Heart irradiation reduces microvascular density and accumulation of HSPA1 in mice

Late Effects of Ionizing Radiation on the Ultrastructure of Hepatocytes and Activity of Lysosomal Enzymes in Mouse Liver Irradiated In Vivo

The study aimed to investigate late radiation-induced changes in the histology, ultrastructure, and activity of lysosomal enzymes in mouse liver exposed to ionizing radiation. The experiment was conducted on C57BL/6J male mice whose distal part of the liver was exposed occasionally to single doses of radiation (6 MV photons) during targeted heart irradiation; estimated doses delivered to analyzed tissue were 0.025 Gy, 0.25 Gy, 1 Gy, and 2 Gy. Tissues were collected 40 weeks after irradiation. We have observed that late effects of radiation have an adaptive nature and their intensity was dose-dependent. Morphological changes in hepatocytes included an increased number of primary lysosomes and autophagic vacuoles, which were visible in tissues irradiated with 0.25 Gy and higher doses. On the other hand, a significant increase in the activity of lysosomal hydrolases was observed only in tissues exposed to 2 Gy. The etiology of these changes may be multifactorial and result, among others, from unintentional irradiation of the distal part of the liver and/or functional interaction of the liver with an irradiated heart. In conclusion, we confirmed the presence of late dose-dependent ultrastructural and biochemical changes in mouse hepatocytes after liver irradiation in vivo.

ATP protects anti-PD-1/radiation-induced cardiac dysfunction by inhibiting anti-PD-1 exacerbated cardiomyocyte apoptosis, and improving autophagic flux

The synergy between radiotherapy and immunotherapy in treating thoracic cancers presents a potent therapeutic advantage, yet it also carries potential risks. The extent and nature of cumulative cardiac toxicity remain uncertain, prompting the need to discern its mechanisms and devise effective mitigation strategies. Radiation alone or in combination with an anti- Programmed cell death protein1 (PD-1) antibody significantly reduced cardiac function in C57BL/6J mice, and this pathologic effect was aggravated by anti-PD-1 (anti-PD-1 + radiation). To examine the cellular mechanism that causes the detrimental effect of anti-PD-1 upon cardiac function after radiation, AC16 human cardiomyocytes were used to study cardiac apoptosis and cardiac autophagy. Radiation-induced cardiomyocyte apoptosis was significantly promoted by anti-PD-1 treatment, while anti-PD-1 combined radiation administration blocked the cardiac autophagic flux. Adenosine 5'-triphosphate (ATP) (a molecule that promotes lysosomal acidification) not only improved autophagic flux in AC16 human cardiomyocytes, but also attenuated apoptosis induced by radiation and anti-PD-1 treatment. Finally, ATP administration in vivo significantly reduced radiation-induced and anti-PD-1-exacerbated cardiac dysfunction. We demonstrated for the first time that anti-PD-1 can aggravate radiation-induced cardiac dysfunction via promoting cardiomyocyte apoptosis without affecting radiation-arrested autophagic flux. ATP enhanced cardiomyocyte autophagic flux and inhibited apoptosis, improving cardiac function in anti-PD-1/radiation combination-treated animals.

Integrative analysis of DNA methylome and transcriptome reveals epigenetic regulation of bisphenols-induced cardiomyocyte hypertrophy

Cardiac hypertrophy, a kind of cardiomyopathic abnormality, might trigger heart contractile and diastolic dysfunction, and even heart failure. Currently, bisphenols (BPs) including bisphenol A (BPA), and its alternatives bisphenol AF (BPAF), bisphenol F (BPF) and bisphenol S (BPS) are ubiquitously applied in various products and potentially possess high cardiovascular risks for humans. However, the substantial experimental evidences of BPs on heart function, and their structure-related effects on cardiomyocyte hypertrophy are still urgently needed. DNA methylation, a typical epigenetics, play key roles in BPs-induced transcription dysregulation, thereby affecting human health including cardiovascular system. Thus, in this study, we performed RNA-seq and reduced representation bisulfite sequencing (RRBS) to profile the landscapes of BPs-induced cardiotoxicity and to determine the key roles of DNA methylation in the transcription. Further, the capabilities of three BPA analogues, together with BPA, in impacting heart function and changing DNA methylation and transcription were compared. We concluded that similar to BPA, BPAF, BPF and BPS exposure deteriorated heart function in a mouse model, and induced cardiomyocyte hypertrophy in a H9c2 cell line. BPAF, BPF and BPS all played BPA-like roles in both transcriptive and methylated hierarchies. Moreover, we validated the expression levels of four cardiomyocyte hypertrophy related candidate genes, Psmc1, Piptnm2, Maz and Dusp18, which were all upregulated and with DNA hypomethylation. The findings on the induction of BPA analogues on cardiomyocyte hypertrophy and DNA methylation revealed their potential detrimental risks in heart function of humans.

Mechanisms of Myocardial Ischemia in Cancer Patients: A State-of-the-Art Review of Obstructive Versus Non-Obstructive Causes

In patients with cancer, myocardial infarction (MI) has distinct features and mechanisms compared to the non-oncology population. Triggers of myocardial ischemia specific to the oncology population have been increasingly identified. Coronary plaque disruption, coronary vasospasm, coronary microvascular dysfunction, spontaneous coronary artery dissection, and coronary oxygen supply-demand mismatch are all causes of MI that have been shown to have specific triggers related to either the treatments or complications of cancer. MI can occur in the presence or absence of atherosclerotic coronary artery disease (CAD). MI with nonobstructive CAD (MINOCA) is a heterogeneous syndrome that has distinct pathophysiology and different epidemiology from MI with significant CAD (MI-CAD). Recognition and differentiation of MI-CAD and MINOCA is essential in the oncology population, due to unique etiology and impact on diagnosis, management, and overall outcomes. There are currently no reports in the literature concerning MINOCA as a unified syndrome in oncology patients. The purpose of this review is to analyze the literature for studies related to known triggers of myocardial ischemia in cancer patients, with a focus on MINOCA. We propose that certain cancer treatments can induce MINOCA-like states, and further research is warranted to investigate mechanisms that may be unique to certain cancer states and types of treatment.

Monte Carlo determination of dose coefficients at different developmental stages of zebrafish (Danio rerio) in experimental condition

The release of liquid effluent of nuclear power into aquatic system increases with the rapid development of nuclear facilities in coastal and inland regions. Aquatic model animals are very important for the study of the radiation hazards to non-human biota in water environment and its extrapolation of dose-effect relationship to human models. However, the study of the radiation dose rate calculation model of the aquatic animal zebrafish is still on the homogeneous isotropic model used for the protection of the environment. A series of zebrafish models (including adults, larvae and embryos, named zebrafish-family: ZF-family) with multiple internal organs are established in this study to investigate the mechanism of radiation damage effect in order to protect non-human species. The internal and external dose coefficients (DCs) of the whole body, heart and gonads of zebrafishes are calculated in water environment with the combination of the real experimental culture condition, using Monte Carlo application package GATE (Geant4 Application for Emission Tomography) and eight nuclides, i.e., ³H, ¹⁴C, ⁹⁰Sr, ⁶⁰Co, ^110mAg, ¹³⁴Cs, ¹³⁷Cs, ¹³¹I, which are commonly found in the liquid effluent of nuclear power plants, as the source items, The results show that the level of nuclide γ energy determines the external DCs (DC_ext), and ⁹⁰Sr plays the most important role in internal DCs (DC_int). The comparison between the external DCs of the heart and gonad and that of the whole body shows that DCs (DC_ext) of heart and gonad for females are 80% and 43% lower than that of whole body, respectively, while for males, the DCs (DC_ext) of heart is 44% lower than that of the whole body, and DCs (DC_ext) of gonad is slightly higher than that of the whole body for most nuclides (up to 25%).The dose of internal radiation makes greater contribution than that of external radiation to pure beta emitter (³H, ¹⁴C, ⁹⁰Sr). This internal DCs of ZF-family model with complex internal structure turns out to demonstrate more sensitive DCs change trend and higher calculation values compared with the internal DCs of the simple ellipsoid model. In this model, the photon emitter with strong penetrating power has higher internal DCs, while the low-energy pure beta nuclide does not alter much. In conclusion, it is vital to carry out refined systematic modeling for model organisms, and the determination of DCs of model organs can promote the evaluation of the radiation effects on non-human species.

Liquid chromatography-tandem mass spectrometry reveals an active response to DNA damage in human spermatozoa

OBJECTIVE

To investigate how endogenously elevated DNA fragmentation alters the human sperm proteome, and whether this fragmentation contributes to genomic deletions.

DESIGN

Research study.

SETTING

Commercial fertility clinic.

PATIENT(S)

Men with low (0%-4%, n = 7) or high (≥16%, n = 6) sperm DNA fragmentation, as assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling assay.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Global sperm proteome, single-nucleotide polymorphism genotyping array.

RESULT(S)

A total of 78 significantly differentially abundant proteins (30 decreased, 48 increased) were observed in control vs. high DNA damage samples. DNA damage resulted in robust proteomic responses, including markers of oxidative stress and apoptosis, DNA damage repair proteins, and transcription/translation and protein turnover machinery. Several key sperm functional proteins were significantly decreased in ejaculates with high DNA damage. We were unable to substantiate a link between increased DNA fragmentation and genomic deletions in human spermatozoa.

CONCLUSION(S)

Developing human spermatozoa initiate an active transcriptional response to endogenous DNA damage, which manifests as alterations in the sperm proteome.

Radio-detoxified LPS alters bone marrow-derived extracellular vesicles and endothelial progenitor cells

Stem cell-based therapies raise hope for cell replacement and provide opportunity for cardiac regenerative medicine and tumor therapy. Extracellular vesicles are a membrane-enclosed intercellular delivery system with the potential to improve the therapeutic efficacy of the treatment of a variety of disorders. As the incidence of breast cancer continues to rise, radiotherapy has emerged as a leading treatment modality. Radiotherapy also increases the risk of coronary heart disease and cardiac mortality. In a chest-irradiated mouse model of cardiac injury, we investigated the effects of local irradiation. We found an increased lethality after 16 Gy irradiation. Importantly, radio-detoxified LPS (RD-LPS) treatment prolonged the survival significantly. By flow cytometry, we demonstrated that upon administration of RD-LPS, the number of bone marrow-derived endothelial progenitor cells increased in the bone marrow and, in particular, in the circulation. Furthermore, mass spectrometry analysis showed that RD-LPS altered the proteomic composition of bone marrow cell-derived small extracellular vesicles (sEVs). RD-LPS treatment increased interferon-induced transmembrane protein-3 (IFITM3) expression markedly both in bone marrow cells and in bone marrow cell-derived small extracellular vesicles. This is the first study to demonstrate that radio-detoxified LPS treatment induces an increase of circulating endothelial progenitor cells (EPCs) in parallel with a reduced radiotherapy-related mortality. While the total number of bone marrow-derived extracellular vesicles was significantly increased 24 h after treatment in the RD-LPS groups, the number of endothelial progenitor cells was reduced in animals injected with GW4896 (a chemical inhibitor of exosome biogenesis) as compared with controls. In contrast to these in vivo results, in vitro experiments did not support the effect of sEVs on EPCs. Our data raise the intriguing possibility that IFITM3 may serve as a marker of the radio-detoxified LPS treatment.

Huangqi Shengmai Yin Protects against Radiation-Induced Cardiac Fibrosis Injury by Regulating the TGF-β1/Smads and MMPs

Background

Radiation-induced heart damage is considered to be a progressive process of fibrosis. Emerging evidence has indicated that the Smads and matrix metalloproteinases (MMPs)/tissue inhibitors of MMPs (TIMP) may be involved in radiation-induced cardiac fibrosis (RICF) by regulating the activation of TGF-β1 signaling pathway. Based on this, the present study was undertaken to characterize the effect of Huangqi Shengmai Yin (HSY) on RICF in a rat model.

Methods

Precardiac region of rats was irradiated with 25 Gy X-rays, and their myocardial pathology scores in terms of injury and collagen volume fraction (CVF) and the expression levels of fibrotic molecules were detected.

Results

The pathology scores and CVF in myocardial tissue increased after irradiation, and the expression of TGF-β1, Col1, and Col3 increased. This change indicated that such irradiation promoted the fibrosis damage in rat hearts. The damage was accompanied by an increase in the expression of Smad 2, Smad3, Smad4, and MMP14 and a decrease in the expression of Smad 7 and TIMP1. Administration of HSY weakened the RICF by decreasing pathology score and CVF and decreased the expression of TGF-β1, Col1, and Col3 in irradiated rat hearts. In addition, Smad2, Smad3, Smad4, and MMP14 were downregulated, while Smad 7 and TIMP1 were upregulated during intervention with HSY.

Conclusions

The involvement of the TGF-β1/Smads and MMPs/TIMP system in RICF was confirmed. This study demonstrated, for the first time, that HSY attenuates the effects of RICF in a rat model. The effect HSY was found to be closely related to the TGF-β1/Smads signaling pathway and MMPs system. These results suggest that HSY is a prospective drug for clinical treatment of RICF.