Glutamine prevents high-fat diet-induced hepatic lipid accumulation in mice by modulating lipolysis and oxidative stress.

Metabolic-associated fatty liver disease (MAFLD) is related to metabolic dysfunction and is characterized by excess fat storage in the liver. Several studies have indicated that glutamine could be closely associated with lipid metabolism disturbances because of its important role in intermediary metabolism. However, the effect of glutamine supplementation on MAFLD progression remains unclear. Here, we used a high-fat diet (HFD)-induced MAFLD C57BL/6 mouse model, and glutamine was supplied in the drinking water at different time points for MAFLD prevention and reversal studies. A MAFLD prevention study was performed by feeding mice an HFD concomitant with 4% glutamine treatment for 24 weeks, whereas the MAFLD reversal study was performed based on 4% glutamine treatment for 13 weeks after feeding mice an HFD for 10 weeks. In the prevention study, glutamine treatment ameliorated serum lipid storage, hepatic lipid injury, and oxidative stress in HFD-induced obese mice, although glutamine supplementation did not affect body weight, glucose homeostasis, energy expenditure, and mitochondrial function. In the MAFLD reversal study, there were no noticeable changes in the basic physiological phenotype and hepatic lipid metabolism. In summary, glutamine might prevent, but not reverse, HFD-induced MAFLD in mice, suggesting that a cautious attitude is required regarding its use for MAFLD treatment.

Cynapanoside A exerts protective effects against obesity-induced diabetic nephropathy through ameliorating TRIM31-mediated inflammation, lipid synthesis and fibrosis.

Obesity is a major predictive factor for the diabetic nephropathy (DN). However, the precise mechanism and therapeutic approach still require to be investigated. Cynapanosides A (CPS-A) is a glycoside derived from the Chinese drug Cynanchum paniculatum that has numerous pharmacological activities, but its regulatory function on obesity-induced kidney disease is still obscure. In the present study, we attempted to explore the renoprotective effects of CPS-A on the established DN in high fat diet (HFD)-fed mice, and the underlying mechanisms. We initially found that CPS-A significantly ameliorated the obesity and metabolic syndrome in mice with HFD feeding. Mice with HFD-induced DN exerted renal dysfunctions, indicated by the elevated functional parameters, including up-regulated blood urea nitrogen (BUN), urine albumin and creatinine, which were significantly attenuated by CPS-A in obese mice. Moreover, histological changes including glomerular enlargement, sclerosis index and collagen deposition in kidney of obese mice were detected, while being strongly ameliorated by CPS-A. Additionally, podocyte loss induced by HFD was also markedly mitigated in mice with CPS-A supplementation. HFD feeding also led to lipid deposition and inflammatory response in renal tissues of obese mice, whereas being considerably attenuated after CPS-A consumption. Intriguingly, we found that tripartite motif-containing protein 31 (TRIM31) signaling might be a crucial mechanism for CPS-A to perform its renoprotective functions in mice with DN. The anti-inflammatory, anti-fibrotic and anti-dyslipidemia capacities of CPS-A were confirmed in the mouse podocytes under varying metabolic stresses, which were however almost abolished upon TRIM31 ablation. These data elucidated that TRIM31 expression was largely required for CPS-A to perform its renoprotective effects. Collectively, our study is the first to reveal that CPS-A may be a promising therapeutic strategy for the treatment of obesity-induced DN or associated kidney disease.

Correlation analysis between mechanical power, transforming growth factor-ß1, and connective tissue growth factor levels in acute respiratory distress syndrome patients and their clinical significance in pulmonary structural remodeling.

BACKGROUND: To identify the clinical correlations between mechanical power and transforming growth factor-ß1 (TGF-ß1) and connective tissue growth factor (CTGF) in acute respiratory distress syndrome (ARDS) patients, their clinical significance in pulmonary structural remodeling in ARDS patients was investigated. METHODS: Ninety-five patients with moderate or severe ARDS, who required mechanical ventilation therapy, were randomly selected among hospitalized patients from January 2017 to February 2019. Their mechanical power was monitored and recorded, the TGF-ß1 and CTGF levels were detected by enzyme-linked immunosorbent assay (ELISA), their relevance was analyzed, and the relationship between mechanical power and 28-day survival rate was investigated. According to the high-resolution computed tomography (HRCT) examination, the patients were divided into an ARDS group and an ARDS pulmonary fibrosis (ARDS-PF) group. The differences in mechanical power, TGF-ß1, and CTGF between the 2 groups were compared, and the significance of TGF-ß1 and CTGF in the diagnosis of ARDS pulmonary interstitial fibrosis were evaluated. RESULTS: A significant positive correlation between mechanical power and serum TGF-ß1 and CTGF in patients with ARDS was found and the correlation coefficients were 0.424 and 0.581, respectively. The difference between mechanical power and 28-day survival rate was statistically significant (P < .05), while the area under the receiver operating characteristic curves of TGF-ß1 and CTGF for the diagnosis of ARDS pulmonary fibrosis was 0.838 and 0.884, respectively (P < .05). CONCLUSION: A significant correlation between mechanical power and serum fibrosis biomarkers TGF-ß1 and CTGF in ARDS patients was found, and its level was related to the survival prognosis of patients. Mechanical power, TGF-ß1, and CTGF were clinically evaluated for the assessment of lung structural remodeling, such as ARDS pulmonary fibrosis. This study has particular significance to the early prevention of ventilator-induced lung injury and pulmonary fibrosis in patients with ARDS receiving mechanical ventilation.

Biosynthesis and characterization of magnesium oxide and manganese dioxide nanoparticles using Matricaria chamomilla L. extract and its inhibitory effect on Acidovorax oryzae strain RS-2.

Bacterial brown stripe (BBS) is one of the most economically important diseases of rice caused by Acidovorax oryzae (Ao). In order to ensure food security and safe consumption, the use of non-chemical approach is necessary. In this study, MgO and MnO2 were synthesized using chamomile flower extract. The synthesized MgO and MnO2 nanoparticles were characterized by UV-Visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission/scanning electron microscopy. The sizes were 18.2 and 16.5 nm for MgO and MnO2 nanoparticles, respectively. The MgO and MnO2 nanoparticles reduced the growth of Ao strain RS-2 by 62.9 and 71.3%, respectively. Also, the biofilm formation and swimming motility were significantly reduced compared to the control. The antibacterial mechanisms of MgO and MnO2 nanoparticles against RS-2 reveals that MgO and MnO2 nanoparticles penetrated the cells and destroyed the cell membrane leading to leakage of cytoplasmic content. Also, the flow cytometry observation reveals that the apoptotic cell ratio of RS-2 increased from 0.97% to 99.52 and 99.94% when treated with MgO and MnO2 nanoparticles, respectively. Altogether, the results suggest that the synthesized MgO and MnO2 nanoparticles could serve as an alternative approach method for the management of BBS.

Role of type IV secretion system genes in virulence of rice bacterial brown stripe pathogen Acidovorax oryzae strain RS-2.

Type IV secretion system (T4SS) is a specialized nanomachine that is utilized for the pathogenicity of gram-negative bacteria. However, the role of T4SS genes in virulence of rice bacterial brown stripe pathogen Acidovorax oryzae (Ao) strain RS-2 is not clear, which contains T4SS gene cluster based on genome-wide analysis. Here we compared the virulence-related phenotypes between the wild-type strain RS-2 and nine T4SS mutants, which were constructed in this study. Results indicated that mutation of pilT, pilM, pilQ, or pilZ3 genes not only significantly reduced bacterial virulence, but also caused a reduction of 20.4-62.0% in biofilm formation and 37.7-47.7% reduction in motility, but had no effect on exopolysaccharide (EPS) production or extracellular enzymatic activities when compared to the wild type. The four T4SS genes had a differential effect on bacterial growth after 24 h post-incubation. The complemented strains of the four T4SS mutants restored similar virulence symptom as the wild type. In addition, no change was observed in bacterial virulence by mutation of the other five T4SS genes. Totally, these results demonstrated that T4SS played vital roles in bacterial virulence, motility and biofilm formation in plant pathogen Ao strain RS-2.

Gene Expression of Type VI Secretion System Associated with Environmental Survival in Acidovorax avenae subsp. avenae by Principle Component Analysis.

Valine glycine repeat G (VgrG) proteins are regarded as one of two effectors of Type VI secretion system (T6SS) which is a complex multi-component secretion system. In this study, potential biological roles of T6SS structural and VgrG genes in a rice bacterial pathogen, Acidovorax avenae subsp. avenae (Aaa) RS-1, were evaluated under seven stress conditions using principle component analysis of gene expression. The results showed that growth of the pathogen was reduced by H2O2 and paraquat-induced oxidative stress, high salt, low temperature, and vgrG mutation, compared to the control. However, pathogen growth was unaffected by co-culture with a rice rhizobacterium Burkholderia seminalis R456. In addition, expression of 14 T6SS structural and eight vgrG genes was significantly changed under seven conditions. Among different stress conditions, high salt, and low temperature showed a higher effect on the expression of T6SS gene compared with host infection and other environmental conditions. As a first report, this study revealed an association of T6SS gene expression of the pathogen with the host infection, gene mutation, and some common environmental stresses. The results of this research can increase understanding of the biological function of T6SS in this economically-important pathogen of rice.

Differentiation in MALDI-TOF MS and FTIR spectra between two pathovars of Xanthomonas oryzae.

Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas oryzae pv. oryzicola (Xoc) strains are closely related phenotypically and genetically, which make it difficult to differentiate between the two pathovars based on phenotypic and DNA-based methods. In this study, a fast and accurate method was developed based on the differences in MALDI-TOF MS and FTIR spectra between the two pathovars. MALDI-TOF MS analysis revealed that 9 and 10 peaks are specific to Xoo and Xoc, respectively, which can be used as biomarkers to identify and differentiate the two closely related pathovars. Furthermore, FTIR analysis showed that there is a significant difference in both the band frequencies and absorption intensity of various functional groups between the two pathovars. In particular, the 6 peaks at 3433, 2867, 1273, 1065, 983 and 951cm(-1) were specific to the Xoo strains, while one peak at 1572cm(-1) was specific to the Xoc strains. Overall, this study gives the first attempt to identify and differentiate the two pathovars of X. oryzae based on mass and FTIR spectra, which will be helpful for the early detection and prevention of the two rice diseases caused by both X. oryzae pathovars.

Synthesis, characterization, and antibacterial activity of cross-linked chitosan-glutaraldehyde.

This present study deals with synthesis, characterization and antibacterial activity of cross-linked chitosan-glutaraldehyde. Results from this study indicated that cross-linked chitosan-glutaraldehyde markedly inhibited the growth of antibiotic-resistant Burkholderia cepacia complex regardless of bacterial species and incubation time while bacterial growth was unaffected by solid chitosan. Furthermore, high temperature treated cross-linked chitosan-glutaraldehyde showed strong antibacterial activity against the selected strain 0901 although the inhibitory effects varied with different temperatures. In addition, physical-chemical and structural characterization revealed that the cross-linking of chitosan with glutaraldehyde resulted in a rougher surface morphology, a characteristic Fourier transform infrared (FTIR) band at 1559 cm⁻¹, a specific X-ray diffraction peak centered at 2θ = 15°, a lower contents of carbon, hydrogen and nitrogen, and a higher stability of glucose units compared to chitosan based on scanning electron microscopic observation, FTIR spectra, X-ray diffraction pattern, as well as elemental and thermo gravimetric analysis. Overall, this study indicated that cross-linked chitosan-glutaraldehyde is promising to be developed as a new antibacterial drug.

Antibacterial activity of two chitosan solutions and their effect on rice bacterial leaf blight and leaf streak.

BACKGROUND: Bacterial leaf blight and leaf streak are the two most damaging bacterial diseases of rice. However, few bactericidal chemicals are available for controlling both diseases. The antibacterial properties of two kinds of chitosan with different molecular weights and degrees of N-deacetylation and their effect on rice bacterial leaf blight and leaf streak were evaluated. RESULTS: Results showed that the two kinds of chitosan solution possess a strong antibacterial activity against both rice bacterial pathogens and significantly reduced disease incidence and severity by comparison with the control under greenhouse conditions. However, the interaction between chitosan and rice pathogens was affected by the type and concentration of chitosan, the bacterial species and the contact time between chitosan and bacteria. The direct antibacterial activity of chitosan may be attributed to both membrane lysis and the destruction of biofilm. In addition, both chitosan solutions significantly increased the activities of phenylalanine ammonia lyase, peroxidase and polyphenol oxidase in rice seedlings following inoculation of two rice pathogens by comparison with the control. CONCLUSION: The role of chitosan in protection of rice against bacterial pathogens has been shown to involve direct antibacterial activity and indirect induced resistance.

Antifungal effect and mechanism of chitosan against the rice sheath blight pathogen, Rhizoctonia solani.

The antifungal properties and mechanism of three types of chitosan against the rice sheath blight pathogen, Rhizoctonia solani, were evaluated. Each chitosan had strong antifungal activity against R. solani and protected rice seedlings from sheath blight, in particular, two types of acid-soluble chitosan caused a 60-91 % inhibition in mycelial growth, 31-84 % inhibition of disease incidence, and 66-91 % inhibition in lesion length. The mechanism of chitosan in protection of rice from R. solani pathogen was attributed to direct destruction of the mycelium, evidenced by scanning and transmission electron microscopic observations and pathogenicity testing; indirect induced resistance was evidenced by the changes in the activities of the defense-related phenylalanine ammonia lyase, peroxidase and polyphenol oxidase in rice seedling. To our knowledge, this is the first report on the antifungal activity of chitosan against rice R. solani.

Application of the molecular combing technique to starch granules.

The molecular combing technique was used to dissociate the nanostructural units of starch granules from the starch fragments after a gelatinization process. With the help of atomic force microscopy (AFM), we observed that some nanostructural chains were just flowing out of the granules. It proves that there are substantive nanostructural units in the starch granules, a phenomenon not previously observed, so these nanostructural units were defined as suspected intermediates. Furthermore, we conclude that blocklets of starch granules are formed through twisting or distortion of nanochains.

[Isolation and identification of endophytic fungi from Ligusticum].

OBJECTIVE: To investigate the correlation between entophytic fungal community, habitations and varieties of Ligusticum. METHOD: The solidified potato dextrose agar (PDA) of plates was applied for the isolation of the endophytic fungi, and the identification was completed by spot-planting method. RESULT: Fifty strains of the entophytic fungi were isolated from the rhizome of L. chuanxiong collected from 6 habitations. They were morphologically identified as belonging to 13 genera, 4 families, 3 orders and 1 class. CONCLUSION: There were some differences at quantity, species and distributing of the entophytic fungi in different habitats and varieties of Ligusticum, which was suggested that entophytic fungal community is related with specific habitat.