Comparative proteomic profiling and possible toxicological mechanism of acute injury induced by carbon ion radiation in pubertal mice testes

The sparing effect of ultra-high dose rate irradiation on the esophagus

Background and purpose

Current studies have substantiated the sparing effect of ultra-high dose rate irradiation (FLASH) in various organs including the brain, lungs, and intestines. Whether this sparing effect extends to esophageal tissue remains unexplored. This study aims to compare the different responses of esophageal tissue in histological and protein expression levels following conventional dose rate irradiation (CONV) and FLASH irradiation to ascertain the presence of a sparing effect.

Methods and materials

C57 female mice were randomly divided into three groups: control, CONV, and FLASH groups. The chest region of the mice in the radiation groups was exposed to a prescribed dose of 20 Gy using a modified electron linear accelerator. The CONV group received an average dose rate of 0.1 Gy/s, while the FLASH group received an average dose rate of 125 Gy/s. On the 10th day after irradiation, the mice were euthanized and their esophagi were collected for histopathological analysis. Subsequently, label-free proteomic quantification analysis was performed on esophageal tissue. The validation process involved analyzing transmission electron microscopy images and utilizing the parallel reaction monitoring method.

Results

Histopathology results indicated a significantly lower extent of esophageal tissue damage in the FLASH group compared to the CONV group (p < 0.05). Label-free quantitative proteomic analysis revealed that the sparing effect observed in the FLASH group may be attributed to a reduction in radiation-induced protein damage associated with mitochondrial functions, including proteins involved in the tricarboxylic acid cycle and oxidative phosphorylation, as well as a decrease in acute inflammatory responses.

Conclusions

Compared with CONV irradiation, a sparing effect on esophageal tissue can be observed after FLASH irradiation. This sparing effect is associated with alleviated mitochondria damage and acute inflammation.

Integrated Transcriptome Analysis Reveals the Crucial mRNAs and miRNAs Related to Fecundity in the Hypothalamus of Yunshang Black Goats during the Luteal Phase

A normal estrus cycle is essential for the breeding of goats, and the luteal phase accounts for most of the estrus cycle. The corpus luteum (CL) formed during the luteal phase is a transient endocrine gland that is crucial for the reproductive cycle and pregnancy maintenance, and is controlled by many regulatory factors. However, the molecular mechanism of the hypothalamus effect on the reproductive performance of different litter sizes during the luteal phase of goats has not been elucidated. In this study, RNA-sequencing was used to analyze the mRNA and miRNA expression profiles of the hypothalamic tissues with the high-fecundity goats during the luteal phase (LP-HF) and low-fecundity goats during the luteal phase (LP-LF). The RNA-seq results found that there were 1963 differentially expressed genes (DEGs) (890 up-regulated and 1073 down-regulated). The miRNA-seq identified 57 differentially expressed miRNAs (DEMs), including 11 up-regulated and 46 down-regulated, of which 199 DEGs were predicted to be potential target genes of DEMs. Meanwhile, the functional enrichment analysis identified several mRNA-miRNA pairs involved in the regulation of the hypothalamic activity, such as the common target gene MEA1 of novel-miR-972, novel-miR-125 and novel-miR-403, which can play a certain role as a related gene of the reproductive development in the hypothalamic-pituitary-gonadal (HPG) axis and its regulated network, by regulating the androgen secretion. While another target gene ADIPOR2 of the novel-miR-403, is distributed in the hypothalamus and affects the reproductive system through a central role on the HPG axis and a peripheral role in the gonadal tissue. An annotation analysis of the DE miRNA-mRNA pairs identified targets related to biological processes, such as anion binding (GO:0043168) and small molecule binding (GO: 0036094). Subsequently, the KEGG(Kyoto Encyclopedia of Genes and Genomes) pathways were performed to analyze the miRNA-mRNA pairs with negatively correlated miRNAs. We found that the GnRH signaling pathway (ko04912), the estrogen signaling pathway (ko04915), the Fc gamma R-mediated phagocytosis (ko04666), and the IL-17 signaling pathway (ko04657), etc., were directly and indirectly associated with the reproductive process. These targeting interactions may be closely related to the reproductive performance of goats. The results of this study provide a reference for further research on the molecular regulation mechanism for the high fertility in goats.

Crocetin Mitigates Irradiation Injury in an In Vitro Model of the Pubertal Testis: Focus on Biological Effects and Molecular Mechanisms

Infertility is a potential side effect of radiotherapy and significantly affects the quality of life for adolescent cancer survivors. Very few studies have addressed in pubertal models the mechanistic events that could be targeted to provide protection from gonadotoxicity and data on potential radioprotective treatments in this peculiar period of life are elusive. In this study, we utilized an in vitro model of the mouse pubertal testis to investigate the efficacy of crocetin to counteract ionizing radiation (IR)-induced injury and potential underlying mechanisms. Present experiments provide evidence that exposure of testis fragments from pubertal mice to 2 Gy X-rays induced extensive structural and cellular damage associated with overexpression of PARP1, PCNA, SOD2 and HuR and decreased levels of SIRT1 and catalase. A twenty-four hr exposure to 50 μM crocetin pre- and post-IR significantly reduced testis injury and modulated the response to DNA damage and oxidative stress. Nevertheless, crocetin treatment did not counteract the radiation-induced changes in the expression of SIRT1, p62 and LC3II. These results increase the knowledge of mechanisms underlying radiation damage in pubertal testis and establish the use of crocetin as a fertoprotective agent against IR deleterious effects in pubertal period.

Quantitative proteomics reveals mitochondrial respiratory chain as a dominant target for carbon ion radiation: Delayed reactive oxygen species generation caused DNA damage

Heavy ion radiotherapy has shown great promise for cancer therapy. Understanding the cellular response mechanism to heavy ion radiation is required to explore measures of overcoming devastating side effects. Here, we performed a quantitative proteomic analysis to investigate the mechanism of carbon ion irradiation on human AHH-1 lymphoblastoid cells. We identified 4602 proteins and quantified 4569 proteins showing high coverage in the mitochondria. Data are available via ProteomeXchange with identifier PXD008351. After stringent filtering, 290 proteins were found to be significantly up-regulated and 16 proteins were down-regulated. Functional analysis revealed that these up-regulated proteins were enriched in the process of DNA damage repair, mitochondrial ribosome, and particularly mitochondrial respiratory chain, accounting for approximately 50% of the accumulated proteins. Bioinformatics and functional analysis demonstrated that these up-regulated mitochondrial respiratory chain proteins enhanced ATP production and simultaneously reactive oxygen species release. More importantly, increased reactive oxygen species led to secondary organelle injury and lagged DNA double-strand breaks. Consistently, the expression of antioxidant enzymes was up-regulated for free radical scavenging. The mechanism of lagged secondary injury originated from disturbances in the mitochondrial respiratory chain. Our results provided a novel target for cell self-repair against heavy ion radiation-induced cellular damage.

Comparative Profiling of MicroRNAs Reveals the Underlying Toxicological Mechanism in Mice Testis Following Carbon Ion Radiation

This study investigated the toxicity of heavy ion radiation to mice testis by microRNA (miRNA) sequencing and bioinformatics analyses. Testicular indices and histology were measured following enterocoelia irradiation with a 2 Gy carbon ion beam, with the testes exhibiting the most serious injuries at 4 weeks after carbon ion radiation (CIR) exposure. Illumina sequencing technology was used to sequence small RNA libraries of the control and irradiated groups at 4 weeks after CIR. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses implicated differential miRNAs in the regulation of target genes involved in metabolism, development, and reproduction. Here, 8 miRNAs, including miR-34c-5p, miR-138, and 6 let-7 miRNA family members previously reported in testis after radiation, were analyzed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) to validate miRNA sequencing data. The differentially expressed miRNAs described here provided a novel perspective for the role of miRNAs in testis toxicity following CIR.

Comparative analysis of the serum proteome for biomarker discovery to reveal hepatotoxicity induced by iron ion radiation in mice

AIMS

Proteomic analysis of serum biomarkers to determine liver toxicity after exposure to cosmic radiation has not been performed previously. This study was to identify serum biomarkers associated with hepatotoxicity following exposure to iron ion radiation.

MAIN METHODS

Male mice were whole-body irradiated with a 2grayunit (Gy) iron ion beam, and after 3months, serum and liver samples were collected. Two-dimensional electrophoresis (2-DE) was used to separate the identified serum proteins, and matrix-assisted laser desorption/ionization tandem mass spectrometry (MALDI-TOF-TOF) was performed to identify differentially expressed proteins. Enzyme-linked immunosorbent assays and immunoblotting were applied to evaluate protein expression, and immunohistochemistry and immunofluorescence were used to investigate protein localization. Real-time polymerase chain reaction (PCR) was performed to confirm altered gene expression.

KEY FINDINGS

A total of 11 spots that showed differential expression were screened and identified as seven proteins. Of these, six proteins were in the same bioinformatics network and included complement component 3, serum amyloid P-component, apolipoprotein E, alpha-2-macroglobulin, fibrinogen alpha chain, and fibrinogen gamma chain. All of these proteins are synthesized by the liver, and may play an important role in liver toxicity. We also confirmed the mRNA transcription, and found that mRNA expression of the six identified proteins increased in the liver in irradiated mice.

SIGNIFICANCE

These results suggest that these proteins may be potential biomarkers of hepatotoxicity in astronauts enduring long space missions.