Irradiation with 365 nm and 405 nm wavelength shows differences in DNA damage of swine pancreatic islets

INTRODUCTION

3D printing is being used more extensively in modern biomedicine. One of the problems is selecting a proper crosslinking method of bioprinted material. Amongst currently used techniques we can distinguish: physical crosslinking (e.g. Ca2+ and Sr2+) and chemical crosslinking-the UV light crosslinking causing the biggest discussion. UV radiation is selectively absorbed by DNA, mainly in the UV-B region but also (to some extent) in UV-A and UV-C regions. DNA excitement results in typical photoproducts. The amount of strand breaks may vary depending on the period of exposition, it can also differ when cells undergo incubation after radiation.

AIM

The aim of this study was to show whether and how the time of irradiation with 405 nm and 365 nm wavelengths affect DNA damage in cell lines and micro-organs (pancreatic islets).

MATERIALS AND METHODS

The degree of DNA damage caused by different wavelengths of radiation (405 nm and 365 nm) was evaluated by a comet assay. The test was performed on fibroblasts, alpha cells, beta cells and porcine pancreatic islets after 24 hours incubation period. Samples without radiation treatment were selected as a control group. Results analysis consisted of determining the percent of cells with damaged DNA and the tail intensity evaluation.

RESULTS

The degree of DNA damage in pancreatic islets after exposure to 405 nm wavelength oscillated between 2% and 6% depending on the tested time period (10 - 300 seconds). However, treating islets using 365 nm wavelength resulted in damage up to 50%. This clearly shows significantly less damage when using 405 nm wavelength. Similar results were obtained for the tested cell lines.

CONCLUSIONS

Crosslinking with 405 nm is better for pancreatic islets than crosslinking with 365 nm UV light.

Adropin, nesfatin-1 and angiotensin II receptor expression in the abdominal aorta in ovariectomized rats after nesfatin-1 treatment

The aim of the research was to assess the effect of nesfatin-1 on the structure, flexibility parameters, and expression of adropin, nesfatin-1, and angiotensin II receptor type 1 (AT1R) in the abdominal aorta in ovariectomized rats. Fragments of aortas were collected after euthanasia of female sham-operated (CONT) and ovariectomized Wistar rats (EXP), which were administered intraperitoneal injection of physiological saline (CONT, n = 7; EXP-O, n = 7) or nesfatin-1 (EXP-N, n = 7) in an amount of 2 μg/kg b.w. once a day for 8 weeks. The samples of aortas were collected for measurement of elasticity as well as histomorphometric, immunohistochemical, FTIR, and Raman spectroscopy analysis. The ovariectomy caused a significant increase in the thickness of the total wall and its particular layers in the aorta, in comparison to the CONT and EXP-N groups. However, the ovariectomy led to a decrease in the amount of elastin, collagen (mature, immature collagen, collagen maturity ratio 1660 - 1690 cm^-1), and amides, with a simultaneous increase in lipids, especially in the tunica intima-media of the abdominal aorta compared to the other groups. The use of nesfatin-1 significantly increased the amount of collagen, elastin and amides with a simultaneous decrease in the amount of lipids and the expression of AT1R, adropin and nesfatin-1 in the abdominal aorta of ovariectomized rats. In conclusion, our study showed that the ovariectomy surgery induced changes in the abdominal aorta wall characteristic for aging females. Application of nesfatin-1 may prevent the negative consequences in the vessel wall structure in females in conditions of estrogen deficiency and prevent atherosclerotic changes in the cardiovascular system.

Supplementation with camelina oil prevents negative changes in the artery in orchidectomized rats

The aim of the research was to examine the influence of orchidectomy on the elasticity and wall structure of the abdominal aorta in male rats and to check whether camelina oil treatment has an effect on aorta wall characteristics in orchidectomized rats. Forty 2-month-old male Wistar rats were used in the experiment: 10 animals underwent a sham testis repositioning operation (SHO) and 30 rats were orchidectomized (ORX). After the convalescence period, the SHO and ORX1 rats were given physiological saline intragastrically for 8 weeks; simultaneously, the other rats received camelina oil at the dose of 5 g/kg/b.w. (ORX2) or 9 g/kg/b.w. (ORX3) once a day. At the end of experiment, the animals were euthanized and fragments of the aorta were sampled for elasticity measurement and for histomorphometric and immunohistochemistry analysis. Orchidectomy caused a significant increase in the thickness of the total wall and its particular layers, mean intensity of elastin fluorescence in the tunica intima-media, and the volume of collagen I in tunica adventitia of the abdominal aorta in comparison to the other groups. The mean intensity of collagen I fluorescence in the tunica adventitia and tunica intima-media was significantly lower in the aorta of the orchidectomized rats. The values of the histomorphometric parameters of animals receiving camelina oil were lower than in the ORX1 group and higher than in the SHO rats. The values of the other parameters analyzed after the camelina oil treatment were similar to those in the SHO rats. In conclusion, our study showed that orchidectomy induced changes in the abdominal aorta wall characteristic for aging. Supplementation with camelina oil prevents negative consequences in the vessel wall structure in males with impaired endocrine function.