Maize Autophagy-Related Protein ZmATG3 Confers Tolerance to Multiple Abiotic Stresses.

Abiotic stresses pose a major increasing problem for the cultivation of maize. Autophagy plays a vital role in recycling and re-utilizing nutrients and adapting to stress. However, the role of autophagy in the response to abiotic stress in maize has not yet been investigated. Here, ZmATG3, which is essential for ATG8-PE conjugation, was isolated from the maize inbred line B73. The ATG3 sequence was conserved, including the C-terminal domains with HPC and FLKF motifs and the catalytic domain in different species. The promoter of the ZmATG3 gene contained a number of elements involved in responses to environmental stresses or hormones. Heterologous expression of ZmATG3 in yeast promoted the growth of strain under salt, mannitol, and low-nitrogen stress. The expression of ZmATG3 could be altered by various types of abiotic stress (200 mM NaCl, 200 mM mannitol, low N) and exogenous hormones (500 µM ABA). GUS staining analysis of ZmATG3-GUS transgenic Arabidopsis revealed that GUS gene activity increased after abiotic treatment. ZmATG3-overexpressing Arabidopsis plants had higher osmotic and salinity stress tolerance than wild-type plants. Overexpression of ZmATG3 up-regulated the expression of other AtATGs (AtATG3, AtATG5, and AtATG8b) under NaCl, mannitol and LN stress. These findings demonstrate that overexpression of ZmATG3 can improve tolerance to multiple abiotic stresses.

Impacts of o-cresol spill on composition and function of river sediment and soil microbial communities.

o-Cresol is a toxic substance with strong irritating and corrosive effects on skin and mucous membranes. To date, information on the effects of o-cresol on microbial communities in the natural environment is very limited. In the present study, 16S rRNA sequencing and metagenomic technique were carried out to elucidate the effects of the o-cresol spill on microbial communities in river sediments and nearby soils. o-Cresol spill induced the increase in the relative abundance of phyla Planctomycetes and Gemmatimonadetes, suggesting their resilience to o-cresol-induced stress. Uncultured Gemmatimonadetes genera and the MND1 genus exhibited enrichment, while the Pseudomonas genus dominated across all samples, indicating their potential pivotal roles in adapting to the o-cresol spill. Moreover, o-cresol spill impaired the metabolic functions of microbes but triggered their defense mechanisms. Under o-cresol pressure, microbial functions related to carbon fixation were upregulated and functions associated with sulfur metabolism were downregulated. In addition, the o-cresol spill led to an increase in functional genes related to the conversion of o-cresol to 3-methylcatechol. Several genes involved in the degradation of aromatic compounds were also identified, potentially contributing to the biodegradation of o-cresol. This study provides fresh insights into the repercussions of an abrupt o-cresol spill on microbial communities in natural environments, shedding light on their adaptability, defense mechanisms, and biodegradation potential.

Effects of Early Risperidone Treatment on Metabolic Parameters in Socially Isolated Rats-Implication of Antipsychotic Intervention across Developmental Stages of Schizophrenia.

BACKGROUND: Second-generation antipsychotics (SGAs) is thought responsible for the metabolic abnormalities of schizophrenic patients, however, some untreated schizophrenic patients had already developed problems with glucose metabolism. The present study examined the hypothesis that schizophrenia itself but not risperidone, an extensively employed SGA, is accountable for metabolic abnormalities. METHODS: A 56-day risperidone regimen (1 mg/kg/day) was employed for rats of social isolation rearing (SIR) beginning at different developmental stage (28 or 56 days after weaning, i.e., adolescent and young adulthood, respectively). Metabolic parameters including body weight, systolic blood pressure (SBP), triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol, and plasma glucose were measured at baseline, 28, and 56 days of the regimen. Oral glucose tolerance test (OGTT) was performed at the end of the regimen. Insulin function was evaluated by area under the curve (AUC) of OGTT, homeostasis model assessment-insulin resistance (HOMA-ir), and Matsuda index. RESULTS: Our results demonstrated that: (i) SIR rats presented higher body weight, plasma triglyceride, and HOMA-ir than social controls. (ii) Higher insulin resistance was specifically presented in young adult rather than adolescent SIR rats. (iii) Adolescent drugged rats showed a lower level of LDL in day 28 of the regimen than young adult. Risperidone led to a lower LDL level in only young adult IR rats in day 56 than undrugged rats. (iv) SIR-induced dysregulation of insulin can be reversed by chronic risperidone treatment beginning at adolescence but not young adulthood. CONCLUSIONS: Our findings support the primary role of schizophrenia in metabolic abnormalities and risperidone appear beneficial when administered earlier.

Impacts of cyanobacterial biomass and nitrate nitrogen on methanogens in eutrophic lakes.

Methanogenesis is a key process in carbon cycling in lacustrine ecosystems. Knowledge of the methanogenic pathway is important for creating mechanistic models as well as predicting methane emissions. Due to low concentrations of methyl substrates in freshwater lakes, the proportion of methylotrophic methanogenesis is believed to be negligible in such environments. However, the high abundance of methylotrophic methanogens previously detected in Dianchi Lake suggests that methylotrophic methanogenesis may be underestimated in eutrophic lakes, whereas their influencing factors and mechanisms are not yet clear. In this study, the effects of cyanobacteria biomass (CB) or/and nitrate nitrogen on methanogenesis, especially methylotrophic pathway, in eutrophic lakes were investigated using microcosm simulation experiments combined with chemical analysis and high-throughput sequencing techniques. The results showed that either CB or nitrate nitrogen had significant effects on methane flux, the archaeal diversity and community structure of methanogens. Functional prediction, together with the result of chemical analysis, revealed that CB could promote methylotrophic methanogenesis by providing methyl organic substrates, while nitrate nitrogen increased the relative abundance of obligate methylotrophic methanogens by competitively inhibiting the other two methanogenic pathways. In eutrophic lake where both CB and nitrate present at a high concentration, methylotrophic methanogenesis could play a much more important role than previously believed.

Sulfonamide-metabolizing microorganisms and mechanisms in antibiotic-contaminated wetland sediments revealed by stable isotope probing and metagenomics.

Sulfonamide (SA) antibiotics are ubiquitous pollutants in livestock breeding and aquaculture wastewaters, which increases the propagation of antibiotic resistance genes. Microbes with the ability to degrade SA play important roles in SA dissipation, but their diversity and the degradation mechanism in the field remain unclear. In the present study, we employed DNA-stable isotope probing (SIP) combined with metagenomics to explore the active microorganisms and mechanisms of SA biodegradation in antibiotic-contaminated wetland sediments. DNA-SIP revealed various SA-assimilating bacteria dominated by members of Proteobacteria, such as Bradyrhizobium, Gemmatimonas, and unclassified Burkholderiaceae. Both sulfadiazine and sulfamethoxazole were dissipated mainly through the initial ipso-hydroxylation, and were driven by similar microbes. sadA gene, which encodes an NADH-dependent monooxygenase, was enriched in the 13C heavy DNA, confirming its catalytic capacity for the initial ipso-hydroxylation of SA in sediments. In addition, some genes encoding dioxygenases were also proposed to participate in SA hydroxylation and aromatic ring cleavage based on metagenomics analysis, which might play an important role in SA metabolism in the sediment ecosystem when Proteobacteria was the dominant active bacteria. Our work elucidates the ecological roles of uncultured microorganisms in their natural habitats and gives a deeper understanding of in-situ SA biodegradation mechanisms.

Anaerobic sulfamethoxazole-degrading bacterial consortia in antibiotic-contaminated wetland sediments identified by DNA-stable isotope probing and metagenomics analysis.

Anaerobic degradation has been demonstrated as an important pathway for the removal of sulfonamide (SA) in contaminated environments, and identifying the microorganisms responsible for the degradation of SA is a key step in developing bioaugmentation approaches. In this study, we investigated the anaerobic degradation activity of three SA [sulfadiazine (SDZ), sulfamethazine (SMZ) and sulfamethoxazole (SMX)] and the associated bacterial community in wetland sediments contaminated by aquaculture (in Fujian Province, coded with FJ), livestock farming (in Sichuan Province, coded with SC), or rural wastewaters (in Guangdong Province, coded with GD). Additionally, the combination of DNA-stable isotope probing (SIP) with metagenomics was further applied to assess the active SA-degrading microbes using SMX as a model SA. Among SDZ, SMZ and SMX, only SMX could be effectively dissipated, and the degradation of SMX was relatively fast in the microcosms of sediments with higher levels of SA contamination (FJ and SC). The anaerobic biotransformation pathway of SMX was initiated by hydrogenation with the cleavage of the N-O bond on the isoxazole ring. DNA-SIP revealed that the in situ active anaerobic SMX-degraders (5, 18 and 3 genera in sediments FJ, SC and GD respectively) were dominated by Proteobacteria in sediments FJ and SC, but by Firmicutes (two Family XVIII members) in sediment GD. Mycobacterium, unclassified Burkholderiaceae and Rhodocyclaceae were identified as the dominant active SMX-degrading bacteria in both sediments FJ and SC. Higher proportions of antibiotic resistance gene and genes involved in various functional categories were observed in sediments FJ and SC.

Synthesis and Characterization of Crosslinked Castor Oil-Based Polyurethane Nanocomposites Based on Novel Silane-Modified Isocyanate and Their Potential Application in Heat Insulating Coating.

An isocyanate with trimethoxysilane groups at the side chains (IPDI-M) was synthesized via an addition between the mercaptopropyl trimethoxysilane groups (MPTMS) and IPDI tripolymer (IPDI-T). Then, silane grafted isocyanate as the functional hard segment, castor oil as the soft segment, poly (ethylene adipate) diol (PEA) as the chain extender, and MPTMS as an end-capping reagent were applied to form a series of organosilicon hybrid bio-based polyurethane (CPUSi). The effect of the IPDI-M contents on the thermal stability, mechanical properties, and surface properties of the resulting product was systematically investigated. Profit from the Si-O-Si crosslinked structures formed from MPTMS curing, the tensile strength, and Young's modulus of the resulting products increased from 9.5 MPa to 22.3 Mpa and 4.05 Mpa to 81.59 Mpa, respectively, whereas the elongation at break decreased from 342% to 101%. The glass transition temperature, thermal stability, transparency, hydrophobicity, and chemical resistance were remarkably strengthened for the obtained organosilicon-modified polyurethane with the increasing MPTMS content. At the end of the work, the thermal insulation coating that was based on CPUSi and ATO can effectively block near-infrared rays, and the temperature difference between the inside and outside of the film reached 15.1 °C.

Health status, healthcare, and access in children with long-term medication use and difficulties with emotion, concentration, and behavior.

PROBLEM: Children with chronic conditions often have difficulties with emotions, concentration, and behaviors (ECB) and are not recognized and treated adequately. In this paper, long-term medication use (LTM) was adopted as a proxy for chronic illness due to the lack of consistent and standardized diagnostic criteria for chronic illnesses in children. METHODS: Children (8-12 years) were selected from the California Health Interview Survey (2017) based on: (1) households with children (<12 years), (2) parent/adult caregivers report about child's health indicating "yes" to, (3) "does your child require prescription medicine for a health condition that has lasted or is expected to last at least 12 months or more," and (4) "difficulties with ECB in past 6 months." FINDINGS: A total of 1600 children were included by the CHIS data set, and children whose parental report had met the selection criteria were children with LTM (n = 144; 7.4 ± 2.9 years), ECB (n = 233; 8.16 ± 2.14), and both LTM + ECB (n = 62; 8.61 ± 1.81). Children with LTM+ ECB were Caucasian (56.4%), Hispanic (19.3%), and males (64.5%). Children with both LTM + ECB had two to three (33.87%) or at least four (53.2%) physician visits, and/or receiving special therapy (45.1%). Children with LTM had prescription delays (n = 144; 5.6%) and were not able to get medical care due to lack of insurance (n = 144; 6.9%). The majority of the children with LTM (54.2%) and LTM + ECB (43.5%) had parental employment-based insurance. More children that have both LTM and ECB (48.4%) than children with LTM, No ECB (32.9%) were on Medi-Cal/Medicaid. CONCLUSION: Children with LTM need further evaluation for difficulties with ECB. Future studies are required to examine health status, healthcare use, and access for children with LTM and ECB.

DNA-SIP reveals an overlooked methanotroph, Crenothrix sp., involved in methane consumption in shallow lake sediments.

Methanotrophs are the main consumers of methane produced in lake sediments. In shallow lakes suffering from eutrophication, methanogenesis is accelerated by the excess organic carbon input, and thus methanotrophs play a key role in regulating this methane flux as well as carbon cycling. Here, we applied nucleic acid stable isotope probing (SIP) to investigate the active methanotrophic microbial community in sediments of several shallow lakes affected by eutrophication. Our results showed that an active methanotrophic community dominated by gamma-proteobacterial methanotrophs, as well as abundant beta-proteobacterial methanol-utilizers, was involved in methane-derived carbon assimilation. Crenothrix, a filamentous methanotroph, was found to be a key methane consumer in all studied lakes. The ecological role of Crenothrix in lacustrine ecosystems is so far poorly understood, with only limited information on its existence in the water column of stratified lakes. Our results provide a novel ecological insight into this group by revealing a wide distribution of Crenothrix in lake sediments. The active methane assimilation by Crenothrix also suggested that it might represent a so far overlooked but crucial biological sink of methane in shallow lakes.

A comprehensive review on biodegradation of tetracyclines: Current research progress and prospect.

The release of tetracyclines (TCs) in the environment is of significant concern because the residual antibiotics may promote resistance in pathogenic microorganisms, and the transfer of antibiotic resistance genes poses a potential threat to ecosystems. Microbial biodegradation plays an important role in removing TCs in both natural and artificial systems. After long-term acclimation, microorganisms that can tolerate and degrade TCs are retained to achieve efficient removal of TCs under the optimum conditions (e.g. optimal operational parameters and moderate concentrations of TCs). To date, cultivation-based techniques have been used to isolate bacteria or fungi with potential degradation ability. Moreover, the biodegradation mechanism of TCs can be unveiled with the development of chemical analysis (e.g. UPLC-Q-TOF mass spectrometer) and molecular biology techniques (e.g. 16S rRNA gene sequencing, multi-omics sequencing, and whole genome sequencing). In this review, we made an overview of the biodegradation of TCs in different systems, refined functional microbial communities and pure isolates relevant to TCs biodegradation, and summarized the biodegradation products, pathways, and degradation genes of TCs. In addition, ecological risks of TCs biodegradation were considered from the perspectives of metabolic products toxicity and resistance genes. Overall, this article aimed to outline the research progress of TCs biodegradation and propose future research prospects.

Metagenomic insights into the profile of antibiotic resistomes in sediments of aquaculture wastewater treatment system.

To meet the rapidly growing global demand for aquaculture products, large amounts of antibiotics were used in aquaculture, which might accelerate the evolution of antibiotic-resistant bacteria (ARB) and the propagation of antibiotic genes (ARGs). In our research, we revealed the ARGs profiles, their co-occurrence with mobile genetic elements (MGEs), and potential hosts in sediments of a crab pond wastewater purification system based on metagenomic analysis. The residual antibiotic seems to increase the propagation of ARGs in the crab pond, but there was no clear relationship between a given antibiotic type and the corresponding resistance genes. The effect of aquaculture on sediment was not as profound as that of other anthropogentic activities, but increased the relative abundance of sulfonamide resistance gene. A higher abundance of MGEs, especially plasmid, increased the potential ARGs dissemination risk in crab and purification ponds. Multidrug and sulfonamide resistance genes had greater potential to transfer because they were more frequently carried by MGEs. The horizontal gene transfer was likely to occur among a variety of microorganisms, and various ARGs hosts including Pseudomonas, Acinetobacter, Escherichia, and Klebsiella were identified. Bacterial community influenced the composition of ARG hosts, and Proteobacteria was the predominant hosts. Overall, our study provides novel insights into the environmental risk of ARGs in sediments of aquaculture wastewater treatment system.

Shifts in structure and function of bacterial community in river and fish pond sediments after a phenol spill.

Phenol is widely used in industrial processes and has microbial toxicity. However, the effects of a phenol spill on the microbial community are not clear. The present study explored the changes of bacterial communities in river and fish pond sediments after a phenol spill. The bacterial richness and diversity in river sediments were lower on day 30 (36 days after the spill) than on day 0, while they increased in fish pond sediments. The structures and functions of bacterial communities in both river and fish pond sediments were changed, and a more dramatical variation was detected in fish pond sediments. In river sediments, Proteobacteria, Chloroflexi, Acidobacteria, Bacteroidetes, and Nitrospirae were the major bacterial phyla, and Chloroflexi was enriched. In fish pond sediments, genera Brevibacillus dominated bacterial communities initially, and bacterial composition showed a dramatic change on day 30. Most predicted metabolism functions, as well as genetic information processing functions of translation, replication, and repair, were enhanced in both river and fish pond sediments, while they showed an opposite change trend for xenobiotic degradation function. This work could strengthen our understanding of the effects of phenol spills on sediment bacterial communities in both lotic and lentic ecosystems.

In-situ active Bisphenol A-degrading microorganisms in mangrove sediments.

Bisphenol A (BPA), as both an endocrine disrupting compound and an important industrial material, is broadly distributed in coastal regions and may cause adverse effects on mangrove ecosystems. Although many BPA degraders have been isolated from various environments, the in-situ active BPA-degrading microorganisms in mangrove ecosystem are still unknown. In this study, DNA-based stable isotope probing in combination with high-throughput sequencing was adopted to pinpoint the microbes actually involved in BPA metabolism in mangrove sediments. Five bacterial genera were speculated to be associated with BPA degradation based on linear discriminant analysis (LDA) effect size (LEfSe) analysis, including Truepera, Methylobacterium, Novosphingobium, Rhodococcus and Rhodobacter. The in-situ BPA degraders were different between mudflat and forest sediments. The Shannon index of microbes in heavy fractions was significantly lower than that in light fractions. Besides, phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) demonstrated that the functional genes relevant to cytochrome P450, benzoate degradation, bisphenol degradation and citrate cycle were up-regulated significantly in in-situ BPA-degrading microbes. These findings greatly expanded the knowledge of indigenous BPA metabolic microorganisms in mangrove ecosystems.

Efficient nested-PCR-based method development for detection and genotype identification of Acanthamoeba from a small volume of aquatic environmental sample.

Acanthamoeba spp. are opportunistic human pathogens that cause granulomatous amoebic encephalitis and keratitis, and their accurate detection and enumeration in environmental samples is a challenge. In addition, information regarding the genotyping of Acanthamoeba spp. using various PCR methods is equally critical. Therefore, considering the diverse niches of habitats, it is necessary to develop an even more efficient genotyping method for Acanthamoeba spp. detection. This study improved the sensitivity of detection to avoid underestimation of Acanthamoeba spp. occurrence in aquatic environmental samples, and to accurately define the pathogenic risk by developing an efficient PCR method. In this study, a new nested genotyping method was established and compared with various PCR-based methods using in silico, lab, and empirical tests. The in silico test showed that many PCR-based methods could not successfully align specific genotypes of Acanthamoeba, except for the newly designed nested PCR and real-time PCR method. Furthermore, 52 water samples from rivers, reservoirs, and a river basin in Taiwan were analysed by six different PCR methods and compared for genotyping and detection efficiency of Acanthamoeba. The newly developed nested-PCR-based method of genotyping was found to be significantly sensitive as it could effectively detect the occurrence of Acanthamoeba spp., which was underestimated by the JDP-PCR method. Additionally, the present results are consistent with previous studies indicating that the high prevalence of Acanthamoeba in the aquatic environment of Taiwan is attributed to the commonly found T4 genotype. Ultimately, we report the development of a small volume procedure, which is a combination of recent genotyping PCR and conventional real-time PCR for enumeration of aquatic Acanthamoeba and acquirement of biologically meaningful genotyping information. We anticipate that the newly developed detection method will contribute to the precise estimation, evaluation, and reduction of the contamination risk of pathogenic Acanthamoeba spp., which is regularly found in the water resources utilised for domestic purposes.

Metagenomic analysis of microbial communities continuously exposed to Bisphenol A in mangrove rhizosphere and non-rhizosphere soils.

Bisphenol A (BPA) is widely distributed in littoral zones and may cause adverse impacts on mangrove ecosystem. Biodegradation and phytoremediation are two primary processes for BPA dissipation in mangrove soils. However, the rhizosphere effects of different mangrove species on BPA elimination are still unresolved. In this study, three typical mangrove seedlings, namely Avicennia marina, Bruguiera gymnorrhiza (L.) and Aegiceras corniculatum, were cultivated in soil microcosms for four months and then subjected to 28-day continuous BPA amendment. Un-planted soil microcosms (as control) were also set up. The BPA residual rates and root exudates were monitored, and the metabolic pathways as well as functional microbial communities were also investigated to decipher the rhizosphere effects based on metagenomic analysis. The BPA residual rates in all planted soils were significantly lower than that in un-planted soil on day 7. Both plantation and BPA dosage had significant effects on bacterial abundance. A distinct separation of microbial structure was found between planted and un-planted soil microcosms. Genera Pseudomonas and Lutibacter got enriched with BPA addition and may play important roles in BPA biodegradation. The shifts in bacterial community structure upon BPA addition were different among the microcosms with different mangrove species. Genus Novosphingobium increased in Avicennia marina and Bruguiera gymnorrhiza (L.) rhizosphere soils but decreased in Aegiceras corniculatum rhizosphere soil. Based on KEGG annotation and binning analysis, the proposal of BPA degradation pathways and the quantification of relevant functional genes were achieved. The roles of Pseudomonas and Novosphingobium may differ in lower BPA degradation pathways. The quantity variation patterns of functional genes during the 28-day BPA amendment were different among soil microcosms and bacterial genera.

Increased thalamo-cortical functional connectivity in patients with diabetic painful neuropathy: A resting-state functional MRI study.

Functional changes in the brain of patients with painful diabetic neuropathy (PDN) have remained largely elusive. The aim of the present study was to explore changes in thalamo-cortical functional connectivity (FC) of patients with PDN using resting-state functional MRI. A total of 20 patients with type 2 diabetes mellitus (T2DM) with non-painful diabetic neuropathy (Group NDN), 19 patients with T2DM with PDN (Group-PDN) and 13 age-, sex- and education-matched healthy controls were recruited. The differences in thalamo-cortical FC among the three groups were compared. Patients in Group PDN had increased FC in the left thalamus, the right angular gyrus and the occipital gyrus as compared to those in Group NDN. Furthermore, patients in Group PDN had increased FC in the right thalamus and angular gyrus as compared to those in Group NDN. In conclusion, the present results suggested that the thalamo-cortical FC is increased in patients with T2DM and PDN. Furthermore, the increased FC in the thalamic-parietal-occipital connectivity may be a central pathophysiological mechanism for PDN. The study was retrospectively registered at ClinicalTrials.gov on 3 October 2018 (identifier no. NCT03700502).

Cyanobacterial bloom induces structural and functional succession of microbial communities in eutrophic lake sediments.

Cyanobacterial blooms have considerable effects on lacustrine microbial communities. The current study explored the temporal pattern of sedimentary archaea and bacteria during cyanobacterial bloom in a eutrophic lake. With the sampling period divided into bloom phase, interval phase and end phase according to the variation of physicochemical parameters, the structures and functions of both kingdoms presented a significant difference among phases. Bloom phases could be characterized with the lowest diversity and up-regulated functions in biodegradation of cyanobacterial metabolites driven by bacteria. Archaeal community showed an increased metabolic function during interval phases, including active methanogenesis sensitive to carbon input. The highest diversity and an enrichment of hub genera in microbial network were both observed in end phase, allowing for closer cooperation among groups involved in cyanobacteria-derived organic matter transformation. Although the archaeal community was less variable or diverse than bacteria, methanogenic functions dramatically fluctuated with cyanobacterial dynamics. And microbial groups related to methane cycling played an important role in microbial network. The results provided new insights into temporal dynamics of lacustrine microbial communities and microbial co-occurrence, and highlighted the significant ecological role of methane cycling-related microbes in lake sediments under the influence of cyanobacterial blooms.

Downregulation of exosomal miR­1273a increases cisplatin resistance of non­small cell lung cancer by upregulating the expression of syndecan binding protein.

Resistance to platinum­based drugs, such as cisplatin (CDDP), has been one of the major factors adversely affecting the clinical prognosis of patients with advanced non­small cell lung cancer (NSCLC). While it has been demonstrated that dysregulation of microRNAs (miRNAs) may contribute to cisplatin resistance in NSCLC, the underlying mechanisms remain largely unclear. In the present study, the effect of exosomal miR­1273a on cisplatin sensitivity of NSCLC was investigated. Microarray analysis was conducted to analyze the miRNA expression profiles in exosomes isolated from A549 cells treated with or without CDDP, and miR­1273a was found to be the most prominently downregulated miRNA in CDDP­treated exosomes. Overexpression of miR­1273a significantly increased the cytotoxicity of CDDP and induced apoptosis in A549 cells. Syndecan binding protein (SDCBP) was predicted to be a direct target of miR­1273a by bioinformatics and was found to be downregulated by miR­1273a in A549 cells. Furthermore, decreased plasma exosomal miR­1273a and increased plasma SDCBP levels were found to be associated with worse therapeutic outcomes of patients with advanced NSCLC receiving platinum­based chemotherapy. These findings suggest that miR­1273a is closely associated with the development of cisplatin resistance and may serve as a potential prognostic biomarker and therapeutic target for NSCLC.

Ammonium Impacts Methane Oxidation and Methanotrophic Community in Freshwater Sediment.

Lacustrine ecosystems are regarded as one of the important natural sources of greenhouse gas methane. Aerobic methane oxidation, carried out by methane-oxidizing bacteria, is a key process regulating methane emission. And ammonium is believed to greatly influence aerobic methane oxidation activity. To date, disagreement exists in the threshold of ammonium effect. Moreover, knowledge about how aerobic methanotrophic community composition and functional gene transcription respond to ammonium is still lacking. In the present study, microcosms with freshwater lake sediment were constructed to explore the effect of ammonium level on aerobic methanotrophs. Methane oxidation potential, and the density, diversity and composition of pmoA gene and its transcripts were examined during 2-week incubation. A negative impact of ammonium on aerobic methane oxidation potential and a positive impact on pmoA gene density were observed only at a very high level of ammonium. However, pmoA gene transcription increased notably at all ammonium levels. The composition of functional pmoA gene and transcripts were also influenced by ammonium. But a great shift was only observed in pmoA transcripts at the highest ammonium level.