SEDDS facilitate cinnamaldehyde crossing the mucus barrier: the perspective of mucus and Caco-2/HT29 co-culture models

Abstract Background Recent accumulating evidence suggests that amino acids have crucial roles in the maintenance of intestinal homeostasis. In inflammatory bowel disease (IBD), amino acid metabolism is changed in both host and the gut microbiota. Among amino acids, L-serine plays a central role in several metabolic processes that are essential for the growth and survival of both mammalian and bacterial cells. However, the role of L-serine in intestinal homeostasis and IBD remains incompletely understood. In this study, we investigated the effect of dietary L-serine on intestinal inflammation in a murine model of colitis. Methods Specific pathogen-free (SPF) mice were fed either a control diet (amino acid-based diet) or an L-serine-deficient diet (SDD). Colitis was induced by the treatment of dextran sodium sulfate (DSS). The gut microbiome was analyzed by 16S rRNA sequencing. We also evaluate the effect of dietary L-serine in germ-free mice and gnotobiotic mice that were colonized by a consortium of non-mucolytic bacterial strains or the consortium plus mucolytic bacterial strains. Results We found that the SDD exacerbated experimental colitis in SPF mice. However, the severity of colitis in SDD-fed mice was comparable to control diet-fed mice in germ-free condition, suggesting that the gut microbiota is required for exacerbation of colitis caused by the restriction of dietary L-serine. The gut microbiome analysis revealed that dietary L-serine restriction fosters the blooms of a mucus-degrading bacterium Akkermansia muciniphila and adherent-invasive Escherichia coli in the inflamed gut. Consistent with the expansion of mucolytic bacteria, SDD-fed mice showed a loss of the intestinal mucus layer. Dysfunction of the mucus barrier resulted in increased intestinal permeability, thereby leading to bacterial translocation to the intestinal mucosa, which subsequently increased the severity of colitis. The increased intestinal permeability and subsequent bacterial translocation were observed in SDD-fed gnotobiotic mice that colonized by mucolytic bacteria. In contrast, dietary L-serine restriction did not alter intestinal barrier integrity in gnotobiotic mice that colonized only by non-mucolytic bacteria. Conclusion Our results suggest that dietary L-serine regulates the integrity of the intestinal mucus barrier during inflammation by limiting the expansion of mucus degrading bacteria.

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The role of KPI-121 0.25% in the treatment of dry eye disease: penetrating the mucus barrier to treat periodic flares

Therapeutic Advances in Ophthalmology ◽

10.1177/25158414211012797 ◽

2021 ◽

Vol 13 ◽

pp. 251584142110127

Author(s):

Preeya K. Gupta ◽

Nandini Venkateswaran

Keyword(s):

Drug Delivery ◽

Dry Eye ◽

Ocular Surface ◽

Dry Eye Disease ◽

Eye Disease ◽

Eye Drops ◽

Short Term ◽

Short Term Treatment ◽

Loteprednol Etabonate ◽

Mucus Barrier

The tear film, which includes mucins that adhere to foreign particles, rapidly clears allergens and pathogens from the ocular surface, protecting the underlying tissues. However, the tear film’s ability to efficiently remove foreign particles during blinking can also pose challenges for topical drug delivery, as traditional eye drops (solutions and suspensions) are cleared from the ocular surface before the drug can penetrate into the conjunctival and corneal epithelium. In the past 15 years, there has been an increase in the development of nanoparticles with specialized coatings that have reduced affinity to mucins and are small enough in size to pass through the mucus barrier. These mucus-penetrating particles (MPPs) have been shown to efficiently penetrate the mucus barrier and reach the ocular surface tissues. Dry eye disease (DED) is a common inflammatory ocular surface disorder that often presents with periodic flares (exacerbations). However, currently approved immunomodulatory treatments for DED are intended for long-term use. Thus, there is a need for effective short-term treatments that can address intermittent flares of DED. Loteprednol etabonate, an ocular corticosteroid, was engineered to break down rapidly after administration to the ocular surface tissues and thereby reduce risks associated with other topical steroids. KPI-121 is an ophthalmic suspension that uses the MPP technology to deliver loteprednol etabonate more efficiently to the ocular tissues, achieving in animal models a 3.6-fold greater penetration of loteprednol etabonate to the cornea than traditional loteprednol etabonate ophthalmic suspensions. In clinical trials, short-term treatment with KPI-121 0.25% significantly reduced signs and symptoms of DED compared with its vehicle (placebo). Recently approved KPI-121 0.25%, with its novel drug delivery design and ease of use, has the potential to effectively treat periodic flares of DED experienced by many patients.

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Integrative Biology of Diabetic Retinal Disease: Lessons from Diabetic Kidney Disease

Journal of Clinical Medicine ◽

10.3390/jcm10061254 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1254

Author(s):

Warren W. Pan ◽

Thomas W. Gardner ◽

Jennifer L. Harder

Keyword(s):

Systems Biology ◽

Kidney Disease ◽

Diabetic Kidney Disease ◽

Vision Loss ◽

Retinal Disease ◽

Diabetic Kidney ◽

New Therapies ◽

Traditional Research ◽

Working Age ◽

Culture Models

Diabetic retinal disease (DRD) remains the most common cause of vision loss in adults of working age. Progress on the development of new therapies for DRD has been limited by the complexity of the human eye, which constrains the utility of traditional research techniques, including animal and tissue culture models—a problem shared by those in the field of kidney disease research. By contrast, significant progress in the study of diabetic kidney disease (DKD) has resulted from the successful employment of systems biology approaches. Systems biology is widely used to comprehensively understand complex human diseases through the unbiased integration of genetic, environmental, and phenotypic aspects of the disease with the functional and structural manifestations of the disease. The application of a systems biology approach to DRD may help to clarify the molecular basis of the disease and its progression. Acquiring this type of information might enable the development of personalized treatment approaches, with the goal of discovering new therapies targeted to an individual’s specific DRD pathophysiology and phenotype. Furthermore, recent efforts have revealed shared and distinct pathways and molecular targets of DRD and DKD, highlighting the complex pathophysiology of these diseases and raising the possibility of therapeutics beneficial to both organs. The objective of this review is to survey the current understanding of DRD pathophysiology and to demonstrate the investigative approaches currently applied to DKD that could promote a more thorough understanding of the structure, function, and progression of DRD.

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Screening for Effects of Inhaled Nanoparticles in Cell Culture Models for Prolonged Exposure

Nanomaterials ◽

10.3390/nano11030606 ◽

2021 ◽

Vol 11 (3) ◽

pp. 606

Author(s):

Claudia Meindl ◽

Kristin Öhlinger ◽

Verena Zrim ◽

Thomas Steinkogler ◽

Eleonore Fröhlich

Keyword(s):

Prolonged Exposure ◽

A549 Cells ◽

Cytokine Release ◽

Transient Effects ◽

Particle Uptake ◽

Particle Accumulation ◽

Low Concentrations ◽

Culture Models ◽

20 Nm ◽

Inhaled Nanoparticles

Respiratory exposure of humans to environmental and therapeutic nanoparticles repeatedly occurs at relatively low concentrations. To identify adverse effects of particle accumulation under realistic conditions, monocultures of Calu-3 and A549 cells and co-cultures of A549 and THP-1 macrophages in the air–liquid interphase culture were exposed repeatedly to 2 µg/cm2 20 nm and 200 nm polystyrene particles with different functionalization. Particle accumulation, transepithelial electrical resistance, dextran (3–70 kDa) uptake and proinflammatory cytokine secretion were determined over 28 days. Calu-3 cells showed constant particle uptake without any change in barrier function and cytokine release. A549 cells preferentially ingested amino- and not-functionalized particles combined with decreased endocytosis. Cytokine release was transiently increased upon exposure to all particles. Carboxyl-functionalized demonstrated higher uptake and higher cytokine release than the other particles in the A549/THP-1 co-cultures. The evaluated respiratory cells and co-cultures ingested different amounts and types of particles and caused small (partly transient) effects. The data suggest that the healthy cells can adapt to low doses of non-cytotoxic particles.

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Factors to consider when interrogating 3D culture models with plate readers or automated microscopes

In Vitro Cellular & Developmental Biology - Animal ◽

10.1007/s11626-020-00537-3 ◽

2021 ◽

Author(s):

Terry Riss ◽

O. Joseph Trask

Keyword(s):

Cell Culture ◽

Three Dimensional ◽

3D Culture ◽

Fluorescent Imaging ◽

Culture Models ◽

Assay Methods ◽

Diffusion Rates ◽

Cell Culture Models ◽

Dimensional Cell ◽

Cells Cultured

AbstractAlong with the increased use of more physiologically relevant three-dimensional cell culture models comes the responsibility of researchers to validate new assay methods that measure events in structures that are physically larger and more complex compared to monolayers of cells. It should not be assumed that assays designed using monolayers of cells will work for cells cultured as larger three-dimensional masses. The size and barriers for penetration of molecules through the layers of cells result in a different microenvironment for the cells in the outer layer compared to the center of three-dimensional structures. Diffusion rates for nutrients and oxygen may limit metabolic activity which is often measured as a marker for cell viability. For assays that lyse cells, the penetration of reagents to achieve uniform cell lysis must be considered. For live cell fluorescent imaging assays, the diffusion of fluorescent probes and penetration of photons of light for probe excitation and fluorescent emission must be considered. This review will provide an overview of factors to consider when implementing assays to interrogate three dimensional cell culture models.

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Microfluidic platform accelerates tissue processing into single cells for molecular analysis and primary culture models

Nature Communications ◽

10.1038/s41467-021-23238-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Jeremy A. Lombardo ◽

Marzieh Aliaghaei ◽

Quy H. Nguyen ◽

Kai Kessenbrock ◽

Jered B. Haun

Keyword(s):

Single Cell ◽

Single Cell Analysis ◽

Single Cells ◽

Cell Analysis ◽

Processing Technologies ◽

Microfluidic Platform ◽

Tissue Processing ◽

Single Cell Rna Sequencing ◽

Culture Models ◽

Tissue Digestion

AbstractTissues are complex mixtures of different cell subtypes, and this diversity is increasingly characterized using high-throughput single cell analysis methods. However, these efforts are hindered, as tissues must first be dissociated into single cell suspensions using methods that are often inefficient, labor-intensive, highly variable, and potentially biased towards certain cell subtypes. Here, we present a microfluidic platform consisting of three tissue processing technologies that combine tissue digestion, disaggregation, and filtration. The platform is evaluated using a diverse array of tissues. For kidney and mammary tumor, microfluidic processing produces 2.5-fold more single cells. Single cell RNA sequencing further reveals that endothelial cells, fibroblasts, and basal epithelium are enriched without affecting stress response. For liver and heart, processing time is dramatically reduced. We also demonstrate that recovery of cells from the system at periodic intervals during processing increases hepatocyte and cardiomyocyte numbers, as well as increases reproducibility from batch-to-batch for all tissues.

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Bisphosphonates Reduce Smoking-Induced Osteoporotic-Like Alterations by Regulating RANKL/OPG in an Osteoblast and Osteoclast Co-Culture Model

International Journal of Molecular Sciences ◽

10.3390/ijms22010053 ◽

2020 ◽

Vol 22 (1) ◽

pp. 53

Author(s):

Sheng Zhu ◽

Victor Häussling ◽

Romina H. Aspera-Werz ◽

Tao Chen ◽

Bianca Braun ◽

...

Keyword(s):

Alternative Therapy ◽

Cigarette Smoke Extract ◽

Matrix Remodeling ◽

Nuclear Factor ◽

Bone Homeostasis ◽

Potential Mechanism ◽

Culture Model ◽

Receptor Activator ◽

Culture Models

Co-culture models have become mandatory for obtaining better insights into bone homeostasis, which relies on the balance between osteoblasts and osteoclasts. Cigarette smoking (CS) has been proven to increase the risk of osteoporosis; however, there is currently no proven treatment for osteoporosis in smokers excluding cessation. Bisphosphonates (BPs) are classical anti-osteoclastic drugs that are commonly used in examining the suitability of bone co-culture systems in vitro as well as to verify the response to osteoporotic stimuli. In the present study, we tested the effects of BPs on cigarette smoke extract (CSE)-affected cells in the co-culture of osteoblasts and osteoclasts. Our results showed that BPs were able to reduce CSE-induced osteoporotic alterations in the co-culture of osteoblasts and osteoclasts such as decreased matrix remodeling, enhanced osteoclast activation, and an up-regulated receptor activator of nuclear factor (NF)-kB-ligand (RANKL)/osteoprotegerin (OPG) ratio. In summary, BPs may be an effective alternative therapy for reversing osteoporotic alterations in smokers, and the potential mechanism is through modulation of the RANKL/OPG ratio.

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