Isorhamnetin Promotes 53BP1 Recruitment through the Enhancement of ATM Phosphorylation and Protects Mice from Radiation Gastrointestinal Syndrome

STING directly interacts with PAR to promote apoptosis upon acute ionizing radiation-mediated DNA damage

Acute ionizing radiation (IR) causes severe DNA damage, leading to cell cycle arrest, cell death, and activation of the innate immune system. The role and signaling pathway of stimulator of interferon genes (STING) in IR-induced tissue damage and cell death are not well understood. This study revealed that STING is crucial for promoting apoptosis in response to DNA damage caused by acute IR both in vitro and in vivo. STING binds to poly (ADP‒ribose) (PAR) produced by activated poly (ADP‒ribose) polymerase-1 (PARP1) upon IR. Compared with that in WT cells, apoptosis was suppressed in Stinggt-/gt- cells. Excessive PAR production by PARP1 due to DNA damage enhances STING phosphorylation, and inhibiting PARP1 reduces cell apoptosis after IR. In vivo, IR-induced crypt cell death was significantly lower in Stinggt-/gt- mice or with low-dose PARP1 inhibitor, PJ34, resulting in substantial resistance to abdominal irradiation. STING deficiency or inhibition of PARP1 function can reduce the expression of the proapoptotic gene PUMA, decrease the localization of Bax on the mitochondrial membrane, and thus reduce cell apoptosis. Our findings highlight crucial roles for STING and PAR in the IR-mediated induction of apoptosis, which may have therapeutic implications for controlling radiation-induced apoptosis or acute radiation symptoms. STING responds to acute ionizing radiation-mediated DNA damage by directly binding to poly (ADP-ribose) (PAR) produced by activated poly (ADP-ribose) polymerase-1 (PARP1), and mainly induces cell apoptosis through Puma-Bax interaction. STING deficiency or reduced production of PAR protected mice against Acute Radiation Syndrome.

Global research trends on the links between gut microbiota and radiotherapy: a bibliometric analysis (2004-2023)

Background

There is a crosstalk between gut microbiota and radiotherapy. The aim of this study is to use bibliometric analysis to explore the research status and development trends of research on gut microbiota and radiotherapy.

Methods

A literature search regarding publications on gut microbiota and radiotherapy from 2004 to 2023 was retrieved. CiteSpace and VOSviewer were used to conduct the bibliometric analysis. The growth rate of publications, leading countries and institutions, preferred journals, top authors and co-cited authors, top co-cited references, keywords and citation were analyzed in this study.

Results

A total of 2821 papers were extracted. The number of papers has increased rapidly over the past decade, especially after 2017. The USA and China had the most publications and made great contributions to this field. The Chinese Academy of Sciences stood out as the institution with the highest number of publications, followed by the Chinese Academy of Medical Sciences & Peking Union Medical College. The most influential authors were Fan Saijun and Li Yuan. PLoS One had the most publications and the most total citations. Highly cited papers and high-frequency keywords illustrated the current status and trends. Furthermore, analysis of keyword with burst revealed that immunotherapy, acid, intestinal barrier, therapy, immunotherapy, fecal microbiota transplantation, etc, are at the forefront of research in this area.

Conclusion

This study provides an overview of research on gut microbiota and radiotherapy, highlighting influential contributors, impactful publications, and emerging trends. Our finding suggests avenues for further exploration to improve clinical outcomes.

Research progress on antitumor effects of sea buckthorn, a traditional Chinese medicine homologous to food and medicine

Sea buckthorn (Hippophae Fructus), as a homologous species of medicine and food, is widely used by Mongolians and Tibetans for its anti-tumor, antioxidant and liver-protecting properties. In this review, the excellent anti-tumor effect of sea buckthorn was first found through network pharmacology, and its active components such as isorhamnetin, quercetin, gallic acid and protocatechuic acid were found to have significant anti-tumor effects. The research progress and application prospect of sea buckthorn and its active components in anti-tumor types, mechanism of action, liver protection, anti-radiation and toxicology were reviewed, providing theoretical basis for the development of sea buckthorn products in the field of anti-tumor research and clinical application.

Radiation injury and gut microbiota-based treatment

The exposure to either medical sources or accidental radiation can cause varying degrees of radiation injury (RI). RI is a common disease involving multiple human body parts and organs, yet effective treatments are currently limited. Accumulating evidence suggests gut microbiota are closely associated with the development and prevention of various RI. This article summarizes 10 common types of RI and their possible mechanisms. It also highlights the changes and potential microbiota-based treatments for RI, including probiotics, metabolites, and microbiota transplantation. Additionally, a 5P-Framework is proposed to provide a comprehensive strategy for managing RI.

Ionizing radiation triggers mitophagy to enhance DNA damage in cancer cells

Radiotherapy is an important cancer treatment strategy that causes DNA damage in tumor cells either directly or indirectly. Autophagy is a physiological process linked to DNA damage. Mitophagy is a form of autophagy, which specifically targets and eliminates impaired mitochondria, thereby upholding cellular homeostasis. However, the connection between DNA damage and mitophagy has yet to be fully elucidated. We found that mitophagy, as an upstream signal, increases ionizing radiation-induced DNA damage by downregulating or overexpressing key mitophagy proteins Parkin and BNIP3. Enhancing the basal level of mitophagy in conjunction with X-ray irradiation can potentially diminish cell cycle arrest at the G2/M phase, substantially elevate the accumulation of γ-H2AX, 53BP1, and PARP1 foci within the nucleus, augment DNA damage, and facilitate the demise of tumor cells. Consequently, this approach prolongs the survival of melanoma-bearing mice. The findings of this study are anticipated to offer a therapeutic approach for enhancing the therapeutic effectiveness of radiotherapy.

Drug Discovery Targeting Post-Translational Modifications in Response to DNA Damages Induced by Space Radiation

DNA damage in astronauts induced by cosmic radiation poses a major barrier to human space exploration. Cellular responses and repair of the most lethal DNA double-strand breaks (DSBs) are crucial for genomic integrity and cell survival. Post-translational modifications (PTMs), including phosphorylation, ubiquitylation, and SUMOylation, are among the regulatory factors modulating a delicate balance and choice between predominant DSB repair pathways, such as non-homologous end joining (NHEJ) and homologous recombination (HR). In this review, we focused on the engagement of proteins in the DNA damage response (DDR) modulated by phosphorylation and ubiquitylation, including ATM, DNA-PKcs, CtIP, MDM2, and ubiquitin ligases. The involvement and function of acetylation, methylation, PARylation, and their essential proteins were also investigated, providing a repository of candidate targets for DDR regulators. However, there is a lack of radioprotectors in spite of their consideration in the discovery of radiosensitizers. We proposed new perspectives for the research and development of future agents against space radiation by the systematic integration and utilization of evolutionary strategies, including multi-omics analyses, rational computing methods, drug repositioning, and combinations of drugs and targets, which may facilitate the use of radioprotectors in practical applications in human space exploration to combat fatal radiation hazards.