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1.
J Neuroendocrinol ; : e13398, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38733120

RESUMO

Phoenixin (PNX) is a conserved secreted peptide that was identified 10 years ago with numerous studies published on its pleiotropic functions. PNX is associated with estrous cycle length, protection from a high-fat diet, and reduction of anxiety behavior. However, no study had yet evaluated the impact of deleting PNX in the whole animal. We sought to evaluate a mouse model lacking the PNX parent gene, small integral membrane protein 20 (Smim20), and the resulting effect on reproduction, energy homeostasis, and anxiety. We found that the Smim20 knockout mice had normal fertility and estrous cycle lengths. Consistent with normal fertility, the hypothalamii of the knockout mice showed no changes in the levels of reproduction-related genes, but the male mice had some changes in energy homeostasis-related genes, such as melanocortin receptor 4 (Mc4r). When placed on a high-fat diet, the wildtype and knockout mice responded similarly, but the male heterozygous mice gained slightly less weight. When placed in an open field test box, the female knockout mice traveled less distance in the outer zone, indicating alterations in anxiety or locomotor behavior. In summary, the homozygous knockout of PNX did not alter fertility and modestly alters a few neuroendocrine genes in response to a high-fat diet, especially in the female mice. However, it altered the behavior of mice in an open field test. PNX therefore may not be crucial for reproductive function or weight, however, we cannot rule out possible compensatory mechanisms in the knockout model. Understanding the role of PNX in physiology may ultimately lead to an enhanced understanding of neuroendocrine mechanisms involving this enigmatic peptide.

2.
Biomedicines ; 12(4)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38672211

RESUMO

Cellular microRNAs (miRNAs) can be selectively secreted or retained, adding another layer to their critical role in regulating human health and disease. To date, select RNA-binding proteins (RBPs) have been proposed to be a mechanism underlying miRNA localization, but the overall relevance of RBPs in systematic miRNA sorting remains unclear. This study profiles intracellular and small extracellular vesicles' (sEVs) miRNAs in NPY-expressing hypothalamic neurons. These findings were corroborated by the publicly available sEV and intracellular miRNA profiles of white and brown adipocytes, endothelium, liver, and muscle from various databases. Using experimentally determined binding motifs of 93 RBPs, our enrichment analysis revealed that sEV-originating miRNAs contained significantly different RBP motifs than those of intracellularly retained miRNAs. Multiple RBP motifs were shared across cell types; for instance, RBM4 and SAMD4 are significantly enriched in neurons, hepatocytes, skeletal muscle, and endothelial cells. Homologs of both proteins physically interact with Argonaute1/2 proteins, suggesting that they play a role in miRNA sorting. Machine learning modelling also demonstrates that significantly enriched RBP motifs could predict cell-specific preferential miRNA sorting. Non-optimized machine learning modeling of the motifs using Random Forest and Naive Bayes in all cell types except WAT achieved an area under the receiver operating characteristic (ROC) curve of 0.77-0.84, indicating a high predictive accuracy. Given that the RBP motifs have a significant predictive power, these results underscore the critical role that RBPs play in miRNA sorting within mammalian cells and reinforce the importance of miRNA sequencing in preferential localization. For the future development of small RNA therapeutics, considering these RBP-RNA interactions could be crucial to maximize delivery effectiveness and minimize off-target effects.

3.
Mol Cell Endocrinol ; 586: 112179, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38387703

RESUMO

Neuropeptide Y (Npy) is an abundant neuropeptide expressed in the central and peripheral nervous systems. NPY-secreting neurons in the hypothalamic arcuate nucleus regulate energy homeostasis, and Npy mRNA expression is regulated by peripheral nutrient and hormonal signals like leptin, interleukin-6 (IL-6), and fatty acids. This study demonstrates that IL-6, which phosphorylates tyrosine 705 (Y705) of STAT3, decreased Npy mRNA in arcuate immortalized hypothalamic neurons. In parallel, inhibitors of STAT3-Y705 phosphorylation, stattic and cucurbitacin I, robustly upregulated Npy mRNA. Chromatin-immunoprecipitation showed high baseline total STAT3 binding to multiple regulatory regions of the Npy gene, which are decreased by IL-6 exposure. The STAT3-Npy interaction was further examined in obesity-related pathologies. Notably, in four different hypothalamic neuronal models where palmitate potently stimulated Npy mRNA, Socs3, a specific STAT3 activity marker, was downregulated and was negatively correlated with Npy mRNA levels (R2 = 0.40, p < 0.001), suggesting that disrupted STAT3 signaling is involved in lipotoxicity-mediated dysregulation of Npy. Finally, human NPY SNPs that map to human obesity or body mass index were investigated for potential STAT3 binding sites. Although none of the SNPs were linked to direct STAT3 binding, analysis show that rs17149106 (-602 G > T) is located on an upstream enhancer element of NPY, where the variant is predicted to disrupt validated binding of KLF4, a known inhibitory cofactor of STAT3 and downstream effector of leptin signaling. Collectively, this study demonstrates that STAT3 signaling negatively regulates Npy transcription, and that disruption of this interaction may contribute to metabolic disorders.


Assuntos
Leptina , Neuropeptídeo Y , Humanos , Neuropeptídeo Y/genética , Neuropeptídeo Y/metabolismo , Leptina/farmacologia , Leptina/metabolismo , Interleucina-6/genética , Interleucina-6/metabolismo , Hipotálamo/metabolismo , Obesidade/metabolismo , Núcleo Arqueado do Hipotálamo/metabolismo , Neurônios/metabolismo , RNA Mensageiro/genética , Fator de Transcrição STAT3/metabolismo
4.
Artigo em Inglês | MEDLINE | ID: mdl-38194391

RESUMO

Infantile spasms (IS) is a neurological disorder causing mental and/or developmental retardation in many infants. Hypsarrhythmia is a typical symptom in the electroencephalography (EEG) signals with IS. Long-term EEG/video monitoring is most frequently employed in clinical practice for IS diagnosis, from which manual screening of hypsarrhythmia is time consuming and lack of sufficient reliability. This study aims to identify potential biomarkers for automatic IS diagnosis by quantitative analysis of the EEG signals. A large cohort of 101 IS patients and 155 healthy controls (HC) were involved. Typical hypsarrhythmia and non-hypsarrhythmia EEG signals were annotated, and normal EEG were randomly picked from the HC. Root mean square (RMS), teager energy (TE), mean frequency, sample entropy (SamEn), multi-channel SamEn, multi-scale SamEn, and nonlinear correlation coefficient were computed in each sub-band of the three EEG signals, and then compared using either a one-way ANOVA or a Kruskal-Wallis test (based on their distribution) and the receiver operating characteristic (ROC) curves. The effects of infant age on these features were also investigated. For most of the employed features, significant ( ) differences were observed between hypsarrhythmia EEG and non-hypsarrhythmia EEG or HC, which seem to increase with increased infant age. RMS and TE produce the best classification in the delta and theta bands, while entropy features yields the best performance in the gamma band. Our study suggests RMS and TE (delta and theta bands) and entropy features (gamma band) to be promising biomarkers for automatic detection of hypsarrhythmia in long-term EEG monitoring. The findings of our study indicate the feasibility of automated IS diagnosis using artificial intelligence.


Assuntos
Espasmos Infantis , Lactente , Humanos , Espasmos Infantis/diagnóstico , Estudos de Coortes , Reprodutibilidade dos Testes , Inteligência Artificial , Eletroencefalografia , Biomarcadores
5.
Genes (Basel) ; 14(9)2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37761913

RESUMO

The hypothalamus is a vital regulator of energy homeostasis. Orexigenic neuropeptide Y (NPY) neurons within the hypothalamus can stimulate feeding and suppress energy expenditure, and dysregulation of these neurons may contribute to obesity. We previously reported that bisphenol A (BPA), an endocrine disruptor with obesogenic properties, alters Npy transcription in hypothalamic neurons by inducing oxidative stress. We hypothesized that hypothalamic microRNAs (miRNAs), a class of small non-coding RNAs, could directly regulate Npy gene expression by binding the 3' untranslated region (UTR). Five predicted Npy-targeting miRNA candidates were uncovered through TargetScan and were detected in Npy-expressing hypothalamic neuronal cell models and hypothalamic neuronal primary cultures. BPA dysregulated the expression of a number of these hypothalamic miRNAs. We examined the effects of putative Npy-targeting miRNAs using miRNA mimics, and we found that miR-143-3p, miR-140-5p, miR-29b-1-5p, and let-7b-3p altered Npy expression in the murine hypothalamic cell lines. Importantly, miR-143-3p targets the mouse Npy 3' UTR, as detected using a luciferase construct containing the potential 3' UTR binding sites. Overall, this study established the first hypothalamic miRNA that directly targets the 3' UTR of mouse Npy, emphasizing the involvement of miRNAs in the NPY system and providing an alternative target for control of NPY levels.

6.
Endocrinology ; 164(9)2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37453100

RESUMO

Since the first microRNA (miRNA) was described in 1993 in the humble worm Caenorhabditis elegans, the miRNA field has boomed, with more than 100 000 related patents filed and miRNAs now in ongoing clinical trials. Despite an advanced understanding of the biogenesis and action of miRNAs, applied miRNA research faces challenges and irreproducibility due to a lack of standardization. This review provides guidelines regarding miRNA investigation, while focusing on the pitfalls and considerations that are often overlooked in prevailing applied miRNA research. These include miRNA annotation and quantification, to modulation, target prediction, validation, and the study of circulating miRNAs.


Assuntos
MicroRNAs , Animais , MicroRNAs/genética , Caenorhabditis elegans/genética , RNA Mensageiro/genética
7.
Front Microbiol ; 14: 1123632, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37283923

RESUMO

Melatonin is a biomolecule that affects plant development and is involved in protecting plants from environmental stress. However, the mechanisms of melatonin's impact on arbuscular mycorrhizal (AM) symbiosis and cold tolerance in plants are still unclear. In this research, AM fungi inoculation and exogenous melatonin (MT) were applied to perennial ryegrass (Lolium perenne L.) seedlings alone or in combination to investigate their effect on cold tolerance. The study was conducted in two parts. The initial trial examined two variables, AM inoculation, and cold stress, to investigate the involvement of the AM fungus Rhizophagus irregularis in endogenous melatonin accumulation and the transcriptional levels of its synthesis genes in the root system of perennial ryegrass under cold stress. The subsequent trial was designed as a three-factor analysis, encompassing AM inoculation, cold stress, and melatonin application, to explore the effects of exogenous melatonin application on plant growth, AM symbiosis, antioxidant activity, and protective molecules in perennial ryegrass subjected to cold stress. The results of the study showed that compared to non-mycorrhizal (NM) plants, cold stress promoted an increase in the accumulation of melatonin in the AM-colonized counterparts. Acetylserotonin methyltransferase (ASMT) catalyzed the final enzymatic reaction in melatonin production. Melatonin accumulation was associated with the level of expression of the genes, LpASMT1 and LpASMT3. Treatment with melatonin can improve the colonization of AM fungi in plants. Simultaneous utilization of AM inoculation and melatonin treatment enhanced the growth, antioxidant activity, and phenylalanine ammonia-lyase (PAL) activity, while simultaneously reducing polyphenol oxidase (PPO) activity and altering osmotic regulation in the roots. These effects are expected to aid in the mitigation of cold stress in Lolium perenne. Overall, melatonin treatment would help Lolium perenne to improve growth by promoting AM symbiosis, improving the accumulation of protective molecules, and triggering in antioxidant activity under cold stress.

8.
Dalton Trans ; 52(14): 4537-4547, 2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-36920839

RESUMO

In order to avoid the complicated control and fussy procedure associated with foreign species and templates in conventional synthesis strategies, a simple reactant conversion-intercalation strategy is developed to synthesize interlayer-expanded MoS2 (E-MoS2) by employing ammonium thiocyanate converted from a thiourea reactant as intercalator. In this strategy, the thiourea plays a bifunctionality role as reactant and intercalator precursor to ensure in situ embedding into the interlayers of MoS2 to expand the interlayer spacing. The optimal E-MoS2 obtained presents superior supercapacitor performance with a specific capacity of 246.8 F g-1 at 0.5 A g-1 in 1 M Na2SO4 electrolyte in a three-electrode system, outperforming pristine MoS2 prepared by a conventional hydrothermal method (42.5 F g-1 at 0.5 A g-1). Furthermore, a symmetric supercapacitor based on an E-MoS2 electrode delivers a high specific capacity of 261.3 F g-1 and energy density of 13.3 W h kg-1 at 0.5 A g-1, and excellent cycling life with 81.7% capacity retention after 3000 cycles at 2 A g-1. Density functional theory calculations reveal that the NH4+ and SCN- can be effectively adsorbed on the surface to be inserted into the interlayers during the growth of MoS2, resulting in an expanded interlayer spacing of 9.4 Å, and the favorable electrochemical performance stems from the large Na+ adsorption capacitance and low diffusion barrier of the E-MoS2. This work offers a novel intercalation strategy that may be generally applicable to other layer-structured materials, shedding some light on the development of high-performance electrode materials via interface engineering for energy applications.

9.
ACS Omega ; 7(40): 35755-35773, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36249366

RESUMO

A major historical breakthrough has been made in the exploration of the GK (the first member of the Qingshankou Formation (K2qn1), Gulong Sag) shale oil of the Songliao Basin. However, few reports have been reported on the pore structure characteristics of this large-scale lacustrine medium-high maturity shale. In addition, the difference between the pore structure characteristics of the GK shale and medium-low maturity marine/continental shale is unknown, and the affecting factors of pore development are still unclear. Therefore, in order to clarify the pore structure characteristics of the GK shale and its affecting factors, this study characterized them experimentally and revealed the law of pore evolution using the mineral composition and geochemical analysis, microscopic observations, and pore quantification techniques. Results indicate that (1) the pore system of GK shale reservoirs is divided into micropores (pore diameter < 10 nm), mesopores (10 nm < pore diameter < 50 nm), and macropores (pore diameter > 50 nm); (2) the pore structure of the GK shale is mainly affected by the clay content, siliceous mineral content, and thermal maturity; and (3) when the content of clay minerals and siliceous minerals in the GK shale reservoir is high, and ∼0.8% < R o < ∼1.4%, the storage capacity and oil content of the GK shale show high values, and it can be considered as a strong candidate for further exploration and development. This research can push the shale oil revolution to a new height and is significant to promote the development of the petroleum industry.

10.
Sci Rep ; 12(1): 17210, 2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36241891

RESUMO

A comprehensive characterisation of the pore structure in shale oil reservoirs is essential for forecasting oil production and exploration risks. This study forecasted these risks in the oil-rich Songliao Basin using combination of high-resolution field emission scanning electron microscopy and quantitative X-ray diffraction to analyze the pore genesis and evolution mode within the first member of the Cretaceous Qingshankou Formation (K2qn1). The results showed the dominance of inorganic pores over organic pores, wherein diagenetic processes, such as compaction, pressure solution, and cementation, were responsible for the destruction of pore structure in the formation. Notably, the pores formed by dissolution and shrinkage cracks resulting from clay mineral transformation improved the oil storage space. Furthermore, according to the geochemical data and clay composition, the K2qn1 shale is in the middle diagenetic stage A, which can be further subdivided into A1 and A2 stages from top to bottom. The porosity slowly decreased in both sub-stages A1 and A2, wherein the decrease was stable in the latter. The diagenetic observations in this study are significant for the exploration of unconventional shale oil in petroliferous basins worldwide.

11.
Front Plant Sci ; 13: 959427, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35982708

RESUMO

Osmotic and ionic induced salt stress suppresses plant growth. In a previous study, Enterobacter ludwigii B30, isolated from Paspalum vaginatum, improved seed germination, root length, and seedling length of bermudagrass (Cynodon dactylon) under salt stress. In this study, E. ludwigii B30 application improved fresh weight and dry weight, carotenoid and chlorophyll levels, catalase and superoxide dismutase activities, indole acetic acid content and K+ concentration. Without E. ludwigii B30 treatment, bermudagrass under salt stress decreased malondialdehyde and proline content, Y(NO) and Y(NPQ), Na+ concentration, 1-aminocyclopropane-1-carboxylate, and abscisic acid content. After E. ludwigii B30 inoculation, bacterial community richness and diversity in the rhizosphere increased compared with the rhizosphere adjacent to roots under salt stress. Turf quality and carotenoid content were positively correlated with the incidence of the phyla Chloroflexi and Fibrobacteres in rhizosphere soil, and indole acetic acid (IAA) level was positively correlated with the phyla Actinobacteria and Chloroflexi in the roots. Our results suggest that E. ludwigii B30 can improve the ability of bermudagrass to accumulate biomass, adjust osmosis, improve photosynthetic efficiency and selectively absorb ions for reducing salt stress-induced injury, while changing the bacterial community structure of the rhizosphere and bermudagrass roots. They also provide a foundation for understanding how the bermudagrass rhizosphere and root microorganisms respond to endophyte inoculation.

12.
Mol Cell Endocrinol ; 557: 111753, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-35981630

RESUMO

Accumulation of excess lipids in non-adipose tissues, such as the hypothalamus, is termed lipotoxicity and causative of free fatty acid-mediated pathology in metabolic disease. This study aimed to elucidate the molecular mechanisms behind oleate (OA)- and palmitate (PA)-mediated changes in hypothalamic neurons. Using the well-characterized hypothalamic neuronal cell model, mHypoE-46, we assessed gene changes through qRT-PCR, cell death with quantitative imaging, PA metabolism using stable isotope labeling, and cellular mechanisms using pharmacological modulation of lipid metabolism and autophagic flux. Palmitate (PA) disrupts gene expression, including Npy, Grp78, and Il-6 mRNA in mHypoE-46 hypothalamic neurons. Blocking PA metabolism using triacsin-C prevented the increase of these genes, implying that these changes depend on PA intracellular metabolism. Co-incubation with oleate (OA) is also potently protective and prevents cell death induced by increasing concentrations of PA. However, OA does not decrease U-13C-PA incorporation into diacylglycerol and phospholipids. Remarkably, OA can reverse PA toxicity even after significant PA metabolism and cellular impairment. OA can restore PA-mediated impairment of autophagy to prevent or reverse the accumulation of PA metabolites through lysosomal degradation, and not through other reported mechanisms. The autophagic flux inhibitor chloroquine (CQ) mimics PA toxicity by upregulating autophagy-related genes, Npy, Grp78, and Il-6, an effect partially reversed by OA. CQ also prevented the OA defense against PA toxicity, whereas the autophagy inducer rapamycin provided some protection. Thus, PA impairment of autophagic flux significantly contributes to its lipotoxicity, and OA-mediated protection requires functional autophagy. Overall, our results suggest that impairment of autophagy contributes to hypothalamic lipotoxicity.


Assuntos
Ácido Oleico , Palmitatos , Autofagia , Cloroquina/farmacologia , Diglicerídeos/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Ácidos Graxos não Esterificados/farmacologia , Hipotálamo/metabolismo , Interleucina-6/metabolismo , Neurônios/metabolismo , Ácido Oleico/farmacologia , Palmitatos/toxicidade , Ácido Palmítico/farmacologia , RNA Mensageiro/metabolismo , Sirolimo/farmacologia
13.
Sci Rep ; 12(1): 2985, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35194139

RESUMO

Scrub typhus is an acute infectious disease in humans. A temporal, spatial and epidemiologic study was conducted to understand the characteristics of scrub typhus in Yunnan, to assist public health prevention and control measures. Based on the data on all cases reported in Yunnan during 2006-2017, we characterized the epidemiological features. Spatio-temporal patterns and Q-type cluster method were adopted to analyze the incidence of scrub typhus in Yunnan. In total, 27,838 scrub typhus cases were reported in Yunnan during 2006-2017. Of these, 49.53% (13,787) were male and 50.47% (14,051) were female (P > 0.05). Most patients were farmers (71.70%) (P < 0.05) and children aged 0-5 years (13.16%) (P < 0.01), which accounted for 84.86% of the total cases. An almost 20-fold increase in the number of patients was observed in 2017 (6,337 cases) compared to 2006 (307 cases). Baoshan and Lincang had the most cases accounting for 41.94%, while Diqing had the lowest incidence (only 3 cases). Sixteen municipalities infected were classified into three groups numbered in sequence. The incidence of scrub typhus in Yunnan is high and the annual incidence increased noticeably over time. Our results also indicate that surveillance and public education need to be focused on Baoshan, Lincang and Dehong.


Assuntos
Tifo por Ácaros/epidemiologia , Tifo por Ácaros/prevenção & controle , Análise Espaço-Temporal , Fatores Etários , Pré-Escolar , China/epidemiologia , Fazendeiros/estatística & dados numéricos , Feminino , Educação em Saúde , Humanos , Incidência , Lactente , Masculino , Saúde Pública , Estações do Ano , Fatores de Tempo
14.
Pharmacol Ther ; 233: 108033, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34763011

RESUMO

Spexin is the most recently discovered member of the galanin/kisspeptin/spexin family of peptides. This 14-amino acid peptide is highly conserved and is implicated in homeostatic functions including, but not limited to, metabolism, energy homeostasis, and reproduction. Spexin is expressed by neurons in the hypothalamus, which coordinate energy homeostasis and reproduction. Critically, levels of spexin appear to be altered in disorders related to energy homeostasis and reproduction, such as obesity, diabetes, and polycystic ovarian syndrome. In this review, we discuss the evidence for the involvement of spexin in the hypothalamic control of energy homeostasis and reproduction. The anorexigenic properties of spexin have been attributed to its effects on the energy-regulating neuropeptide Y/agouti-related peptide neurons and proopiomelanocortin neurons. While the role of spexin in reproduction remains unclear, there is evidence that gonadotropin-releasing hormone expressing neurons may produce and respond to spexin. Furthermore, we discuss the disorders and concomitant treatments, which have been reported to alter spexin expression, as well as the underlying signaling mechanisms that may be involved. Finally, we discuss the biochemical basis of spexin, its interaction with its cognate receptors, and how this information can be adapted to develop therapeutics for disorders related to the alteration of energy homeostasis and reproduction.


Assuntos
Hipotálamo , Hormônios Peptídicos , Metabolismo Energético/fisiologia , Hormônio Liberador de Gonadotropina , Homeostase , Humanos , Hipotálamo/metabolismo , Hormônios Peptídicos/metabolismo , Reprodução/fisiologia
15.
J Colloid Interface Sci ; 608(Pt 2): 1377-1383, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34742059

RESUMO

The obtainment of low-cost, easily prepared and high-powered LiMn2O4 is the key to achieve its wide application in various electronic devices. In this work, a mild and easily scaled molten salt method (KCl@LiCl) is utilized to convert commercial MnO2 to the high-performance LiMn2O4. At the same reaction temperature, the molten salt method leads to the formation of K+-doped LiMn2O4 with higher crystallinity compared to the conventional solid state method, which contributes to the improved inner charge transfer. The Li3PO4 protective layer is coated on the surface of K+-doped LiMn2O4 to elevate the interfacial stability and the Li+ transfer on interface. Thus, the optimized electrode shows a higher specific discharge capacity (103/60 mAh g-1 at 0.02/2 A g-1) and a longer cyclic life (80 mAh g-1 after 500 cycles at 0.5 A g-1) compared to those of LiMn2O4 by solid state method (49/2 mAh g-1 at 0.02/2 A g-1 and 20 mAh g-1 after 500 cycles at 0.5 A g-1).

16.
J Neurochem ; 159(3): 574-589, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34482548

RESUMO

A contributing factor to the development of obesity is the consumption of a diet high in saturated fatty acids, such as palmitate. These fats induce hypothalamic neuroinflammation, which dysregulates neuronal function and induces orexigenic neuropeptide Y (Npy) to promote food intake. An inflammatory cytokine array identified multiple candidates that could mediate palmitate-induced up-regulation of Npy mRNA levels. Of these, visfatin or nicotinamide phosphoribosyltransferase (NAMPT), macrophage migratory inhibitory factor (MIF), and IL-17F were chosen for further study. Direct treatment of the neuropeptide Y/agouti-related peptide (NPY/AgRP)-expressing mHypoE-46 neuronal cell line with the aforementioned cytokines demonstrated that visfatin could directly induce Npy mRNA expression. Preventing the intracellular metabolism of palmitate through long-chain acyl-CoA synthetase (ACSL) inhibition was sufficient to block the palmitate-mediated increase in Npy gene expression. Furthermore, thin-layer chromatography revealed that in neurons, palmitate is readily incorporated into ceramides and defined species of phospholipids. Exogenous C16 ceramide, dipalmitoyl-phosphatidylcholine, and dipalmitoyl-phosphatidylethanolamine were sufficient to significantly induce Npy expression. This study suggests that the intracellular metabolism of palmitate and elevation of metabolites, including ceramide and phospholipids, are responsible for the palmitate-mediated induction of the potent orexigen Npy. Furthermore, this suggests that the regulation of Npy expression is less reliant on inflammatory cytokines per se than palmitate metabolites in a model of NPY/AgRP neurons. These lipid species likely induce detrimental downstream cellular signaling events ultimately causing an increase in feeding, resulting in an overweight phenotype and/or obesity.


Assuntos
Citocinas/farmacologia , Neuropeptídeo Y/biossíntese , Palmitatos/farmacologia , Acil Coenzima A/metabolismo , Animais , Linhagem Celular , Ceramidas/metabolismo , Meios de Cultivo Condicionados , Dieta Hiperlipídica , Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Nicotinamida Fosforribosiltransferase/farmacologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética
17.
Microb Ecol ; 81(2): 410-424, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32894355

RESUMO

To predict the effects of nitrogen deposition on nitrogen-mineralizing enzyme activity and soil microbial community structure in artificial temperate forests in northern China, we studied the soil properties, nitrogen-mineralizing enzyme activity, and microbial community structure in the soil of a Korean pine plantation in which different concentrations (0, 20, 40, 80 kg N ha-1 year-1) of ammonium nitrate were applied for 5 consecutive years. The results showed that nitrogen addition at different concentrations did not significantly affect the soil pH. High nitrogen addition (80 kg N ha-1 year-1) significantly increased the soil organic matter, ammonium nitrogen, and nitrate nitrogen content in the Korean pine plantation, and ammonium nitrogen was the key factor that influenced the soil fungal community structure. The urease activity under the moderate nitrogen addition treatment (40 kg N ha-1 year-1) was significantly lower than that under the control (0 kg N ha-1 year-1), and the protease activity in the three treatments was also significantly lower than that in the control. There was no significant correlation between microbial community structure and the four mineralizing enzymes. After nitrogen addition at different concentrations, the Simpson and Shannon indexes of soil bacteria decreased significantly under low nitrogen addition (20 kg N ha-1 year-1), but the α-diversity index of soil fungi did not show significant differences under nitrogen addition. The microbial community composition was significantly changed by the different treatments. PLS-DA analysis showed that Tardiphaga was an important genus that made the greatest contribution to the differences in bacterial community composition among treatments, as was Taeniolella for fungal community composition. The low level of nitrogen addition inhibited nitrogen mineralization in the Korean pine plantation by reducing the relative abundances of Nitrosomonadaceae and Betaproteobacteriales and by reducing the abundances of symbiotrophic fungi. Berkelbacteria and Polyporales were bacteria and fungi, respectively, that changed significantly under the high nitrogen addition treatment (80 kg N ha-1 year-1). This study provides more data to support predictions of the changes in nitrogen-mineralizing enzyme activity and microbial community structure in artificial temperate forest soils in response to increased nitrogen deposition.


Assuntos
Microbiota , Nitrogênio/metabolismo , Microbiologia do Solo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , China , Florestas , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Nitratos/análise , Nitratos/metabolismo , Nitrogênio/análise , Peptídeo Hidrolases/metabolismo , Pinus/microbiologia , Solo/química , Urease/metabolismo
18.
Artigo em Inglês | MEDLINE | ID: mdl-32595600

RESUMO

Obesity is a prominent metabolic disease that predisposes individuals to multiple comorbidities, including type 2 diabetes mellitus, cardiovascular diseases, and cancer. Elevated circulating levels of fatty acids contribute to the development of obesity, in part, by targeting the hypothalamus. Palmitate, the most abundant circulating saturated fatty acid, has been demonstrated to dysregulate NAMPT and circadian clock proteins, as well as induce neuroinflammation. These effects ultimately result in hypothalamic dysregulation of feeding behavior and energy homeostasis. NAMPT is the rate-limiting enzyme of the NAD+ salvage pathway and its expression is under the control of the circadian clock. NAD+ produced from NAMPT can modulate the circadian clock, demonstrating bidirectional interactions between circadian and metabolic pathways. Using NPY/AgRP-expressing mHypoE-46 neurons as well as the novel mHypoA-BMAL1-WT/F and mHypoA-BMAL1-KO/F cell lines, we studied whether there were any interactions between NAMPT and the core circadian clock protein BMAL1 in the palmitate-mediated induction of neuroinflammation. We report that palmitate altered Nampt, Bmal1, Per2 and the inflammatory genes Nf-κb, IκBα, Il-6, and Tlr4. Contrary to studies performed with peripheral tissues, the palmitate-mediated induction in Nampt was independent of BMAL1, and basal Nampt levels did not appear to exhibit rhythmic expression. Palmitate-induced downregulation of Bmal1 and Per2 was independent of NAMPT. However, NAMPT and BMAL1 were both involved in the regulation of Nf-κb, IκBα, Il-6, and Tlr4, as NAMPT inhibition resulted in the repression of basal Nf-κb and IκBα and normalized palmitate-mediated increases in Il-6, and Tlr4. On the other hand, BMAL1 deletion repressed basal Nf-κb, but increased basal Il-6. We conclude that NAMPT and BMAL1 do not interact at the transcriptional level in hypothalamic neurons, but are independently involved in the expression of inflammatory genes.


Assuntos
Fatores de Transcrição ARNTL/fisiologia , Citocinas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Hipotálamo/patologia , Inflamação/patologia , Neurônios/patologia , Nicotinamida Fosforribosiltransferase/metabolismo , Palmitatos/farmacologia , Animais , Citocinas/genética , Feminino , Hipotálamo/efeitos dos fármacos , Hipotálamo/imunologia , Hipotálamo/metabolismo , Inflamação/induzido quimicamente , Inflamação/imunologia , Inflamação/metabolismo , Mediadores da Inflamação , Masculino , Camundongos , Camundongos Knockout , Neurônios/efeitos dos fármacos , Neurônios/imunologia , Neurônios/metabolismo , Nicotinamida Fosforribosiltransferase/genética
19.
Environ Pollut ; 262: 114264, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32142977

RESUMO

Atrazine has been used on Chinese farmlands for a long time and over a wide range. The concentration of atrazine (1.86-1100 mg kg-1) has exceeded the allowable limit in the soil (1.0 mg kg-1), and concern is increasing about the potential harm to farmland soil. Four treatments (AT0, AT6, AT10, AT16) were established to reveal the effects of the long-term application of atrazine on soil health. The results showed a nonlinear regulation of the atrazine residue concentrations in the four treatments. The highest concentration of atrazine residue was in AT6, at 167 mg kg-1, and the lowest concentration of atrazine residue was in AT16, at 102 mg kg-1, but there was no significant difference between AT10 and AT16. The soil urease activity decreased significantly with the increase in the years of atrazine application, the saccharase and cellulase activities in the AT6 were significantly higher than those observed in the other three treatments, the catalase activity gradually decreased with the increase in atrazine application years, and the activity in AT6 was significantly higher than that in AT16. A total of 238 genera were identified by Illumina MiSeq sequencing, and 28 dominant genera were screened. Atrazine significantly increased the relative abundance of Actinobacteria and contributed to the relative abundance of Rubrobacter, Blastococcus, Promicromonospora, Jiangella, Psychroglaciecola and Acetobacteraceae_uncultured, which exhibited significantly higher abundance in AT16 than in AT0. Although there were atrazine-degrading bacteria in the soil, and the atrazine residue decreased with the increase in application years, the concentration of the atrazine residue was still nearly 100 times higher than the allowable limit in the soil, which is a great threat to the soil health.


Assuntos
Atrazina/análise , Herbicidas/análise , Poluentes do Solo/análise , China , Fazendas , Solo , Microbiologia do Solo
20.
J Environ Sci (China) ; 20(6): 646-51, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18763556

RESUMO

The present study dealt with relationships between the degradation and humification process that the organic matter underwent during bacteria-mineral technology. An inverse correlation was found between the protein, lipid, and some of the humification indices considered, suggesting that the humification theory is actually humic substances produced from simple-structured natural organic substrates. Weight-average molecular weight (Mw), number-average molecular weight (Mn), and the ratio Mw/Mn of dissolved organic matters at different stages of the process were measured by gel permeation chromatography. The results showed that Mn and Mw increased with reaction time from 352 to 17,191, and from 78,707 to 104,564, respectively. The ratio of Mn/Mw decreased from 223.3 to 6.1. This reflected the growth of the polymerization degree of dissolvable organic matters in the process; furthermore, it indicated the formation of complex molecules (humic substances) from more simple molecules. Bacteria-mineral water (BMW) (the effluent of the process) treatments can exert hormone-like activity for enhanced seed germination of wheat and rice and greatly improved chlorophyll synthesis in wheat and rice leaves. Major polyamines (plant regulators) putrescine, spermidine, and spermine, were found in BMW by a high performance liquid chromatography (HPLC) method, which may explain the hormone-like activity of BMW.


Assuntos
Animais Domésticos , Bactérias/metabolismo , Esterco , Minerais/metabolismo , Gerenciamento de Resíduos/métodos , Animais , Carboidratos/análise , Clorofila/química , Germinação , Substâncias Húmicas/análise , Lipídeos/análise , Peso Molecular , Oryza/anatomia & histologia , Oryza/fisiologia , Poliaminas/análise , Proteínas/análise , Triticum/anatomia & histologia , Triticum/fisiologia
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