Characterization of Amycolatopsis 75iv2 dye-decolorizing peroxidase on O-glycosides.

Dye-decolorizing peroxidases are heme peroxidases with a broad range of substrate specificity. Their physiological function is still largely unknown, but a role in the depolymerization of plant cell wall polymers has been widely proposed. Here, a new expression system for bacterial dye-decolorizing peroxidases as well as the activity with previously unexplored plant molecules are reported. The dye-decolorizing peroxidase from Amycolatopsis 75iv2 (DyP2) was heterologously produced in the Gram-positive bacterium Streptomyces lividans TK24 in both intracellular and extracellular forms without external heme supplementation. The enzyme was tested on a series of O-glycosides, which are plant secondary metabolites with a phenyl glycosidic linkage. O-glycosides are of great interest, both for studying the compounds themselves and as potential models for studying specific lignin-carbohydrate complexes. The primary DyP reaction products of salicin, arbutin, fraxin, naringin, rutin, and gossypin were oxidatively coupled oligomers. A cleavage of the glycone moiety upon radical polymerization was observed when using arbutin, fraxin, rutin, and gossypin as substrates. The amount of released glucose from arbutin and fraxin reached 23% and 3% of the total substrate, respectively. The proposed mechanism suggests a destabilization of the ether linkage due to the localization of the radical in the para position. In addition, DyP2 was tested on complex lignocellulosic materials such as wheat straw, spruce, willow, and purified water-soluble lignin fractions, but no remarkable changes in the carbohydrate profile were observed, despite obvious oxidative activity. The exact action of DyP2 on such lignin-carbohydrate complexes therefore remains elusive. IMPORTANCE: Peroxidases require correct incorporation of the heme cofactor for activity. Heterologous overproduction of peroxidases often results in an inactive enzyme due to insufficient heme synthesis by the host organism. Therefore, peroxidases are incubated with excess heme during or after purification to reconstitute activity. S. lividans as a production host can produce fully active peroxidases both intracellularly and extracellularly without the need for heme supplementation. This reduces the number of downstream processing steps and is beneficial for more sustainable production of industrially relevant enzymes. Moreover, this research has extended the scope of dye-decolorizing peroxidase applications by studying naturally relevant plant secondary metabolites and analyzing the formed products. A previously overlooked artifact of radical polymerization leading to the release of the glycosyl moiety was revealed, shedding light on the mechanism of DyP peroxidases. The key aspect is the continuous addition, rather than the more common approach of a single addition, of the cosubstrate, hydrogen peroxide. This continuous addition allows the peroxidase to complete a high number of turnovers without self-oxidation.

Methanogenic partner influences cell aggregation and signalling of Syntrophobacterium fumaroxidans.

For several decades, the formation of microbial self-aggregates, known as granules, has been extensively documented in the context of anaerobic digestion. However, current understanding of the underlying microbial-associated mechanisms responsible for this phenomenon remains limited. This study examined morphological and biochemical changes associated with cell aggregation in model co-cultures of the syntrophic propionate oxidizing bacterium Syntrophobacterium fumaroxidans and hydrogenotrophic methanogens, Methanospirillum hungatei or Methanobacterium formicicum. Formerly, we observed that when syntrophs grow for long periods with methanogens, cultures tend to form aggregates visible to the eye. In this study, we maintained syntrophic co-cultures of S. fumaroxidans with either M. hungatei or M. formicicum for a year in a fed-batch growth mode to stimulate aggregation. Millimeter-scale aggregates were observed in both co-cultures within the first 5 months of cultivation. In addition, we detected quorum sensing molecules, specifically N-acyl homoserine lactones, in co-culture supernatants preceding the formation of macro-aggregates (with diameter of more than 20 µm). Comparative transcriptomics revealed higher expression of genes related to signal transduction, polysaccharide secretion and metal transporters in the late-aggregation state co-cultures, compared to the initial ones. This is the first study to report in detail both biochemical and physiological changes associated with the aggregate formation in syntrophic methanogenic co-cultures. KEYPOINTS: • Syntrophic co-cultures formed mm-scale aggregates within 5 months of fed-batch cultivation. • N-acyl homoserine lactones were detected during the formation of aggregates. • Aggregated co-cultures exhibited upregulated expression of adhesins- and polysaccharide-associated genes.

TP53/p53 Facilitates Stress-Induced Exosome and Protein Secretion by Adipocytes.

Besides the secretion of fatty acids, lipolytic stimulation of adipocytes results in the secretion of triglyceride-rich extracellular vesicles and some free proteins (e.g., fatty acid binding protein 4) that, in sum, affect adipose homeostasis as well as the development of metabolic disease. At the mechanistic level, lipolytic signals activate p53 in an adipose triglyceride lipase-dependent manner, and pharmacologic inhibition of p53 attenuates adipocyte-derived extracellular vesicle (AdEV) protein and FABP4 secretion. Mass spectrometry analyses of the lipolytic secretome identified proteins involved in glucose and fatty acid metabolism, translation, chaperone activities, and redox control. Consistent with a role for p53 in adipocyte protein secretion, activation of p53 by the MDM2 antagonist nutlin potentiated AdEV particles and non-AdEV protein secretion from cultured 3T3-L1 or OP9 adipocytes while the levels of FABP4 and AdEV proteins were significantly reduced in serum from p53-/- mice compared with wild-type controls. The genotoxin doxorubicin increased AdEV protein and FABP4 secretion in a p53-dependent manner and DNA repair-depleted ERCC1-/Δ-haploinsufficient mice expressed elevated p53 in adipose depots, along with significantly increased serum FABP4. In sum, these data suggest that lipolytic signals, and cellular stressors such as DNA damage, facilitate AdEV protein and FABP4 secretion by adipocytes in a p53-dependent manner.

Interactions of Natural Flavones with Iron Are Affected by 7-O-Glycosylation, but Not by Additional 6″-O-Acylation.

In iron-fortified bouillon, reactivity of the iron ion with (acylated) flavone glycosides from herbs can affect product color and bioavailability of iron. This study investigates the influence of 7-O-glycosylation and additional 6″-O-acetylation or 6″-O-malonylation of flavones on their interaction with iron. Nine (6″-O-acylated) flavone 7-O-apiosylglucosides were purified from celery (Apium graveolens), and their structures were elucidated by mass spectrometry (MS) and nuclear magnetic resonance (NMR). In the presence of iron, a bathochromic shift and darker color were observed for the 7-O-apiosylglucosides compared to the aglycon of flavones that only possess the 4-5 site. Thus, the ability of iron to coordinate to the flavone 4-5 site is increased by 7-O-glycosylation. For flavones with an additional 3'-4' site, less discoloration was observed for the 7-O-apiosylglucoside compared to the aglycon. Additional 6″-O-acylation did not affect the color. These findings indicate that model systems used to study discoloration in iron-fortified foods should also comprise (acylated) glycosides of flavonoids.

Safety Net Program to Improve Statin Initiation Among Adults With High Low-Density Lipoprotein Cholesterol.

INTRODUCTION: Despite their effectiveness in reducing low-density lipoprotein cholesterol and cardiovascular disease risk, high-intensity statins are underutilized among adults with low-density lipoprotein cholesterol ≥190 mg/dL. This study determined whether a safety net program (SureNet) facilitating medication and laboratory test orders improved statin initiation and laboratory test completions after (SureNet period: April 2019-September 2021) and before implementation (pre-SureNet period: January 2016-September 2018). METHODS: Kaiser Permanente Southern California members aged 20-60 years with low-density lipoprotein cholesterol ≥190 mg/dL and no statin use in previous 2-6 months were included in this retrospective cohort study. Statin orders within 14 days and statin fills, laboratory test completions, and improved low-density lipoprotein cholesterol within 180 days of the high low-density lipoprotein cholesterol (pre-SureNet) or outreach (SureNet period) were compared. Analyses were conducted in 2022. RESULTS: Overall, 3,534 and 3,555 adults were eligible for statin initiation during the pre-SureNet and SureNet periods, respectively. Overall, 759 (21.5%) and 976 (27.5%) had a statin approved by their physician during pre-SureNet and SureNet periods, respectively (p<0.001). After multivariable adjustment for demographics and clinical characteristics, adults during the SureNet period had a higher likelihood of receiving a statin order (prevalence ratio=1.36, 95% CI=1.25, 1.48), filling their statin (prevalence ratio=1.32, 95% CI=1.26, 1.38), completing their laboratories (prevalence ratio=1.41, 95% CI=1.26, 1.58), and improving low-density lipoprotein cholesterol (prevalence ratio=1.21, 95% CI=1.07, 1.37) than in pre-Surenet period. CONCLUSIONS: The SureNet program was able to improve prescription orders, fills, laboratory test completions, and lower low-density lipoprotein cholesterol. Optimizing both physician adherence to treatment guidelines; and patient adherence to the program may improve low-density lipoprotein cholesterol lowering.

Comparison of Blood Pressure Measurements from Clinical Practice and a Research Study At Kaiser Permanente Southern California.

BACKGROUND: Accurate blood pressure (BP) measurement is essential to identify and manage hypertension. Prior studies have reported a difference between BP measured in routine patient care and in research studies. We aimed to investigate the agreement between BP measured in routine care and research-grade BP in Kaiser Permanente Southern California, a large, integrated healthcare system with initiatives to standardize BP measurements during routine patient care visits. METHODS: We included adults ≥65 years old with hypertension, taking antihypertensive medication, and participating in the Ambulatory Blood Pressure in Older Adults (AMBROSIA) study in 2019-2021. Clinic BP from routine care visits was extracted from the electronic health record. Research-grade BP was obtained by trained AMBROSIA study staff via an automatic oscillometric device. The mean difference between routine care and research-grade BP, limits of agreement, and correlation were assessed. RESULTS: We included 309 participants (mean age 75 years; 54% female; 49% non-Hispanic white). Compared with measurements from routine care, mean research-grade systolic BP (SBP) was 0.1 mm Hg higher (95% CI: -1.5 to 1.8) and diastolic BP (DBP) was 0.4 mm Hg lower (95% CI: -1.6 to 0.7). Limits of agreement were -29 to 30 mm Hg for SBP and -21 to 20 mm Hg for DBP. The intraclass correlation coefficient was 0.42 (95% CI: 0.33 to 0.51) for SBP and 0.43 (95% CI: 0.34 to 0.52) for DBP. CONCLUSIONS: High within-person variation and moderate correlation were present between BP measured in routine care and following a research protocol suggesting the importance of standardized measurements.

The impact of entrepreneurship research on other academic fields.

The remarkable ascent of entrepreneurship witnessed as a scientific field over the last 4 decades has been made possible by entrepreneurship's ability to absorb theories, paradigms, and methods from other fields such as economics, psychology, sociology, geography, and even biology. The respectability of entrepreneurship as an academic discipline is now evidenced by many other fields starting to borrow from the entrepreneurship view. In the present paper, seven examples are given from this "pay back" development. These examples were first presented during a seminar at the Erasmus Entrepreneurship Event called what has the entrepreneurship view to offer to other academic fields? This article elaborates on the core ideas of these presentations and focuses on the overarching question of how entrepreneurship research impacts the development of other academic fields. We found that entrepreneurship research questions the core assumptions of other academic fields and provides new insights into the antecedents, mechanisms, and consequences of their respective core phenomena. Moreover, entrepreneurship research helps to legitimize other academic fields both practically and academically.

Entrepreneurship research questions the core assumptions of other academic fields and legitimizes them both practically and academically. Since the 1980s, entrepreneurship research has seen tremendous growth and development, establishing itself as an academic field. Entrepreneurship is also taught extensively in leading business schools around the world. Indeed, few business schools do not address entrepreneurship in their curriculum. This represents a sea change: although entrepreneurs and new ventures had a remarkable impact on society, academia barely noticed it in the 1980s. Simply put: economics and business students rarely, if ever, encountered any mention of entrepreneurship during their studies. While entrepreneurship research has now developed its own methodological toolbox, it has extensively borrowed perspectives, theories, and methods from other fields. In the 2020s, we now find that entrepreneurship scholars are sharing its toolbox with other academic fields, questioning the core assumptions of other academic fields and providing new insights into the antecedents, mechanisms, and consequences of their respective core phenomena. Moreover, entrepreneurship research helps to legitimize other academic fields both practically and academically. Hence, entrepreneurship research now plays not just an important role in entrepreneurship education, practice, and policy but also throughout many other research fields.

Demographic and cultural correlates of traditional eating among Alaska Native adults at risk for cardiovascular disease.

This cross-sectional study assessed how traditional eating relates to cultural and community factors. Alaska Native adults from the Norton Sound region were recruited and surveyed between 2015-2018 for a randomized clinical trial of multiple risk behavior change interventions for cardiovascular disease prevention. Participants (n = 291) were 49% female with a mean age of 47 years (SD = 14). A 34-item food frequency questionnaire assessed consumption of foods traditional and nontraditional to the regional Alaska Native diet. A novel measure, termed the "traditional foods index", was computed as weekly servings of culturally traditional food consumption divided by total foods reported. Overall, the sample's traditional foods index averaged 21%±16%, with higher values reported by participants assessed in summer (23%±17%) than winter (19%±15%, p<0.05); by women (22%±16%) than men (19%±16%, p < .05); and by residents of smaller communities (22%±17%) than the comparatively larger community of Nome (17%±14%, p<0.05). The traditional foods index was correlated with age (r = .26, p < .01), as well as the cultural variables of community connectedness (r = .19, p < .01), community standing (r = .15, p < .01), and traditional language comprehension (r = .19, p < .01). In a multivariate regression model, age, community connectedness, and community standing remained significantly associated with traditional diet. These findings may inform the design and evaluation of community-based, culturally-relevant dietary initiatives for heart health.

Relative Lung and Systemic Bioavailability Along with Oropharyngeal Deposition of Salbutamol Post-Inhalation: A Pharmacokinetic Evaluation of Novel Inhaler Technique Training Gadgets.

Background: Suboptimal use of pressurized metered dose inhaler (pMDI) remains a major barrier to inhaled therapy success. Verbal inhaler technique training (VT) fails to maintain patients' good pMDI use, thus training tools might help. Trainhaler® (THR device) and Flo-Tone® CR (FTCR device), two novel pMDI technique training tools, were evaluated and compared in terms of relative lung and systemic bioavailability and oropharyngeal deposition of salbutamol inhaled from Ventolin® Evohaler® (GlaxoSmithKline) either alone following THR or connected to FTCR. Methods: Sixteen healthy adults inhaled 2 × 100 µg salbutamol puffs (1 minute apart) from Ventolin using the THR device or FTCR device in a two-period, randomized crossover study. A 7-day washout separated THR and FTCR approaches. Immediately after each puff inhalation, each subject gargled with 20 mL water for oropharyngeal deposition determination. Urine samples were collected 0.5 hour (pre-inhalation) and 0.5, 1.0, and 2.0 hours post-inhalation. Urine was then pooled till 24-hour post-inhalation. The relative lung bioavailability (0- to 0.5-hour urinary salbutamol excretion-USAL0.5) and relative systemic bioavailability (0- to 24-hour urinary excretion of salbutamol and its metabolite-USALMET24) were determined. Results: The mean (standard deviation [SD]) USAL0.5 of the THR and FTCR groups was 5.70 (6.43) and 11.39 (9.67) µg, respectively. The mean (SD) oropharyngeal deposition was 11.11 (4.37) and 6.09 (1.89) µg, respectively. The THR and FTCR devices were statistically significantly different in USAL0.5 and oropharyngeal deposition (p < 0.001), whereas there was no statistically significant difference in USALMET24. Conclusion: The THR device and the FTCR device showed positive impact on inhaled pMDI delivery. Indeed, the FTCR device doubled the relative lung bioavailability and minimized the unwanted oropharyngeal deposition of inhaled salbutamol. In practice, these pMDI trainers would complement and maintain VT. Study Registration: The study was registered on the ISRCTN registry (Reference: ISRCTN88332465-06/12/2017 [Prospectively Registered]).

Detecting Sources of Immune Activation and Viral Rebound in HIV Infection.

Anti-retroviral therapy (ART) generally suppresses HIV replication to undetectable levels in peripheral blood, but immune activation associated with increased morbidity and mortality is sustained during ART, and infection rebounds when treatment is interrupted. To identify drivers of immune activation and potential sources of viral rebound, we modified RNAscope in situ hybridization to visualize HIV-producing cells as a standard against which to compare the following assays of potential sources of immune activation and virus rebound following treatment interruption: (i) envelope detection by induced transcription-based sequencing (EDITS) assay; (ii) HIV-Flow; (iii) Flow-FISH assays that can scan tissues and cell suspensions to detect rare cells expressing env mRNA, gag mRNA/Gag protein and p24; and (iv) an ultrasensitive immunoassay that detects p24 in cell/tissue lysates at subfemtomolar levels. We show that the sensitivities of these assays are sufficient to detect one rare HIV-producing/env mRNA+/p24+ cell in one million uninfected cells. These high-throughput technologies provide contemporary tools to detect and characterize rare cells producing virus and viral antigens as potential sources of immune activation and viral rebound. IMPORTANCE Anti-retroviral therapy (ART) has greatly improved the quality and length of life for people living with HIV, but immune activation does not normalize during ART, and persistent immune activation has been linked to increased morbidity and mortality. We report a comparison of assays of two potential sources of immune activation during ART: rare cells producing HIV and the virus' major viral protein, p24, benchmarked on a cell model of active and latent infections and a method to visualize HIV-producing cells. We show that assays of HIV envelope mRNA (EDITS assay), gag mRNA, and p24 (Flow-FISH, HIV-Flow. and ultrasensitive p24 immunoassay) detect HIV-producing cells and p24 at sensitivities of one infected cell in a million uninfected cells, thereby providing validated tools to explore sources of immune activation during ART in the lymphoid and other tissue reservoirs.

Best practices and tools for reporting reproducible fluorescence microscopy methods.

Although fluorescence microscopy is ubiquitous in biomedical research, microscopy methods reporting is inconsistent and perhaps undervalued. We emphasize the importance of appropriate microscopy methods reporting and seek to educate researchers about how microscopy metadata impact data interpretation. We provide comprehensive guidelines and resources to enable accurate reporting for the most common fluorescence light microscopy modalities. We aim to improve microscopy reporting, thus improving the quality, rigor and reproducibility of image-based science.

Insights in the Recalcitrance of Theasinensin A to Human Gut Microbial Degradation.

Due to low bioavailability of dietary phenolic compounds in small intestine, their metabolism by gut microbiota is gaining increasing attention. The microbial metabolism of theasinensin A (TSA), a bioactive catechin dimer found in black tea, has not been studied yet. Here, TSA was extracted and purified for in vitro fermentation by human fecal microbiota, and epigallocatechin gallate (EGCG) and procyanidin B2 (PCB2) were used for comparison. Despite the similarity in their flavan-3-ol skeletons, metabolic fate of TSA was distinctively different. After degalloylation, its core biphenyl-2,2',3,3',4,4'-hexaol structure remained intact during fermentation. Conversely, EGCG and PCB2 were promptly degraded into a series of hydroxylated phenylcarboxylic acids. Computational analyses comparing TSA and PCB2 revealed that TSA's stronger interflavanic bond and more compact stereo-configuration might underlie its lower fermentability. These insights in the recalcitrance of theasinensins to degradation by human gut microbiota are of key importance for a comprehensive understanding of its health benefits.

The effect of Clip-tone® and its smartphone application on optimisation of metered-dose inhalers inhalation technique.

BACKGROUNDS: Although metered-dose inhalers (pMDI) therapy is convenient and widely prescribed, its use usually results in repetitive inhalation technique errors. One of the most repetitive errors is inhaling too fast through the pMDI. The present study aimed to evaluate the effect of Clip-tone® along with smartphone visual feedback application on the subject's inhalation time. METHODS: Two hundred subjects were included in the study. They were randomised into four groups. Group 1 received only verbal counselling; group 2 received verbal counselling with resistance (a modified Clip-tone® that does not produce whistle attached to their pMDI); group 3 received verbal counselling plus whistle (as audio feedback) from ordinary Clip-tone® and group 4 received verbal counselling plus audio feedback (whistle) from Clip-tone® and visual feedback (smartphone application). Inhalation time through the pMDI for each subject was recorded three times and inter and intra-subjects variations were calculated. RESULTS: Verbal counselling plus audio feedback and verbal counselling plus audio and visual feedbacks groups had 45/50 (90%) and 37/50 (74%) subjects respectively, having correct inhalation flow (inhaling at between 3 to 7 seconds). Verbal counselling plus audio feedback and verbal counselling plus audio and visual feedbacks groups' inter and intra-subjects variations were lower than that of verbal counselling and verbal counselling with resistance groups which had 28/50 (52%) and 20/50 (40%) subjects respectively, with inhalation time between 3 and 7 seconds. CONCLUSIONS: Providing audio feedback by the Clip-tone® along with smartphone visual feedback application maintained the deep and slow inhalation through pMDI much better compared to verbal counselling only. We recommend the patients to take all their inhaled doses using pMDI attached to a training device like Clip-tone® along with a smartphone visual feedback application for optimisation of the aerosol delivery from the pMDI.

Decreased mechanotransduction prevents nuclear collapse in a Caenorhabditis elegans laminopathy.

The function of the nucleus depends on the integrity of the nuclear lamina, an intermediate filament network associated with the linker of nucleoskeleton and cytoskeleton (LINC) complex. The LINC complex spans the nuclear envelope and mediates nuclear mechanotransduction, the process by which mechanical signals and forces are transmitted across the nuclear envelope. In turn, the AAA+ ATPase torsinA is thought to regulate force transmission from the cytoskeleton to the nucleus. In humans, mutations affecting nuclear envelope-associated proteins cause laminopathies, including progeria, myopathy, and dystonia, though the extent to which endogenous mechanical stresses contribute to these pathologies is unclear. Here, we use the Caenorhabditis elegans germline as a model to investigate mechanisms that maintain nuclear integrity as germ cell nuclei progress through meiotic development and migrate for gametogenesis-processes that require LINC complex function. We report that decreasing the function of the C. elegans torsinA homolog, OOC-5, rescues the sterility and premature aging caused by a null mutation in the single worm lamin homolog. We show that decreasing OOC-5/torsinA activity prevents nuclear collapse in lamin mutants by disrupting the function of the LINC complex. At a mechanistic level, OOC-5/torsinA promotes the assembly or maintenance of the lamin-associated LINC complex and this activity is also important for interphase nuclear pore complex insertion into growing germline nuclei. These results demonstrate that LINC complex-transmitted forces damage nuclei with a compromised nuclear lamina. Thus, the torsinA-LINC complex nexus might comprise a therapeutic target for certain laminopathies by preventing damage from endogenous cellular forces.

Successful and unsuccessful recruitment and retainment strategies in a UK multicentre drug trial for a rare chronic pain condition which performed above target.

INTRODUCTION: Recruitment into trials in rare chronic pain conditions can be challenging, so such trials consequently are underpowered or fail. METHODS: Drawing from our experience in conducting, to date, the largest academic trial in a rare chronic pain condition, complex regional pain syndrome, we have identified recruitment and retention strategies for successful trial conduct. RESULTS: We present 13 strategies grouped across the categories of 'setting the recruitment rate', 'networking', 'patient information', 'trial management' and 'patient retention'. Moreover, six recruitment risks are also discussed. A conservative recruitment estimate, based on audits of newly referred patients to the trial centres without taking into account availability of 'old' patients or recruitment from outside centres, and assuming a 55% patient refusal rate yielded accurate numbers. CONCLUSION: Appreciation of these identified recruitment challenges and opportunities may contribute to supporting prospective investigators when they design clinical trials for chronic pain patient population groups where it has been historically difficult to conduct high-quality and robust clinical trials.

Correction to: Effects of Bang® Keto Coffee Energy Drink on Metabolism and Exercise Performance in Resistance-Trained Adults: A Randomized, Double-blind, Placebo-controlled, Crossover Study.

An amendment to this paper has been published and can be accessed via the original article.