Overexpression of hUMP1/POMP proteasome accessory protein enhances proteasome-mediated antioxidant defence

SAM and HD domain-containing protein 1 (SAMHD1) is a host factor that restricts reverse transcription of lentiviruses such as HIV in myeloid cells and resting T cells through its dNTP triphosphohydrolase (dNTPase) activity. Lentiviruses counteract this restriction by expressing the accessory protein Vpx or Vpr, which targets SAMHD1 for proteasomal degradation. SAMHD1 is conserved among mammals, and the feline and bovine SAMHD1 proteins (fSAM and bSAM) restrict lentiviruses by reducing cellular dNTP concentrations. However, the functional regions of fSAM and bSAM that are required for their biological functions are not well-characterized. Here, to establish alternative models to investigate SAMHD1 in vivo, we studied the restriction profile of fSAM and bSAM against different primate lentiviruses. We found that both fSAM and bSAM strongly restrict primate lentiviruses and that Vpx induces the proteasomal degradation of both fSAM and bSAM. Further investigation identified one and five amino acid sites in the C-terminal domain (CTD) of fSAM and bSAM, respectively, that are required for Vpx-mediated degradation. We also found that the CTD of bSAM is directly involved in mediating bSAM's antiviral activity by regulating dNTPase activity, whereas the CTD of fSAM is not. Our results suggest that the CTDs of fSAM and bSAM have important roles in their antiviral functions. These findings advance our understanding of the mechanism of fSAM- and bSAM-mediated viral restriction and might inform strategies for improving HIV animal models.

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Treatment with ascorbic acid normalizes the aerobic capacity, antioxidant defence, and cell death pathways on thermally stressed Mytilus galloprovincialis

Comparative Biochemistry and Physiology Part B Biochemistry and Molecular Biology ◽

10.1016/j.cbpb.2021.110611 ◽

2021 ◽

pp. 110611

Author(s):

Konstantinos Feidantsis ◽

Ioannis Georgoulis ◽

Ioannis A. Giantsis ◽

Basile Michaelidis

Keyword(s):

Cell Death ◽

Ascorbic Acid ◽

Aerobic Capacity ◽

Mytilus Galloprovincialis ◽

Antioxidant Defence ◽

Cell Death Pathways ◽

Thermally Stressed

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The Effect of Repeated Whole-Body Cryotherapy on Sirt1 and Sirt3 Concentrations and Oxidative Status in Older and Young Men Performing Different Levels of Physical Activity

Antioxidants ◽

10.3390/antiox10010037 ◽

2020 ◽

Vol 10 (1) ◽

pp. 37

Author(s):

Gabriela Wojciak ◽

Jadwiga Szymura ◽

Zbigniew Szygula ◽

Joanna Gradek ◽

Magdalena Wiecek

Keyword(s):

Physical Activity ◽

Young Men ◽

Oxidative Status ◽

Whole Body ◽

Stress Index ◽

Blood Levels ◽

Long Distance ◽

Antioxidant Defence ◽

Whole Body Cryotherapy ◽

The Impact

Background: The activity of antioxidant enzymes and sirtuins (Sirt) decreases along with age, which is counteracted by aerobic training. Sirtuins increase antioxidant defence. Whole-body cryotherapy (WBC) increases total antioxidant capacity (TAC) in young men. The aim of our study was to assess the impact of 24 WBC treatments on the blood concentration of selected sirtuins and the level of antioxidant defence as well as oxidative stress index of training and non-training men depending on age. Methods: The study involved 40 males. In each group, there were 10 non-training older and young men (60 NTR and 20 NTR), and 10 older and young long-distance runners (60 TR, 20 TR). During an 8-week period, participants underwent 24 WBC treatments (3 min −130 °C), which were performed three times a week (Monday, Wednesday, Friday). The concentrations of Sirt1, Sirt3, TAC, total oxidative status and the activity of superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) in the blood were determined before 1 WBC and after 1 WBC, 12 WBC and 24 WBC. Results: After 1 WBC, the activity of GPx and the concentration of Sirt1 and TAC in 60 TR and TAC in 60 NTR increased. After 12 WBC, the level of Sirt1 in 20 NTR and SOD in 20 TR increased. After 24 WBC, the level of Sirt1 increased in 60 TR and in 20 NTR, Sirt3 in 60 TR and SOD in 20 TR. Conclusions: Cryogenic temperatures increase blood levels of Sirt1 and Sirt3 and systemic antioxidant defence in men, but the effect is dependent on age, level of performed physical activity and the number of applied treatments.

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