ABSTRACT
Relevant research data shows that there is a certain degree of energy metabolism imbalance in highland residents. Protein phosphatase 4 (PP4) has been found as a new factor in the regulation of sugar and lipid metabolism. Here, we investigate the differential expression of PP4 at a simulated altitude of 4,500 m in the heart, lung, and brain tissues of rats. A hypoxic plateau rat model was established using an animal decompression chamber. A blood routine test was performed by an animal blood cell analyzer on rats cultured for different hypoxia periods at 4,500 m above sea level. Quantitative polymerase chain reaction (qPCR) and western blot were used to detect the changes of protein phosphatase 4 catalytic subunit (PP4C) gene and protein in heart, lung, and brain tissues. The PP4C gene with the highest expression level found in rats slowly entering the high altitude area (20 m-2200 m-7 d-4500 m-3 d) was about twice as high as the low elevation group (20 m above sea level). The simulated high-altitude hypoxia induced an increase of PP4C expression level in all tissues, and the expression in the lung tissue was twice as expressed as heart and brain tissue at high altitude (P < 0.05). These results suggest that the PP4 phosphatase complex is ubiquitously expressed in rat tissues and likely involved in adaptation to or disease associated with high-altitude hypoxia.
ABSTRACT
Aims: In order to understand the role of allelopathy in invasion success, effects of root exudates from Solanum rostratum Dunal on germination and primary growth of wheat and cabbage seeds were studied by vitro bioassay. These results indicated the allelopathy of root exudates and would be helpful for understanding Solanum rostratum Dunal invasion. Study Design: The roots were washed clean for three times with distilled water before they were gathered in a big bucket. The container was filled with distilled water, enough to submerge the roots, and air was aerated constantly with an air pump. The water extract was collected per 24 hs and for four times totally. The water extract from Solanum rostratum was concentrated with a rotary evaporator at 40°C and deposited in a refrigerator at 4°C. All the root exudates were pooled around 1500 mL, and the fresh weight of Solanum rostratum used for exudates collection was 1208 g, the exudate concentration was then marked as 0.8g f w/mL. Place and Duration of Study: Solanum rostratum was grown in the greenhouse on April 15th, 2019, its seeds were collected from the invaded fields in Chaoyang city (Liaoning province, China). Methodology: Petri dish bioassay was applied to test the effects of root exudates of Solanum rostratum on the seeds of wheat and Chinese cabbage. For test of allelochemicals exudated through the root, The compounds in organic fraction of root exudates analysed by GC-MS. Results: These results indicated the allelopathy of root exudates and would be helpful for understanding Solanum rostratum Dunal invasion. Conclusion: Root exudates of Solanum rostratum contained some allelochemicals, which could inhibit the germination and radicle growth of wheat and Chinese cabbage, though the effects of root exudates on shoot growth are different, with a stimulation on Chinese cabbage while a inhibition on wheat. The difference indicated a selectivity of allelopathy effect of root exudates from Solanum rostratum Dunal.
ABSTRACT
Glycosylation of proteins is an essential process in all eukaryotes. Mucin‑type O‑linked glycosylation is an evolutionarily conserved protein modification as a kind of glycosylation of proteins. The role of O‑glycosylation was well documented in multiple cancers. While in breast cancer, the enzymes that catalyzed the initiation of O‑glycosylation remained elusive. In this review, we briefly introduced the process of the initiation of O‑glycosylation and summarized the roles of enzymes that catalyzed the initiation step of O‑glycosylation in the breast cancer carcinogenesis, development, and progression. Finally, we summarized some attempts exploring the therapy against aberrant O‑glycosylation.
ABSTRACT
As an essential trace element, copper can be toxic in mammalian cells when present in excess. Metallothioneins (MTs) are small, cysteine-rich proteins that avidly bind copper and thus play an important role in detoxification. Yeast CUP1 is a member of the MT gene family. The aim of this study was to determine whether yeast CUP1 could bind copper effectively and protect cells against copper stress. In this study, CUP1 expression was determined by quantitative real-time PCR, and copper content was detected by inductively coupled plasma mass spectrometry. Production of intracellular reactive oxygen species (ROS) was evaluated using the 2',7'-dichlorofluorescein-diacetate (DCFH-DA) assay. Cellular viability was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the cell cycle distribution of CUP1 was analyzed by fluorescence-activated cell sorting. The data indicated that overexpression of yeast CUP1 in HeLa cells played a protective role against copper-induced stress, leading to increased cellular viability (P<0.05) and decreased ROS production (P<0.05). It was also observed that overexpression of yeast CUP1 reduced the percentage of G1 cells and increased the percentage of S cells, which suggested that it contributed to cell viability. We found that overexpression of yeast CUP1 protected HeLa cells against copper stress. These results offer useful data to elucidate the mechanism of the MT gene on copper metabolism in mammalian cells.