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 β cell (HOMA-β) 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-β 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, β-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-β-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.

[A prospective cohort study on refractive status of schoolchildren in Huangzhong District, Xining City, Qinghai Province]

Objective: To determine the characteristics and progress of the visual acuity and refractive state of schoolchildren in Huangzhong District, Xining City, Qinghai Province in China. Methods: Cohort study. Department of Ophthalmology, Beijing Children's Hospital carried out a cohort study by collecting the visual acuity and refractive state of Grade 1-5 schoolchildren among 16 primary schools in Huangzhong District, Xining City, Qinghai Province in September 2020 and July 2021. Cycloplegic retinoscopy with eye drop which contained tropicamide (0.5%) and phenylephrine hydrochloride (0.5%) was performed in children with low vision(<1.0). Myopia was defined as the spherical equivalent (SE) ≤-0.5 D after cycloplegic retinoscopy. Measurement data was analyzed by t-test and enumeration data was analyzed by χ² test. Multiple linear regression was used to analyze the influencing factors. Results: The 2 489 individuals with repeated tests in two years were included in the follow-up study, among whom the prevalence of myopia was 26.24%(653/2 489) in 2020, while 32.94% (820/2 489)respectively in 2021. The incidence of myopia in one school year from grades 1 to 5 was 11.19%(47/420), 5.44%(21/386), 6.39%(25/391), 11.52%(44/382) and 11.67%(30/257). The average SE of children in all grades in 2021 increased negatively from the previous year (Grade 1 to Grade 5 increased respectively: 0.40 D, 0.69 D, 0.62 D, 0.52 D and 0.37 D). Conclusions: The prevalence of myopia among schoolchildren in Huangzhong District, Xining City, Qinghai Province was relatively high. There were two peaks of myopia incidence in the first, fourth and fifth grades. Female, age, and the baseline of SE were the related influencing factors for myopia progression.

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.

[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.

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-βH1 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 β-cells from T2DM rats.

CONCLUSION

Our data unambiguously demonstrated H-1-2 administration alleviated T2DM by enhancing Sirt1 expression through inhibition of hypoxia.

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.

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.

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.

[The clinical features of laryngeal malignant lymphoma with 5 cases reported]

OBJECTIVE

To improve the diagnosis and treatment of laryngeal malignant lymphoma.

METHOD

Clinical features of 5 cases were reported and recent literatures were reviewed.

RESULT

2 cases presented with large ulcerated lesions and their laryngeal structure were destroyed, their prognosis were poor. Another 3 cases were local primary lesions, they were generally associated with a relatively short history of hoarseness and dysphagia and exhibited grey-white neoplasms with preferential involvement in the supraglottic parts of larynx, but non-ulcerated lesions, they were treated with operation and radiotherapy or chemotherapy or combinations. The prognosis were very well after 2 to 6 years follow up.

CONCLUSION

It is important for the local primary lesion to be diagnosed correctly for the treatment and prognosis.

PsaD is required for the stable binding of PsaC to the photosystem I core protein of Synechococcus sp. PCC 6301

The psaC gene product from Synechococcus sp. PCC 7002 and the psaD gene product from Nostoc sp. PCC 8009 were synthesized in Escherichia coli and purified to homogeneity. Incubation of the PsaC apoprotein with the Synechoccus sp. PCC 6301 photosystem I core protein in the presence of FeCl3, Na2S, and beta-mercaptoethanol resulted in a time-dependent transition in the flash-induced absorption change from a 1.2-ms, P700+ FX- back-reaction to a long-lived, P700+ [FA/FB]- back-reaction. ESR studies showed that FB and FA were photoreduced about equally at 19 K, and while the resonances were shifted upfield, they remained as broad as in the free PsaC holoprotein. When the reconstituted complex was purified in a sucrose gradient containing 0.1% Triton X-100, most of the optical absorption transient reverted to that characteristic of the P700+ FX- back-reaction. Addition of purified PsaD to the incubation mixture led to a greater extent of recovery of electron flow to FA/FB for any given concentration of PsaC. ESR studies showed that FA, rather than FB, became the preferred electron acceptor at 19 K; moreover, the resonances moved upfield and sharpened to become nearly identical with those of a control photosystem I complex. When the sample was purified in a sucrose gradient containing 0.1% Triton X-100, the long-lived P700+ [FA/FB]- optical transient remained stable. Analysis by denaturing polyacrylamide gel electrophoresis showed that the PsaC and PsaD proteins had rebound to the photosystem I core. The data indicate that although PsaC can bind loosely, the presence of PsaD leads to a stable, isolatable photosystem I complex which is spectroscopically indistinguishable from the native complex. Since a PsaC1 fusion protein which contains an amino-terminal extension of five amino acids (MEHSM...) does not bind in the absence of PsaD [Zhao, J., et al. (1990) FEBS Lett. 276, 175-180], the N-terminus of the PsaC protein could provide a site of interaction with the photosystem I core. We propose that the binding of PsaC to the PsaA/PsaB heterodimer is potentiated by insertion of the FA/FB clusters into PsaC, and stabilized by the presence of PsaD.

Reconstitution of electron transport in photosystem I with PsaC and PsaD proteins expressed in Escherichia coli

A fusion protein, denoted PsaC1, which contains an amino-terminal extension of five amino acids (MEHSM...) and is derived from an in vitro modified form of the psaC gene of Synechococcus sp. PCC 7002, has been over-expressed in Escherichia coli. The product of the psaD gene of Nostoc sp. PCC 8009 has similarly been over-expressed. The PsaC1 and PsaD proteins can be combined with the photosystem I core protein of Synechococcus sp. PCC 6301 to reconstitute electron transport from P700 to the terminal FA/FB acceptors. Reconstitution was found to be absolutely dependent on reinsertion of the iron-sulfur clusters in the PsaC1 apoprotein and on the presence of the PsaD protein. This implies that the PsaC1 holoprotein does not bind solely to the PsaA/PsaB heterodimer but rather that its interaction with these proteins is mediated through the PsaD protein.

Sequential effects of sodium depletion on photosystem II in Synechocystis

Incubation of Synechocystis PCC 6714 in liquid medium devoid of Na+ results in a light-dependent loss in photosynthetic O2 evolving capacity within 1 h. Photosynthetic activity is fully restored and normal growth resumes after Na+ is supplied to culture medium of depleted cells. If external Na+ is provided as soon as inhibition becomes complete, normal photosynthesis is restored within 3 min. However, if cells are further illuminated for several h under Na+ stress, then full recovery takes much longer, and requires new protein synthesis. Electron transport assays using isolated membranes demonstrate that the immediate inhibition resulting from Na+ depletion involves the O2 evolving site, while the secondary effect requiring new protein synthesis occurs near the reaction center of Photosystem II. Experiments conducted at different pH values and in the absence of inorganic carbon demonstrate that within the short time duration of these experiments Na+ does not inhibit photosynthesis by restricting bicarbonate movement into the cells. These experiments extend previous results with other cyanobacteria which demonstrated that Ca2+ and Na+ stress cause reversible damage at a site near the reaction center of Photosystem II. The damage can be characterized as a primary ion effect at the oxygen evolving site and a secondary photoinhibition near the reaction center of Photosystem II.

Long-term follow-up observations of the therapeutic effect of PVNO on human silicosis

The effect of PVNO treatment on human silicosis was observed in 7 cases over a period of 9 years lasting from 1965 to 1974. The drug was given intramuscularly and by way of inhalation, respectively. The comparison of the radiographs taken before, during and 3 years after the administration of PVNO showed that during treatment the tendency of fibrotic progression was delayed in 4 cases while 2 cases were slightly progressive, and one was markedly progressive, 3 years after discontinuation of the PVNO treatment, only one case remained stable, two cases were slightly and 4 cases markedly progressive. These observations indicate that PVNO treatment may have an effect on the delay and control of silicosis progression in a portion of patients, but after discontinuation of the treatment further progression is possible.