Neutrophil Heterogeneity Is Modified during Acute Lung Inflammation in Apoa1-/- Mice.

Neutrophils play important roles in inflammatory airway diseases. In this study, we assessed whether apolipoprotein A-I modifies neutrophil heterogeneity as part of the mechanism by which it attenuates acute airway inflammation. Neutrophilic airway inflammation was induced by daily intranasal administration of LPS plus house dust mite (LPS+HDM) to Apoa1-/- and Apoa1+/+ mice for 3 d. Single-cell RNA sequencing was performed on cells recovered from bronchoalveolar lavage fluid on day 4. Unsupervised profiling identified 10 clusters of neutrophils in bronchoalveolar lavage fluid from Apoa1-/- and Apoa1+/+ mice. LPS+HDM-challenged Apoa1-/- mice had an increased proportion of the Neu4 neutrophil cluster that expressed S100a8, S100a9, and Mmp8 and had high maturation, aggregation, and TLR4 binding scores. There was also an increase in the Neu6 cluster of immature neutrophils, whereas neutrophil clusters expressing IFN-stimulated genes were decreased. An unsupervised trajectory analysis showed that Neu4 represented a distinct lineage in Apoa1-/- mice. LPS+HDM-challenged Apoa1-/- mice also had an increased proportion of recruited airspace macrophages, which was associated with a reciprocal reduction in resident airspace macrophages. Increased expression of a common set of proinflammatory genes, S100a8, S100a9, and Lcn2, was present in all neutrophils and airspace macrophages from LPS+HDM-challenged Apoa1-/- mice. These findings show that Apoa1-/- mice have increases in specific neutrophil and macrophage clusters in the lung during acute inflammation mediated by LPS+HDM, as well as enhanced expression of a common set of proinflammatory genes. This suggests that modifications in neutrophil and macrophage heterogeneity contribute to the mechanism by which apolipoprotein A-I attenuates acute airway inflammation.

A possible mechanism for the enhanced toxicity of beta-amyloid protofibrils in Alzheimer's disease.

The amyloid-beta peptide (Aß) is a driver of Alzheimer's disease (AD). Aß monomers can aggregate and form larger soluble (oligomers/protofibrils) and insoluble (fibrils) forms. There is evidence that Aß protofibrils are the most toxic form, but the reasons are not known. Consistent with a critical role for this form of Aß in AD, a recently FDA-approved therapeutic antibody targeted against protofibrils, lecanemab, slows the progression of AD in patients. The plasma contact system, which can promote coagulation and inflammation, has been implicated in AD pathogenesis. This system is activated by Aß which could lead to vascular and inflammatory pathologies associated with AD. We show here that the contact system is preferentially activated by protofibrils of Aß. Aß protofibrils bind to coagulation factor XII and high molecular weight kininogen and accelerate the activation of the system. Furthermore, lecanemab blocks Aß protofibril activation of the contact system. This work provides a possible mechanism for Aß protofibril toxicity in AD and why lecanemab is therapeutically effective.

A Direct Link Implicating Loss of SLC26A6 to Gut Microbial Dysbiosis, Compromised Barrier Integrity, and Inflammation.

BACKGROUND & AIMS: Putative anion transporter-1 (PAT1, SLC26A6) plays a key role in intestinal oxalate and bicarbonate secretion. PAT1 knockout (PKO) mice exhibit hyperoxaluria and nephrolithiasis. Notably, diseases such as inflammatory bowel disease are also associated with higher risk of hyperoxaluria and nephrolithiasis. However, the potential role of PAT1 deficiency in gut-barrier integrity and susceptibility to colitis is currently elusive. METHODS: Age-matched PKO and wild-type littermates were administered 3.5% dextran sulfate sodium in drinking water for 6 days. Ileum and colon of control and treated mice were harvested. Messenger RNA and protein expression of tight junction proteins were determined by reverse transcription polymerase chain reaction and western blotting. Severity of inflammation was assessed by measuring diarrheal phenotype, cytokine expression, and hematoxylin and eosin staining. Gut microbiome and associated metabolome were analyzed by 16S ribosomal RNA sequencing and mass spectrometry, respectively. RESULTS: PKO mice exhibited significantly higher loss of body weight, gut permeability, colonic inflammation, and diarrhea in response to dextran sulfate sodium treatment. In addition, PKO mice showed microbial dysbiosis and significantly reduced levels of butyrate and butyrate-producing microbes compared with controls. Co-housing wild-type and PKO mice for 4 weeks resulted in PKO-like signatures on the expression of tight junction proteins in the colons of wild-type mice. CONCLUSIONS: Our data demonstrate that loss of PAT1 disrupts gut microbiome and related metabolites, decreases gut-barrier integrity, and increases host susceptibility to intestinal inflammation. These findings, thus, highlight a novel role of the oxalate transporter PAT1 in promoting gut-barrier integrity, and its deficiency appears to contribute to the pathogenesis of inflammatory bowel diseases.

Impact of therapeutic inhibition of oncogenic cell signaling tyrosine kinase on cell metabolism: in vivo-detectable metabolic biomarkers of inhibition.

BACKGROUND: Inhibition of kinases is the ever-expanding therapeutic approach to various types of cancer. Typically, assessment of the treatment response is accomplished by standard, volumetric imaging procedures, performed weeks to months after the onset of treatment, given the predominantly cytostatic nature of the kinase inhibitors, at least when used as single agents. Therefore, there is a great clinical need to develop new monitoring approaches to detect the response to kinase inhibition much more promptly. Noninvasive 1H magnetic resonance spectroscopy (MRS) can measure in vitro and in vivo concentration of key metabolites which may potentially serve as biomarkers of response to kinase inhibition. METHODS: We employed mantle cell lymphoma (MCL) cell lines demonstrating markedly diverse sensitivity of inhibition of Bruton's tyrosine kinase (BTK) regarding their growth and studied in-depth effects of the inhibition on various aspects of cell metabolism including metabolite synthesis using metabolomics, glucose and oxidative metabolism by Seahorse XF technology, and concentration of index metabolites lactate, alanine, total choline and taurine by 1H MRS. RESULTS: Effective BTK inhibition profoundly suppressed key cell metabolic pathways, foremost pyrimidine and purine synthesis, the citrate (TCA) cycle, glycolysis, and pyruvate and glutamine/alanine metabolism. It also inhibited glycolysis and amino acid-related oxidative metabolism. Finally, it profoundly and quickly decreased concentration of lactate (a product of mainly glycolysis) and alanine (an indicator of amino acid metabolism) and, less universally total choline both in vitro and in vivo, in the MCL xenotransplant model. The decrease correlated directly with the degree of inhibition of lymphoma cell expansion and tumor growth. CONCLUSIONS: Our results indicate that BTK inhibition exerts a broad and profound suppressive effect on cell metabolism and that the affected index metabolites such as lactate, alanine may serve as early, sensitive, and reliable biomarkers of inhibition in lymphoma patients detectable by noninvasive MRS-based imaging method. This kind of imaging-based detection may also be applicable to other kinase inhibitors, as well as diverse lymphoid and non-lymphoid malignancies.

A rare biofilm dispersion strategy demonstrated by Staphylococcus aureus under oxacillin stress.

Staphylococcus aureus (S. aureus), a versatile Gram-positive bacterium, is implicated in a spectrum of infections, and its resilience is often attributed to biofilm formation. This study investigates the effect of sub-inhibitory doses of oxacillin on biofilm formation by methicillin-resistant S. aureus (MRSA). Specifically, it examines how these doses influence biofilms' development, maturation, and dispersal. The biofilm's zenith reached 48 hours (h) of incubation, followed by a noteworthy decline at 96 h and a distinctive clearance zone around biofilm-positive cells exposed to oxacillin. Scanning electron micrographs unveiled an intriguing active biofilm dispersal mechanism, a rarity in this species. Among 180 isolates, only three carrying the elusive icaD gene exhibited this phenomenon. icaD gene was absent in their counterparts. Notably, the icaD gene emerges as a distinctive marker, crucial in regulating biofilm dispersion and setting these isolates apart. The captivating interplay of oxacillin, biofilm dynamics, and genetic signatures disintegrate novel dimensions in understanding MRSA's adaptive strategies and underscores the importance of the icaD gene in engineering biofilm resilience.

Host-induced RNA interference targeting the neuromotor gene FMRFamide-like peptide-14 (Mi-flp14) perturbs Meloidogyne incognita parasitic success in eggplant.

KEY MESSAGE: The study demonstrates the successful management of Meloidogyne incognita in eggplant using Mi-flp14 RNA interference, showing reduced nematode penetration and reproduction without off-target effects across multiple generations. Root-knot nematode, Meloidogyne incognita, causes huge yield losses worldwide. Neuromotor function in M. incognita governed by 19 neuropeptides is vital for parasitism and parasite biology. The present study establishes the utility of Mi-flp14 for managing M. incognita in eggplant in continuation of our earlier proof of concept in tobacco (US patent US2015/0361445A1). Mi-flp14 hairpin RNA construct was used for generating 19 independent transgenic eggplant events. PCR and Southern hybridization analysis confirmed transgene integration and its orientation, while RT-qPCR and Northern hybridization established the generation of dsRNA and siRNA of Mi-flp14. In vitro and in vivo bio-efficacy analysis of single-copy events against M. incognita showed reduced nematode penetration and development at various intervals that negatively impacted reproduction. Interestingly, M. incognita preferred wild-type plants over the transgenics even when unbiased equal opportunity was provided for the infection. A significant reduction in disease parameters was observed in transgenic plants viz., galls (40-48%), females (40-50%), egg masses (35-40%), eggs/egg mass (50-55%), and derived multiplication factor (60-65%) compared to wild type. A unique demonstration of perturbed expression of Mi-flp14 in partially penetrated juveniles and female nematodes established successful host-mediated RNAi both at the time of penetration even before the nematodes started withdrawing plant nutrients and later stage, respectively. The absence of off-target effects in transgenic plants was supported by the normal growth phenotype of the plants and T-DNA integration loci. Stability in the bio-efficacy against M. incognita across T1- to T4-generation transgenic plants established the utility of silencing Mi-flp14 for nematode management. This study demonstrates the significance of targeting Mi-flp14 in eggplant for nematode management, particularly to address global agricultural challenges posed by M. incognita.

Serotonin Transporter Deficiency Induces Metabolic Alterations in the Ileal Mucosa.

Serotonin transporter (SERT) deficiency has been implicated in metabolic syndrome, intestinal inflammation, and microbial dysbiosis. Interestingly, changes in microbiome metabolic capacity and several alterations in host gene expression, including lipid metabolism, were previously observed in SERT-/- mice ileal mucosa. However, the precise host or microbial metabolites altered by SERT deficiency that may contribute to the pleiotropic phenotype of SERT KO mice are not yet understood. This study investigated the hypothesis that SERT deficiency impacts lipid and microbial metabolite abundances in the ileal mucosa, where SERT is highly expressed. Ileal mucosal metabolomics was performed by Metabolon on wild-type (WT) and homozygous SERT knockout (KO) mice. Fluorescent-activated cell sorting (FACS) was utilized to measure immune cell populations in ileal lamina propria to assess immunomodulatory effects caused by SERT deficiency. SERT KO mice exhibited a unique ileal mucosal metabolomic signature, with the most differentially altered metabolites being lipids. Such changes included increased diacylglycerols and decreased monoacylglycerols in the ileal mucosa of SERT KO mice compared to WT mice. Further, the ileal mucosa of SERT KO mice exhibited several changes in microbial-related metabolites known to play roles in intestinal inflammation and insulin resistance. SERT KO mice also had a significant reduction in the abundance of ileal group 3 innate lymphoid cells (ILC3). In conclusion, SERT deficiency induces complex alterations in the ileal mucosal environment, indicating potential links between serotonergic signaling, gut microbiota, mucosal immunity, intestinal inflammation, and metabolic syndrome.

Effect of boron fertilization on productivity and sustainability of rice-wheat cropping system in Tarai region, North-West India.

Extensive global dependency on rice and wheat crops has necessitated the adoption of intensive cultivation practices, thereby compelling to closely monitor the potential yield-limiting factors, among which, boron (B) deficiency stands out to be a prime concern. The present study explores the effects of B fertilization strategies within the Rice-Wheat Cropping System (RWCS) in the Tarai region of North-West India. A comprehensive six-year field experiment was conducted (2013-2019) at G.B. Pant University of Agriculture and Technology, Uttarakhand, India. The experiment tested graded B doses (0.5, 1.0, 1.5, and 2.0 kg ha-1) at varied frequencies (single, alternate, and annual) in a factorial design. The study revealed significant impacts of alternate B application at 1.5 kg ha-1 on crop yields and the Sustainable Yield Index (SYI). The System Rice Equivalent Yield (SREY) exhibited an increase of 6.7% with B supplementation over B-deprived plots, highlighting the pivotal role of B fertilizer in enhancing productivity within the RWCS. The economic optimum B dose was found to be 1.422 kg ha-1 using a linear plus plateau model, resulting in a calculated annual SREY of 9.73 t ha-1 when applied alternately to the cropping system. Continuous application and higher B rates demonstrated substantial increases in various B fractions, while the mobility factor remained within 10%, depicting safe ecological limits. The distribution of fractions in B-treated plots on average followed the order: residual B > organically-bound B > oxide bound B > specifically adsorbed B > readily soluble B. Similarities in the distribution patterns of B fractions between B-treated plots and the control indicated potential influence of biotic or abiotic processes on B fraction dynamics, even in the absence of external B application. To sum up, B application in alternate years at 1.5 kg ha-1 was most sustainable in enhancing the SREY, SYI, available soil B, and B fractions and lowering the environmental hazards.

The Looming Future of Private Equity in Plastic Surgery.

Private equity acquisition of independent private practices has grown dramatically in the last decade, with private equity firms increasingly investing in surgical specialties that practice in outpatient ambulatory centers. This trend has slowly started to creep into plastic surgery; therefore, understanding the concepts of private equity ownership in healthcare and its benefits and risks is critical. This article provides a fundamental economic background on private equity, describes its current state in healthcare, including trends in plastic surgery, and provides recommendations for plastic surgeons considering private equity acquisition.

Deciphering the potential of Sargassum tenerrimum extract: metabolic profiling and pathway analysis of groundnut (Arachis hypogaea) in response to Sargassum extract and Sclerotium rolfsii.

Seaweed extracts have enormous potential as bio-stimulants and demonstrated increased growth and yield in different crops. The presence of physiologically active component stimulate plant stress signaling pathways, enhances growth and productivity, as well as serve as plant defense agents. The seaweed extracts can reduce the use of chemicals that harm the environment for disease management. In the present study, the Sargassum tenerrimum extract treatment was applied, alone and in combination with Sclerotium rolfsii, to Arachis hypogea, to study the differential metabolite expression. The majority of metabolites showed maximum accumulation with Sargassum extract-treated plants compared to fungus-treated plants. The different classes of metabolite compounds like sugars, carboxylic acids, polyols, showed integrated peaks in different treatments of plants. The sugars were higher in Sargassum extract and Sargassum extract + fungus treatments compared to control and fungus treatment, respectively. Interestingly, Sargassum extract + fungus treatment showed maximum accumulation of carboxylic acids. Pathway enrichment analysis showed regulation of different metabolites, highest impact with galactose metabolism pathway, identifying sucrose, myo-inositol, glycerol and fructose. The differential metabolite profiling and pathway analysis of groundnut in response to Sargassum extract and S. rolfsii help in understanding the groundnut- S. rolfsii interactions and the potential role of the Sargassum extract towards these interactions. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-024-01418-9.

Comparison of midpoint transverse process to pleura (MTP) block and erector spinae plane block (ESP) for postoperative analgesia in modified radical mastectomy patients: A double-blinded, randomized control trial.

Background and Aims: Modified radical mastectomy (MRM) is associated with moderate severity of postoperative pain. Besides intravenous (IV) analgesics, various nerve blocks are being described for pain relief of MRM patients. We compared erector spinae plane (ESP) block with midpoint transverse process to pleura (MTP) block in these patients for postoperative analgesia. Material and Methods: After receiving ethical committee approval from the institutional ethics committee (AIIMS, Jodhpur) and written informed consent from study participants, 66 patients who were assigned American Society of Anesthesiologists (ASA) physical status I and II, aged 18-75 years, and were scheduled to undergo MRM were enrolled and randomly allocated into two groups. Unilateral block was given before surgery at T3 or T4 level and with 15 ml of 0.5% ropivacaine in both the groups. Infusion of 0.5% ropivacaine (Neon laboratories limited, Mumbai, India) and 0.2% ropivacaine at a rate of 5 ml/h was maintained intraoperatively and postoperatively, respectively. Pain was assessed using the Visual Analogue Scale (VAS) for the next 24 hours. The total number of patients needing rescue analgesia, the total amount of rescue analgesics consumed in the next 24 hours, and patient satisfaction score were also compared between groups. Results: Demographics and baseline vitals were comparable in the groups. On comparing VAS scores in both the groups during rest and movement at different time intervals, there was no difference in pain scores during the initial two hours. From the third hour, there was a statistically significant difference (P < 0.001) in pain VAS scores in both groups. The ESP group had lower VAS scores compared to the MTP group when followed for the next 24 hours. There was a statistically significant difference in patient satisfaction. Conclusion: ESP block is more efficacious when compared to MTP block for postoperative analgesia in MRM patients.

ATP-binding cassette protein ABCA7 deficiency impairs sphingomyelin synthesis, cognitive discrimination, and synaptic plasticity in the entorhinal cortex.

Sphingomyelin (SM) is an abundant plasma membrane and plasma lipoprotein sphingolipid. We previously reported that ATP-binding cassette family A protein 1 (ABCA1) deficiency in humans and mice decreases plasma SM levels. However, overexpression, induction, downregulation, inhibition, and knockdown of ABCA1 in human hepatoma Huh7 cells did not decrease SM efflux. Using unbiased siRNA screening, here, we identified that ABCA7 plays a role in the biosynthesis and efflux of SM without affecting cellular uptake and metabolism. Since loss of function mutations in the ABCA7 gene exhibit strong associations with late-onset Alzheimer's disease across racial groups, we also studied the effects of ABCA7 deficiency in the mouse brain. Brains of ABCA7-deficient (KO) mice, compared with WT, had significantly lower levels of several SM species with long chain fatty acids. In addition, we observed that older KO mice exhibited behavioral deficits in cognitive discrimination in the active place avoidance task. Next, we performed synaptic transmission studies in brain slices obtained from older mice. We found anomalies in synaptic plasticity at the intracortical synapse in layer II/III of the lateral entorhinal cortex but not in the hippocampal CA3-CA1 synapses in KO mice. These synaptic abnormalities in KO brain slices were rescued with extracellular SM supplementation but not by supplementation with phosphatidylcholine. Taken together, these studies identify a role of ABCA7 in brain SM metabolism and the importance of SM in synaptic plasticity and cognition, as well as provide a possible explanation for the association between ABCA7 and late-onset Alzheimer's disease.

(Re-)Directing Oligomerization of a Single Building Block into Two Specific Dynamic Covalent Foldamers through pH.

Dynamic foldamers are synthetic folded molecules which can change their conformation in response to an external stimulus and are currently at the forefront of foldamer chemistry. However, constitutionally dynamic foldamers, which can change not only their conformation but also their molecular constitution in response to their environment, are without precedent. We now report a size- and shape-switching small dynamic covalent foldamer network which responds to changes in pH. Specifically, acidic conditions direct the oligomerization of a dipeptide-based building block into a 16-subunit macrocycle with well-defined conformation and with high selectivity. At higher pH the same building block yields another cyclic foldamer with a smaller ring size (9mer). The two foldamers readily and repeatedly interconvert upon adjustment of the pH of the solution. We have previously shown that addition of a template can direct oligomerization of the same building block to yet other rings sizes (including a 12mer and a 13mer, accompanied by a minor amount of 14mer). This brings the total number of discrete foldamers that can be accessed from a single building block to five. For a single building block system to exhibit such highly diverse structure space is unique and sets this system of foldamers apart from proteins. Furthermore, the emergence of constitutional dynamicity opens up new avenues to foldamers with adaptive behavior.

Association of ACEI/ARB and statin prescribing patterns with mortality after Transcatheter Aortic Valve Replacement (TAVR): Findings from real-world claims data.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) has become the standard of care for most patients with severe aortic stenosis (AS), but the impact of medical therapy prescribing patterns on post-TAVR patients has not been thoroughly investigated. METHODS: We analyzed Optum claims data from 9,012 adults who received TAVR for AS (January 2014-December 2018). Pharmacy claims data were used to identify patients who filled ACEI/ARB and/or statin prescriptions during the study's 90-day landmark period post-TAVR. Kaplan-Meier and adjusted Cox Proportional Hazards models were used to evaluate the association of prescribing patterns with mortality during the 3-year follow-up period. Subgroup analyses were performed to examine the impact of 11 potential confounders on the observed associations. RESULTS: A significantly lower adjusted 3-year mortality was observed for patients with post-TAVR prescription for ACEI/ARBs (hazard ratio [HR] = 0.82, 95% confidence interval [CI] 0.74-0.91, P = .0003) and statins (HR = 0.85, 95% CI 0.77-0.94, P = .0018) compared to patients who did not fill prescriptions for these medications post-TAVR. Subgroup analyses revealed that the survival benefit associated with ACEI/ARB prescription was not affected by any of the potential confounding variables, except preoperative ACEI/ARB prescription was associated with significantly lower risk of mortality vs postoperative prescription only. No other subgroup variables had significant interactions associated with survival benefits, including preoperative use of statins. CONCLUSIONS: In this large-scale, real-world analysis of patients undergoing TAVR, the prescription of ACEI/ARB and statins was associated with a significantly lower risk of mortality at 3-years, especially in those where the medications were initiated preoperatively.

Circulating mitochondrial DNA is a proinflammatory DAMP in sickle cell disease.

The pathophysiology of sickle cell disease (SCD) is driven by chronic inflammation fueled by damage associated molecular patterns (DAMPs). We show that elevated cell-free DNA (cfDNA) in patients with SCD is not just a prognostic biomarker, it also contributes to the pathological inflammation. Within the elevated cfDNA, patients with SCD had a significantly higher ratio of cell-free mitochondrial DNA (cf-mtDNA)/cell-free nuclear DNA compared with healthy controls. Additionally, mitochondrial DNA in patient samples showed significantly disproportionately increased hypomethylation compared with healthy controls, and it was increased further in crises compared with steady-state. Using flow cytometry, structured illumination microscopy, and electron microscopy, we showed that circulating SCD red blood cells abnormally retained their mitochondria and, thus, are likely to be the source of the elevated cf-mtDNA in patients with SCD. Patient plasma containing high levels of cf-mtDNA triggered the formation of neutrophil extracellular traps (NETs) that was substantially reduced by inhibition of TANK-binding kinase 1, implicating activation of the cGAS-STING pathway. cf-mtDNA is an erythrocytic DAMP, highlighting an underappreciated role for mitochondria in sickle pathology. These trials were registered at www.clinicaltrials.gov as #NCT00081523, #NCT03049475, and #NCT00047996.

A single amino acid change led to structural and functional differentiation of PvHd1 to control flowering in switchgrass.

Switchgrass, a forage and bioenergy crop, occurs as two main ecotypes with different but overlapping ranges of adaptation. The two ecotypes differ in a range of characteristics, including flowering time. Flowering time determines the duration of vegetative development and therefore biomass accumulation, a key trait in bioenergy crops. No causal variants for flowering time differences between switchgrass ecotypes have, as yet, been identified. In this study, we mapped a robust flowering time quantitative trait locus (QTL) on chromosome 4K in a biparental F2 population and characterized the flowering-associated transcription factor gene PvHd1, an ortholog of CONSTANS in Arabidopsis and Heading date 1 in rice, as the underlying causal gene. Protein modeling predicted that a serine to glycine substitution at position 35 (p.S35G) in B-Box domain 1 greatly altered the global structure of the PvHd1 protein. The predicted variation in protein compactness was supported in vitro by a 4 °C shift in denaturation temperature. Overexpressing the PvHd1-p.35S allele in a late-flowering CONSTANS-null Arabidopsis mutant rescued earlier flowering, whereas PvHd1-p.35G had a reduced ability to promote flowering, demonstrating that the structural variation led to functional divergence. Our findings provide us with a tool to manipulate the timing of floral transition in switchgrass cultivars and, potentially, expand their cultivation range.

Central role of intestinal epithelial glucocorticoid receptor in alcohol- and corticosterone-induced gut permeability and systemic response.

Corticosterone, the stress hormone, exacerbates alcohol-associated tissue injury, but the mechanism involved is unknown. We examined the role of the glucocorticoid receptor (GR) in corticosterone-mediated potentiation of alcohol-induced gut barrier dysfunction and systemic response. Hepatocyte-specific GR-deficient (GRΔHC ) and intestinal epithelial-specific GR-deficient (GRΔIEC ) mice were fed ethanol, combined with corticosterone treatment. Intestinal epithelial tight junction integrity, mucosal barrier function, microbiota dysbiosis, endotoxemia, systemic inflammation, liver damage, and neuroinflammation were assessed. Corticosterone potentiated ethanol-induced epithelial tight junction disruption, mucosal permeability, and inflammatory response in GRΔHC mouse colon; these effects of ethanol and corticosterone were absent in GRΔIEC mice. Gut microbiota compositions in ethanol-fed GRΔHC and GRΔIEC mice were similar to each other. However, corticosterone treatment in ethanol-fed mice shifted the microbiota composition to distinctly different directions in GRΔHC and GRΔIEC mice. Ethanol and corticosterone synergistically elevated the abundance of Enterobacteriaceae and Escherichia coli and reduced the abundance of Lactobacillus in GRΔHC mice but not in GRΔIEC mice. In GRΔHC mice, corticosterone potentiated ethanol-induced endotoxemia and systemic inflammation, but these effects were absent in GRΔIEC mice. Interestingly, ethanol-induced liver damage and its potentiation by corticosterone were observed in GRΔHC mice but not in GRΔIEC mice. GRΔIEC mice were also resistant to ethanol- and corticosterone-induced inflammatory response in the hypothalamus. These data indicate that the intestinal epithelial GR plays a central role in alcohol- and corticosterone-induced gut barrier dysfunction, microbiota dysbiosis, endotoxemia, systemic inflammation, liver damage, and neuroinflammation. This study identifies a novel target for potential therapeutic for alcohol-associated tissue injury.

The vertebrate muscle superlattice: discovery, consequences, and link to geometric frustration.

Early x-ray diffraction studies of muscle revealed spacings larger than the basic thick filament lattice spacing and led to a number of speculations on the mutual rotations of the filaments in the myosin lattice. The nature of the arrangements of the filaments was resolved by John Squire and Pradeep Luther using careful electron microscopy and image analysis. The intriguing disorder in the rotations, that they termed the myosin superlattice, remained a curiosity, until work with Rick Millane and colleagues showed a connection to "geometric frustration," a well-known phenomenon in statistical and condensed matter physics. In this review, we describe how this connection gives a satisfying physical basis for the myosin superlattice, and how recent work has shown relationships to muscle mechanical behaviour.

Cryo-electron tomography of intact cardiac muscle reveals myosin binding protein-C linking myosin and actin filaments.

Myosin binding protein C (MyBP-C) is an accessory protein of the thick filament in vertebrate cardiac muscle arranged over 9 stripes of intervals of 430 Å in each half of the A-band in the region called the C-zone. Mutations in cardiac MyBP-C are a leading cause of hypertrophic cardiomyopathy the mechanism of which is unknown. It is a rod-shaped protein composed of 10 or 11 immunoglobulin- or fibronectin-like domains labelled C0 to C10 which binds to the thick filament via its C-terminal region. MyBP-C regulates contraction in a phosphorylation dependent fashion that may be through binding of its N-terminal domains with myosin or actin. Understanding the 3D organisation of MyBP-C in the sarcomere environment may provide new light on its function. We report here the fine structure of MyBP-C in relaxed rat cardiac muscle by cryo-electron tomography and subtomogram averaging of refrozen Tokuyasu cryosections. We find that on average MyBP-C connects via its distal end to actin across a disc perpendicular to the thick filament. The path of MyBP-C suggests that the central domains may interact with myosin heads. Surprisingly MyBP-C at Stripe 4 is different; it has weaker density than the other stripes which could result from a mainly axial or wavy path. Given that the same feature at Stripe 4 can also be found in several mammalian cardiac muscles and in some skeletal muscles, our finding may have broader implication and significance. In the D-zone, we show the first demonstration of myosin crowns arranged on a uniform 143 Å repeat.

Antimicrobial resistomes in food chain microbiomes.

The safety and integrity of the global food system is in a constant state of flux with persistent chemical and microbial risks. While chemical risks are being managed systematically, microbial risks pose extra challenges. Antimicrobial resistant microorganism and persistence of related antibiotic resistance genes (ARGs) in the food chain adds an extra dimension to the management of microbial risks. Because the food chain microbiome is a key interface in the global health system, these microbes can affect health in many ways. In this review, we systematically summarize the distribution of ARGs in foods, describe the potential transmission pathway and transfer mechanism of ARGs from farm to fork, and discuss potential food safety problems and challenges. Modulating antimicrobial resistomes in the food chain facilitates a sustainable global food production system.