Epithelial Layer Research Articles

Clinically compliant cryopreservation of differentiated retinal pigment epithelial cells

Background aimsAge-related macular degeneration (AMD) is the most common cause of blindness in elderly patients within developed countries, affecting more than 190 million worldwide. In AMD, the retinal pigment epithelial (RPE) cell layer progressively degenerates, resulting in subsequent loss of photoreceptors and ultimately vision. There is currently no cure for AMD, but therapeutic strategies targeting the complement system are being developed to slow the progression of the disease. MethodsReplacement therapy with pluripotent stem cell-derived (hPSC) RPEs is an alternative treatment strategy. A cell therapy product must be produced in accordance with Good Manufacturing Practices at a sufficient scale to facilitate extensive pre-clinical and clinical testing. Cryopreservation of the final cell product is therefore highly beneficial, as the manufacturing, pre-clinical and clinical testing can be separated in time and location. ResultsWe found that mature hPSC-RPE cells do not survive conventional cryopreservation techniques. However, replating the cells 2–5 days before cryopreservation facilitates freezing. The replated and cryopreserved hPSC-RPE cells maintained their identity, purity and functionality as characteristic RPEs, shown by cobblestone morphology, pigmentation, transcriptional profile, RPE markers, transepithelial resistance and pigment epithelium–derived factor secretion. Finally, we showed that the optimal replating time window can be tracked noninvasively by following the change in cobblestone morphology. ConclusionsThe possibility of cryopreserving the hPSC-RPE product has been instrumental in our efforts in manufacturing and performing pre-clinical testing with the aim for clinical translation.

Coordinated Motion of Epithelial Layers on Curved Surfaces.

Coordinated cellular movements are key processes in tissue morphogenesis. Using a cell-based modeling approach we study the dynamics of epithelial layers lining surfaces with constant and varying curvature. We demonstrate that extrinsic curvature effects can explain the alignment of cell elongation with the principal directions of curvature. Together with specific self-propulsion mechanisms and cell-cell interactions this effect gets enhanced and can explain observed large-scale, persistent, and circumferential rotation on cylindrical surfaces. On toroidal surfaces the resulting curvature coupling is an interplay of intrinsic and extrinsic curvature effects. These findings unveil the role of curvature and postulate its importance for tissue morphogenesis.

Platelet Rich Fibrin as a Potential Treatment for Corneal Neovascularization due to Infective Keratitis: An Experimental Study

Abstract
 Introduction & Objectives : Platelet-rich fibrin (PRF) as a source of growth factor has been widely used in various therapeutic fields so that it could accelerate the wound healing process. This study investigated the effect of platelet-rich fibrin PRF in inhibiting neovascularization, inhibiting the expression of vascular endothelial growth factor (VEGF) and stimulating pigment epithelial-derived factor (PEDF) in the infective keratitis animal model.
 Methods : A total of 12 New Zealand white rabbits (Oryctalogus cuniculus) were subjected to keratitis induction by inoculation of Pseudomonas aeruginosa. The rabbits were divided into two groups, the first group as control was treated antibiotic-only, and the second as treatment group was treated with antibiotic and PRF graft. The corneal neovascularization area was clinically measured before and after treatment. Expression of VEGF and PEDF in the corneal epithelium, stroma, and endothelium were evaluated by immunohistochemical examination on day 10 after keratitis induction.
 Results : There were significant differences in VEGF expression between groups in the epithelial layer (p=0.008), but no significant difference in the stromal (p=0.934) and endothelial (p=0.935) layers. PEDF expression showed a significant difference between groups in the epithelial (p = 0.004) and stroma layers (p = 0.029) but no significant difference in the endothelial layer (p = 0.157). However, there was no significant difference in clinical neovascularization between the two groups (p=0.526).
 Conclusion : PRF could inhibit VEGF expression and stimulate PEDF expression in the cornea of Pseudomonas aeruginosa keratitis animal model that potentially reduces the corneal neovascularization in the longer observation.

Gas-propelled nanomotors alleviate colitis through the regulation of intestinal immunoenvironment-hematopexis-microbiota circuits

The progression of ulcerative colitis (UC) is associated with immunologic derangement, intestinal hemorrhage, and microbiota imbalance. While traditional medications mainly focus on mitigating inflammation, it remains challenging to address multiple symptoms. Here, a versatile gas-propelled nanomotor was constructed by mild fusion of post-ultrasonic CaO2 nanospheres with Cu2O nanoblocks. The resulting CaO2–Cu2O possessed a desirable diameter (291.3 nm) and a uniform size distribution. It could be efficiently internalized by colonic epithelial cells and macrophages, scavenge intracellular reactive oxygen/nitrogen species, and alleviate immune reactions by pro-polarizing macrophages to the anti-inflammatory M2 phenotype. This nanomotor was found to penetrate through the mucus barrier and accumulate in the colitis mucosa due to the driving force of the generated oxygen bubbles. Rectal administration of CaO2–Cu2O could stanch the bleeding, repair the disrupted colonic epithelial layer, and reduce the inflammatory responses through its interaction with the genes relevant to blood coagulation, anti-oxidation, wound healing, and anti-inflammation. Impressively, it restored intestinal microbiota balance by elevating the proportions of beneficial bacteria (e.g., Odoribacter and Bifidobacterium) and decreasing the abundances of harmful bacteria (e.g., Prevotellaceae and Helicobacter). Our gas-driven CaO2–Cu2O offers a promising therapeutic platform for robust treatment of UC via the rectal route.

Incidence Of Photokeratitis In Factory Workers After Ultraviolet C Exposure and Its Management : A Case Series

Introduction : Ultraviolet C lamps have been used in industry and healthcare to disinfect rooms, air, water, and surfaces. However, exposure to UV-C may cause serious damage to human eyes.
 Case Illustration : This were photokeratitis case series of 4 factory workers that occurred simultaneously after 4 hours exposure to UV-C lamp about one meter away without any protective eyewear. Several hours after exposure, they complained swollen, red and watery eyes, photophobia, sandy sensation, and blurry vision. One day after, they were taken to the Emergency Unit. Diagnosis of photokeratitis was established by using biomicroscopic examination. All subjects were treated with antibiotic eye drops, lubricants, oral anti-inflammatory drugs, and cold compress. Evaluation after 1 week showed clinical improvement and all subjects were able to return to work normally.
 Discussion : Photokeratitis or ultraviolet keratitis is an inflammatory condition of the cornea after ultraviolet exposure for 30 minutes to 12 hours. The corneal epithelial layer functions as protector for corneal stroma and endothelium. However, the longer corneal epithelium is exposed to ultraviolet light, the more damaged it is. This caused subepithelial nerve plexus exposed, resulting in severe pain, photophobia, and bilateral epiphora. Injection and chemosis of bulbar conjunctiva, epiphora, and punctate keratopathy of cornea were found in examination. The management given is supportive therapy, and should be immediately given until corneal epithelium healed.
 Conclusion : Photokeratitis may occurred in daily work. Regulation, warning, training and appropriate protective eyewear for workers in workplaces using UV-C lamps are mandatory. Immediate and adequate treatment can save the sight of workers exposed to UV-C.

Elovl4b knockout zebrafish as a model for ocular very-long-chain PUFA deficiency

Very-long-chain PUFAs (VLC-PUFAs) are a group of lipids with chain lengths >24 carbons, and the ELOVL4 (elongation of very-long-chain FA-4) enzyme is responsible for vertebrate VLC-PUFA biosynthesis. Studies on the role of VLC-PUFAs in vision have been hindered because of the need for adequate animal models to capture the global loss of VLC-PUFAs. Since homozygous Elovl4 ablation is lethal in neonatal mice because of catastrophic drying from the loss of their protective skin barrier, we established a zebrafish (Danio rerio) model of Elovl4 ablation. We generated Elovl4b KO zebrafish by creating a 56-bp deletion mutation in exon 2 of the Elovl4b gene using CRISPR-Cas9. We used GC-MS and LC-MS/MS to analyze the VLC-PUFA and lipid profiles from wild-type and Elovl4b KO fish eyes. We also performed histology and visual-behavioral tests. We found that heterozygous and homozygous Elovl4b KO zebrafish eyes had altered lipid profiles and a significantly lower C30 to C36 VLC-PUFA abundance than wild-type fish. Moreover, Elovl4b+/− and Elovl4b−/− KO larvae had significantly lower motor activity in response to light-dark cycles than their age-matched controls. Elovl4b−/− adult fish showed no obvious differences in gross retinal morphology and lamination compared with wild type, except for the presence of lipid droplets within the retinal pigment epithelial cell layer of Elovl4b−/− fish. Our data indicate that the loss of Elovl4b in zebrafish changes ocular lipid profiles and leads to visual abnormalities and subtle retinal changes. These findings highlight the use of zebrafish as a model for VLC-PUFA depletion and ELOVL4-related dysfunction.

Biomimetic biphasic microsphere preparation based on the thermodynamic incompatibility of glycosaminoglycan with gelatin methacrylate for hair regeneration

Hair follicle (HF) tissue engineering is promising for hair loss treatment especially for androgenetic alopecia. Physiologically, the initiation of HF morphogenesis relies on the interactions between hair germ mesenchymal and epithelial layers. To simulate this intricate process, in this study, a co-flowing microfluidic-assisted technology was developed to produce dual aqueous microdroplets capturing growth factors and double-layer cells for subsequent use in hair regeneration. Microspheres, called G/HAD, were generated using glycosaminoglycan-based photo-crosslinkable biological macromolecule (HAD) shells and gelatin methacrylate (GelMA) cores to enclose mesenchymal cells (MSCs) and mouse epidermal cells (EPCs). The findings indicated that the glycosaminoglycan-based HAD shells display thermodynamic incompatibility with GelMA cores, resulting in the aqueous phase separation of G/HAD cell spheres. These G/HAD microspheres exhibited favorable characteristics, including sustained growth factor release and wet adhesion properties. After transplantation into the dorsal skin of BALB/c nude mice, G/HAD cell microspheres efficiently induced the regeneration of HFs. This approach enables the mass production of approximately 250 dual-layer microspheres per minute. Thus, this dual-layer microsphere fabrication method holds great potential in improving current hair regeneration techniques and can also be combined with other tissue engineering techniques for various regenerative purposes.

PH-sensitive dual-preventive siRNA-based nanomicrobicide reactivates autophagy and inhibits HIV infection in vaginal CD4+ cells

Women are more susceptible to HIV transmission through unprotected heterosexual intercourse due to biological and social vulnerabilities. Intravaginal delivery of siRNAs targeting viral genes, host genes, or in combination has shown promising outcomes against HSV, HPV and HIV. Therefore, in this study, we designed, developed and evaluated a pH-sensitive RNAi-based combination nanomicrobide for the prevention/reduction of vaginal transmission of HIV. The nanomicrobide was composed of siRNA-PEI encapsulated PLGA-PEG nanoparticles (siRNA NP) loaded in a HEC gel dosage form with siRNA targeting host gene CCR5 and the viral gene Nef as a dual preventive strategy. Knocking down CCR5, a co-receptor for HIV could prevent HIV from attaching to and entering host cells and knocking down Nef could reactivate autophagy that was inhibited by Nef to improve the elimination of intracellular virus that escaped the first line of defense. The siRNA NP showed a desirable particle size and zeta potential for intravaginal delivery and a pH-dependent release profile whereby low amounts of siRNA was released under acidic vaginal conditions (vaginal fluid simulant; VFS, pH 4.2) (6.0 ± 0.4% released over 15 days) but significantly higher amounts of siRNA was released under neutral pH conditions (phosphate buffered saline; PBS, pH 7.4) (22.9 ± 0.4% released over 15 days). The CCR5-Nef-specific siRNA NP efficiently knocked down CCR5 and Nef protein expression by 43% and 63%, respectively, reactivated Nef-blocked autophagy and inhibited the replication of HIV in vitro (71.8% reduction in p24 expression). After being formulated into a gel dosage form, siRNA NP could be readily released from the gel, penetrate the vaginal epithelial layer, get taken up into the target cells and knockdown Nef and CCR5 without causing cytotoxicity in a vaginal mucosal co-culture model. Functionalization of siRNA NP with anti-CD4 antibody and loaded into a 0.5% HEC gel improved vaginal distribution and uptake of siRNA in a mouse model with distribution of siRNA restricted to the reproductive tract without any unwanted systemic uptake. The 0.5% HEC gel loaded with siRNA NP-(m)CD4 significantly downregulated approximately 40% of CCR5 protein in the lower vagina and 36% of CCR5 protein in the upper vaginal and cervical region. In contrast, 0.5% HEC gel loaded with siRNA NP-IgG did not result in significant gene knockdown.

Regulatory T cells Are Increased and Correlate With Mast Cells in Eosinophilic Esophagitis.

The incidence of eosinophilic esophagitis (EoE) has been increasing recently. The role of regulatory T cells (Tregs) and correlations with other inflammatory cells in EoE remain unknown. We aim to clarify the role of Tregs and their correlations with inflammatory cells in EoE patients. Biopsies from controls and EoE patients before and after treatments were analyzed. Eosinophil infiltration was evaluated by hematoxylin and eosin staining. Immunohistochemical staining was performed to examine infiltration of T cells, Tregs, and mast cells. Gene expressions of chemokines were evaluated by reverse transcription-quantitative polymerase chain reaction. Tregs and mast cells were increased in the esophageal epithelial layers of EoE patients. After treatments, Tregs and mast cells were decreased when histologic remission was achieved. Infiltration of Tregs correlated significantly with numbers of eosinophils and mast cells. Filaggrin mRNA was decreased in patients with EoE before treatment and upregulated after treatment, even when histologic remission was not achieved. Tregs were increased in esophageal epithelium of patients with EoE, and correlated with mast cell infiltration.

Histological Assessment of the Effect Laser Irradiation on Full-Thickness Skin Wound Healing in Rabbits Models

Since there is currently no ideal treatment, wound healing impairment is a significant clinical challenge that is the subject of ongoing research into effective wound healing strategies. As a result, it has been demonstrated that low level laser therapy (LLLT), which is used for wound healing, can effectively control both the local and the systemic response. This study was conducted on 24 adult, clinically healthy male rabbits for this purpose. On each animal's back, full-thickness excisional wounds measuring 2 cm x 2 cm were created following sterile skin preparation. The animals were randomly split into two equal groups, each with twelve rabbits. In the group that acts as a control; 5 milliliters of phosphate-buffered saline was used to treat wounds. In the group treated; for the first seven days, the wounds were only treated with (LLLT) at a rate of 5/5 second at 8j/cm2. At the seventh, fourteenth, and 35th days of healing, histopathological biopsies were performed. The control group's histopathology revealed hemorrhage with inflammatory cell infiltration, primarily neutrophils, and congested blood vessels in the gap seven days after surgery. Necrotized neutrophils, hemolysis, and granulation tissue under the dermis were present in the gap at fourteen days. Between the muscle fibers, there was hemolysis. At 35 days, there was irregular proliferation of fibrous connective tissue, and congested blood vessels with mononuclear cell infiltration could be seen in the gap. At seven days, the treated group has completely sloughed the epidermis and a thin crust on the skin's surface with a small incision. In the dermis, there is a lot of infiltration of inflammatory cells, mostly lymphocytes and macrophages. There is also a lot of granulation tissue and a lot of adipose tissue with a lot of thick collagen network. At fourteen days, the epidermis' epithelial layers have healed completely and a keratinized layer is present. In the dermis, a proliferating and thick collagen network, scattered inflammatory cells, and regular fibrosis with hemorrhage and the development of a new B.V. At day 35, look for narrow scar tissue with complete epithelization, a keratinized layer above the epidermis, new vascularization with a lot of regular fibrosis and few regular collagen, new hair follicles, new blood vessels, and scattered macrophages. We concluded that full-thickness wound healing is positively influenced by the use of low level laser therapy (LLLT), which creates a microenvironment favorable to cell growth and differentiation.

Campylobacter jejuni Surface-Bound Protease HtrA, but Not the Secreted Protease nor Protease in Shed Membrane Vesicles, Disrupts Epithelial Cell-to-Cell Junctions.

Fundamental functions of the intestinal epithelium include the digestion of food, absorption of nutrients, and its ability to act as the first barrier against intruding microbes. Campylobacter jejuni is a major zoonotic pathogen accounting for a substantial portion of bacterial foodborne illnesses. The germ colonizes the intestines of birds and is mainly transmitted to humans through the consumption of contaminated poultry meat. In the human gastrointestinal tract, the bacterium triggers campylobacteriosis that can progress to serious secondary disorders, including reactive arthritis, inflammatory bowel disease and Guillain-Barré syndrome. We recently discovered that C. jejuni serine protease HtrA disrupts intestinal epithelial barrier functions via cleavage of the tight and adherens junction components occludin, claudin-8 and E-cadherin. However, it is unknown whether epithelial damage is mediated by the secreted soluble enzyme, by HtrA contained in shed outer-membrane vesicles (OMVs) or by another mechanism that has yet to be identified. In the present study, we investigated whether soluble recombinant HtrA and/or purified OMVs induce junctional damage to polarized intestinal epithelial cells compared to live C. jejuni bacteria. By using electron and confocal immunofluorescence microscopy, we show that HtrA-expressing C. jejuni bacteria trigger efficient junctional cell damage, but not soluble purified HtrA or HtrA-containing OMVs, not even at high concentrations far exceeding physiological levels. Instead, we found that only bacteria with active protein biosynthesis effectively cleave junctional proteins, which is followed by paracellular transmigration of C. jejuni through the epithelial cell layer. These findings shed new light on the pathogenic activities of HtrA and virulence strategies of C. jejuni.

Background and common lesions in the female reproductive organs of giant anteaters (Myrmecophaga tridactyla).

The giant anteater (Myrmecophaga tridactyla) is a vulnerable species in South America and is considered endangered or near extinction in Central America. Therefore, studies describing the reproductive characteristics of this species are pivotal for its conservation. Thus, this study aimed to provide a morphological description of the female reproductive tissues of this species. We collected tissue samples from six female giant anteaters and performed gross, morphological, and histochemical analyses. Five adult subjects and one juvenile were included in the study. In the ovary, classifications were made according to the follicle and oocyte sizes: primordial, primary, secondary, early antral, or antral. Typical follicles with a single oocyte surrounded by a simple or stratified layer of cubic epithelium, atretic follicles, corpora lutea, corpora albicans, and ovarian cysts were also observed. No ovarian lesions were observed. By contrast, endometritis, metritis, mucometra, and endometrial cysts were identified in the uterus. Uterine alterations in these subjects were frequent and could affect reproduction.

Recent Advancement in Inhaled Nano-drug Delivery for Pulmonary, Nasal, and Nose-to-brain Diseases.

Pulmonary, nasal, and nose-to-brain diseases involve clinical approaches, such as bronchodilators, inhaled steroids, oxygen therapy, antibiotics, antihistamines, nasal steroids, decongestants, intranasal drug delivery, neurostimulation, and surgery to treat patients. However, systemic medicines have serious adverse effects, necessitating the development of inhaled formulations that allow precise drug delivery to the airways with minimum systemic drug exposure. Particle size, surface charge, biocompatibility, drug capacity, and mucoadhesive are unique chemical and physical features that must be considered for pulmonary and nasal delivery routes due to anatomical and permeability considerations. The traditional management of numerous chronic diseases has a variety of drawbacks. As a result, targeted medicine delivery systems that employ nanotechnology enhancer drug efficiency and optimize the overall outcome are created. The pulmonary route is one of the most essential targeted drug delivery systems because it allows the administering of drugs locally and systemically to the lungs, nasal cavity, and brain. Furthermore, the lungs' beneficial characteristics, such as their ability to inhibit first-pass metabolism and their thin epithelial layer, help treat several health complications. The potential to serve as noninvasive self-administration delivery sites of the lung and nasal routes is discussed in this script. New methods for treating respiratory and some systemic diseases with inhalation have been explored and highlight particular attention to using specialized nanocarriers for delivering various drugs via the nasal and pulmonary pathways. The design and development of inhaled nanomedicine for pulmonary, nasal, and respiratory medicine applications is a potential approach for clinical translation.

P079 Low-intensity Pulsed Ultrasound reflects the status of mucosal injury and repair through stage-specific miRNAs in experimental model of Ulcerative Colitis

Abstract Background Diagnosis and therapeutic efficacy monitoring of Ulcerative Colitis (UC) are based on a multidisciplinary approach comprising symptomatology and invasive endoscopic assessment coupled to the histopathological characterization of gut tissue biopsies. New technologies that non-invasively reflect tissue-specific changes remains an unmet need. Here we exploited Low Intensity Pulsed Ultrasound (LIPUS) to induce tissue stage-specific miRNAs in circulating blood as a non-invasive approach to reflect the status of the colonic mucosa in experimental model of colitis. Methods Based on our previous study, LIPUS was applied at a frequency of 38 kHz and at an intensity of 0 (as control) or 150 mW/cm2 for 3 min, using a device dedicated for in vivo studies. Acute and chronic colitis were induced in C57BL/6N mice (5 animals/group) by administration of 2 and 2.5% ad libitum dextran sodium sulfate (DSS) respectively in their drinking water for 7 days for the acute and three cycles of 7 days for the chronic model. miRNA array profiling was performed on extracellular vesicles (EVs) isolated from plasma of both acute and chronic models, at both active and remission state, 2 h after LIPUS stimulation. miRNA were correlated to the mucosal status by multiplexed immunofluorescence staining using Opal Multiplex IHC (CD4, CD8, CD68, pan-cytokeratin and CD31 markers) and EVs characterized by MACSplex surface epitope detection. Results An enrichment of EVs characterized mainly by stromal and immune cell surface markers was found in both acute and chronic inflammatory states, LIPUS stimulation significantly modulated miRNA profiles and clearly discriminated between active acute and chronic phases. 61 miRNAs in acute and 28 in chronic colitis were specifically and significantly upregulated by LIPUS in the active phase, with a fold change ranging from 2 to 1500 compared to control. Both acute and chronic disease showed a miRNA profile coherent with the active inflammatory state of intestinal mucosa. Only 10 and 23 miRNAs were upregulated in acute and chronic remission respectively. The enhancement of miR-18a-3p and miR-301b-3p in the recovery phases correlated to instetin with reduced immune cell infiltration and epithelial layer regeneration. Conclusion An optimal LIPUS dosage that non-invasively targets the colon induces the tissue to release specific miRNAs that reflect the mucosal status. LIPUS may open a new era of non-image ultrasound diagnostics that works as disruptive liquid biopsy allowing the detection of tissue biomarkers for monitoring IBD disease progression.

P086 Identification of a Novel Immunometabolic Target and Agonist for PLXDC2 for Amelioration of DSS Colitis Model in Mice

Abstract Background PLXDC2 is expressed on the cell surface of macrophage, dendritic and specific mesenchymal and epithelial cells whose activation shifts cellular metabolism and reduces oxidative stress to rebalance the immune response and decrease inflammation. It’s role in IBD pathogenesis is unknown. PLXDC2 activation improves disease severity in rheumatoid arthritis models1, while loss of PLXDC2 exacerbates the severity of disease in DSS colitis2. PX-04 is a novel, first-in-class, orally active PLXDC2 agonist. Here, we report on the consequences of activating PLXDC2 using PX-04 in an acute DSS colitis model. Methods Mice were given DSS in drinking water for seven days to induce disruption of the epithelial layer. At project initiation, mice were 8 weeks of age and began once daily dosing with 20mg/kg of PX-04 24 hours after being placed on DSS. Mice were weighed and scored daily for 15 symptoms of disease (weight loss, diarrhea, rectal bleeding, rectal inflammation, pain, & overall behavior). Colons were collected and digested, and the resultant cellular suspensions were filtered to produce single cell suspensions. Colonic Lamina Propria Immune cells were isolated by Percoll gradient centrifugation. Cells were labeled with mixtures of extracellular (CD45, CD3, CD4, CD8, CD19, NK1.1, CD25, F4/80, CD11b, Gr1, CX3CR1, CD64) and intracellular (Tbet, RORγT, FOXP3, IFNγ, IL17, IL10, TNFα) antibodies in a sequential live staining in 96-well plates. Data was acquired using a FACS Celesta flow cytometer with FACSDiva software. Results Oral PX-04 treatment decreased the cumulative disease activity of mice challenged with DSS (FIG 1A). Immunologically, PX-04 affected both the adaptive and innate immune responses. First, PX-04 greatly decreased Th17 cells in the colon, while providing a slight increase to regulatory CD4+ T cells (FIG. 1C). A lower proportion of Natural Killer (NK) cells (FIG. 7D) produced IFNγ. Meanwhile, the proportion of TNF producing dendritic cells was decreased by PX-04 treatment. Conclusion Conclusion: PLXDC2 is expressed in cells relevant to IBD pathogenesis. PX-04, which binds to and activates PLXDC2, effectively decreases levels of effector T cells and myeloid cells, as well as overall disease severity in acute DSS colitis, warranting further investigation. 1Tubau-Juni et al. J Immunol 206(Supp) 2Tubau-Juni et al. Sci Rep 10(1)

Programmed disassembly of a microtubule-based membrane protrusion network coordinates 3D epithelial morphogenesis in Drosophila.

Comprehensive analysis of cellular dynamics during the process of morphogenesis is fundamental to understanding the principles of animal development. Despite recent advancements in light microscopy, how successive cell shape changes lead to complex three-dimensional tissue morphogenesis is still largely unresolved. Using in vivo live imaging of Drosophila wing development, we have studied unique cellular structures comprising a microtubule-based membrane protrusion network. This network, which we name here the Interplanar Amida Network (IPAN), links the two wing epithelium leaflets. Initially, the IPAN sustains cell-cell contacts between the two layers of the wing epithelium through basal protrusions. Subsequent disassembly of the IPAN involves loss of these contacts, with concomitant degeneration of aligned microtubules. These processes are both autonomously and non-autonomously required for mitosis, leading to coordinated tissue proliferation between two wing epithelia. Our findings further reveal that a microtubule organization switch from non-centrosomal to centrosomal microtubule-organizing centers (MTOCs) at the G2/M transition leads to disassembly of non-centrosomal microtubule-derived IPAN protrusions. These findings exemplify how cell shape change-mediated loss of inter-tissue contacts results in 3D tissue morphogenesis.

Graphite as a Skin and Epithelium Dosimeter at mammographic energies

Use is made of 50 μm high purity graphite foils, investigating the potential of these in evaluation of dose in dermal and epithelial layers, measuring the thermoluminescence yield obtained as a result of irradiation at mammographic energies. In particular the effort supports the ICRU recommendation that skin dose be assessed at a skin depth 0.07 mm, equating to the uniquely mitotically active dermal layer responsible for the replenishment of skin cells. Support for the results of empirical investigation have been sought from Monte Carlo simulations using the TOPAS code. In study of x-rays generated in the 25- to 30 kVp range, the energetic electrons produced in interaction with the graphite have an approximate range of ∼7 μm, so that with a stacked graphite layer arrangement dose assessment is provided at 7 μm, 57 μm, 107 μm etc. TL yield results for the first three layers of graphite, covering nominal depths from the surface through to 150 μm, obtained on a 50 μm spatial resolution scale, show deposited dose values to be approximately flat to within ±5% throughout this depth. The indication is that for irradiations made using x-ray energies of a few tens of keV use of the present graphite layer arrangement can provide estimation of dermal and epithelial dose.

Morphogenesis of fungiform papillae in developing miniature pigs

ObjectiveFungiform papillae contain taste buds and play a critical role in mastication and the gustatory system. In this study, we report a series of sequential observations of organogenesis of fungiform papillae in miniature pigs, as well as changes in the expression of BMP2, BMP4, Wnt5a, Sox2, and Notch1 signaling pathway components. DesignIn this study, we investigated the spatiotemporal expression patterns of BMP, Wnt, Sox2 and Notch in the fungiform papillae of miniature pigs at the bud stage (E40), cap stage (E50) and bell stage (E60). Pregnant miniature pigs were obtained, and the samples were processed for histological staining. Immunohistochemistry and real-time PCR were used to detect the mRNA and protein expression levels of BMP2, BMP4, Wnt5a, Sox2, and Notch1. ResultsAt E40, fungiform papillae were present on the anterior two-thirds of the tongue in a specific array and pattern. The fungiform papillae were enlarged and basically developed at E50 and were largest at the earlier stage (E60). Most of the BMP2 was concentrated in the epithelial layer and the connective tissue core of the fungal papilloma and gradually accumulated from E40-E60. BMP-4 was weakly expressed in the fungiform papillae epithelia, but BMP-4-positive cells were also observed in the developing tongue muscle at E50 and E60. Wnt5a-positive cells were observed in the fungiform papillae epithelia and developing tongue muscle at all three time points. Sox2-positive cells were observed only in fungiform papillae epithelial cells, and Notch1-positive cells could not be detected. ConclusionsThis study provides primary data regarding the morphogenesis and expression of developmental signals in the fungiform papillae of miniature pigs, establishing a foundation for further research in both this model and humans.

Evaluation of biophysical alterations in the epithelial and endothelial layer of patients with Bullous Keratopathy

The cornea is a fundamental ocular tissue for the sense of sight. Thanks to it, the refraction of two-thirds of light manages to participate in the visual process and protect against mechanical damage. Because it is transparent, avascular, and innervated, the cornea comprises five main layers: Epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. Each layer plays a key role in the functionality and maintenance of ocular tissue, providing unique ultrastructural and biomechanical properties. Bullous Keratopathy (BK) is an endothelial dysfunction that leads to corneal edema, loss of visual acuity, epithelial blisters, and severe pain, among other symptoms. The corneal layers are subject to changes in their biophysical properties promoted by Keratopathy. In this context, the Atomic Force Microscopy (AFM) technique in air was used to investigate the anterior epithelial surface and the posterior endothelial surface, healthy and with BK, using a triangular silicone tip with a nominal spring constant of 0.4 N/m. Six human corneas (n = 6) samples were used for each analyzed group. Roughness data, calculated by third-order polynomial adjustment, adhesion, and Young's modulus, were obtained to serve as a comparison and identification of morphological and biomechanical changes possibly associated with the pathology, such as craters and in the epithelial layer and exposure of a fibrotic layer due to loss of the endothelial cell wall. Endothelial cell membrane area and volume data were calculated, obtaining a relevant comparison between the control and patient. Such results may provide new data on the physical properties of the ocular tissue to understand the physiology of the cornea when it has pathology.

Properties of gelatin-polyethylene glycol hydrogel loaded with silver nanoparticle Chlorella and its effects on healing of infected full-thickness skin defect wounds in mice

Properties of gelatin-polyethylene glycol hydrogel loaded with silver nanoparticle Chlorella and its effects on healing of infected full-thickness skin defect wounds in mice