There is accumulating evidence that mitochondria and mitochondrial STAT3 are involved in the activation of mast cells. The mitochondria-targeted curcuminoids Mitocur-1 and Mitocur-3 have been suggested to reduce antigen-dependent mast cell activation by inhibiting mitochondrial STAT3. The aim of the current work was to investigate the mechanisms of action of these mitocurcuminoids on mast cells and mitochondrial functions. The pretreatment of rat basophilic leukemia cells RBL-2H3 with Mitocur-1 and Mitocur-3 decreased antigen-dependent degranulation but did not affect spontaneous degranulation. Both compounds caused mitochondrial fragmentation and increased mitochondrial ROS. Inhibition of Drp1 prevented mitochondrial fragmentation induced by Mitocur-3 but not by Mitocur-1. The antioxidant N-acetylcysteine inhibited mitochondrial fission induced by Mitocur-1 but not Mitocur-3. Mitochondrial fragmentation caused by Mitocur-3 but not Mitocur-1 was accompanied by activation of Drp1 and AMPK. These data suggest a distinct mechanism of action of mitocurcuminoids on the mitochondria of RBL-2H3 cells: Mitocur-3 stimulated AMPK and caused Drp1-dependent mitochondrial fragmentation, while Mitocur-1-induced mitochondrial fission was ROS-dependent. This difference may contribute to the higher toxicity of Mitocur-3 compared to Mitocur-1. The findings contribute to further drug development for inflammatory and allergic diseases.

Potato virus Y, an important viral pathogen of potato, has several genetic variants and geographic distributions which could be affected by environmental factors, aphid vectors, and reservoir plants. PVY is transmitted to virus-free potato plants by aphids and passed on to the next vegetative generations through tubers, but the effects of tuber transmission in PVY is largely unknown. By using high-throughput sequencing, we investigated PVY populations transmitted to potato plants by aphids in different climate zones of Russia, namely the Moscow and Astrakhan regions. We analyzed sprouts from the tubers produced by field-infected plants to investigate the impact of tuber transmission on PVY genetics. We found a significantly higher diversity of PVY isolates in the Astrakhan region, where winters are shorter and milder and summers are warmer compared to the Moscow region. While five PVY types, NTNa, NTNb, N:O, N-Wi, and SYR-I, were present in both regions, SYRI-II, SYRI-III, and 261-4 were only found in the Astrakhan region. All these recombinants were composed of the genome sections derived from PVY types O and N, but no full-length sequences of such types were present. The composition of the PVY variants in the tuber sprouts was not always the same as in their parental plants, suggesting that tuber transmission impacts PVY genetics.

Potato virus Y (PVY; genus Potyvirus, family Potyviridae) is one of the most devastating and economically important potato pathogens. Members of the Potyviridae family demonstrate high recombination rates. In nature, five major parental variants of PVY were identified with at least 35 recombinants. In this study, we report two novel PVY recombinants discovered in the sprouts of potato tubers produced in field conditions in the Astrakhan region of Russia in 2021 using high-throughput sequencing and de novo genome assembly. These recombinants, which were named Ast-A-I and Ast-A-II, have previously unknown arrangements of genome sections derived from PVY^O and PVY^N, with a novel recombination junction at position 7,850 nt of the PVY genome in the middle part of the RNA-dependent RNA polymerase (NIb) gene, with PVY^O type sequence at the 5′ end relative to this junction and PVY^N type at the 3′ end. Other recombinant junctions in the novel PVY variants were previously found in PVY^NTNa and PVY^NTNb. This includes those at positions 2,390 and 9,200 (PVY^N at the 5′ end and PVYIS° at the 3′ end), which were present in both novel recombinants, and at position 500 (PVY^O at the 5′ end and PVY^N at the 3′ end), which present in Ast-A-II. The presence of PVY variants with a novel recombinant point is verified by Sanger sequencing. Phylogenetic analysis of genomic RNA showed that the sequences of these recombinants form a separate branch that do not cluster with previously described PVY strains.