Exosomal lncRNA NEAT1 Inhibits NK-Cell Activity to Promote Multiple Myeloma Cell Immune Escape via an EZH2/PBX1 Axis.

Exosomal long noncoding RNAs (lncRNA) derived from cancer cells are implicated in various processes, including cancer cell proliferation, metastasis, and immunomodulation. We investigated the role and underlying mechanism of exosome-transmitted lncRNA NEAT1 in the immune escape of multiple myeloma cells from natural killer (NK) cells. Multiple myeloma cells and samples from patients with multiple myeloma were obtained. The effects of multiple myeloma cell-derived exosomes (multiple myeloma exosomes) and exosomal NEAT1 on the functions of NK cells were evaluated using EdU staining, CCK-8, flow cytometry, and ELISA. Chromatin and RNA immunoprecipitation were performed to identify interactions between NEAT1, enhancer of Zeste Homolog 2 (EZH2), and pre-B-cell leukemia transcription factor 1 (PBX1). A xenograft tumor model was constructed to verify the effects of exosomal NEAT1 on tumor growth. qRT-PCR, Western blot analysis, and IHC were conducted to detect related genes. NEAT1 levels were upregulated in multiple myeloma tumor tissues, multiple myeloma cells, and multiple myeloma exosomes. Multiple myeloma exosomes suppressed cell proliferation, promoted apoptosis, reduced natural killer group 2, member D (NKG2D)-positive cells, and the production of TNFα) and interferon-gamma (IFN-γ) in NK cells, whereas NEAT1-silenced exosomes had little effect. NEAT1 silenced PBX1 by recruiting EZH2. PBX1 knockdown abrogated the effects of NEAT1-silenced exosomes on NK and multiple myeloma cells. NEAT1-silenced exosomes inhibited tumor growth in mice, decreased Ki67 and PD-L1, and increased NKG2D, TNFα, and IFNγ in tumor tissues. In summary, multiple myeloma cell-derived exosomal NEAT1 suppressed NK-cell activity by downregulating PBX1, promoting multiple myeloma cell immune escape. This study suggests a potential strategy for treating multiple myeloma. IMPLICATIONS: This study reveals that exosomal NEAT1 regulates EZH2/PBX1 axis to inhibit NK-cell activity, thereby promoting multiple myeloma cell immune escape, which offers a novel therapeutic potential for multiple myeloma.

[Effects of Short-term Exogenous Nitrogen and Carbon Input on Soil Respiration Under Changing Precipitation Pattern].

The responses of soil respiration to exogenous carbon (C) and nitrogen (N) inputs under changing precipitation patterns were explored via in-situ field experiments. In 2014, a typical temperate grassland on the Xilin River of Inner Mongolia was taken as the research site, and soil respiration was measured in the following treatments:addition of water alone (CK), addition of water + N fertilizer[CN, 2.5 g·(m2·a)-1], addition of water + labile C[CG, 24 g·(m2·a)-1], and addition of water + N fertilizer+ labile C[CNG, 2.5 g·(m2·a)-1+24 g·(m2·a) -1], and the correlations of soil respiration with soil temperature, soil moisture, soil dissolved organic C (DOC), and soil microbial biomass C (MBC) were analyzed. During the first water application event (FWE) with the frequency of natural precipitation, cumulative CO2 efflux over 168 hours significantly increased in the CG and CNG treatments, whereas there was no such change in the CN treatment. In addition, soil MBC contents in the CG and CNG treatments were significantly higher than that in the CK and CN treatments, and the correlation of average soil respiration rate with soil MBC content among these treatments was positively significant (P<0.05). In contrast with during the FWE, cumulative CO2 efflux over 168 hours and soil MBC content significantly decreased during the second water application event (SWE) with no natural precipitation (P<0.05), whereas soil DOC content significantly increased (P<0.05). The cumulative CO2 efflux over 168 hours significantly decreases in the CN and CG treatments (P<0.05).During both the water application events, soil respiration rate had a positive relationship with soil temperature and soil volume water content (P<0.05). Therefore, it is proposed that the distribution of natural precipitation influences soil water content, which controls the effects of exogenous C and N on soil respiration in semiarid grassland ecosystems.

[Effect of Irrigation Patterns on Soil CO2 and N2O Emissions from Winter Wheat Field in North China Plain].

The water-saving irrigation is the trend of modernized agriculture. This paper aimed to study the effect of water-saving irrigation on soil CO2 and N2O emissions. The field experiments were conducted under micro sprinkler irrigation of integrated water and fertilizer (MSI) and conventional flooding irrigation (FI) in winter wheat growth season in the west of North China Plain during 2013- 2014 using the static chamber method. This paper analyzed the seasonal variation of soil CO2and N2O emissions under MSI and FI, and then compared the soil CO2 and N2O emissions from treatments located in different vertical distance away from micro sprinkler pipe. Root exclusion was used to estimate the components of soil respiration and agricultural carbon sequestration intensity under MSI and FI in winter wheat field. The results indicated that: (1) The average soil CO2 emissions under MSI and FI were 418.19 mg (m² · h)⁻¹ and 372.14 mg · (m² · h)⁻¹ respectively with no significant difference, and cumulative CO2 emissions under MSI and FI were 2 150.6 g · m⁻² and 1 904.6 g · m⁻², respectively. (2) During returning green stage to harvest stage of winter wheat, the highest soil CO2 cumulative emissions were found at the closest site to the micro sprinkler irrigated pipes under MSI. However, there were no significant differences among spatial treatments. (3) Under MSI and FI, soil heterotrophic respiration (C) was 468.49 g · m⁻² and 427.31 g · m⁻², and the net primary productivity (3) was 1988.21 g · m⁻² and 1770.54 g · m⁻²; the carbon sink (C) during winter wheat growing season was 1 519.72 g · m⁻² and 1 343.24 g · m⁻², respectively. (4) The average N2O emissions under MSI and FI were 50.77 µg · (m² · h)⁻¹ and 28.81 µg · (m² · h)⁻¹ respectively with no significant difference. Cumulative N2O emission under MSI and FI was 272.67 mg · m⁻² and 154.08 mg · m⁻², respectively. (5) During returning green stage to harvest stage of winter wheat, the farther the distance away from the micro sprinkler irrigated pipes, the smaller the soil N2O emissions. Moreover, there were no significant differences among sptial treatment under MSI. Therefore, despite of the increase of soil CO2and N2O emissions, the intensity of carbon sink increased during the transformation from traditional flood irrigation to micro sprinkler irrigation in winter wheat fields.

MicroRNA-140-3p inhibits proliferation, migration and invasion of lung cancer cells by targeting ATP6AP2.

MicroRNAs are small noncoding RNA molecules that regulate gene expression at the post-transcriptional level. Compelling evidence reveals that there is a causative link between microRNAs deregulation and lung cancer development and metastasis. The aim of present study was to explore the function of miR-140-3p in the development and metastasis of lung cancer cell. Using real-time PCR, we detected the miR-140-3p expression of lung cancer tissues and its pared non-lung cancer tissue. Then, we evaluated the role of miR-140-3p in cell proliferation, invasion and migration using MTT, colony formation assay, Transwell invasion and Transwell migration assay in lung cancer cell lines. As a result, miR-140-3p expression level was lower in lung cancer tissues compared to adjacent normal lung cancer tissue. After miR-140-3p was upregulated in A549 or H1299 cells, cell proliferation, invasion and migration was notably attenuated. Furthermore, we identified ATP6AP2, which is associated with adenosine triphosphatases (ATPases), was a directly target of miR-140-3p in lung cancer cells. In conclusion, our data suggest miR-140-3p/ATP6AP2 axis might act as a potential therapeutic biomarker for lung cancer.

[Effects and mechanism of freeze-thawing cycles on key processes of nitrogen cycle in terrestrial ecosystem].

As a widespread natural phenomenon in the soil of middle and high latitude as well as high altitude, freeze-thawing cycles have a great influence on the nitrogen cycle of terrestrial ecosystem in non-growing season. Freeze-thawing cycles can alter the physicochemical and biological properties of the soil, which thereby affect the migration and transformation of soil nitrogen. The impacts of freeze-thawing cycles on key processes of nitrogen cycle in terrestrial ecosystem found in available studies remain inconsistent, the mechanism is still not clear, and the research methods also need to be further explored and innovated. So it is necessary to sum up and analyze the existing achievements in order to better understand the processes of soil nitrogen cycle subjected to freeze-thawing cycles. This paper reviewed the research progress in China and abroad about the effects and mechanisms of freeze-thawing cycles on key processes of nitrogen cycle in terrestrial ecosystem, including mineralization, immobilization, nitrification and denitrification, N leakage and gaseous loss, and analyzed the deficiencies of extant research. The possible key research topics that should be urgently paid more attention to in the future were also discussed.

[Microbial response mechanism for drying and rewetting effect on soil respiration in grassland ecosystem: a review].

As one of the most important and wide distribution community type among terrestrial ecosystems, grassland ecosystem plays a critical role in the global carbon cycles and climate regulation. China has extremely rich grassland resources, which have a huge carbon sequestration potential and are an important part of the global carbon cycle. Drying and rewetting is a common natural phenomenon in soil, which might accelerate soil carbon mineralization process, increase soil respiration and exert profound influence on microbial activity and community structure. Under the background of the global change, the changes in rainfall capacity, strength and frequency would inevitably affect soil drying and wetting cycles, and thus change the microbial activity and community structure as well as soil respiration, and then exert important influence on global carbon budget. In this paper, related references in recent ten years were reviewed. The source of soil released, the trend of soil respiration over time and the relationship between soil respiration and microbial biomass, microbial activity and microbial community structure during the processes of dry-rewetting cycle were analyzed and summarized, in order to better understand the microbial response mechanism for drying and rewetting effecting on soil respiration in grassland ecosystem, and provide a certain theoretical basis for more accurate evaluation and prediction of future global carbon balance of terrestrial ecosystems and climate change.

Adeno-associated virus vectors simultaneously encoding VEGF and angiopoietin-1 enhances neovascularization in ischemic rabbit hind-limbs.

AIM: Angiopoietin-1 (Ang1) and vascular endothelial growth factor A (VEGF) play important roles in vascular formation and maturation, suggesting a combination of these 2 would be a promising therapy for ischemic diseases. So we constructed an adeno-associated virus (AAV) vector, simultaneously encoding human VEGF(165) and Ang1 (AAV-VEGF/Ang1), and investigated its therapeutic effect in a rabbit ischemic hind-limb model. METHODS: Four experimental groups were used to prepare the rabbit ischemic hind-limb model following AAV vectors intramuscular administration as follows: PBS (phosphate buffered solution), AAV-VEGF, AAV-Ang1, AAV-VEGF/Ang1. RESULTS: Eight weeks after administration, human VEGF(165) and Ang1 were detected by RT-PCR, Western blotting and histochemical staining methods in AAV-VEGF/Ang1 transduced muscles. Group AAV-VEGF/Ang1 showed a significantly increased blood-flow recovery in ischemic hind-limbs compared with the other groups. Histological staining for alkaline phosphatase showed that capillary density of group AAV-VEGF/Ang1 or AAV-VEGF was significantly higher than that of group PBS or AAV-Ang1. Histological immunostaining for smooth muscle alpha-actin (alpha-SMA) revealed that group AAV-VEGF/Ang1 had the highest density of alpha-SMA-positive vessels compared with the other groups. Vascular leakage, one of the major adverse effects induced by VEGF, was very severe in group AAV-VEGF, but the permeability was obviously reduced when VEGF was co-expressed with Ang1 in group AAV-VEGF/Ang1. CONCLUSION: AAV vectors can simultaneously encode 2 proteins which can be efficiently and stably co-expressed in transduced tissues. AAV-mediated VEGF and Ang1 gene transfer enhances neovascularization, prevents capillary leakage, and improves blood flow in a rabbit hind-limb ischemic model. These findings suggest that intramuscular administration of AAV-VEGF/Ang1 may be useful in the treatment of ischemic diseases.

The relation between HLA-DQA1 genes and genetic susceptibility to duodenal ulcer in Wuhan Hans.

AIM:To study the genetic susceptibility of HLA-DQA1 alleles to duodenal ulcer in Wuhan Hans.METHODS:Seventy patients with duodenal ulcer and fifty healthy controls were examined for HLA-DQA1 genotypes.HLA-DQA1 typing was carried out by digesting the locus specific polymerase chain reaction amplified products with alleles specific restriction enzymes (PCR-RFLP), i.e.,Apal I, Bsaj- I, Hph I, Fok I, Mbo II and Mnl I.RESULTS:The allele frequencies of DQA10301 and DQA1-0102 in patients with duodenal ulcer were significantly higher and lower respectively than those in healthy controls (0.40 vs 0.20, P = 0.003, P(corret) = 0.024) and (0.05 vs 0.14, P = 0.012, but P(corret) > 0.05), respectively.CONCLUSION: DQA1(*)0301 is a susceptible gene for duodenal ulcer in Wuhan Hans, and there are immunogenetic differences in HLA-DQA1 locus between duodenal ulcer patients and healthy controls.