MiR-101 promotes pain hypersensitivity in rats with chronic constriction injury via the MKP-1 mediated MAPK pathway.

This study was performed to characterize the effect of microRNA-101 (miR-101) on the pain hypersensitivity in CCI rat models with the involvement of mitogen-activated protein kinase phosphatase 1 (MKP-1) in spinal cord microglial cells. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) in the developed CCI models were determined to assess the hypersensitivity of rats to mechanical stimulation and thermal pain. To assess inflammation, the levels of interleukin (IL)-1ß, IL-6 and tumour necrosis factor-α (TNF-α) in the spinal dorsal horns of CCI rats and lipopolysaccharide (LPS)-activated microglial cells were examined. miR-101 and MKP-1 gain- and loss-of-function experiments were conducted in in vivo and in vitro settings to examine the roles of miR-101 and MKP-1 in CCI hypersensitivity and inflammation. The results showed that miR-101 was highly expressed in the spinal dorsal horn and microglial cells of CCI rat models. Furthermore, overexpression of miR-101 promoted the pain hypersensitivity in CCI rat models by reducing MWT and TWL. The overexpression of miR-101 also promoted inflammation in LPS-exposed microglial cells, as indicated by increased levels of IL-1ß, IL-6 and TNF-α. MiR-101 was shown to target MKP-1, inhibiting its expression. Moreover, miR-101 promoted pain hypersensitivity in CCI rat models by inhibiting MKP-1 expression and activating the mitogen-activated protein kinase (MAPK) signalling pathway. Taken together, miR-101 could potentially promote hypersensitivity and inflammatory response of microglial cells and aggravate neuropathic pain in CCI rat models by inhibiting MKP-1 in the MAPK signalling pathway.

MicroRNA-153-3p increases autophagy in sevoflurane-preconditioned mice to protect against ischaemic/reperfusion injury after knee arthroplasty.

The use of tourniquet during total knee arthroplasty (TKA) can result in ischaemia/reperfusion injury (IRI). Of interest, microRNAs (miRs) are reported to be involved in various kinds of IRI due to their ability in modulating autophagy. Therefore, the study aimed to investigate the effect of miR-153-3p on autophagy in IRI in vitro and in vivo under sevoflurane preconditioning. In the in vitro model, chondrocytes from naive mice were treated with 0% FBS alone or in combination with sevoflurane. Additionally, in vivo assays were conducted in mouse models with tourniquet-induced IRI after TKA under or without sevoflurane preconditioning. The pathological observation in vivo validated that sevoflurane preconditioning protected the knee joint against IRI. Moreover, miR-153-3p expression was diminished in chondrocytes of the in vitro model and in cartilage tissue of the in vivo model, but its expression was appreciably up-regulated in the presence of sevoflurane preconditioning. Mechanistic study showed that miR-153-3p disrupted the interaction between Bcl-2 and Beclin1 by targeting Bcl-2, thereby facilitating autophagy in chondrocytes under sevoflurane preconditioning. Furthermore, the experiments in human chondrocytes also verified the protective effects of miR-153-3p against IRI were realized through inhibiting Bcl-2. Collectively, miR-153-3p overexpression blocks the interaction between Bcl-2 and Beclin1 via down-regulation of Bcl-2 to promote autophagy of chondrocytes, thus protecting knee joint against IRI after TKA under sevoflurane preconditioning.

Down-regulation of microRNA-34c-5p alleviates neuropathic pain via the SIRT1/STAT3 signaling pathway in rat models of chronic constriction injury of sciatic nerve.

Neuropathic pain is an unfavorable pathological pain, often persistent over time, thus leading to significant impairment of quality of life and public health burden. Notably, microRNAs have been implicated in the pathophysiological process of neuropathic pain. The potential mechanism by which miR-34c-5p functions in neuropathic pain remains unclear. This study aimed to test the hypothesis that miR-34c-5p can modulate neuropathic pain in rat models with chronic constriction injury (CCI) of sciatic nerve, via interaction with the SIRT1/STAT3 signaling pathway SIRT1 was validated as a target gene of miR-34c-5p and could be negatively regulated by miR-34c-5p. We induced miR-34c-5p overexpression/inhibition, SIRT1 knockdown, and STAT3 knockdown in the model rats to assess pain behavior patterns. Meanwhile, dorsal root ganglion (DRG) was transduced with overexpression or knockdown of miR-34c-5p or lipopolysaccharide to induce the production of inflammatory factors. It was observed that miR-34c-5p was up-regulated, and SIRT1 was under-expressed in the DRG neurons of dorsal spinal cords of the CCI rats. Furthermore, the ectopic expression of miR-34c-5p and knockdown of SIRT1 in CCI rats resulted in increased hyperalgesia and inflammation, corresponding to reduced paw withdrawal threshold and paw withdrawal latency, and elevated levels of IL-6, IL-1ß, and TNF-α. More importantly, miR-34c-5p inhibition reduced the hyperalgesia and inflammation by blocking the STAT3 signaling pathway through up-regulation of SIRT1. Conjointly, our results indicated that the down-regulation of miR-34c-5p could potentially provide sustained relief in neuropathic pain by promoting SIRT1 expression through STAT3 signaling pathway inactivation.

Description of Azotobacter chroococcum subsp. isscasi subsp. nov. isolated from paddy soil and establishment of Azotobacter chroococcum subsp. chroococcum subsp. nov.

Three aerobic, asymbiotic, N2-fixing bacterial strains, designated P205T, P204 and P207, were isolated from a paddy soil in Yanting County, China. Based on 16S rRNA gene sequences, the three strains were closely related to Azotobacter chroococcum IAM 12666T (=ATCC 9043T) (99.00-99.79 % similarities). Strain P205T formed an individual branch distinct from the other two newly isolated strains and other related type strains in phylogenetic analyses based on 16S rRNA gene and 92 core genes. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values based on genome sequences of strain P205T and A. chroococcum ATCC 9043T, P204, P207 were near or slightly higher than the thresholds for species circumscription (95-96, 95-96 and 70 %, respectively), and the dDDH values were significantly lower than the threshold for delineating subspecies (79-80 %), which strongly supported that strain P205T belonged to A. chroococcum but was a novel subspecies distinct from the type strain of A. chroococcum. This finding was further corroborated by distinct phenotypic characteristics such as growth in Luria-Bertani (LB) medium, carbon source utilization and chemical sensitivity to vancomycin. Therefore, strain P205T represents a novel subspecies of Azotobacter chroococcum, for which the name Azotobacter chroococcum subsp. isscasi subsp. nov. is proposed with the type strain P205T (=KCTC 72233T=CGMCC 1.16846T=CCTCC AB 2019080T). The subspecies Azotobacter chroococcum subsp. chroococcum subsp. nov. is created automatically with the type strain ATCC 9043T (=DSM 2286T=JCM 20725T=JCM 21503T=LMG 8756T=NBRC 102613T=NCAIM B.01391T=NRRL B-14346T=VKM B-1616T).

Biochar application as a tool to decrease soil nitrogen losses (NH3 volatilization, N2 O emissions, and N leaching) from croplands: Options and mitigation strength in a global perspective.

Biochar application to croplands has been proposed as a potential strategy to decrease losses of soil-reactive nitrogen (N) to the air and water. However, the extent and spatial variability of biochar function at the global level are still unclear. Using Random Forest regression modelling of machine learning based on data compiled from the literature, we mapped the impacts of different biochar types (derived from wood, straw, or manure), and their interactions with biochar application rates, soil properties, and environmental factors, on soil N losses (NH3 volatilization, N2 O emissions, and N leaching) and crop productivity. The results show that a suitable distribution of biochar across global croplands (i.e., one application of <40 t ha-1 wood biochar for poorly buffered soils, such as those characterized by soil pH<5, organic carbon<1%, or clay>30%; and one application of <80 t ha-1 wood biochar, <40 t ha-1 straw biochar, or <10 t ha-1 manure biochar for other soils) could achieve an increase in global crop yields by 222-766 Tg yr-1 (4%-16% increase), a mitigation of cropland N2 O emissions by 0.19-0.88 Tg N yr-1 (6%-30% decrease), a decline of cropland N leaching by 3.9-9.2 Tg N yr-1 (12%-29% decrease), but also a fluctuation of cropland NH3 volatilization by -1.9-4.7 Tg N yr-1 (-12%-31% change). The decreased sum of the three major reactive N losses amount to 1.7-9.4 Tg N yr-1 , which corresponds to 3%-14% of the global cropland total N loss. Biochar generally has a larger potential for decreasing soil N losses but with less benefits to crop production in temperate regions than in tropical regions.

A fast chemical oxidation method for predicting the long-term mineralization of biochar in soils.

Biochar stability determines the effectiveness of biochar's functions such as carbon sequestration, soil structure improvement, soil fertility enhancement and soil pollution remediation. However, a fast method for accurately predicting biochar long-term stability in soil remains elusive. Here, firstly, an incubation experiment was conducted on mineralization dynamics of different 13C-labelled biochars over 368 days to explore their actual mineralization in soils and establish their mineralization model. Thereafter, ten treatments of fast chemical oxidation methods using K2Cr2O7 (0.1 M) with different H+ concentrations and oxidation times were applied to the biochars to reveal which method best matches the mineralization of biochar in soils. Results showed that the percentage of biochar­carbon oxidized by the solution containing 0.1 M K2Cr2O7 and 0.2 M H+ at 100 °C for 2 h was in accordance with the one that potentially would be mineralized in soils at a 100-year scale (R2 > 0.99; REMS = 2.53; RD = 15.3). The results provided a chemical oxidation method that was robust, effective, low cost and highly available for measuring the long-term stability of biochar in soils.

Impacts of Mo application on biological nitrogen fixation and diazotrophic communities in a flooded rice-soil system.

Molybdenum (Mo) deficiency in the farmland of China may limit biological nitrogen fixation (BNF), however, the impact of Mo application on BNF capacities and diazotrophic communities in rice-soil systems is unclear. In this experiment, treatments in a 6.7 atom% 15N2-labelling field-based growth chamber for 74 days and treatments in a 99 atom% 15N2-labelling microcosm experiment for 40 days combined with 16S rRNA gene sequencing and DNA-stable isotope probing (SIP) were used to investigate the impacts of Mo application on BNF and diazotrophic communities. Our results showed that under the condition that no nitrogen (N) fertilizer was applied, Mo application (500 g sodium molybdate ha-1) significantly increased N2 fixation in a rice-Inceptisol system, from 22.3 to 53.1 kg N ha-1. Mo application significantly increased the number of nifH gene copies and the relative abundance of cyanobacteria in both growth chamber and microcosm experiments. Among cyanobacteria, the relative abundances of the most abundant genera Leptolyngbya and Microcoleus were significantly increased by Mo application. 15N2-DNA-SIP further demonstrated that Leptolyngbya and Microcoleus incorporated 15N2. Mo application greatly increased BNF in Mo-deficient paddy field (≤0.068 mg kg-1) and stimulated the growth of cyanobacteria. These results indicated that Mo application in Mo-deficient paddy field could be a useful measure to increase soil N input under no N fertilization.