Phellinus igniarius Polysaccharides Ameliorate Hyperglycemia by Modulating the Composition of the Gut Microbiota and Their Metabolites in Diabetic Mice

Gut microbiota dysbiosis has been reported as a risk factor in the development of type 2 diabetes mellitus (T2DM). Polysaccharides from Phellinus igniarius (P. igniarius) possess various properties that help manage metabolic diseases; however, their underlying mechanism of action remains unclear. Therefore, in this study, we aimed to evaluate the effect of P. igniarius polysaccharides (SH-P) on improving hyperglycemia in mice with T2DM and clarified its association with the modulation of gut microbiota and their metabolites using 16S rDNA sequencing and liquid chromatography-mass spectrometry. Fecal microbiota transplantation (FMT) was used to verify the therapeutic effects of microbial remodeling. SH-P supplementation alleviated hyperglycemia symptoms in T2DM mice, ameliorated gut dysbiosis, and significantly increased the abundance of Lactobacillus in the gut. Pathway enrichment analysis indicated that SH-P treatment altered metabolic pathways associated with the occurrence and development of diabetes. Spearman's correlation analysis revealed that changes in the dominant bacterial genera were significantly correlated with metabolite levels closely associated with hyperglycemia. Additionally, FMT significantly improved insulin sensitivity and antioxidative capacity and reduced inflammation and tissue injuries, indicating improved glucose homeostasis. These results indicate that the ameliorative effects of SH-P on hyperglycemia are associated with the modulation of gut microbiota composition and its metabolites.

Cordyceps cicadae polysaccharides alleviate hyperglycemia by regulating gut microbiota and its mmetabolites in high-fat diet/streptozocin-induced diabetic mice

Introduction

The polysaccharides found in Cordyceps cicadae (C. cicadae) have received increasing academic attention owing to their wide variety of therapeutic activities.

Methods

This study evaluated the hypoglycemic, antioxidant, and anti-inflammatory effects of polysaccharides from C. cicadae (CH-P). In addition, 16s rDNA sequencing and untargeted metabolomics analysis by liquid chromatography-mass spectrometry (LC-MS) were used to estimate the changes and regulatory relationships between gut microbiota and its metabolites. The fecal microbiota transplantation (FMT) was used to verify the therapeutic effects of microbial remodeling.

Results

The results showed that CH-P treatment displayed hypoglycemic, antioxidant, and anti-inflammatory effects and alleviated tissue damage induced by diabetes. The CH-P treatment significantly reduced the Firmicutes/Bacteroidetes ratio and increased the abundance of Bacteroides, Odoribacter, Alloprevotella, Parabacteroides, Mucispirillum, and significantly decreased the abundance of Helicobacter and Lactobacillus compared to the diabetic group. The alterations in the metabolic pathways were mostly related to amino acid biosynthesis and metabolic pathways (particularly those involving tryptophan) according to the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Correlation analysis showed that Bacteroides, Odoribacter, Alloprevotella, Parabacteroides, and Mucispirillum were positively correlated with indole and its derivatives, such as 5-hydroxyindole-3-acetic acid. Indole intervention significantly improved hyperglycemic symptoms and insulin sensitivity, and increased the secretion of glucagon-like peptide-1 (GLP-1) in diabetic mice. FMT reduced blood glucose levels, improved glucose tolerance, and increased insulin sensitivity in diabetic mice. However, FMT did not significantly improve GLP-1 levels.

Discussion

This indicates that C. cicadae polysaccharides alleviate hyperglycemia by regulating the production of metabolites other than indole and its derivatives by gut microbiota. This study provides an important reference for the development of novel natural products.

Delays in diagnosis and treatment of pulmonary tuberculosis in AFB smear-negative patients with pneumonia

BACKGROUND

Diagnostic and treatment delays increase the severity and transmission of pulmonary tuberculosis (PTB). This study aimed to evaluate TB diagnostic and treatment delays in acid-fast bacilli (AFB) smear-negative patients.

METHODS

This was a retrospective observational study. Patients with positive AFB culture of Mycobacterium tuberculosis complex (MTC) were selected from among hospitalised patients with a diagnosis of pneumonia. Admission ward, anti-tuberculosis treatment and the duration of AFB culture were compared between smear-positive and smear-negative patients.

RESULTS

Of the 70 patients with positive isolation of MTC in AFB culture, 27 (38.5%) were smear-negative; of these, 18 (66.7%) were not isolated while in hospital, and 17 (63%) were neither diagnosed nor treated for TB. In contrast, 41 of the 43 smear-positive patients (95.3%) were directly admitted or quickly transferred to the isolation room and started on anti-tuberculosis treatment (P < 0.001). Samples from smear-negative patients required more time to grow MTC in AFB culture than those of smear-positive patients (23 days vs. 14 days, P < 0.001). Diabetes was significantly associated with AFB smear positivity, with an odds ratio of 12.2.

CONCLUSIONS

Negative AFB smears caused significant diagnostic and treatment delay. Patients staying in the general ward were exposed to TB patients who were not diagnosed in time.

Differential Protein Expression between Type 1 Diabetic Cataract and Age-Related Cataract Patients

Diabetes has become one of the major diseases affecting human health. Diabetic cataracts (DCs) are considered a common complication in diabetic patients. The present study investigated differences in lens proteomic profiles between DCs and age-related cataracts (ACs) to determine the mechanism underlying the formation of DCs. Intrasurgical samples were collected from eight DC patients and 12 AC patients, and lens proteins were extracted by lysis and separated using two-dimensional gel electrophoresis (2-DE). The electrophoretic bands were analysed using PD-Quest software 8.0.1. Differentially expressed proteins were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and peptide mass fingerprinting combined with protein database searching. In the 2-DE maps, the DC and AC lens proteins migrated in the region of pH 5-9 with a relative molecular weight (RMW) of 14-97 kDa, whereas the RMW of more abundant crystallin was 20-31 kDa. Approximately three protein spots with differential intensity were detected. Two crystallin proteins (αB and βB1) were identified using MALDI-TOF-MS. Proteomic analysis of the crystalline humour is feasible, and the proteins can be well separated; moreover, differentially expressed lens proteins can be analysed using 2-DE and mass spectrometry to compare DC and AC. The present results indicate that the αB and βB1 crystallins may accelerate the development of DCs. These techniques offer new avenues for mechanistic evaluation and future prevention or therapy of DCs.

Paraoxonase 1 status in keratoconus: a preliminary study of activity and polymorphism

OBJECTIVE

To determine the activity of paraoxonase 1 (PON1) in keratoconus in a Malaysian population in comparison with non-keratoconic subjects.

METHODS

Clinical eye examinations were performed on patients with keratoconus and non-keratoconic subjects after questionnaires were completed. Blood samples were collected and subjected to spectrophotometric analysis of paraoxonase and diazoxonase activities for the determination of the status of PON1 of every individual.

RESULTS

Of the 11 keratoconic patients and 55 non-keratoconic control samples collected, eight patients of Indian ethnicity were keratoconic (73%), whereas 33 non-Indians were non-keratoconic (60%; p = 0.047). Paraoxonase activity was lower in Indians compared to the non-Indians ie Malays and Chinese (p = 0.008). Keratoconic subjects had a lower paraoxonase activity compared to non-keratoconics (p = 0.038).

CONCLUSIONS

The reduced paraoxonase activity in keratoconic patients suggests that the keratoconic corneas were more susceptible to oxidative stress. Reduced paraoxonase activity and keratoconus status appears to be associated with ethnicity.

Catalpol attenuates MPTP induced neuronal degeneration of nigral-striatal dopaminergic pathway in mice through elevating glial cell derived neurotrophic factor in striatum

The protective effect of an iridoid catalpol extracted and purified from the traditional Chinese medicinal herb Rehmannia glutinosa on the neuronal degeneration of nigral-striatal dopaminergic pathway was studied in a chronic 1-methyl-4-phenyl-1,2,3,4-tetrahydropyridine (MPTP)/probenecid C57BL/6 mouse model and in 1-methyl-4-phenylpyridimium (MPP(+)) intoxicated cultured mesencephalic neurons. Rotarod performance revealed that the locomotor ability of mice was significantly impaired after completion of model production and maintained thereafter for at least 4 weeks. Catalpol orally administered for 8 weeks (starting from the second week of model production) dose dependently improved the locomotor ability. HPLC revealed that catalpol significantly elevated striatal dopamine levels without changing the metabolite/dopamine ratios. Nor did it bind to dopamine receptors. Therefore it is unlikely that catalpol resembles any of the known compounds for treating Parkinsonism. Instead, catalpol dose dependently raised the tyrosine hydroxylase (TH) neuron number in substantia nigra pars compacta (SNpc), the striatal dopamine transporter (DAT) density and the striatal glial cell derived neurotrophic factor (GDNF) protein level. Linear regression revealed that both the TH neuron number and DAT density were positively correlated to the GDNF level. In the cultured mesencephalic neurons, MPP(+) decreased the dopaminergic neuron number and shortened the neurite length, whereas catalpol showed protective effect dose dependently. Furthermore, the expression of GDNF mRNA was up-regulated by catalpol to a peak nearly double of normal control in neurons intoxicated with MPP(+) for 24 h but not in normal neurons. The GDNF receptor tyrosine kinase RET inhibitor 4-amino-5-(4-methyphenyl)-7-(t-butyl)-pyrazolo-[3,4-d]pyrimidine (PP1) abolished the protective effect of catalpol either partially (TH positive neuron number) or completely (neurite length). Taken together, catalpol improves locomotor ability by attenuating the neuronal degeneration of nigral-striatal dopaminergic pathway, and this attenuation is at least partially through elevating the striatal GDNF expression.

Is post-Lipiodol CT better than i.v. contrast CT scan for early detection of HCC? A single liver transplant center experience

Hepatocellular carcinoma is a highly vascular neoplasm usually arising from a cirrhotic liver. Delayed, noncontrast, computed tomography (CT) imaging after 7 to 14 days reveals an oil-based contrast agent to be concentrated in the tumor but not in normal hepatic parenchyma. The aim of this study was to retrospectively correlate the post Lipiodol CT scan findings with respect to tumor size in the explanted liver. We retrospectively reviewed adult patients who had undergone orthotopic liver transplantation between November 1995 and December 2004 and also had an hepatic arteriogram with Lipiodol injection as part of their pretransplant workup. We calculated sensitivity, specificity, false-negativity, false-positivity, and accuracy of the test, as well as positive and negative predictive values. Lipiodol CT exam had sensitivity of 1.0; specificity of 0.6 with a calculated positive predictive value of 0.89 and a negative predictive value of 1.0. Overall accuracy of Lipiodol CT scan test was found to be 0.91, which was superior to an intravenous contrast CT alone. In conclusion, because of the higher sensitivity and accuracy values, hepatic arterial Lipiodol injection can be considered during the pretransplantation workup of high-risk cirrhotic patients, since the current model for End-stage Liver Disease scoring system for hepatocellular carcinoma is built on the ultimate bulk of the tumor. Further multicenter, controlled, large-volume prospective studies are warranted to verify this observation.

Deceleration time in ischemic cardiomyopathy: relation to echocardiographic and scintigraphic indices of myocardial viability and functional recovery after revascularization

BACKGROUND

In patients with heart failure secondary to left ventricular (LV) systolic dysfunction, a short deceleration time (DT) successfully predicts clinical outcome. The impact of myocardial viability and revascularization on the mitral inflow velocities, however, is unknown.

METHODS AND RESULTS

Forty patients with ischemic cardiomyopathy underwent (201)Tl scintigraphy (SPECT) and 2D, Doppler, and dobutamine echocardiography (DE, to 40 microg. kg(-1). min(-1)) 2 days before CABG. Echocardiography was repeated 3 months after revascularization to determine recovery of function. Significant correlations were present between DT and LV contractile reserve by DE (r=0.72), scar perfusion defect by SPECT (r=-0.69), and the change in ejection fraction (DeltaEF) after surgery (r=0.77) (all P:<0.01). DT >150 ms effectively identified (sensitivity 79%, specificity 81%) patients with DeltaEF >/=5%. The population was divided into 2 groups according to DT: group 1 (DT >150 ms, n=21) and group 2 (DT </=150 ms, n=19). At baseline, NYHA class, LV EF, age, and use of cardiovascular drugs were similar between the 2 groups. The number of viable segments by both DE and SPECT, however, was higher in group 1 (both P:<0.01), and only patients in group 1 had an increase in EF (29+/-4.8% to 40+/-8%, P:<0.01) after surgery. Death and heart transplantation occurred in 7 patients from group 2 and 1 patient from group 1 (P:=0.017).

CONCLUSIONS

In patients with ischemic cardiomyopathy, the reduced amount of viable myocardium results in a restrictive mitral inflow pattern, which in turn predicts poor survival.

Benzo[a]pyrene-DNA adducts inhibit the DNA helicase activity of the bacteriophage T7 gene 4 protein

The gene 4 protein of bacteriophage T7 provides the essential helicase and primase activities for the replication of the T7 genome. In addition, it also displays a DNA-dependent deoxyribonucleoside triphosphatase activity, the preferred substrate of which is dTTP. Previous investigations have demonstrated that the translocation of the gene 4 protein along single-stranded DNA is blocked by the presence of benzo[a]pyrene-DNA adducts and that the gene 4 protein is likely to be sequestered at the sites of these adducts. In the present study, we directly show that the helicase activity of the gene 4 protein is also profoundly inhibited by the benzo[a]pyrene-DNA adducts. The inhibitory effects of these adducts are strand-specific in that they block the DNA helicase activity of the gene 4 protein only when they are located in the DNA strand where the gene 4 protein translocates when it unwinds double-stranded DNA. Consistent with the hypothesis that the gene 4 protein is sequestered at the adduct site, we also show that the complexes formed by the gene 4 protein and benzo[a]pyrene-modified DNA are far more stable than those formed by the gene 4 protein and unmodified DNA.

Developmental changes in the localization of the transplasma membrane NADH-dehydrogenases in the rat brain

The function of transplasma membrane oxidoreductases (PMO's) has been further studied by means of investigating the postnatal (PN) developmental changes in the tissue localization of six isoenzymes previously characterized (see accompanying paper). The changes were followed in the midbrain for PMO-I, -II, and -V and in the brainstem for PMO-III, -IV and -VI. PMO-I is not observed before PN5 and develops as long vertical fibers located mainly in the pontine nucleus and in the dorsal raphe nucleus until it merges all over the midbrain except for the aqueduct and the superior colliculus after PN10. At that stage it is highly expressed in the trigeminal nucleus and the dorsal raphe, but its expression then strongly decreases and PMO-I disappears almost completely later on. Similarly PMO-II only develops around PN5, first in the dorsal and caudal linear raphe and later on (at PN7) also in the pontine nucleus and in the median raphe; at PN10 PMO-II gradually had vanished from these areas and strongly developed in the dorsal raphe and in the mesencephalic trigeminal nucleus. Later on PMO-II also decreases from these areas. PMO-III slowly develops within the gigantocellular reticular nucleus from PN1 to PN5 and later on reaches the facial nucleus (after PN5), the density of PMO-III in these regions at PN10 being much higher than in the adult. PMO-IV follows a similar developmental pattern in the midbrain, with an optimal density around PN10 also. PMO-V appears only at about PN5, first within the dorsal raphe in parallel fibers and in multipolar neurons. It disappears from the fibers around PN10 and remains present in neurons up to adulthood. PMO-VI appears at early stages within the gigantocellular reticular nucleus and after PN5 within the central gray in vertical fibers. At later stages PMO-VI is found in the spinal trigeminal nucleus, at first within the neuropil then in multipolar neurons that remain present up to adulthood. These datas suggested that the different isoenzymes are expressed at various stages in specific areas. The role of PMO's in neuronal development is discussed.

Distribution of six transplasma membrane NADH-dehydrogenases in rat brain tissue

Transplasma membrane redox plays a significant role in cellular activation and growth. Six isoenzymes could be prepared from purified rat brain synaptic plasma membrane. Polyclonal antibodies have been prepared against six transplasma membrane oxydoreductases (PMO-I to PMO-VI) and the tissue distribution of the various iso-enzymes have been investigated in adult rat brains by means of immunohistochemistry. PMO-I is densely observed in layers I, IV and V of the parietal cortex, in CA1 of the hippocampus (except for the molecular layer), in the caudate putamen, in the dorsal, granular and ventral parts of the auditory nuclei, in some loci of the vestibular nuclei as well as in the deep cerebellar nucleus and in the granular layer of the cerebellar cortex. PMO-II is mainly located in the polymorphic layer of the dentate gyrus and in the deep cerebellar nucleus and in the granular layer of the cerebellar cortex. PMO-III is abundant in the piriform cortex, in the pyramidal layers of both CA1 and CA2, in the diagonal band of the basal ganglia, in the supraoptic nucleus and in various loci of the magnetocellular paraventricular nucleus of the hippothalamus as well as in the vestibular nuclei from the brain stem. In addition PMO-III is also densely present in motor nuclei (oculomotor, facial, hypoglossal and ambiguus nuclei), in the reticular formation and in the deep cerebellar nucleus as well as in the Purkinje layer of the cerebellar cortex. PMO-IV has a similar location but is less abundant in the vestibular nuclei of the sensory brain stem and in the motor nucleus. PMO-V in contrast is poorly present in most brain areas compared to the other iso-enzymes, apart of the Purkinje layer of the cerebellar cortex. Finally PMO-VI is mainly present in the oriens layer and in the stratum radiatum of the hippocampus formation, in the supraoptic and lateral magnocellular nucleus of the hypothalamus, in the mesencephalic trigeminal nucleus, in the ventral auditory nucleus and in the facial nucleus of the brain stem as well as in red nucleus of the reticular formation and in the Purkinje layer of the cerebellar cortex. These data show that the iso-enzymes are located in specific brain nuclei. The significance of the results in respect to the yet very poorly defined function of PMO's is discussed.

Nucleotide and DNA-induced conformational changes in the bacteriophage T7 gene 4 protein

The bacteriophage T7 gene 4 protein is a multifunctional enzyme that has DNA helicase, primase, and deoxyribonucleotide 5'-triphosphatase activities. Prior studies have shown that in the presence of dTTP or dTDP the gene 4 protein assembles into a functionally active hexamer prior to binding to single-stranded DNA. In this study, we have examined the effects of different nucleotide cofactors on the conformation of the gene 4 protein in the presence and absence of DNA. Gel retardation analysis, partial protease digestion, and DNA footprinting all suggest that the gene 4 protein undergoes a conformational change when dTTP is hydrolyzed to dTTP and that in the presence of dTDP the complex with DNA is more open or extended. We have also found that the dissociation constant of the gene 4 protein.DNA complex in the presence of dTDP was 10-fold lower than that determined in the presence of dTTP, further suggesting that these cofactors exerts different allosteric effects on the DNA-binding site of the gene 4 protein.