Attenuation of Radiation-Induced Lung Injury by Hyaluronic Acid Nanoparticles.

PURPOSE: Therapeutic thorax irradiation as an intervention in lung cancer has its limitations due to toxic effects leading to pneumonitis and/or pulmonary fibrosis. It has already been confirmed that hyaluronic acid (HA), an extracellular matrix glycosaminoglycan, is involved in inflammation disorders and wound healing in lung tissue. We examined the effects after gamma irradiation of hyaluronic acid nanoparticles (HANPs) applied into lung prior to that irradiation in a dose causing radiation-induced pulmonary injuries (RIPI). MATERIALS AND METHODS: Biocompatible HANPs were first used for viability assay conducted on the J774.2 cell line. For in vivo experiments, HANPs were administered intratracheally to C57Bl/6 mice 30 min before thoracic irradiation by 17 Gy. Molecular, cellular, and histopathological parameters were measured in lung and peripheral blood at days 113, 155, and 190, corresponding to periods of significant morphological and/or biochemical alterations of RIPI. RESULTS: Modification of linear hyaluronic acid molecule into nanoparticles structure significantly affected the physiological properties and caused long-term stability against ionizing radiation. The HANPs treatments had significant effects on the expression of the cytokines and particularly on the pro-fibrotic signaling pathway in the lung tissue. The radiation fibrosis phase was altered significantly in comparison with a solely irradiated group. CONCLUSIONS: The present study provides evidence that application of HANPs caused significant changes in molecular and cellular patterns associated with RIPI. These findings suggest that HANPs could diminish detrimental radiation-induced processes in lung tissue, thereby potentially decreasing the extracellular matrix degradation leading to lung fibrosis.

Simple Detection of Primary Cilia by Immunofluorescence.

Primary cilia are dynamically regulated during cell cycle progression, specifically during the G0/G1 phases of the cell cycle, being resorbed prior to mitosis. Primary cilia can be visualized with highly sophisticated methods, including transmission electron microscopy, 3D imaging, or using software for the automatic detection of primary cilia. However, immunofluorescent staining of primary cilia is needed to perform these methods. This publication describes a protocol for the easy detection of primary cilia in vitro by staining acetylated alpha tubulin (axoneme) and gamma tubulin (basal body). This immunofluorescent staining protocol is relatively simple and results in high-quality images. The present protocol describes how four cell lines (C2C12, MEF, NHLF, and skin fibroblasts) expressing primary cilia were fixed, immunostained, and imaged with a fluorescent or confocal microscope.

Substituted Piperazines as Novel Potential Radioprotective Agents.

The increasing risk of radiation exposure underlines the need for novel radioprotective agents. Hence, a series of novel 1-(2-hydroxyethyl)piperazine derivatives were designed and synthesized. Some of the compounds protected human cells against radiation-induced apoptosis and exhibited low cytotoxicity. Compared to the previous series of piperazine derivatives, compound 8 exhibited a radioprotective effect on cell survival in vitro and low toxicity in vivo. It also enhanced the survival of mice 30 days after whole-body irradiation (although this increase was not statistically significant). Taken together, our in vitro and in vivo data indicate that some of our compounds are valuable for further research as potential radioprotectors.

Biological dosimetry and modern (-omic) methods.

The increased risk of acute large-scale radiation exposure of the population underlies the necessity to develop new methods that could provide a rapid assessment of the doses received while using modern high-throughput technologies. At the same time, there is a growing interest in discovering new biomarkers enabling the categorization of irradiated individuals that could be used in epidemiological studies to correlate the estimated absorbed doses with the consequent impact on patients health. The aim of this study was to summarize the current literature on biological dosimetry, specifically ionizing radiation-responsive biomarkers. We briefly describe current knowledge in the field of radiation genomics, metabolomics, and proteomics. Although the majority of studies that provided a plethora of useful information were conducted in animal models, oncological patients remain the crucial experimental model. The authors describe various biological materials that could be potentially used to predict the effect of ionizing radiation. Plasma proteins appear to be ideal for this purpose. Out of many candidate markers, the ferredoxin reductase (FDXR) seems to be promising, as it has been confirmed in several biodosimetric studies at the level of both human gene and protein.

INVESTIGATION OF THE RADIOPROTECTIVE EFFECT OF ORTHOVANADATE IN MICE AFTER TOTAL BODY IRRADIATION.

The increasing risk of acute large-scale exposure of ionising irradiation on the population underlines the necessity of developing effective radioprotective and mitigating agents. The aim of this work was to investigate the effect of sodium orthovanadate pre-treatment on mice exposed to high doses of gamma rays (from 5 to 13 Gy). The determination of median lethal dose within 30 days confirmed that orthovanadate applied to total-body-irradiated mice intra-peritoneally has a radioprotective but not a mitigating effect. With orthovanadate pre-treatment, the composition of cellularity in the bone marrow improved substantially and the main lymphocyte populations restored during the first month after irradiation. These findings contribute to 'gap-filling' in radioprotective effects and demonstrate the importance of haematological parameters in radiation-response prediction.

CHANGES IN BLOOD COUNT AND LYMPHOCYTE MICRONUCLEI IN PIGLETS AFTER WHOLE-BODY IRRADIATION.

Biodosimetry is focused on effects of ionizing radiation at cellular and molecular levels of living organisms so that a qualified retrospective estimate of radiation load can be made. Two biodosimetry methods were evaluated in irradiated piglets: complete blood count analysis and quantification of chromosomal aberrations in lymphocytes using a micronucleus test. Animals were whole-body irradiated with gamma radiation at doses of 0-10 Gy. The analysis of complete blood count was performed at intervals ranging from 0 to 48 hours. Micronuclei were measured at 4 hours after irradiation. Changes in lymphocyte counts and increased levels of micronuclei reflected received dose of ionizing radiation.

Cytokines and radiation-induced pulmonary injuries.

Radiation therapy is one of the most common treatment strategies for thorax malignancies. One of the considerable limitations of this therapy is its toxicity to normal tissue. The lung is the major dose-limiting organ for radiotherapy. That is because ionizing radiation produces reactive oxygen species that induce lesions, and not only is tumor tissue damaged, but overwhelming inflammatory lung damage can occur in the alveolar epithelium and capillary endothelium. This damage may result in radiation-induced pneumonitis and/or fibrosis. While describing the lung response to irradiation generally, the main focus of this review is on cytokines and their roles and functions within the individual stages. We discuss the relationship between radiation and cytokines and their direct and indirect effects on the formation and development of radiation injuries. Although this topic has been intensively studied and discussed for years, we still do not completely understand the roles of cytokines. Experimental data on cytokine involvement are fragmented across a large number of experimental studies; hence, the need for this review of the current knowledge. Cytokines are considered not only as molecular factors involved in the signaling network in pathological processes, but also for their diagnostic potential. A concentrated effort has been made to identify the significant immune system proteins showing positive correlation between serum levels and tissue damages. Elucidating the correlations between the extent and nature of radiation-induced pulmonary injuries and the levels of one or more key cytokines that initiate and control those damages may improve the efficacy of radiotherapy in cancer treatment and ultimately the well-being of patients.