Targeting Disease through Metabolism.

The links between cellular and systemic metabolism and different pathologies, including cancer, are on the rise. Cell editor Lara Szewczak asked Doug Green, Ralph DeBerardinis, and Mark Febbraio about what the prospects are for being able to target metabolism therapeutically. An annotated excerpt of the conversation appears below, and the full conversation is available with the article online.

AMPK regulation of Raptor and TSC2 mediate metformin effects on transcriptional control of anabolism and inflammation.

Despite being the frontline therapy for type 2 diabetes, the mechanisms of action of the biguanide drug metformin are still being discovered. In particular, the detailed molecular interplays between the AMPK and the mTORC1 pathway in the hepatic benefits of metformin are still ill defined. Metformin-dependent activation of AMPK classically inhibits mTORC1 via TSC/RHEB, but several lines of evidence suggest additional mechanisms at play in metformin inhibition of mTORC1. Here we investigated the role of direct AMPK-mediated serine phosphorylation of RAPTOR in a new RaptorAA mouse model, in which AMPK phospho-serine sites Ser722 and Ser792 of RAPTOR were mutated to alanine. Metformin treatment of primary hepatocytes and intact murine liver requires AMPK regulation of both RAPTOR and TSC2 to fully inhibit mTORC1, and this regulation is critical for both the translational and transcriptional response to metformin. Transcriptionally, AMPK and mTORC1 were both important for regulation of anabolic metabolism and inflammatory programs triggered by metformin treatment. The hepatic transcriptional response in mice on high-fat diet treated with metformin was largely ablated by AMPK deficiency under the conditions examined, indicating the essential role of this kinase and its targets in metformin action in vivo.

Weight and metabolic changes in early psychosis-association with daily quantification of medication exposure during the first hospitalization.

BACKGROUND: The most common causes of death in schizophrenia are cardiovascular disorders, which are closely related to metabolic syndrome/obesity. To better understand the development of metabolic alterations early in the course of illness, we quantified daily medication exposure in the first days of the first hospitalization for psychosis and related it to changes in weight and metabolic markers. STUDY DESIGN: We recruited participants with first episode psychosis (FEP, N = 173) during their first psychiatric hospitalization and compared them to controls (N = 204). We prospectively collected weight, body mass index, metabolic markers, and exact daily medication exposure at admission and during hospitalization. STUDY RESULTS: Individuals with FEP gained on average 0.97 ± 2.26 BMI points or 3.46 ± 7.81 kg of weight after an average of 44.6 days of their first inpatient treatment. Greater antipsychotic exposure was associated with greater BMI increase, but only in people with normal/low baseline BMI. Additional predictors of weight gain included type of medication and duration of treatment. Medication exposure was not directly related to metabolic markers, but higher BMI was associated with higher TGC, TSH, and lower HDL. Following inpatient treatment, participants with FEP had significantly higher BMI, TGC, prolactin, and lower fT4, HDL than controls. CONCLUSION: During their first admission, people with FEP, especially those with normal/low baseline BMI, showed a rapid and clinically significant weight increase, which was associated with exposure to antipsychotics, and with metabolic changes consistent with metabolic syndrome. These findings emphasize weight monitoring in FEP and suggest a greater need for caution when prescribing metabolically problematic antipsychotics to people with lower BMI.

Effects of Increased Central Cholinergic Activity on the Metabolic Challenge Induced by Submaximal Exercise in Rats: Adrenomedullary Secretion Influences.

AIM: The aim of this study was to assess the influence of adrenomedullary secretion on the plasma glucose, lactate, and free fatty acids (FFAs) during running exercise in rats submitted to intracerebroventricular (i.c.v.) injection of physostigmine (PHY). PHY i.c.v. was used to activate the central cholinergic system. METHODS: Wistar rats were divided into sham-saline (sham-SAL), sham-PHY, adrenal medullectomy-SAL, and ADM-PHY groups. The plasma concentrations of glucose, lactate, and FFAs were determined immediately before and after i.c.v. injection of 20 µL of SAL or PHY at rest and during running exercise on a treadmill. RESULTS: The i.c.v. injection of PHY at rest increased plasma glucose in the sham group, but not in the ADM group. An increase in plasma glucose, lactate, and FFAs mobilization from adipose tissue was observed during physical exercise in the sham-SAL group; however, the increase in plasma glucose was greater with i.c.v. PHY. Moreover, the hyperglycemia induced by exercise and PHY in the ADM group were blunted by ADM, whereas FFA mobilization was unaffected. CONCLUSION: These results indicate that there is a dual metabolic control by which activation of the central cholinergic pathway increases plasma glucose but not FFA during rest and exercise, and that this hyperglycemic response is dependent on adrenomedullary secretion.

The Arabidopsis AtGCD3 protein is a glucosylceramidase that preferentially hydrolyzes long-acyl-chain glucosylceramides.

Cellular membranes contain many lipids, some of which, such as sphingolipids, have important structural and signaling functions. The common sphingolipid glucosylceramide (GlcCer) is present in plants, fungi, and animals. As a major plant sphingolipid, GlcCer is involved in the formation of lipid microdomains, and the regulation of GlcCer is key for acclimation to stress. Although the GlcCer biosynthetic pathway has been elucidated, little is known about GlcCer catabolism, and a plant GlcCer-degrading enzyme (glucosylceramidase (GCD)) has yet to be identified. Here, we identified AtGCD3, one of four Arabidopsis thaliana homologs of human nonlysosomal glucosylceramidase, as a plant GCD. We found that recombinant AtGCD3 has a low Km for the fluorescent lipid C6-NBD GlcCer and preferentially hydrolyzes long acyl-chain GlcCer purified from Arabidopsis leaves. Testing of inhibitors of mammalian glucosylceramidases revealed that a specific inhibitor of human ß-glucosidase 2, N-butyldeoxynojirimycin, inhibits AtGCD3 more effectively than does a specific inhibitor of human ß-glucosidase 1, conduritol ß-epoxide. We also found that Glu-499 and Asp-647 in AtGCD3 are vital for GCD activity. GFP-AtGCD3 fusion proteins mainly localized to the plasma membrane or the endoplasmic reticulum membrane. No obvious growth defects or changes in sphingolipid contents were observed in gcd3 mutants. Our results indicate that AtGCD3 is a plant glucosylceramidase that participates in GlcCer catabolism by preferentially hydrolyzing long-acyl-chain GlcCers.

Thiamine, Ascorbic Acid, and Hydrocortisone As a Metabolic Resuscitation Cocktail in Sepsis: A Meta-Analysis of Randomized Controlled Trials With Trial Sequential Analysis.

OBJECTIVES: Sepsis is a common condition in the ICU. Despite much research, its prognosis remains poor. In 2017, a retrospective before/after study reported promising results using a combination of thiamine, ascorbic acid, and hydrocortisone called "metabolic resuscitation cocktail" and several randomized controlled trials assessing its effectiveness were performed. DESIGN: We conducted a systematic review and meta-analysis of randomized controlled trials in septic ICU patients to assess the effects of this combination therapy. SETTING: PubMed, Embase, and the Cochrane library databases were searched from inception to March of 2021. Data were extracted independently by two authors. The main outcome was the change in Sequential Organ Failure Assessment score within 72 hours. Secondary outcomes included renal composite endpoints (acute kidney injury) Kidney Disease - Improving Global Outcome organization stage 3 or need for renal replacement therapy, vasopressor duration, and 28-day mortality. SUBJECTS: We included randomized controlled trials with patients admitted to the ICU with sepsis or septic shock. INTERVENTION: The trials compared a combination of thiamine, ascorbic acid, and hydrocortisone to standard care or placebo in patients admitted to ICU with sepsis or septic shock. MEASUREMENTS AND MAIN RESULTS: We included eight randomized controlled trials (n = 1,335 patients). Within 72 hours, the median of mean improvement was -1.8 and -3.2 in the control and intervention groups, respectively (eight randomized controlled trials, n = 1,253 patients); weighted mean difference -0.82 (95% CI, -1.15 to -0.48). Data were homogeneous and the funnel plot did not suggest any publication bias. Duration of vasopressor requirement was significantly reduced in the intervention group (six randomized controlled trials). There was no evidence of a difference regarding the ICU mortality and the renal composite outcome (acute kidney injury KDIGO 3 or need for renal replacement therapy, seven randomized controlled trials). CONCLUSIONS: Metabolic resuscitation cocktail administrated in ICU septic patients improves change in Sequential Organ Failure Assessment score within 72 hours. However, this improvement is modest and its clinical relevance is questionable. The impact on renal failure and mortality remains unclear.

Zinc finger protein-440 promotes cartilage degenerative mechanisms in human facet and knee osteoarthritis chondrocytes.

OBJECTIVES: To investigate the role of zinc finger protein 440 (ZNF440) in the pathophysiology of cartilage degeneration during facet joint (FJ) and knee osteoarthritis (OA). METHODS: Expression of ZNF440 in FJ and knee cartilage was determined by immunohistochemistry, quantitative (q)PCR, and Western blotting (WB). Human chondrocytes isolated from FJ and knee OA cartilage were cultured and transduced with ZNF440 or control plasmid, or transfected with ZNF440 or control small interfering RNA (siRNA), with/without interleukin (IL)-1ß. Gene and protein levels of catabolic, anabolic and apoptosis markers were determined by qPCR or WB, respectively. In silico analyses were performed to determine compounds with potential to inhibit expression of ZNF440. RESULTS: ZNF440 expression was increased in both FJ and knee OA cartilage compared to control cartilage. In vitro, overexpression of ZNF440 significantly increased expression of MMP13 and PARP p85, and decreased expression of COL2A1. Knockdown of ZNF440 with siRNA partially reversed the catabolic and cell death phenotype of human knee and FJ OA chondrocytes stimulated with IL-1ß. In silico analysis followed by validation assays identified scriptaid as a compound with potential to downregulate the expression of ZNF440. Validation experiments showed that scriptaid reduced the expression of ZNF440 in OA chondrocytes and concomitantly reduced the expression of MMP13 and PARP p85 in human knee OA chondrocytes overexpressing ZNF440. CONCLUSIONS: The expression of ZNF440 is significantly increased in human FJ and knee OA cartilage and may regulate cartilage degenerative mechanisms. Furthermore, scriptaid reduces the expression of ZNF440 and inhibits its destructive effects in OA chondrocytes.

Orexin-2 receptor antagonism in the cornu ammonis 1 region of hippocampus prevented the antinociceptive responses induced by chemical stimulation of the lateral hypothalamus in the animal model of persistent pain.

Orexins are excitatory neuropeptides, mainly produced by neurons located in the lateral hypothalamus, which project to many brain areas. The orexinergic system plays a fundamental role in arousal, sleep/wakefulness, feeding, energy homeostasis, motivation, reward, stress and pain modulation. As a prominent part of the limbic system, the hippocampus has been involved in formalin-induced nociception modulation. Moreover, hippocampus regions express both orexin-1 (OX1) and orexin-2 (OX2) receptors. The present study investigated the role of OX2 receptors (OX2R) within the cornu ammonis 1 (CA1) region of the hippocampus in the mediation of lateral hypothalamus-induced antinociception. Fifty-three male Wistar rats were unilaterally implanted with two separate cannulae into the lateral hypothalamus and CA1. Animals were pretreated with intra-CA1 TCS OX2 29 as an OX2R antagonist before intra-lateral hypothalamus administration of carbachol (250 nM) as a muscarinic agonist for chemical stimulation of orexinergic neurons. Formalin test was used as an animal model of persistent pain, following intra-lateral hypothalamus carbachol microinjection. Results showed that the chemical stimulation of the lateral hypothalamus significantly attenuated formalin-evoked nociceptive behaviors during both phases of the formalin test, and administration of TCS OX2 29 into the CA1 blocked these antinociceptive responses in both phases, especially in the late phase. These findings suggest that OX2 receptors in the CA1 partially mediate the lateral hypothalamus-induced antinociceptive responses in persistent inflammatory pain.

A Novel Method for the Production of an Autologous Anti-Inflammatory and Anti-Catabolic Product (Cytorich) from Human Blood: A Prospective Treatment for the COVID-19-Induced Cytokine Storm.

BACKGROUND Autologous blood-derived products can target specific inflammatory molecular pathways and have potentially beneficial therapeutic effects on inflammatory pathologies. The purpose of this study was to assess in vitro the anti-inflammatory and anti-catabolic potential of an autologous blood product as a possible treatment for COVID-19-induced cytokine storm. MATERIAL AND METHODS Blood samples from healthy donors and donors who had recovered from COVID-19 were incubated using different techniques and analyzed for the presence of anti-inflammatory, anti-catabolic, regenerative, pro-inflammatory, and procatabolic molecules. RESULTS The highest concentrations of therapeutic molecules for targeting inflammatory pathways were found in the blood that had been incubated for 24 h at 37°C, whereas a significant increase was observed after 6 h of incubation in blood from COVID-19-recovered donors. Beneficially, the 6-h incubation process did not downregulate anti-COVID-19 immunoglobulin G concentrations. Unfortunately, increases in matrix metalloproteinase 9, tumor necrosis factor alpha, and interleukin-1 were detected in the product after incubation; however, these increases could be blocked by adding citric acid, with no effect on the concentration of the target therapeutic molecules. Our data allow for safer and more effective future treatments. CONCLUSIONS An autologous blood-derived product containing anti-inflammatory and anti-catabolic molecules, which we term Cytorich, has a promising therapeutic role in the treatment of a virus-induced cytokine storm, including that associated with COVID-19.

Inhibition of Autophagy at Different Stages by ATG5 Knockdown and Chloroquine Supplementation Enhances Consistent Human Disc Cellular Apoptosis and Senescence Induction rather than Extracellular Matrix Catabolism.

The intervertebral disc is the largest avascular organ. Autophagy is an important cell survival mechanism by self-digestion and recycling damaged components under stress, primarily nutrient deprivation. Resident cells would utilize autophagy to cope with the harsh disc environment. Our objective was to elucidate the roles of human disc cellular autophagy. In human disc cells, serum deprivation and pro-inflammatory interleukin-1ß (IL-1ß) stimulation increased autophagy marker microtubule-associated protein 1 light chain 3 (LC3)-II and decreased autophagy substrate p62/sequestosome 1 (p62/SQSTM1), indicating enhanced autophagy. Then, RNA interference (RNAi) of autophagy-related gene 5 (ATG5), essential for autophagy, showed decreases in ATG5 protein (26.8%-27.4%, p < 0.0001), which suppressed early-stage autophagy with decreased LC3-II and increased p62/SQSTM1. Cell viability was maintained by ATG5 RNAi in serum-supplemented media (95.5%, p = 0.28) but reduced in serum-free media (80.4%, p = 0.0013) with IL-1ß (69.9%, p = 0.0008). Moreover, ATG5 RNAi accelerated IL-1ß-induced changes in apoptosis and senescence. Meanwhile, ATG5 RNAi unaffected IL-1ß-induced catabolic matrix metalloproteinase release, down-regulated anabolic gene expression, and mitogen-activated protein kinase pathway activation. Lysosomotropic chloroquine supplementation presented late-stage autophagy inhibition with apoptosis and senescence induction, while catabolic enzyme production was modest. Disc-tissue analysis detected age-related changes in ATG5, LC3-II, and p62/SQSTM1. In summary, autophagy protects against human disc cellular apoptosis and senescence rather than extracellular matrix catabolism.

Zwitterion-Based Hydrogen Sulfide Nanomotors Induce Multiple Acidosis in Tumor Cells by Destroying Tumor Metabolic Symbiosis.

Destruction of tumor metabolism symbiosis is an attractive cancer treatment method which targets tumor cells with little harm to normal cells. Yet, a single intervention strategy and poor penetration of the drug in tumor tissue result in limited effect. Herein, we propose a zero-waste zwitterion-based hydrogen sulfide (H2 S)-driven nanomotor based on the basic principle of reaction in human body. When loaded with monocarboxylic acid transporter inhibitor α-cyano-4-hydroxycinnamic acid (α-CHCA), the nanomotor can move in tumor microenvironment and induce multiple acidosis of tumor cells and inhibit tumor growth through the synergistic effect of motion effect, driving force H2 S and α-CHCA. Given the good biosafety of the substrate and driving gas of this kind of nanomotor, as well as the limited variety of nanomotors currently available to move in the tumor microenvironment, this kind of nanomotor may provide a competitive candidate for the active drug delivery system of cancer treatment.

Comparison of the effects of soluble corn fiber and fructooligosaccharides on metabolism, inflammation, and gut microbiome of high-fat diet-fed mice.

Dietary fibers are essential components of a balanced diet and have beneficial effects on metabolic functions. To gain insight into their impact on host physiology and gut microbiota, we performed a direct comparison of two specific prebiotic fibers in mice. During an 8-wk follow up, mice fed a high-fat diet (HFD) were compared with mice on a normal diet (basal condition, controls) and to mice fed the HFD but treated with one of the following prebiotics: fructooligosaccharides (FOS) or soluble corn fiber (SCF). Both prebiotic fibers led to a similar reduction of body weight and fat mass, lower inflammation and improved metabolic parameters. However, these health benefits were the result of different actions of the fibers, as SCF impacted energy excretion, whereas FOS did not. Interestingly, both fibers had very distinct gut microbial signatures with different short-chain fatty acid profiles, indicating that they do not favor the growth of the same bacterial communities. Although the prebiotic potential of different fibers may seem physiologically equivalent, our data show that the underlying mechanisms of action are different, and this by targeting different gut microbes. Altogether, our data provide evidence that beneficial health effects of specific dietary fibers must be documented to be considered a prebiotic and that studies devoted to understanding how structures relate to specific microbiota modulation and metabolic effects are warranted.

Effects of intrauterine insulin-like growth factor-1 therapy for fetal growth restriction on adult metabolism and body composition are sex specific.

Fetal growth restriction (FGR) is associated with compromised growth and metabolic function throughout life. Intrauterine therapy of FGR with intra-amniotic insulin-like growth factor-1 (IGF1) enhances fetal growth and alters perinatal metabolism and growth in a sex-specific manner, but the adult effects are unknown. We investigated the effects of intra-amniotic IGF1 treatment of FGR on adult growth and body composition, adrenergic sensitivity, and glucose-insulin axis regulation. Placental embolization-induced FGR was treated with four weekly doses of 360 µg intra-amniotic IGF1 (FGRI) or saline (FGRS). Offspring were raised to adulthood (18 mo: FGRI, n = 12 females, 12 males; FGRS, n = 13 females, 10 males) alongside offspring from unembolized and untreated sheep (CON; n = 12 females, 21 males). FGRI females had increased relative lean mass compared with CON but not FGRS (P < 0.05; 70.6 ± 8.2% vs. 61.4 ± 8.2% vs. 67.6 ± 8.2%), decreased abdominal adipose compared with CON and FGRS (P < 0.05; 43.7 ± 1.2% vs. 49.3 ± 0.9% vs. 48.5 ± 1.0%), increased glucose utilization compared with FGRS but not CON (P < 0.05; 9.6 ± 1.0 vs. 6.0 ± 0.9 vs. 7.6 ± 0.9 mg·kg-1·min-1), and increased ß-hydroxybutyric acid:nonesterified fatty acid ratio in response to adrenaline compared with CON and FGRS (P < 0.05; 3.9 ± 1.4 vs. 1.1 ± 1.4 vs. 1.8 ± 1.4). FGRS males were smaller and lighter compared with CON but not FGRI (P < 0.05; 86.8 ± 6.3 vs. 93.5 ± 6.1 vs. 90.7 ± 6.3 kg), with increased peak glucose concentration (10%) in response to a glucose load but few other differences. These effects of intra-amniotic IGF1 therapy on adult body composition, glucose-insulin axis function, and adrenergic sensitivity could indicate improved metabolic regulation during young adulthood in female FGR sheep.

Targeting Enteropeptidase with Reversible Covalent Inhibitors To Achieve Metabolic Benefits.

Inhibition of the serine protease enteropeptidase (EP) opens a new avenue to the discovery of chemotherapeutics for the treatment of metabolic diseases. Camostat has been used clinically for treating chronic pancreatitis in Japan; however, the mechanistic basis of the observed clinical efficacy has not been fully elucidated. We demonstrate that camostat is a potent reversible covalent inhibitor of EP, with an inhibition potency (k inact/KI) of 1.5 × 104 M-1s-1 High-resolution liquid chromatography-mass spectrometry (LC-MS) showed addition of 161.6 Da to EP after the reaction with camostat, consistent with insertion of the carboxyphenylguanidine moiety of camostat. Covalent inhibition of EP by camostat is reversible, with an enzyme reactivation half-life of 14.3 hours. Formation of a covalent adduct was further supported by a crystal structure resolved to 2.19 Å, showing modification of the catalytic serine of EP by a close analog of camostat, leading to formation of the carboxyphenylguanidine acyl enzyme identical to that expected for the reaction with camostat. Of particular note, minor structural modifications of camostat led to changes in the mechanism of inhibition. We observed from other studies that sustained inhibition of EP is required to effect a reduction in cumulative food intake and body weight, with concomitant improved blood glucose levels in obese and diabetic leptin-deficient mice. Thus, the structure-activity relationship needs to be driven by not only the inhibition potency but also the mechanistic and kinetic characterization. Our findings support EP as a target for the treatment of metabolic diseases and demonstrate that reversible covalent EP inhibitors show clinically relevant efficacy. SIGNIFICANCE STATEMENT: Interest in targeted covalent drugs has expanded in recent years, particularly so for kinase targets, but also more broadly. This study demonstrates that reversible covalent inhibition of the serine protease enteropeptidase is a therapeutically viable approach to the treatment of metabolic diseases and that mechanistic details of inhibition are relevant to clinical efficacy. Our mechanistic and kinetic studies outline a framework for detailed inhibitor characterization that is proving essential in guiding discovery efforts in this area.

Regulator of Calcineurin 1 helps coordinate whole-body metabolism and thermogenesis.

Increasing non-shivering thermogenesis (NST), which expends calories as heat rather than storing them as fat, is championed as an effective way to combat obesity and metabolic disease. Innate mechanisms constraining the capacity for NST present a fundamental limitation to this approach, yet are not well understood. Here, we provide evidence that Regulator of Calcineurin 1 (RCAN1), a feedback inhibitor of the calcium-activated protein phosphatase calcineurin (CN), acts to suppress two distinctly different mechanisms of non-shivering thermogenesis (NST): one involving the activation of UCP1 expression in white adipose tissue, the other mediated by sarcolipin (SLN) in skeletal muscle. UCP1 generates heat at the expense of reducing ATP production, whereas SLN increases ATP consumption to generate heat. Gene expression profiles demonstrate a high correlation between Rcan1 expression and metabolic syndrome. On an evolutionary timescale, in the context of limited food resources, systemic suppression of prolonged NST by RCAN1 might have been beneficial; however, in the face of caloric abundance, RCAN1-mediated suppression of these adaptive avenues of energy expenditure may now contribute to the growing epidemic of obesity.

Selenium supplementation during pregnancy and lactation promotes metabolic changes in Wistar rats' offspring.

Epidemiological and animal studies have demonstrated a strong association between selenium (Se) supplementation and metabolic disorders, we aimed to evaluate whether maternal Se supplementation was able to change metabolic parameters in rats' offspring. Moreover, as Se is a deiodinase (DIO) cofactor, we decided to investigate how thyroid hormones (THs) would be involved in such metabolic changes. Thereby, two groups (n = 6, ~250 g) of female Wistar rats underwent isotonic saline or sodium selenite (1 mg/kg, p.o.) treatments. Although there were no significant differences in body weight between groups, the Se treatment during pregnancy and lactation increased milk intake and the visceral white adipose tissue (WAT) in offspring. The rats whose mothers were treated with Se also presented an improvement in the glucose tolerance test and in the glucose-stimulated insulin secretion. Regarding the lipid metabolism, the Se group had a reduction of triglycerides in the liver and in WAT. These metabolic changes were accompanied by an increase in serum triiodothyronine (T3 ) and in DIO 2 expression in brown adipose tissue (BAT). We further demonstrate an increased expression of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α) and nuclear respiratory factor-1 (NRF-1) mRNA in the liver. In adulthood offspring, Se supplementation programs thyroid function, glucose homeostasis, and feeding behaviour. Taken together, there is no indication that Se programming causes insulin resistance. Moreover, we conjecture that these metabolic responses are induced by increased thyroxine (T4 ) to T3 conversion by DIO2 in BAT and mediated by altered transcription factors expression associated with oxidative metabolism control in the liver.

A Compound Isolated from Phyllanthus tenellus Demonstrates Metabolic and Vascular Effects In Vitro.

Common chronic conditions such as metabolic syndrome and diabetes are increasingly associated to metabolic and cardiovascular complications. Although Phyllanthus tenellus leaves have been used in decoctions as a popular remedy to control blood glucose levels and hypertension, its use needs a scientific basis. This study was therefore undertaken to report a phytochemical analysis of P. tenellus leaves and to test if the main active compound has potential to simultaneously tackle several pathophysiological features of metabolic syndrome and diabetes-related metabolic and vascular disorders such as hyperglycaemia, increased platelet activation, and endothelial dysfunction. We performed a partition of the methanolic extract of P. tenellus leaves among different organic solvents followed by chromatographic separation guided by the rat liver microsomal glucose-6-phosphatase assay. Two known tannins were identified by spectroscopic methods as pinocembrin-7-O-[3″-O-galloyl-4″,6″-(S)-hexahydroxydiphenoyl]-α-D-glucose, named P7OG by us, and gemin D. The structural determination of the isolated compounds was based on spectral data. The ability of the main active component, P7OG, to inhibit human platelet aggregation and to modify vascular reactivity of rat aortic rings incubated with high glucose (D-glucose 55 mM) was then evaluated. P7OG was further able to inhibit platelet aggregation induced by adenosine 5'-diphosphate and collagen, showed vasorelaxant effects in arteries precontracted with phenylephrine, and reverted the endothelium-dependent impairment effect of high glucose in rat aortic rings. In conclusion, one tannin isolated from P. tenellus showed promising metabolic, antiaggregant, and vascular effects, which suggests the potential beneficial use of P. tenellus to tackle complex cardiometabolic diseases.

Combined Effect of Light and Nutrients on the Micromorphology of the White rot Fungus Cerrena Unicolor.

Light influences developmental pathways in fungi. Recent transcriptomic and biochemical analyses have demonstrated that light influences the metabolism of a white-rot basidiomycete Cerrena unicolor. However, the expression profile of genes involved in the growth and development, or micromorphological observations of the mycelium in response to variable lighting and culturing media, have not performed. We aim to reveal the effect of light and nutrients on C. unicolor growth and a potential relationship between the culture medium and lighting conditions on fungus micromorphological structures. Confocal laser scanning microscopy and scanning electron microscopy were employed for morphological observations of C. unicolor mycelium cultivated in red, blue, green, and white light and darkness on mineral and sawdust media. A comprehensive analysis of C. unicolor differentially expressed genes (DEGs) was employed to find global changes in the expression profiles of genes putatively involved in light-dependent morphogenesis. Both light and nutrients influenced C. unicolor growth and development. Considerable differences in the micromorphology of the mycelia were found, which were partially reflected in the functional groups of DEGs observed in the fungus transcriptomes. A complex cross-interaction of nutritional and environmental signals on C. unicolor growth and morphology was suggested. The results are a promising starting point for further investigations of fungus photobiology.

In Vivo Metabolic Response upon Exposure to Gold Nanorod Core/Silver Shell Nanostructures: Modulation of Inflammation and Upregulation of Dopamine.

With the increasing applications of silver nanoparticles (Ag NPs), the concerns of widespread human exposure as well as subsequent health risks have been continuously growing. The acute and chronic toxicities of Ag NPs in cellular tests and animal tests have been widely investigated. Accumulating evidence shows that Ag NPs can induce inflammation, yet the overall mechanism is incomplete. Herein, using gold nanorod core/silver shell nanostructures (Au@Ag NRs) as a model system, we studied the influence on mice liver and lungs from the viewpoint of metabolism. In agreement with previous studies, Au@Ag NRs' intravenous exposure caused inflammatory reaction, accompanying with metabolic alterations, including energy metabolism, membrane/choline metabolism, redox metabolism, and purine metabolism, the disturbances of which contribute to inflammation. At the same time, dopamine metabolism in liver was also changed. This is the first time to observe the production of dopamine in non-neural tissue after treatment with Ag NPs. As the upregulation of dopamine resists inflammation, it indicates the activation of antioxidant defense systems against oxidative stress induced by Au@Ag NRs. In the end, our findings deepened the understanding of molecular mechanisms of Ag NPs-induced inflammation and provide assistance in the rational design of their biomedical applications.

O-Antigen-Dependent Colicin Insensitivity of Uropathogenic Escherichia coli.

The outer membrane of Gram-negative bacteria presents a significant barrier for molecules entering the cell. Nevertheless, colicins, which are antimicrobial proteins secreted by Escherichia coli, can target other E. coli cells by binding to cell surface receptor proteins and activating their import, resulting in cell death. Previous studies have documented high rates of nonspecific resistance (insensitivity) of various E. coli strains toward colicins that is independent of colicin-specific immunity and is instead associated with lipopolysaccharide (LPS) in the outer membrane. This observation poses a contradiction: why do E. coli strains have colicin-expressing plasmids, which are energetically costly to retain, if cells around them are likely to be naturally insensitive to the colicin they produce? Here, using a combination of transposon sequencing and phenotypic microarrays, we show that colicin insensitivity of uropathogenic E. coli sequence type 131 (ST131) is dependent on the production of its O-antigen but that minor changes in growth conditions render the organism sensitive toward colicins. The reintroduction of O-antigen into E. coli K-12 demonstrated that it is the density of O-antigen that is the dominant factor governing colicin insensitivity. We also show, by microscopy of fluorescently labelled colicins, that growth conditions affect the degree of occlusion by O-antigen of outer membrane receptors but not the clustered organization of receptors. The result of our study demonstrate that environmental conditions play a critical role in sensitizing E. coli toward colicins and that O-antigen in LPS is central to this role.IMPORTANCEEscherichia coli infections can be a major health burden, especially with the organism becoming increasingly resistant to "last-resort" antibiotics such as carbapenems. Although colicins are potent narrow-spectrum antimicrobials with potential as future antibiotics, high levels of naturally occurring colicin insensitivity have been documented which could limit their efficacy. We identify O-antigen-dependent colicin insensitivity in a clinically relevant uropathogenic E. coli strain and show that this insensitivity can be circumvented by minor changes to growth conditions. The results of our study suggest that colicin insensitivity among E. coli organisms has been greatly overestimated, and as a consequence, colicins could in fact be effective species-specific antimicrobials targeting pathogenic E. coli such as uropathogenic E. coli (UPEC).