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Physiology (Bethesda, Md.) May 2017The main function of the lung is to support gas exchange, and defects in lung development or diseases affecting the structure and function of the lung can have fatal... (Review)
Review
The main function of the lung is to support gas exchange, and defects in lung development or diseases affecting the structure and function of the lung can have fatal consequences. Most of what we currently understand about human lung development and disease has come from animal models. However, animal models are not always fully able to recapitulate human lung development and disease, highlighting an area where in vitro models of the human lung can compliment animal models to further understanding of critical developmental and pathological mechanisms. This review will discuss current advances in generating in vitro human lung models using primary human tissue, cell lines, and human pluripotent stem cell derived lung tissue, and will discuss crucial next steps in the field.
Topics: Animals; Cell Culture Techniques; Cell Line; Disease Models, Animal; Homeostasis; Humans; In Vitro Techniques; Lung; Lung Diseases; Models, Biological; Pluripotent Stem Cells; Regeneration
PubMed: 28404740
DOI: 10.1152/physiol.00041.2016 -
Veterinary Medicine and Science Mar 2024Forages are widely used in horse diets. Different in vitro techniques are being tried to determine the fermentation levels of forages in the horse digestive tract.
BACKGROUND
Forages are widely used in horse diets. Different in vitro techniques are being tried to determine the fermentation levels of forages in the horse digestive tract.
OBJECTIVES
This study aimed to evaluate the digestion levels of four dry forages commonly used in horse nutrition: alfalfa herbage, meadow hay, wheat straw, and Italian ryegrass. In vitro total digestion (TDT), in vitro Sunvold-large intestine digestion (SDT) and in vitro Menke-large intestine digestion (MDT) techniques were compared.
METHODS
The study determined in vitro true dry matter digestion (T-DMD), in vitro true organic matter digestion (T-OMD) and in vitro true neutral detergent fibre digestion (T-NDFD). Additionally, concentrations of straight short-chain fatty acids (SCFAs; acetic acid - AA, propionic acid , butyric acid, and valeric acid ) and branched short-chain fatty acids (BSCFA) were assessed.
RESULTS
The highest in vitro T-DMD, T-OMD and T-NDFD values were determined by the in vitro TDT for the four forages (p < 0.05). In vitro T-DMD and T-OMD values of alfalfa herbage were higher than those of Italian ryegrass, meadow hay and wheat straw in the in vitro TDT (p < 0.001). In addition, in vitro T-DMD and T-OMD values of alfalfa herbage in the in vitro SDT were higher than those of meadow hay and wheat straw (p < 0.001). In the in vitro TDT, the molarity of AA, total SCFA and BSCFA in the digestion fluid of alfalfa herbage was higher than those of other forages (p < 0.05).
CONCLUSION
The in vitro total enzymatic + fermentative digestion technique for horse forages revealed higher values than the in vitro fermentative digestion techniques. In general, the higher the non-structural carbohydrate and crude protein contents in the forage, the higher the results of the in vitro TDT compared to the other techniques.
Topics: Animals; Horses; Animal Feed; Digestion; Diet; Triticum; Fatty Acids, Volatile; In Vitro Techniques
PubMed: 38369823
DOI: 10.1002/vms3.1373 -
Current Opinion in Genetics &... Oct 2020Hematopoietic stem cells (HSCs) can regenerate all lineages of the adult blood and immune systems long-term following transplantation via a combination of self-renewal... (Review)
Review
Hematopoietic stem cells (HSCs) can regenerate all lineages of the adult blood and immune systems long-term following transplantation via a combination of self-renewal and multipotent differentiation. HSCs are therefore an important cell type in both basic research and in the clinic, where HSC transplantation is a curative therapy for a range of diseases. However, as a rare bone marrow cell population, the characterization and collection of HSCs can often be challenging. This has led to a large search for in vitro culture conditions that support the growth of functional HSCs and the in vitro stabilization of the HSC state represents a major goal in the field. Here, we review recent progress towards stabilizing HSCs in vitro.
Topics: Animals; Cell Culture Techniques; Cell Differentiation; Cell Lineage; Hematopoietic Stem Cell Transplantation; Hematopoietic Stem Cells; Humans; In Vitro Techniques
PubMed: 32570191
DOI: 10.1016/j.gde.2020.05.035 -
Veterinary Research Mar 2021Organoids are self-organizing, self-renewing three-dimensional cellular structures that resemble organs in structure and function. They can be derived from adult stem... (Review)
Review
Organoids are self-organizing, self-renewing three-dimensional cellular structures that resemble organs in structure and function. They can be derived from adult stem cells, embryonic stem cells, or induced pluripotent stem cells. They contain most of the relevant cell types with a topology and cell-to-cell interactions resembling that of the in vivo tissue. The widespread and increasing adoption of organoid-based technologies in human biomedical research is testament to their enormous potential in basic, translational- and applied-research. In a similar fashion there appear to be ample possibilities for research applications of organoids from livestock and companion animals. Furthermore, organoids as in vitro models offer a great possibility to reduce the use of experimental animals. Here, we provide an overview of studies on organoids in livestock and companion animal species, with focus on the methods developed for organoids from a variety of tissues/organs from various animal species and on the applications in veterinary research. Current limitations, and ongoing research to address these limitations, are discussed. Further, we elaborate on a number of fields of research in animal nutrition, host-microbe interactions, animal breeding and genomics, and animal biotechnology, in which organoids may have great potential as an in vitro research tool.
Topics: Animal Husbandry; Animal Nutritional Physiological Phenomena; Animals; Biotechnology; Breeding; Genomics; Host Microbial Interactions; In Vitro Techniques; Livestock; Organoids; Pets; Poultry; Veterinary Medicine
PubMed: 33691792
DOI: 10.1186/s13567-021-00904-2 -
Veterinary Journal (London, England :... Mar 2016Osteoarthritis (OA) is a prevalent disease of most mammalian species and is a significant cause of welfare and economic morbidity in affected individuals and... (Review)
Review
Osteoarthritis (OA) is a prevalent disease of most mammalian species and is a significant cause of welfare and economic morbidity in affected individuals and populations. In vitro models of osteoarthritis are vital to advance research into the causes of the disease, and the subsequent design and testing of potential therapeutics. However, a plethora of in vitro models have been used by researchers but with no consensus on the most appropriate model. Models attempt to mimic factors and conditions which initiate OA, or dissect the pathways active in the disease. Underlying uncertainty as to the cause of OA and the different attributes of isolated cells and tissues used mean that similar models may produce differing results and can differ from the naturally occurring disease. This review article assesses a selection of the in vitro models currently used in OA research, and considers the merits of each. Particular focus is placed on the more prevalent cytokine stimulation and load-based models. A brief review of the mechanism of these models is given, with their relevance to the naturally occurring disease. Most in vitro models have used supraphysiological loads or cytokine concentrations (compared with the natural disease) in order to impart a timely response from the cells or tissue assessed. Whilst models inducing OA-like pathology with a single stimulus can answer important biological questions about the behaviour of cells and tissues, the development of combinatorial models encompassing different physiological and molecular aspects of the disease should more accurately reflect the pathogenesis of the naturally occurring disease.
Topics: Animals; Animals, Domestic; Biomechanical Phenomena; Cytokines; Disease Models, Animal; In Vitro Techniques; Osteoarthritis
PubMed: 26831151
DOI: 10.1016/j.tvjl.2015.07.011 -
Journal of Cerebral Blood Flow and... Oct 2018The development of realistic in vitro blood-brain barrier (BBB) models that recapitulate the physiological parameters and molecular aspect of the neurovascular unit... (Review)
Review
The development of realistic in vitro blood-brain barrier (BBB) models that recapitulate the physiological parameters and molecular aspect of the neurovascular unit (NVU) is of fundamental importance not only in CNS drug discovery but also in translational research. Successful modeling of the NVU would provide an invaluable tool to aid in dissecting out the pathological factors, mechanism of action (and corresponding targets) prodromal to the onset of CNS disorders. The field of BBB in vitro modeling has seen many radical changes in the last few years with the introduction on novel technologies and methods to improve over existing models and develop new ones. Therefore, the goal of this review is to provide the readers with updated technical and operational details concerning current BBB platforms with special focus on stem cell technology used to establish a functional BBB model in vitro. Furthermore, we provide a detailed update on rapidly advancing 3D printing technologies used for engineering BBB models which use is now fast expanding among researchers.
Topics: Blood-Brain Barrier; Humans; In Vitro Techniques; Models, Biological
PubMed: 30058456
DOI: 10.1177/0271678X18788769 -
Journal of Neuroscience Research May 2021Neurological disorders are the leading cause of disability and the second largest cause of death worldwide. Despite significant research efforts, neurology remains one... (Review)
Review
Neurological disorders are the leading cause of disability and the second largest cause of death worldwide. Despite significant research efforts, neurology remains one of the most failure-prone areas of drug development. The complexity of the human brain, boundaries to examining the brain directly in vivo, and the significant evolutionary gap between animal models and humans, all serve to hamper translational success. Recent advances in microfluidic in vitro models have provided new opportunities to study human cells with enhanced physiological relevance. The ability to precisely micro-engineer cell-scale architecture, tailoring form and function, has allowed for detailed dissection of cell biology using microphysiological systems (MPS) of varying complexities from single cell systems to "Organ-on-chip" models. Simplified neuronal networks have allowed for unique insights into neuronal transport and neurogenesis, while more complex 3D heterotypic cellular models such as neurovascular unit mimetics and "Organ-on-chip" systems have enabled new understanding of metabolic coupling and blood-brain barrier transport. These systems are now being developed beyond MPS toward disease specific micro-pathophysiological systems, moving from "Organ-on-chip" to "Disease-on-chip." This review gives an outline of current state of the art in microfluidic technologies for neurological disease research, discussing the challenges and limitations while highlighting the benefits and potential of integrating technologies. We provide examples of where such toolsets have enabled novel insights and how these technologies may empower future investigation into neurological diseases.
Topics: Animals; Biological Transport; Blood-Brain Barrier; Brain; Epigenesis, Genetic; Humans; In Vitro Techniques; Microfluidics; Nervous System Diseases; Organoids
PubMed: 33583054
DOI: 10.1002/jnr.24794 -
Current Osteoporosis Reports Apr 2020The purpose of this review is to describe the in vitro and in vivo methods that researchers use to model and investigate bone marrow adipocytes (BMAds). (Review)
Review
PURPOSE OF THE REVIEW
The purpose of this review is to describe the in vitro and in vivo methods that researchers use to model and investigate bone marrow adipocytes (BMAds).
RECENT FINDINGS
The bone marrow (BM) niche is one of the most interesting and dynamic tissues of the human body. Relatively little is understood about BMAds, perhaps in part because these cells do not easily survive flow cytometry and histology processing and hence have been overlooked. Recently, researchers have developed in vitro and in vivo models to study normal function and dysfunction in the BM niche. Using these models, scientists and clinicians have noticed that BMAds, which form bone marrow adipose tissue (BMAT), are able to respond to numerous signals and stimuli, and communicate with local cells and distant tissues in the body. This review provides an overview of how BMAds are modeled and studied in vitro and in vivo.
Topics: Adipocytes; Adipose Tissue; Animals; Bone Marrow; Bone Marrow Cells; Coculture Techniques; Culture Techniques; Flow Cytometry; Humans; In Vitro Techniques; Mice; Models, Biological; Rabbits; Rats
PubMed: 32124181
DOI: 10.1007/s11914-020-00569-4 -
Viruses Jun 2021Bacteriophages or phages, the viruses of bacteria, are abundant components of most ecosystems, including those where bacteria predominantly occupy biofilm niches....
Bacteriophages or phages, the viruses of bacteria, are abundant components of most ecosystems, including those where bacteria predominantly occupy biofilm niches. Understanding the phage impact on bacterial biofilms therefore can be crucial toward understanding both phage and bacterial ecology. Here, we take a critical look at the study of bacteriophage interactions with bacterial biofilms as carried out in vitro, since these studies serve as bases of our ecological and therapeutic understanding of phage impacts on biofilms. We suggest that phage-biofilm in vitro experiments often may be improved in terms of both design and interpretation. Specific issues discussed include (a) not distinguishing control of new biofilm growth from removal of existing biofilm, (b) inadequate descriptions of phage titers, (c) artificially small overlying fluid volumes, (d) limited explorations of treatment dosing and duration, (e) only end-point rather than kinetic analyses, (f) importance of distinguishing phage enzymatic from phage bacteriolytic anti-biofilm activities, (g) limitations of biofilm biomass determinations, (h) free-phage interference with viable-count determinations, and (i) importance of experimental conditions. Toward bettering understanding of the ecology of bacteriophage-biofilm interactions, and of phage-mediated biofilm disruption, we discuss here these various issues as well as provide tips toward improving experiments and their reporting.
Topics: Bacteria; Bacteriolysis; Bacteriophages; Biofilms; In Vitro Techniques; Microbial Interactions
PubMed: 34205417
DOI: 10.3390/v13061175 -
Seminars in Cell & Developmental Biology Jul 2020The islet of Langerhans contains at least five types of endocrine cells producing distinct hormones. In response to nutrient or neuronal stimulation, islet endocrine... (Review)
Review
The islet of Langerhans contains at least five types of endocrine cells producing distinct hormones. In response to nutrient or neuronal stimulation, islet endocrine cells release biochemicals including peptide hormones to regulate metabolism and to control glucose homeostasis. It is now recognized that malfunction of islet cells, notably insufficient insulin release of β-cells and hypersecretion of glucagon from α-cells, represents a causal event leading to hyperglycemia and frank diabetes, a disease that is increasing at an alarming rate to reach an epidemic level worldwide. Understanding the mechanisms regulating stimulus-secretion coupling and investigating how islet β-cells maintain a robust secretory activity are important topics in islet biology and diabetes research. To facilitate such studies, a number of biological systems and assay platforms have been developed for the functional analysis of islet cells. These technologies have enabled detailed analyses of individual islets at the cellular level, either in vitro, in situ, or in vivo.
Topics: Diabetes Mellitus; Humans; In Vitro Techniques; In Vivo Dosimetry; Islets of Langerhans
PubMed: 32081627
DOI: 10.1016/j.semcdb.2020.02.002