Characterization of gut microbial and metabolite alterations in faeces of Goto Kakizaki rats using metagenomic and untargeted metabolomic approach.

BACKGROUND: In recent years, the incidence of type 2 diabetes (T2DM) has shown a rapid growth trend. Goto Kakizaki (GK) rats are a valuable model for the study of T2DM and share common glucose metabolism features with human T2DM patients. A series of studies have indicated that T2DM is associated with the gut microbiota composition and gut metabolites. We aimed to systematically characterize the faecal gut microbes and metabolites of GK rats and analyse the relationship between glucose and insulin resistance. AIM: To evaluate the gut microbial and metabolite alterations in GK rat faeces based on metagenomics and untargeted metabolomics. METHODS: Ten GK rats (model group) and Wistar rats (control group) were observed for 10 wk, and various glucose-related indexes, mainly including weight, fasting blood glucose (FBG) and insulin levels, homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of ß cell (HOMA-ß) were assessed. The faecal gut microbiota was sequenced by metagenomics, and faecal metabolites were analysed by untargeted metabolomics. Multiple metabolic pathways were evaluated based on the differential metabolites identified, and the correlations between blood glucose and the gut microbiota and metabolites were analysed. RESULTS: The model group displayed significant differences in weight, FBG and insulin levels, HOMA-IR and HOMA-ß indexes (P < 0.05, P < 0.01) and a shift in the gut microbiota structure compared with the control group. The results demonstrated significantly decreased abundances of Prevotella sp. CAG:604 and Lactobacillus murinus (P < 0.05) and a significantly increased abundance of Allobaculum stercoricanis (P < 0.01) in the model group. A correlation analysis indicated that FBG and HOMA-IR were positively correlated with Allobaculum stercoricanis and negatively correlated with Lactobacillus murinus. An orthogonal partial least squares discriminant analysis suggested that the faecal metabolic profiles differed between the model and control groups. Fourteen potential metabolic biomarkers, including glycochenodeoxycholic acid, uric acid, 13(S)-hydroxyoctadecadienoic acid (HODE), N-acetylaspartate, ß-sitostenone, sphinganine, 4-pyridoxic acid, and linoleic acid, were identified. Moreover, FBG and HOMA-IR were found to be positively correlated with glutathione, 13(S)-HODE, uric acid, 4-pyridoxic acid and allantoic acid and ne-gatively correlated with 3-α, 7-α, chenodeoxycholic acid glycine conjugate and 26-trihydroxy-5-ß-cholestane (P < 0.05, P < 0.01). Allobaculum stercoricanis was positively correlated with linoleic acid and sphinganine (P < 0.01), and 2-methyl-3-hydroxy-5-formylpyridine-4-carboxylate was negatively associated with Prevotella sp. CAG:604 (P < 0.01). The metabolic pathways showing the largest differences were arginine biosynthesis; primary bile acid biosynthesis; purine metabolism; linoleic acid metabolism; alanine, aspartate and glutamate metabolism; and nitrogen metabolism. CONCLUSION: Metagenomics and untargeted metabolomics indicated that disordered compositions of gut microbes and metabolites may be common defects in GK rats.

Effect of berberine on hyperglycaemia and gut microbiota composition in type 2 diabetic Goto-Kakizaki rats.

BACKGROUND: A recent investigation showed that the prevalence of type 2 diabetes mellitus (T2DM) is 12.8% among individuals of Han ethnicity. Gut microbiota has been reported to play a central role in T2DM. Goto-Kakizaki (GK) rats show differences in gut microbiota compared to non-diabetic rats. Previous studies have indicated that berberine could be successfully used to manage T2DM. We sought to understand its hypoglycaemic effect and role in the regulation of the gut microbiota. AIM: To determine whether berberine can regulate glucose metabolism in GK rats via the gut microbiota. METHODS: GK rats were acclimatized for 1 wk. The GK rats were randomly divided into three groups and administered saline (Mo), metformin (Me), or berberine (Be). The observation time was 8 wk, and weight, fasting blood glucose (FBG), insulin, and glucagon-like peptide-1 (GLP-1) were measured. Pancreatic tissue was observed for pathological changes. Additionally, we sequenced the 16S rRNA V3-V4 region of the gut microbiota and analysed the structure. RESULTS: Compared with the Mo group, the Me and Be groups displayed significant differences in FBG (P < 0.01) and GLP-1 (P < 0.05). A significant decrease in weight and homeostatic model assessment-insulin resistance was noted in the Be group compared with those in the Me group (P < 0.01). The pancreatic islets of the Me- and Be-treated rats showed improvement in number, shape, and necrosis compared with those of Mo-treated rats. A total of 580 operational taxonomic units were obtained in the three groups. Compared to the Mo group, the Me and Be groups showed a shift in the structure of the gut microbiota. Correlation analysis indicated that FBG was strongly positively correlated with Clostridia_UCG-014 (P < 0.01) and negatively correlated with Allobaculum (P < 0.01). Body weight showed a positive correlation with Desulfovibrionaceae (P < 0.01) and a negative correlation with Akkermansia (P < 0.01). Importantly, our results demonstrated that Me and Be could significantly decrease Bacteroidetes (P < 0.01) and the Bacteroidetes/Firmicutes ratio (P < 0.01). Furthermore, Muribaculaceae (P < 0.01; P < 0.05) was significantly decreased in the Me and Be groups, and Allobaculum (P < 0.01) was significantly increased. CONCLUSION: Berberine has a substantial effect in improving metabolic parameters and modulating the gut microbiota composition in T2DM rats.

Effect of vitamin D on ventricular remodelling in heart failure: a meta-analysis of randomised controlled trials.

OBJECTIVES: The level of vitamin D is considered to be associated with the development and progression of heart failure (HF). However, it is still unclear whether supplementation of vitamin D could improve ventricular remodelling in patients with HF. This study aimed to systematically evaluate the influence and safety of additional vitamin D supplementation on ventricular remodelling in patients with HF. DESIGN: This study is a meta-analysis of randomised controlled trials (RCTs). SETTING: The PubMed, EMBASE, CNKI, Cochrane library, Web of Science databases and grey literature were searched for RCTs regarding the effect of vitamin D on ventricular remodelling in patients with HF (from database creation to October 2017). RevMan V.5.3 software was employed for data analysis. PARTICIPANTS: Seven RCTs with a total of 465 patients, including 235 cases in the vitamin D group and 230 cases in the control group, were included. PRIMARY AND SECONDARY OUTCOME MEASURES: Left ventricular end-diastolic dimension (LVEDD), left ventricular ejection fraction (LVEF) and the incidence of adverse reactions. RESULTS: Compared with the control group, a decrease in the LVEDD (mean difference (MD)=-2.31 mm, 95% CI -4.15 to -0.47, p=0.01) and an increase in the LVEF (MD=4.18%, 95% CI 0.36 to 7.99, p=0.03) were observed in the vitamin D group. Subgroup analysis also revealed a reduced LVEDD in adults (>18 years) and adolescents (<18 years) of the vitamin D group relative to that in those of the control group. High-dose vitamin D (>4000 IU/day) was more effective at reducing the LVEDD than low-dose vitamin D (<4000 IU/day). Moreover, vitamin D supplementation was more effective at reducing the LVEDD and increasing the LVEF in patients with reduced ejection fraction than in patients without reduced ejection fraction. CONCLUSION: Vitamin D supplementation inhibits ventricular remodelling and improves cardiac function in patients with HF. TRIAL REGISTRATION NUMBER: CRD42017073893.

Novel Polysaccharide H-1-2 from Pseudostellaria Heterophylla Alleviates Type 2 Diabetes Mellitus.

BACKGROUND/AIMS: To investigate the potential therapeutic effect of novel polysaccharide H-1-2 from pseudostellaria heterophylla against type 2 Diabetes Mellitus (T2DM) and elucidate the underling molecular mechanisms. METHODS: Relative expression of HIF1α and Sirt1 in T2DM patients was determined via real-time PCR. The direct binding of HIF1α on Sirt1 promoter was validated by ChIP assay. The inhibitory regulation of Sirt1 by HIF1α was analyzed using luciferase reporter assay. The endogenous protein of HIF1α and Sirt1 in response to H-1-2 treatment was quantified by western blotting. The blood glucose, secreted insulin and serous lipid profiles were measured with ELISA kits. RESULTS: We consolidated that HIF1α and Sirt1 was dysregulated in T2DM patients and subjected to H-1-2 modulation. H-1-2 significantly inhibited hypoxia and up-regulated Sirt1 expression in EndoC-ßH1 cells. Accordingly, H-1-2 enhanced glucose-stimulation insulin secretion and improved blood glucose and lipid profiles in T2DM cells, and elevated the glucose and insulin tolerance simultaneously. Furthermore, we demonstrated that H-1-2 alleviated T2DM via inhibition of hypoxia and up-regulation of Sirt1 in isolated pancreatic ß-cells from T2DM rats. CONCLUSION: Our data unambiguously demonstrated H-1-2 administration alleviated T2DM by enhancing Sirt1 expression through inhibition of hypoxia.

[Research advances on astragaloside-IV in treatment of diabetes mellitus and its complications pharmacological effects].

Diabetes has become a global public health problem that seriously threatens human health. Traditional Chinese medicine, the characteristics of the role of multiple targets, has a unique advantage in the prevention and treatment of diabetes mellitus and its complications. Astragaloside-Ⅳ (AS-Ⅳ), one of the main activities of Astragalus membranaceus, has a series of pharmacological effects including improvement in the function of endothelial cells and neovascularization, anti-inflammatory, antioxidant, regulating energy metabolism, protectionnervous, anti-cancer and so on. In this paper, AS-Ⅳ to prevent and treat diabetes and its complications has been reviewed, which has effect on lowering blood sugar, lowering blood pressure, improving insulin resistance, inhibiting inflammatory reaction and oxidative stress. Additionally, it also can improve the diabetic animal and cell model of diabetic vascular disease, diabetic nephropathy, diabetic retinopathy, diabetic peripheral neuropathy, diabetic cardiomyopathy and other pathological damages. AS-Ⅳ may be a potential active substance for the treatment of diabetes and its complications.

Integrated transcriptomic and proteomic analysis of the global response of Synechococcus to high light stress.

Sufficient light is essential for the growth and physiological functions of photosynthetic organisms, but prolonged exposure to high light (HL) stress can cause cellular damage and ultimately result in the death of these organisms. Synechococcus sp. PCC 7002 (hereafter Synechococcus 7002) is a unicellular cyanobacterium with exceptional tolerance to HL intensities. However, the molecular mechanisms involved in HL response by Synechococcus 7002 are not well understood. Here, an integrated RNA sequencing transcriptomic and quantitative proteomic analysis was performed to investigate the cellular response to HL in Synechococcus 7002. A total of 526 transcripts and 233 proteins were identified to be differentially regulated under HL stress. Data analysis revealed major changes in mRNAs and proteins involved in the photosynthesis pathways, resistance to light-induced damage, DNA replication and repair, and energy metabolism. A set of differentially expressed mRNAs and proteins were validated by quantitative RT-PCR and Western blot, respectively. Twelve genes differentially regulated under HL stress were selected for knockout generation and growth analysis of these mutants led to the identification of key genes involved in the response of HL in Synechococcus 7002. Taken altogether, this study established a model for global response mechanisms to HL in Synechococcus 7002 and may be valuable for further studies addressing HL resistance in photosynthetic organisms.

Proteogenomic analysis and global discovery of posttranslational modifications in prokaryotes.

We describe an integrated workflow for proteogenomic analysis and global profiling of posttranslational modifications (PTMs) in prokaryotes and use the model cyanobacterium Synechococcus sp. PCC 7002 (hereafter Synechococcus 7002) as a test case. We found more than 20 different kinds of PTMs, and a holistic view of PTM events in this organism grown under different conditions was obtained without specific enrichment strategies. Among 3,186 predicted protein-coding genes, 2,938 gene products (>92%) were identified. We also identified 118 previously unidentified proteins and corrected 38 predicted gene-coding regions in the Synechococcus 7002 genome. This systematic analysis not only provides comprehensive information on protein profiles and the diversity of PTMs in Synechococcus 7002 but also provides some insights into photosynthetic pathways in cyanobacteria. The entire proteogenomics pipeline is applicable to any sequenced prokaryotic organism, and we suggest that it should become a standard part of genome annotation projects.

Global phosphoproteomic analysis reveals diverse functions of serine/threonine/tyrosine phosphorylation in the model cyanobacterium Synechococcus sp. strain PCC 7002.

Increasing evidence shows that protein phosphorylation on serine (Ser), threonine (Thr), and tyrosine (Tyr) residues is one of the major post-translational modifications in the bacteria, involved in regulating a myriad of physiological processes. Cyanobacteria are one of the largest groups of bacteria and are the only prokaryotes capable of oxygenic photosynthesis. Many cyanobacteria strains contain unusually high numbers of protein kinases and phosphatases with specificity on Ser, Thr, and Tyr residues. However, only a few dozen phosphorylation sites in cyanobacteria are known, presenting a major obstacle for further understanding the regulatory roles of reversible phosphorylation in this group of bacteria. In this study, we carried out a global and site-specific phosphoproteomic analysis on the model cyanobacterium Synechococcus sp. PCC 7002. In total, 280 phosphopeptides and 410 phosphorylation sites from 245 Synechococcus sp. PCC 7002 proteins were identified through the combined use of protein/peptide prefractionation, TiO2 enrichment, and LC-MS/MS analysis. The identified phosphoproteins were functionally categorized into an interaction map and found to be involved in various biological processes such as two-component signaling pathway and photosynthesis. Our data provide the first global survey of phosphorylation in cyanobacteria by using a phosphoproteomic approach and suggest a wide-ranging regulatory scope of this modification. The provided data set may help reveal the physiological functions underlying Ser/Thr/Tyr phosphorylation and facilitate the elucidation of the entire signaling networks in cyanobacteria.

Efficacy of percutaneous kyphoplasty in treating osteoporotic multithoracolumbar vertebral compression fractures.

Percutaneous kyphoplasty is a minimally invasive technique that has become an effective and routine alternative for managing osteoporotic vertebral compression fractures. This article reports the clinical outcome of a series of 54 cases of osteoporotic thoracolumbar vertebrae compression fractures treated by percutaneous kyphoplasty. Fifty-four patients with confirmed osteoporosis and at least 1 level of thoracolumbar vertebrae compression fracture were retrospectively selected. Pre- and postoperative and last follow-up clinical evaluation and radiological data were analyzed, including change of visual analog scale (VAS), reduced use of painkillers, locomotor activity, Cobb's angle, and average vertebral body height. Mean follow-up was 20.4 months (range, 6-36 months). In all cases, percutaneous kyphoplasty treatment was successful, significantly increasing vertebral body height, diminishing kyphosis in the fractured vertebrae, and decreasing painkiller use. In all patients, percutaneous kyphoplasty partially or completely relieved back pain. No new deformity was found within the follow-up period, nor were any other complications. The cement leakage rate was 3.86% (8 of 207 vertebrae) with percutaneous kyphoplasty, but no neurological or other complaints were received. Percutaneous kyphoplasty is a simple and safe procedure in managing osteoporotic vertebrae compression fractures. It relieves pain quickly, restores vertebral height, prevents further fracture, and improves patient quality of life.

[Expression and characterization of FNRD in cyanobacterium Synechococcus sp. PCC 7002].

The petHL genes under the control of Lac and Kan promoters were transformed into Synechococcus sp. PCC 7002, respectively. Both of the petHL genes are integrated into the cyanobacterium chromosomes, which is inferred from the results of Southern blot analysis. Western blot analysis results show that both petHL genes are expressed in the transformed cells, and Kan promoter is more effective than Lac promoter. The FNRD in vivo shows the same stability as that of FNR holoenzyme. Some FNRD molecules are probably acylated as judged by the result of Triton X-114 phase partition test. FNRD in vivo might act as a component in photosynthetic electron transport chain, which increases the photosynthetic oxygen evolution rate.

Genome-wide ORFeome cloning and analysis of Arabidopsis transcription factor genes.

Here, we report our effort in generating an ORFeome collection for the Arabidopsis transcription factor (TF) genes. In total, ORFeome clones representing 1,282 Arabidopsis TF genes have been obtained in the Gateway high throughput cloning pENTR vector, including 411 genes whose annotation lack cDNA support. All the ORFeome inserts have also been mobilized into a yeast expression destination vector, with an estimated 85% rate of expressing the respective proteins. Sequence analysis of these clones revealed that 34 of them did not match with either the reported cDNAs or current predicted open-reading-frame sequences. Among those, novel alternative splicing of TF gene transcripts is responsible for the observed differences in at least five genes. However, those alternative splicing events do not appear to be differentially regulated among distinct Arabidopsis tissues examined. Lastly, expression of those TF genes in 17 distinct Arabidopsis organ types and the cultured cells was profiled using a 70-mer oligo microarray.