Measuring the phagocytic activity of cells

A comprehensive review of the phytochemistry, pharmacology, pharmacokinetics, and green nanotechnological significance of Boerhavia diffusa Linn

A comprehensive study of Boerhavia diffusa Linn., an important medicinal herb in India's Ayurvedic tradition known as Punarnava. The herb, which thrives in tropical and subtropical areas, has long been prized for its amazing medicinal powers. A literature search was conducted using PubMed, Web of Science, Google Scholar, Springer, and Elsevier with the search term "Boerhavia diffusa" phytochemical makeup comprises alkaloids, flavonoids, glycosides, phenolics, and saponins, all of which contribute to its various pharmacological properties. These chemicals have a variety of biological actions, including anti-inflammatory, anticancer, hepatoprotective, antidiabetic, and antibacterial effects. Boerhavia diffusa has long been used to treat illnesses such as liver disease, arthritis, asthma, and kidney problems. The paper goes into the pharmacokinetic problems of Boerhavia diffusa's bioactive chemicals, including their low bioavailability. It demonstrates the growing interest in using green nanotechnology to improve the transport and efficacy of these substances. Environmentally friendly nanocarriers are being created to transport Boerhavia diffusa chemicals more efficiently, especially in cancer therapies, wound healing, and antibacterial treatments. These nanocarriers improve targeted medication delivery, reduce toxicity, and increase bioavailability, resulting in a sustainable and friendly solution. Combining green nanotechnology with Boerhavia diffusa opens up new possibilities for modern medical applications, providing a more efficient, safe, and environmentally responsible solution. This review emphasizes Boerhavia diffusa's enormous potential as both a traditional medicine and a component of modern therapeutic breakthroughs, integrating millennia of Indigenous knowledge with cutting-edge scientific advances.

A new model measuring bacterial phagocytosis and phagolysosomal oxidation in humans using the intradermal injection of methylene blue-labeled Escherichia coli

Phagocytosis is an important leukocyte function; however, using existing models it cannot be measured in human tissues in vivo. To address this, we characterized a new phagocytosis model using intradermal methylene blue-labeled Escherichia coli injection (MBEC). Methylene blue (MB) is a licensed human medicine and bacterial stain potentially useful for labeling E. coli that is safe for human injection. Ex vivo coculture of leukocytes with MBEC caused MB to transfer into neutrophils and macrophages by phagocytosis. During this, a "red shift" in MB fluorescence was shown to be caused by phagolysosomal oxidation. Hence, MBEC coculture could be used to measure phagocytosis and phagolysosomal oxidation in humans, ex vivo. In healthy volunteers, inflammatory exudate sampling using suction blisters 2 to 24 h after intradermal MBEC injection showed that tissue-acquired neutrophils and monocytes contained more MB than their circulating counterparts, whereas blood and inflamed tissue T, B, and natural killer cells were MBlo. This was validated with spectral flow cytometry by visualizing the MB emission spectrum in tissue-acquired neutrophils. Neutrophil MB emission spectra demonstrated more red shift at 24 h compared with earlier time points, in keeping with progressive phagolysosomal MB oxidation in neutrophils over time in vivo. This new MBEC model can therefore measure bacterial phagocytosis and phagolysosomal oxidation in human skin, in vivo. This has a number of important research applications, e.g. in studying human phagocyte biology, testing novel antimicrobials, and understanding why certain groups such as males, the elderly or those with diabetes, recent surgery, or malnutrition are at increased risk of bacterial infection.

A critical assessment of the cellular defences of the avian respiratory system: are birds in general and poultry in particular relatively more susceptible to pulmonary infections/afflictions?

In commercial poultry farming, respiratory diseases cause high morbidities and mortalities, begetting colossal economic losses. Without empirical evidence, early observations led to the supposition that birds in general, and poultry in particular, have weak innate and adaptive pulmonary defences and are therefore highly susceptible to injury by pathogens. Recent findings have, however, shown that birds possess notably efficient pulmonary defences that include: (i) a structurally complex three-tiered airway arrangement with aerodynamically intricate air-flow dynamics that provide efficient filtration of inhaled air; (ii) a specialised airway mucosal lining that comprises air-filtering (ciliated) cells and various resident phagocytic cells such as surface and tissue macrophages, dendritic cells and lymphocytes; (iii) an exceptionally efficient mucociliary escalator system that efficiently removes trapped foreign agents; (iv) phagocytotic atrial and infundibular epithelial cells; (v) phagocytically competent surface macrophages that destroy pathogens and injurious particulates; (vi) pulmonary intravascular macrophages that protect the lung from the vascular side; and (vii) proficiently phagocytic pulmonary extravasated erythrocytes. Additionally, the avian respiratory system rapidly translocates phagocytic cells onto the respiratory surface, ostensibly from the subepithelial space and the circulatory system: the mobilised cells complement the surface macrophages in destroying foreign agents. Further studies are needed to determine whether the posited weak defence of the avian respiratory system is a global avian feature or is exclusive to poultry. This review argues that any inadequacies of pulmonary defences in poultry may have derived from exacting genetic manipulation(s) for traits such as rapid weight gain from efficient conversion of food into meat and eggs and the harsh environmental conditions and severe husbandry operations in modern poultry farming. To reduce pulmonary diseases and their severity, greater effort must be directed at establishment of optimal poultry housing conditions and use of more humane husbandry practices.

Characterization of microglia behaviour in healthy and pathological conditions with image analysis tools

Microglia are very sensitive to changes in the environment and respond through morphological, functional and metabolic adaptations. To depict the modifications microglia undergo under healthy and pathological conditions, we developed free access image analysis scripts to quantify microglia morphologies and phagocytosis. Neuron-glia cultures, in which microglia express the reporter tdTomato, were exposed to excitotoxicity or excitotoxicity + inflammation and analysed 8 h later. Neuronal death was assessed by SYTOX staining of nucleus debris and phagocytosis was measured through the engulfment of SYTOX⁺ particles in microglia. We identified seven morphologies: round, hypertrophic, fried egg, bipolar and three 'inflamed' morphologies. We generated a classifier able to separate them and assign one of the seven classes to each microglia in sample images. In control cultures, round and hypertrophic morphologies were predominant. Excitotoxicity had a limited effect on the composition of the populations. By contrast, excitotoxicity + inflammation promoted an enrichment in inflamed morphologies and increased the percentage of phagocytosing microglia. Our data suggest that inflammation is critical to promote phenotypical changes in microglia. We also validated our tools for the segmentation of microglia in brain slices and performed morphometry with the obtained mask. Our method is versatile and useful to correlate microglia sub-populations and behaviour with environmental changes.

Isolation, characterization and in-vitro antigenicity studies of outer membrane proteins (OMPs) of Salmonella gallinarum coated gold nanoparticles (AuNPs)

The development of biomimetic nanoparticles by combining the natural cellular material with synthetic nanoparticles has inspired innovative therapeutic strategies as compared to traditional line of therapeutics. Therefore, the research was conducted to prepare the outer membrane proteins (OMPs) from Salmonella gallinarum and coated on to the surface of synthetic gold nanoparticles (AuNPs). The size of the final product was characterized by Zeta sizer and Zeta potential. The coating of outer membrane proteins onto the gold nanoparticles (AuNPs) was confirmed by transmission electron microscopy (TEM). The sterility, stability and safety of the prepared antigen was confirmed by standard culture media, in biological buffer solution and in-vitro pyrogenic testing, respectively. In-vitro antigenicity of outer membrane protein alone and coated with gold nanoparticles were observed through macrophage phagocytosis assay. On the basis of results, it was anticipated that bacterial outer membrane protein has immunogenic antigenic properties and coating of bacterial outer membrane protein on the surfaces of synthetic gold nanoparticles not only preserved the complex biological characteristics of bacteria but also provided greater immune responses as compared to outer membrane protein alone. So, it was concluded that the coating of bacterial outer membrane proteins on the surface of synthetic gold nanoparticles have synergistic effects to induce the immune responses and promising potential to develop the effective antibacterial vaccine against salmonellosis in poultry birds.

Doxycycline-Doped Polymeric Membranes Induced Growth, Differentiation and Expression of Antigenic Phenotype Markers of Osteoblasts

Polymeric membranes are employed in guided bone regeneration (GBR) as physical barriers to facilitate bone in-growth. A bioactive and biomimetic membrane with the ability to participate in the healing and regeneration of the bone is necessary. The aim of the present study was to analyze how novel silicon dioxide composite membranes functionalized with zinc or doxycycline can modulate the osteoblasts' proliferation, differentiation, and expression of selected antigenic markers related to immunomodulation. Nanostructured acrylate-based membranes were developed, blended with silica, and functionalized with zinc or doxycycline. They were subjected to MG63 osteoblast-like cells culturing. Proliferation was assessed by MTT-assay, differentiation by evaluating the alkaline phosphatase activity by a spectrophotometric method and antigenic phenotype was assessed by flow cytometry for selected markers. Mean comparisons were conducted by one-way ANOVA and Tukey tests (p < 0.05). The blending of silica nanoparticles in the tested non-resorbable polymeric scaffold improved the proliferation and differentiation of osteoblasts, but doxycycline doped scaffolds attained the best results. Osteoblasts cultured on doxycycline functionalized membranes presented higher expression of CD54, CD80, CD86, and HLA-DR, indicating a beneficial immunomodulation activity. Doxycycline doped membranes may be a potential candidate for use in GBR procedures in several challenging pathologies, including periodontal disease.

Dynamic organization of intracellular organelle networks

Intracellular organelles are membrane-bound and biochemically distinct compartments constructed to serve specialized functions in eukaryotic cells. Through extensive interactions, they form networks to coordinate and integrate their specialized functions for cell physiology. A fundamental property of these organelle networks is that they constantly undergo dynamic organization via membrane fusion and fission to remodel their internal connections and to mediate direct material exchange between compartments. The dynamic organization not only enables them to serve critical physiological functions adaptively but also differentiates them from many other biological networks such as gene regulatory networks and cell signaling networks. This review examines this fundamental property of the organelle networks from a systems point of view. The focus is exclusively on homotypic networks formed by mitochondria, lysosomes, endosomes, and the endoplasmic reticulum, respectively. First, key mechanisms that drive the dynamic organization of these networks are summarized. Then, several distinct organizational properties of these networks are highlighted. Next, spatial properties of the dynamic organization of these networks are emphasized, and their functional implications are examined. Finally, some representative molecular machineries that mediate the dynamic organization of these networks are surveyed. Overall, the dynamic organization of intracellular organelle networks is emerging as a fundamental and unifying paradigm in the internal organization of eukaryotic cells. This article is categorized under: Metabolic Diseases > Molecular and Cellular Physiology.

Phagocytosis activity of three sulfated polysaccharides purified from a marine diatom cultured in a semi-continuous system

An efficient process has been developed for bioactive polysaccharide production and purification from a local diatom isolate, Halamphora sp. AQ4. First, a semi-continuous system with fixed harvesting frequency was employed to cultivate AQ4 for the production of cell mass and polysaccharides for more than 285 days with a high yield of biomass. Six cultivation sets are performed according to different harvesting volumes per 3 days with or without Na₂CO₃ supplement. The addition of Na₂CO₃ increases both cell mass and polysaccharide production. Furthermore, three different sulfated polysaccharides (PK1~PK3) were purified from the freshly-grown AQ4 diatoms following anion-exchange chromatography. Among them, polysaccharide PK3 not only has a high content of fucose and uronic acid, but also has a strong activity to stimulate murine macrophage cells and increase their phagocytosis rate up to 170%. This study demonstrates that diatom AQ4 is an important bioresource for the production of bioactive polysaccharides.

A practical guide for assessing respiratory burst and phagocytic cell activity in the fathead minnow, an emerging model for immunotoxicity

Measures of respiratory burst and phagocytic cell activity are frequently utilized to assess cellular immune function in teleosts. Respiratory burst predominately occurs in neutrophils and causes the release of reactive oxygen species to kill pathogens. Phagocytosis is the process by which pathogens are engulfed and destroyed by various immune cells. Though a variety of approaches have been utilized to measure respiratory burst and phagocytic cell activity, assays that rely only on common laboratory equipment (e.g., plate reader) may offer advantages over those that rely on more specialized equipment (e.g., flow cytometer). The goal of the current study was to optimize and validate the use of a colorimetric plate-based respiratory burst and fluorometric plate-based phagocytic cell activity assays for use with kidney cells from the fathead minnow (Pimephales promelas), an emerging immunotoxicity model. In addition, a protocol for the dissection of kidney tissue followed by the extraction of kidney cells, as well as recommendations and resources for future experiments utilizing each of these assays, are provided.•

All methods are optimized for use with the fathead minnow or similar teleost species.

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Respiratory burst and phagocytic cell activity are measured using a standard plate reader.

Methods for monitoring the progression of cell death, cell disassembly and cell clearance

Cell death through apoptosis, necrosis, necroptosis and pyroptosis, as well as the clearance of dead cells are crucial biological processes in the human body. Likewise, disassembly of dying cells during apoptosis to generate cell fragments known as apoptotic bodies may also play important roles in regulating cell clearance and intercellular communication. Recent advances in the field have led to the development of new experimental systems to identify cells at different stages of cell death, measure the levels of apoptotic cell disassembly, and monitor the cell clearance process using a range of in vitro, ex vivo and in vivo models. In this article, we will provide a comprehensive review of the methods for monitoring the progression of cell death, cell disassembly and cell clearance.