[Expression and significance of NF-κB and MIF in lung tissue of silicon-stained rats].

OBJECTIVE: To investigate the distribution and expression of nuclear transcription factor(NF-κB) and macrophage migration inhibitory factor(MIF) in the lung tissue of rats exposed to silica. METHODS: Atotal of sixty-four adult rats aged 10 to 12 weeks(cleaning grade) were randomly divided into control group and silica dust group(32 rats each). At day 3, 7, 14, and 28 after modeling, 8 rats were randomly sacrificed in each group. Immunohistochemistry was used to detect the distribution and expression of NF-B and MIF in lung tissue. RESULTS: The positive result of NF-κB p65 were localized in the nucleus and cytoplasm, and were mainly expressed in bronchial wall epithelial cells, macrophages, neutrophils, lung mesenchymal cells, and alveolar epithelial cells. The IOD value of NF-κB p65 in the dust-exposed group was compared with the control group at each time point, and the difference was statistically significant(P<0. 05). The result of MIF immunohistochemistry in rat lung tissue showed that: MIF-positive cells were mainly alveolar epithelial cells, mesenchymal macrophages and alveolar macrophages. Among them, positive expression was also found in part of the capillary endothelium, and in smooth muscle cells of the vessel wall There is also a small amount of expression. The MIF IOD value of the dust-exposed group was compared with the control group at each time point, and the difference was statistically significant(P<0. 05). CONCLUSION: Both NF-κB and MIF are positively expressed in the lung tissue of silica-exposed rats, which has certain reference significance in the early diagnosis and treatment of silicosis in the future.

N-glycosylation of SnRK2s affects NADPH maintenance in peroxisomes during prolonged ABA signalling.

Unfavourable conditions, such as prolonged drought and high salinity, pose a threat to the survival and agricultural yield of plants. The phytohormone ABA plays a key role in the regulation of plant stress adaptation and is often maintained at high levels for extended periods. While much is known about ABA signal perception and activation in the early signalling stage, the molecular mechanism underlying desensitization of ABA signalling remains largely unknown. Here we demonstrate that in the endoplasmic reticulum (ER)-Golgi network, the key regulators of ABA signalling, SnRK2.2/2.3, undergo N-glycosylation, which promotes their redistribution from the nucleus to the peroxisomes in Arabidopsis roots and influences the transcriptional response in the nucleus during prolonged ABA signalling. On the peroxisomal membrane, SnRK2s can interact with glucose-6-phosphate (G6P)/phosphate translocator 1 (GPT1) to maintain NADPH homeostasis through increased activity of the peroxisomal oxidative pentose phosphate pathway (OPPP). The resulting maintenance of NADPH is essential for the modulation of hydrogen peroxide (H2O2) accumulation, thereby relieving ABA-induced root growth inhibition. The subcellular dynamics of SnRK2s, mediated by N-glycosylation suggest that ABA responses transition from transcriptional regulation in the nucleus to metabolic processes in the peroxisomes, aiding plants in adapting to long-term environmental stress.