISC-proliferative cytokine, could be delivered to the site of injury in a targeted manner. In this study, we transferred C3H10/RSPO1 intravenously via the retro-orbital sinus into mice suffering from abdominal irradiation at lethal dosages. Our findings demonstrated that C3H10/RSPO1 cells are able to directionally migrate to the injury site; enhance ISC survival, proliferation, and differentiation; and effectively repair the radiation-damaged intestinal epithelial cells. This study suggests that the directional delivery of RSPO1 by MSCs is a promising strategy to ameliorate, and even cure, RIII., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

To assess the therapeutic effects of the human umbilical cord blood (hUCB) derived mesenchymal stem cells (MSCs) on rat bone marrow (BM) exposed to gamma rays, 3 groups (n=15 each) of adult male Wistar albino rats were utilized as follows: the 1st group received PBS (control group), the 2nd group was exposed to gamma rays 1.04Gy/min (R group) and the 3rd group exposed to same dose as RG and injected hUCB-MSCs. The BM of femurs was processed for histological and immunohistochemical staining with proliferating cell nuclear antigen antibody (PCNA), anti human CD105 and anti human CD34. Hb content, leukocytes and platelet counts were analyzed as well as fat cells and megakaryocytic counts. Also, the BM vascular spaces and the optical density of immunostaining for PCNA were analyzed. The leukocytes and platelet counts were significantly lower in the R (2.85±235.8; P=0.000 and 95.27±3.01; P=0.000 respectively) when compared with the control (10.40±443.2; P=0.000 and 430.18±20.28; P=0.000 respectively). The fat cell count was significantly higher in the R (36.55±1.83; P=0.000) than in control (7.64±0.61; P=0.000) and in R injected h-MSCs tissues (18.82±2.03; P=0.000). The megakaryocytic count was significantly higher in the R injected h-MSCs (5.36±0.310; P=0.000) than in control (2.82±0.263; P=0.000) and in the R BM (0.45±0.157; P=0.000). The vascular spaces were dilated and significantly increased in the R injected h-MSCs (50.10±2.40; P=0.000) than in control (33.36±1.01; P=0.000). The optical density of PCNA expression was significantly lower in R (0.18±0.11; P=0.005) than in control (0.41±0.40; P=0.005) and in R injected h-MSCs groups (0.30±0.17; P=0.005). The present study concluded that injection of hUCB-MSCs improves destructive effects of bone marrow induced by gamma radiation. Use of radio-protective agents during exposure is recommended., (Copyright © 2016 Elsevier GmbH. All rights reserved.)

We evaluated the mitigating effects of fibroblast growth factor 4 and 7 (FGF4 and FGF7, respectively) in comparison with long acting protected graft copolymer (PGC)-formulated FGF4 and 7 (PF4 and PF7, respectively) administered to C57BL/6J mice a day after exposure to LD50/30 (15.7 Gy) partial body irradiation (PBI) which targeted the gastrointestinal (GI) system. The PGC that we developed increased the bioavailability of FGF4 and FGF7 by 5- and 250-fold compared to without PGC, respectively, and also sustained a 24 hr presence in the blood after a single subcutaneous administration. The dose levels tested for mitigating effects on radiation injury were 3 mg/kg for the PF4 and PF7 and 1.5 mg each for their combination (PF4/7). Amifostine administered prior to PBI was used as a positive control. The PF4, PF7, or PF4/7 mitigated the radiation lethality in mice. The mitigating effect of PF4 and PF7 was similar to the positive control and PF7 was better than other mitigators tested. The plasma citrulline levels and hematology parameters were early markers of recovery and survival. GI permeability function appeared to be a late or full recovery indicator. The villus length and crypt number correlated with plasma citrulline level, indicating that it can act as a surrogate marker for these histology evaluations. The IL-18 concentrations in jejunum as early as day 4 and TPO levels in colon on day 10 following PBI showed statistically significant changes in irradiated versus non-irradiated mice which makes them potential biomarkers of radiation exposure. Other colon and jejunum cytokine levels are potentially useful but require larger numbers of samples than in the present study before their full utility can be realized.