Enhanced fucosylation of GA1 in the digestive tracts of X-ray-irradiated mice

Role of low-dose radiation in senescence and aging: A beneficial perspective

Cellular senescence refers to the permanent arrest of cell cycle caused by intrinsic and/or extrinsic stressors including oncogene activation, irradiation, DNA damage, oxidative stress, and certain cytokines (including senescence associated secretory phenotype). Cellular senescence is an important factor in aging. Accumulation of senescent cells has been implicated in the causation of various age-related organ disorders, tissue dysfunction, and chronic diseases. It is widely accepted that the biological effects triggered by low-dose radiation (LDR) are different from those caused by high-dose radiation. Experimental evidence suggests that LDR may promote growth and development, enhance longevity, induce embryo production, and delay the progression of chronic diseases. The underlying mechanisms of these effects include modulation of immune response, stimulation of hematopoietic system, antioxidative effect, reduced DNA damage and improved ability for DNA damage repair. In this review, we discuss the possible mechanisms by which LDR prevents senescence and aging from the perspectives of inhibiting cellular senescence and promoting the removal of senescent cells. We review a wide broad of evidence about the beneficial impact of LDR in senescence and aging models (including cardiovascular diseases, neurological diseases, arthritis and osteoporosis, chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis) to highlight the potential value of LDR in preventing aging and age-related diseases. However, there is no consensus on the effect of LDR on human health, and several important aspects require further investigation.

Exploring the optimal dose of low ionizing radiation to enhance immune function: a rabbit model

Primary liver cancer is one of the most common malignant tumors in China. Currently, immunotherapy for liver cancer is a research hotspot. Experimental studies and epidemiological investigations have confirmed the antineoplastic activity of low ionizing radiation. The aim of this study was to explore the optimal dose of low ionizing radiation to enhance immune function. Twenty-five New Zealand rabbits were randomly divided into five groups (n = 5 each): experimental group 1 (25 mGy), experimental group 2 (50 mGy), experimental group 3 (75 mGy), experimental group 4 (100 mGy), and the control group (0 mGy). VX-2 tumor tissue was injected into rabbits using a high-frequency B-ultrasound probe (3.5 MHz). Rabbits were irradiated, and on day 4 after irradiation, blood was collected from each rabbit. Blood chemistry, interleukin (IL)-4, interferon (IFN)-γ, immunoglobulin (Ig)G, and IgM levels were assessed. On day 15 after irradiation, macrophage phagocytic function was assessed. The rabbits were sacrificed, and the spleen was removed and weighed to calculate its spleen index. Each parameter was highest in the experimental group 3 (75 mGy). Thus, we suspect the optimal low ionizing radiation dose to improve immune function may be 75 mGy.

Spermatogenesis-associated changes of fucosylated glycolipids in murine testis

By targeted deletion of either the FUT1- or FUT2-gene for α1,2-fucosyltransferase, expression of FGM1 and FGA1, in murine testis was revealed to be sustained through unique interchangeability of the genes, indicating their significant roles for spermatogenesis. Accordingly, we examined the amounts of FGM1 and FGA1 in the testes of mice at 1-42 days after birth in comparison to those of several glycolipids including seminolipid. Although Forssman antigen and GM1 were present in relatively constant amounts during the period examined, GM3, which was the major one at 1 day, quickly decreased during development and had completely disappeared at 4 weeks. The following glycolipids were expressed in stage-specific manners, FGM1 for primary spermatocytes at 1 week, a seminolipid for secondary spermatocytes at 2 weeks, and GM3 lactone and FGA1 for spermatids and spermatozoa at 3 weeks. In fact, immunohistochemical staining with anti-FGM1 and anti-FGA1 antibodies demonstrated that FGM1 and FGA1 were distributed in the spermatocytes, and the spermatids and spermatozoa, respectively, and FGA1, together with seminolipid, were the immunogenic markers of spermatozoa. Thus, the fucosylation of glycolipids is a spermatogenesis-associated event, which should occur even with use of either the FUT1- or FUT2-gene.