Two-photon microscopy imaging of oxidative stress in human living erythrocytes

The Effect of Low-Energy Laser-Driven Ultrashort Pulsed Electron Beam Irradiation on Erythropoiesis and Oxidative Stress in Rats

Anemia is a commonly observed consequence of whole-body exposure to a dose of X-ray or gamma irradiation of the order of the mean lethal dose in mammals, and it is an important factor for the determination of the survival of animals. The aim of this study was to unravel the effect of laser-driven ultrashort pulsed electron beam (UPEB) irradiation on the process of erythropoiesis and the redox state in the organism. Wistar rats were exposed to laser-driven UPEB irradiation, after which the level of oxidative stress and the activities of different antioxidant enzymes, as well as blood smears, bone marrow imprints and sections, erythroblastic islets, hemoglobin and hematocrit, hepatic iron, DNA, and erythropoietin levels, were assessed on the 1st, 3rd, 7th, 14th, and 28th days after irradiation. Despite the fact that laser-driven UPEB irradiation requires quite low doses and repetition rates to achieve the LD₅₀ in rats, our findings suggest that whole-body exposure with this new type of irradiation causes relatively mild anemia in rats, with subsequent fast recovery up to the 28th day. Moreover, this novel type of irradiation causes highly intense processes of oxidative stress, which, despite being relatively extinguished, did not reach the physiologically stable level even at the 28th day after irradiation due to the violations in the antioxidant system of the organism.

The role of women scientists in the development of ultrashort pulsed laser technology-based biomedical research in Armenia

PURPOSE

To describe the contribution of women scientists in the development of biomedical studies conducted on research facilities based on the ultrashort pulsed laser technologies in Armenia.

CONCLUSION

Given the opportunities provided by the ultrashort pulsed laser driven two-photon microscopy and electron beam linac facilities at CANDLE Synchrotron Research Institute, the Armenian women scientists initiated and conducted interdisciplinary research to understand of the biomedical effects of ultrashort pulsed electron beam irradiation, as well as to experience and apply the advantages of the two-photon microscopy in their fields of research. Women scientists had a crucial role and unique impact in the development of ultrashort pulsed laser technology-based biomedical studies in Armenia.

Helix pomatia albumen gland water soluble protein extract as powerful antiaging agent

Accounting for increasingly developed population aging and dramatic elevation of aging-related severe disorders worldwide, search of the efficient antiaging agents is becoming one of the urgent problems of contemporary biomedical science. The aim of current study was to reveal the potential protective effects of water-soluble proteins extracted from albumen gland of snails against aging processes. We evaluated the antioxidant effect of the extract in 20 older adult rats in vivo and on 60 human blood samples ex vivo at the cellular level under physiological and oxidative stress conditions using the methods of spectrophotometric analysis, two-photon imaging and cell viability assay. The in vivo animal experiments showed significant increase in the levels of catalase and superoxide dismutase in treated older adult rats, compared to non-treated group. The ex vivo studies involving three human groups (young, middle aged and older adult), demonstrated that the extract has no effect on the cell viability, moreover significantly increases the number of erythrocytes, decreases age-related oxidative stress and the percentage of hemolysis of erythrocytes by aging. Thus, the snails albumen gland protein extract can be considered as effective natural antioxidative antiaging agent in prevention of aging-related pathological processes associated with oxidative stress.

Advances in Imaging Reactive Oxygen Species

Reactive oxygen species (ROS) play a pivotal role in many cellular processes and can be either beneficial or harmful. The design of ROS-sensitive fluorophores has allowed for imaging of specific activity and has helped elucidate mechanisms of action for ROS. Understanding the oxidative role of ROS in the many roles it plays allows us to understand the human body. This review provides a concise overview of modern advances in the field of ROS imaging. Indeed, much has been learned about the role of ROS throughout the years; however, it has recently been shown that using nanoparticles, rather than individual small organic fluorophores, for ROS imaging can further our understanding of ROS.

Identification of potential oxidative stress biomarkers for spinal cord injury in erythrocytes using mass spectrometry

Oxidative stress is a hallmark of secondary injury associated with spinal cord injury. Identifying stable and specific oxidative biomarkers is of important significance for studying spinal cord injury-associated secondary injury. Mature erythrocytes do not contain nuclei and mitochondria and cannot be transcribed and translated. Therefore, mature erythrocytes are highly sensitive to oxidative stress and may become a valuable biomarker. In the present study, we revealed the proteome dynamics of protein expression in erythrocytes of beagle dogs in the acute and subacute phases of spinal cord injury using mass spectrometry-based approaches. We found 26 proteins that were differentially expressed in the acute (0-3 days) and subacute (7-21 days) phases of spinal cord injury. Bioinformatics analysis revealed that these differentially expressed proteins were involved in glutathione metabolism, lipid metabolism, and pentose phosphate and other oxidative stress pathways. Western blot assays validated the differential expression of glutathione synthetase, transaldolase, and myeloperoxidase. This result was consistent with mass spectrometry results, suggesting that erythrocytes can be used as a novel sample source of biological markers of oxidative stress in spinal cord injury. Glutathione synthetase, transaldolase, and myeloperoxidase sourced from erythrocytes are potential biomarkers of oxidative stress after spinal cord injury. This study was approved by the Experimental Animal Centre of Ningxia Medical University, China (approval No. 2017-073) on February 13, 2017.

Two-photon imaging of oxidative stress in living erythrocytes as a measure for human aging

According to the "oxidative stress theory" of aging, this process is accompanied by a progressive and irreversible accumulation of oxidative damage caused by reactive oxygen species (ROS). This, in turn, has a deleterious impact on molecular mechanisms in aging thereby altering the physiological function of the organism, increasing the risk of different aging-related diseases, as well as impacting the life span. The aim of the current study was to investigate oxidative stress in living red blood cells (RBCs) in human aging as an oxidative stress-related pathological condition. Two-photon laser scanning and light microscopy techniques were applied to analyze the oxidative stress in RBCs and the cell viability. Spectrophotometric analyzes were performed to determine the percentage of RBC hemolysis, activities of superoxide dismutase and catalase in RBCs, as well as the ferroxidase activities of ceruloplasmin in blood plasma samples. The studies included three human aging groups, young, middle-aged, and elderly. According to the results, the two-photon fluorescence of carboxy-DCFDA, indicating the intensity of oxidative stress, significantly increase in RBCs by the increase of age (P < 0.05), and these intensities are in statistically significant positive correlation with age (P < 0.001) and a strong negative correlation (P < 0.05) with the activity of catalase in RBCs and ferroxidase activity of ceruloplasmin in plasma. In conclusion, two-photon fluorescent imaging of oxidative stress in human living RBCs is a valuable and accurate method for the determination of aging processes in humans and can be suggested as a novel indicator for human aging processes in individual aging.

Oxidative status of erythrocytes, hyperglycemia, and hyperlipidemia in diabetic cats

Background

Erythrocytes of diabetic cats have decreased superoxide dismutase activity, possibly indicative of oxidative stress.

Hypothesis

Erythrocytes of diabetic cats undergo oxidative stress, which is caused by hyperglycemia and hyperlipidemia, and improves with treatment.

Animals

Twenty‐seven client‐owned cats with diabetes mellitus, 11 matched healthy cats, and 21 purpose‐bred healthy cats.

Methods

Prospective study. Advanced oxidized protein products, carbonyls (protein oxidation by‐products), and thiols (antioxidants) were quantified in erythrocyte membrane, thiobarbituric acid reactive substances (TBAR, lipid peroxidation by‐products), and thiols in erythrocyte cytoplasm of all cats. Comparison were performed between diabetic and matched healthy cats, between diabetic cats achieving remission or not, and among purpose‐bred cats after 10 days of hyperglycemia (n = 5) or hyperlipidemia (n = 6) versus controls treated with saline (n = 5) or untreated (n = 5).

Results

Compared with controls, erythrocytes of diabetic cats initially had higher median membrane carbonyls (4.6 nmol/mg total protein [range: 0.1‐37.7] versus 0.7 [0.1‐4.7], P < .001) and lower cytoplasmic TBAR (1.9 nmol/mg [0.5‐2.4] versus 2.4 [1.4‐3.5] P < .001), and thiols (419 nmol/mg [165‐621] versus 633 [353‐824], P < 0.001). After 12‐16 weeks of treatment in diabetic cats, carbonyls decreased by 13% (P < .001), but remained higher (P < .001) and TBAR and thiols lower (P = .02, P < .001) than those in controls. No differences were observed between diabetic cats achieving remission or not, and among purpose‐bred cats.

Conclusions and Clinical Importance

Diabetes mellitus is associated with increased protein oxidation and reduced antioxidant defenses, which persist during treatment and remission, although mild improvement in protein oxidation occurs. Short‐term hyperglycemia or hyperlipidemia does not cause oxidative stress. The reason for decreased TBAR remains unknown.