Secretion system

Hereditary, or vertically-transmitted, symbioses affect a large number of animal species and some plants. The precise mechanisms underlying transmission of functions of these associations are often difficult to describe, due to the difficulty in separating the symbiotic partners. This is especially the case for plant-bacteria hereditary symbioses, which lack experimentally tractable model systems. Here, we demonstrate the potential of the leaf symbiosis between the wild yam Dioscorea sansibarensis and the bacterium Orrella dioscoreae (O...

In this review, we highlight studies where whole genome sequencing, comparative genomics and population genomics have provided unprecedented insights into past and ongoing pathogen evolution. These include new understanding of adaptive evolution of secretion systems and their effectors. We focus on Xanthomonas pathosystems that have seen intensive study and improved our understanding of pathogen emergence and evolution, particularly in the context of host specialization: citrus canker, bacterial blight of rice, and bacterial spot of tomato and pepper...

The escalating crisis of polyethylene terephthalate (PET) microplastic contamination in biological wastewater treatment systems is a pressing environmental concern. These microplastics inevitably accumulate in sewage sludge due to the absence of effective removal technologies. Addressing this urgent issue, this study introduces a novel approach using DuraPETase, a potent enzyme with enhanced PET hydrolytic activity at ambient temperatures. Remarkably, this enzyme was successfully secreted from Comamonas testosteroni CNB-1, a dominant species in the active sludge...

The therapeutic effect of gefitinib on colorectal cancer (CRC) is unclear, but it has been reported that stromal cells in the tumor microenvironment may have an impact on drug sensitivity. Herein, we established a microfluidic co-culture system and explored the sensitivity of CRC cells co-cultured with cancer-associated fibroblasts (CAFs) to gefitinib. The system consisted of a multichannel chip and a Petri dish. The chambers in the chip and dish were designed to continuously supply nutrients for long-term cell survival and create chemokine gradients for driving cell invasion without any external equipment...

A novel bacterial symbiont, strain A19T , was previously isolated from a root-nodule of Aeschynomene indica and assigned to a new lineage in the photosynthetic clade of the genus Bradyrhizobium. Here data are presented for the detailed genomic and taxonomic analyses of novel strain A19T . Emphasis is placed on the analysis of genes of practical or ecological significance (photosynthesis, nitrous oxide reductase and nitrogen fixation genes). Phylogenomic analysis of whole genome sequences as well as 50 single-copy core gene sequences placed A19T in a highly supported lineage distinct from described Bradyrhizobium species with B...

The Stanford Biodesign needs-centric framework can guide healthcare innovators to successfully adopt the 'Identify, Invent and Implement' framework and develop new healthcare innovations products to address patients' needs. This scoping review explored the application of the Stanford Biodesign framework for healthcare innovation training and the development of novel healthcare innovative products. Seven electronic databases were searched from their respective inception dates till April 2023: PubMed, Embase, CINAHL, PsycINFO, Web of Science, Scopus, ProQuest Dissertations, and Theses Global...

UNLABELLED: Enterobacter cloacae is an emerging pathogen isolated in healthcare-associated infections. A major virulence factor of this bacterium is the type VI secretion system (T6SS). The genome of E. cloacae harbors two T6SS gene clusters (T6SS-1 and T6SS-2), and the functional characterization of both systems showed that these two T6SSs are not expressed under the same conditions. Here, we report that the major histone-like protein HU positively regulates the expression of both T6SSs and, therefore, the function that each T6SS exerts in E...

The intestinal microbiome harbors fungi that pose a significant risk to human health as opportunistic pathogens and drivers of inflammation. Inflammatory and autoimmune diseases are associated with dysbiotic fungal communities and the expansion of potentially pathogenic fungi. The gut is also the main reservoir for disseminated fungal infections. Immune interactions are critical for preventing commensal fungi from becoming pathogenic. Significant strides have been made in defining innate and adaptive immune pathways that regulate intestinal fungi, and these discoveries have coincided with advancements in our understanding of the fungal molecular pathways and effectors involved in both commensal colonization and pathogenesis within the gut...

Organoid cell culture systems can recapitulate the complexity observed in tissues, making them useful in studying host-pathogen interactions, evaluating drug efficacy and toxicity, and tissue bioengineering. However, applying these models for the described reasons may be limited because of the three-dimensional (3D) nature of these models. For example, using 3D enteroid culture systems to study digestive diseases is challenging due to the inaccessibility of the intestinal lumen and its secreted substances. Indeed, stimulation of 3D organoids with pathogens requires either luminal microinjection, mechanical disruption of the 3D structure, or generation of apical-out enteroids...

Mitochondria (mt) represent the vital hub of the molecular physiology of the cell, being decision-makers in cell life/death and information signaling, including major redox regulations and redox signaling. Now we review recent advances in understanding mitochondrial redox homeostasis, including superoxide sources and H2O2 consumers, i.e., antioxidant mechanisms, as well as exemplar situations of physiological redox signaling, including the intramitochondrial one and mt-to-cytosol redox signals, which may be classified as acute and long-term signals...

Redox status plays a multifaceted role in the intricate physiology and pathology of pancreatic beta-cells, the pivotal regulators of glucose homeostasis through insulin secretion. They are highly responsive to changes in metabolic cues where reactive oxygen species are part of it, all arising from nutritional intake. These molecules not only serve as crucial signaling intermediates for insulin secretion but also participate in the nuanced heterogeneity observed within the beta-cell population. A central aspect of beta-cell redox biology revolves around the localized production of hydrogen peroxide and the activity of NADPH oxidases which are tightly regulated and serve diverse physiological functions...

Owing to the increasing need for green synthesis and environmental protection, the utilization of biological organism-derived carbons as supports for noble-metal electrocatalysts has garnered public interest. Nevertheless, the mechanism by which microorganisms generate nanometals has not been fully understood yet. In the present study, we used genetically engineered bacteria of Shewanella oneidensis MR-1 (∆SO4317, ∆SO4320, ∆SO0618 and ∆SO3745) to explore the effect of surface substances including biofilm-associated protein (bpfA), protein secreted by type I secretion systems (TISS) and type II secretion systems (T2SS), and lipopolysaccharide in microbial synthesis of metal nanoparticles...

Neuroinflammation, blood-brain barrier (BBB) dysfunction, neuron and glia injury/death and myelin damage are common central nervous system (CNS) pathologies observed in various neurological diseases and injuries. Serine protease inhibitor (Serpin) clade A member 3n (Serpina3n), and its human orthologue SERPINA3, is an acute-phase inflammatory glycoprotein secreted primarily by the liver into the bloodstream in response to systemic inflammation. Clinically, SERPINA3 is dysregulated in brain cells, cerebrospinal fluid and plasma in various neurological conditions...

Brain iron deficiency (ID) and, to a degree, systemic ID have been implicated in restless leg syndrome (RLS) pathogenesis. Previously, we found increased ferritin in neuron-derived extracellular vesicles (NDEVs) in RLS, suggesting a mechanism for depleting intracellular iron by secreting ferritin-loaded NDEVs. In this study, we hypothesized that increased NDEV ferritin occurs even in RLS accompanied by systemic ID and that neuronal intracellular iron depletion in RLS also manifests as NDEV abnormalities in other iron regulatory proteins, specifically, decreased transferrin receptor (TfR) and increased ferroportin...

Citrus canker, a highly contagious bacterial disease caused by Xanthomonas citri subsp. citri ( Xcc ), poses a substantial threat to citrus crops, leading to serious reductions in fruit yield and economic losses. Most commonly used bactericides against Xcc lead to the rapid development of resistant subpopulations. Therefore, it is imperative to create novel drugs, such as type III secretion system (T3SS) inhibitors, that specifically target bacterial virulence factors rather than bacterial viability. In our study, we designed and synthesized a series of mandelic acid derivatives including 2-mercapto-1,3,4-thiazole...

HIV-infection of microglia and macrophages (MMs) induces neuronal injury and chronic release of inflammatory stimuli through direct and indirect molecular pathways. A large percentage of people with HIV-associated neurologic and psychiatric co-morbidities have high levels of circulating inflammatory molecules. Microglia, given their susceptibility to HIV infection and long-lived nature, are reservoirs for persistent infection. MMs and neurons possess the molecular machinery to detect pathogen nucleic acids and proteins to activate innate immune signals...

BACKGROUND: Gestational diabetes insipidus (DI) is a very rare complication of pregnancy. We present a case of gestational DI combining two different types of DI. Case Presentation . A 39-year-old pregnant woman suddenly presented with thirst, polydipsia, and polyuria after 31 gestation weeks (GWs). Based on laboratory findings of hypotonic urine (78 mOsm/kgH2 O) with higher plasma osmolality (298 mOsm/kgH2 O) and higher serum sodium levels (149 mEq/L), gestational DI was suspected, and the clinical course was monitored without therapy until the results of a measurement of plasma arginine vasopressin (AVP) levels were available...

BACKGROUND: Beta-defensins (BDs) are antimicrobial peptides secreted upon epithelial injury. Both chemotactic and antimicrobial properties of BDs function as initial steps in host defense and prime the adaptive immune system in the body. Psoriasis, a chronic immune-mediated inflammatory disease, has both visible cutaneous manifestations as well as known associations with higher incidence of cardiometabolic complications and vascular inflammation. OBJECTIVES: We aimed to investigate the circulating expression of beta-defensin-2 (BD2) in psoriasis at baseline compared to control subjects, along with changes in BD2 levels following biologic treatment at one-year...

OBJECTIVE: To develop an artificial intelligence vaginal secretion analysis system based on deep learning and to evaluate the accuracy of automated microscopy in the clinical diagnosis of aerobic vaginitis (AV). METHODS: In this study, the vaginal secretion samples of 3769 patients receiving treatment at the Department of Obstetrics and Gynecology, West China Second Hospital, Sichuan University between January 2020 and December 2021 were selected. Using the results of manual microscopy as the control, we developed the linear kernel SVM algorithm, an artificial intelligence (AI) automated analysis software, with Python Scikit-learn script...

Brain-derived neurotrophic factor (BDNF), a key neurotrophin within the brain, by selectively activating the TrkB receptor, exerts multimodal effects on neurodevelopment, synaptic plasticity, cellular integrity and neural network dynamics. In parallel, glucocorticoids (GCs), vital steroid hormones, which are secreted by adrenal glands and rapidly diffused across the mammalian body (including the brain), activate two different groups of intracellular receptors, the mineralocorticoid and the glucocorticoid receptors, modulating a wide range of genomic, epigenomic and postgenomic events, also expressed in the neural tissue and implicated in neurodevelopment, synaptic plasticity, cellular homeostasis, cognitive and emotional processing...