Epithelial Cell Morphology Research Articles

OP31 High fat diet exacerbates colitis through microbial metabolite deoxycholic acids induced-ferroptosis

Abstract Background High-fat diet (HFD) is closely related to the occurrence and development of IBD, which increases the level of deoxycholic acid (DCA). DCA-treated mice showed pro-inflammatory cell infiltration and colonic inflammation. Ferroptosis, a newly recognized form of cell death characterized by iron overload and the generation of reactive oxygen species (ROS) has recently been observed in colitis. Whether DCA affects ferroptosis and whether it contributes to colitis has not been explored. Methods Twenty-four Female C57BL/6 mice were randomly divided into 4 groups: control group, DCA group, DSS group, and DSS plus DCA group. Real-time PCR and Western blotting were used to detect the transcription and protein expression of ferroptosis-related genes. RNA sequencing was used to analyze the changes of differential genes in the intestinal tissue of mice treated with DCA. Transmission electron microscope was employed to observed the changes of intestinal epithelial cell morphology and intracellular mitochondria. Finally, the binding force between DCA and HIF-2α was calculated by molecular dynamics to explore the structural biological basis of the interaction between DCA and HIF-2α, and screen innovative drugs. Results We found that DCA exacerbated the disease activity index, histological damage and cell death in mice with colitis. In vivo, ferroptosis KEGG pathway was enriched by RNA sequencing in colonic tissues. DCA treatment significantly induced ferroptosis in DSS-induced mice, as evidenced by iron overload, ROS and MDA production, accompanied by decreased expression of GPX4 and increased expression of ACSL4. Transmission electron microscopy also confirmed the occurrence of ferroptosis in colonic tissues. In vitro, DCA induced ferroptosis were also observed in IEC-6 cells and Caco-2 cells under the combined treatment of Lipopolysaccharide (LPS). Interestingly, RNA sequencing revealed that the expression levels of the apical iron divalent metal transporter-1 (DMT1) were significantly upregulated in DCA treated-mice with colitis. DMT1 is a direct target gene of hypoxia inducible factor (HIF)-2α. We also found that DCA could increase the level of DMT1 and HIF-2α in the intestinal epithelial cell lines. Pharmacological inhibition of HIF-2α significantly inhibited the expression of DMT1 and blocked the promotion of ferroptosis by DCA. These data provide a mechanistic basis for the widely reported link between ferroptosis and colitis risk. Conclusion Taken together, these findings suggest that DCA aggravates colitis through the induction of ferroptosis in the HIF2α-DMT1 signaling pathway and provides a new perspective for UC prevention in the future.

Histologic Diversity of Thymic Epithelial Tumors in Patients with Myasthenia Gravis

Background and Objective:Thymic epithelial tumors (TETs) include thymic carcinomas and thymomas, the latter of which can be further categorized by the World Health Organization (WHO) histologic classification based on the morphology of epithelial cells and the ratio of lymphocyte to epithelial cells. TETs are rare malignancies with an incidence of 0.15 per 100,000 in the United States. While their etiologies remain unknown, these tumors are associated with distinctly high rates of autoimmune disorders and paraneoplastic syndromes. Approximately 30% of patients with thymoma also carry a diagnosis of myasthenia gravis (MG). For the present retrospective study, we created a database of patients with TETs and examined prevalence of each histologic subtype in patients with MG.
 Methods:Drs. Patrick Loehrer, Kenneth Kesler, and colleagues have collaborated at the Indiana University Simon Comprehensive Cancer Center to care for over 1000 patients with TETs. The electronic health records of these patients were accessed via Cerner and used to input demographic, diagnostic, and histologic data into a REDCap database. These tumors were further categorized by WHO classification, and those comprising multiple histologic types were included separately in each subgroup.
 Results:Of 626 patients deemed to have sufficient documented histologic and diagnostic data, 110 had both MG and a TET diagnosis confirmed by pathology report. The greatest prevalence of WHO histologic type in patients with thymoma and MG was Type B2 (47), followed by Type B3 (34), Type B1 (22), Type A (9), Type AB (7), and unspecified thymoma (7). Notably, only 3 of 159 (1.87%) total patients with thymic carcinoma had comorbid MG in contrast to 107 of 467 (22.91%) patients with thymoma and MG; this suggests a uniquely favorable microenvironment of thymoma in patients with MG.
 Clinical Impact and Implications:Future work will aim to determine whether histologic classification has a predictive value for tumor prognosis in patients with and without MG. Furthermore, patterns of gene expression associated with thymoma in patients with and without MG may elucidate the etiologic mechanisms for the development of this autoimmune disorder.

The Effect of Dietary Phospholipids on the Ultrastructure and Function of Intestinal Epithelial Cells.

Dietary composition substantially determines human health and affects complex diseases, including obesity, inflammation and cancer. Thus, food supplements have been widely used to accommodate dietary composition to the needs of individuals. Among the promising supplements are dietary phospholipids (PLs) that are commonly found as natural food ingredients and as emulsifier additives. The aim of the present study was to evaluate the effect of major PLs found as food supplements on the morphology of intestinal epithelial cells upon short-term and long-term high-dose feeding in mice. In the present report, the effect of short-term and long-term high dietary PL content was studied in terms of intestinal health and leaky gut syndrome in male mice. We used transmission electron microscopy to evaluate endothelial morphology at the ultrastructural level. We found mitochondrial damage and lipid droplet accumulation in the intracristal space, which rendered mitochondria more sensitive to respiratory uncoupling as shown by a mitochondrial respiration assessment in the intestinal crypts. However, this mitochondrial damage was insufficient to induce intestinal permeability. We propose that high-dose PL treatment impairs mitochondrial morphology and acts through extensive membrane utilization via the mitochondria. The data suggest that PL supplementation should be used with precaution in individuals with mitochondrial disorders.

Accelerated maturation of ARPE‐19 cells for the translational assessment of gene therapy

AbstractPurpose: Retinal pigment epithelium (RPE) modulates the exchange of metabolite products to and from the retina, and are paramount to maintain retinal function. The human RPE cell‐line ARPE‐19 is commercially available and widely used as an alternative to primary RPE. However, these cells undergo epithelial‐mesenchymal transition (EMT) losing many features of primary RPE such as polarity, pigmentation, and expression of RPE signature markers. We aimed to determine whether a combination of RPE‐specific laminin (LN) coating and media supplementation with nicotinamide (NAM) could improve ARPE‐19 expression of genes and proteins, along with morphological phenotype resembling mature RPE to improve assessment of RPE‐specific gene therapy strategies.Methods: ARPE‐19 cells were propagated on tissue culture plastic with or without NAM supplementation and/or coated with human recombinant LN‐521. Cell morphology was evaluated by phase microscopy. RPE maturation was performed by immunocytochemistry and gene expression by qPCR. Viral transduction experiments with adeno associated virus (AAV)1 or AAV2, VMD2‐driven GFP, were assessed at 2‐ and 4‐weeks post‐plating in the different culturing condition with low multiplicity of infection.Results: The combination of LN‐521 coating with NAM supplementation promoted cytoskeletal and tight junction proteins reorganization, and expression of differentiation markers such as VMD2, RPE65 and PDGFRB. In addition, the combination reduced the expression of the EMT markers, TNFα and TGF‐β1; and NCAM1, an immature phenotype RPE marker. Both AAV1‐ and AAV2‐VMD2‐GFP expression was detected from 2‐weeks and improved at 4‐weeks post‐plating.Conclusions: Our study demonstrates that the combination of NAM with LN‐521 accelerated the kinetics of expression of mature RPE signature genes, reduced expression of EMT genes, accompanied with improved epithelial cell morphology and cytoskeletal organization, bringing the dedifferentiated ARPE‐19 closer to their in vivo phenotype. Moreover, viral‐mediated RPE‐specific gene expression demonstrates the amenability of the combinatorial cultures for translational assessment of RPE gene therapies.

Long-Term Culture of Canine Ocular Cells That Maintain Canine Papillomaviruses.

Canine ocular papillomas occur on the haired skin of eyelids, conjunctival epithelium, and rarely on the cornea. Using PCR typing assays with canine papillomavirus type-specific primer sets, our study confirmed that the papillomas contained canine papillomavirus type 1. The positive result from a rolling circle amplification assay indicated the CPV1 viral genome in the cells is a circular episomal form. We also successfully established the first canine corneal cell line using the conditional reprogramming method. The cells exhibited an epithelial cell morphology, grew rapidly in vitro, and could be maintained long term. For the continued growth of the canine corneal cells, feeder cells played a more important role than Rho-kinase inhibitor Y-27632. More importantly, the viral CPV1 genome was maintained in the canine corneal cells during the long-term expansion. Unlimited supplies of these cells provide as a model for the study CPV in dog cells, and a platform for drug screening for effective therapies against canine papillomavirus infection in the future.

Oral Peroxisome Proliferator-Activated Receptor-α Agonist Enhances Corneal Nerve Regeneration in Patients With Type 2 Diabetes.

Diabetic corneal neuropathy (DCN) is a common complication of diabetes. However, there are very limited therapeutic options. We investigated the effects of a peroxisome proliferator-activated receptor-α (PPAR-α) agonist, fenofibrate, on 30 patients (60 eyes) with type 2 diabetes. On invivo confocal microscopy evaluation, there was significant stimulation of corneal nerve regeneration and a reduction in nerve edema after 30 days of oral fenofibrate treatment, as evidenced by significant improvement in corneal nerve fiber density (CNFD) and corneal nerve fiber width, respectively. Corneal epithelial cell morphology also significantly improved in cell circularity. Upon clinical examination, fenofibrate significantly improved patients' neuropathic ocular surface status by increasing tear breakup time along with a reduction of corneal and conjunctival punctate keratopathy. Tear substance P (SP) concentrations significantly increased after treatment, suggesting an amelioration of ocular surface neuroinflammation. The changes in tear SP concentrations was also significantly associated with improvement in CNFD. Quantitative proteomic analysis demonstrated that fenofibrate significantly upregulated and modulated the neurotrophin signaling pathway and linolenic acid, cholesterol, and fat metabolism. Complement cascades, neutrophil reactions, and platelet activation were also significantly suppressed. Our results showed that fenofibrate could potentially be a novel treatment for patients with DCN.

Abstract 13595: Lactobacillus Supplementation Augments Right Ventricular Function in Preclinical Pulmonary Arterial Hypertension

Introduction: Gut microbiome dysbiosis induces hyperactivation of the immune systemic in multiple diseases. In pulmonary arterial hypertension (PAH), dysbiosis could therefore regulate right ventricular (RV) function because inflammatory glycoprotein 130 (GP130) signaling pathologically restructures RV microtubules and junctophilin-2 (JPH2) to promote RV dysfunction (RVD) in MCT rats. Interestingly, increases in intestinal Lactobacillus, an anti-inflammatory bacteria, by intermittent fasting enhance RV function in monocrotaline (MCT) rats. However, it is unknown if Lactobacillus supplementation can restructure the microbiome to suppress GP130-mediated RVD. Methods: Male rats were randomly allocated into 3 groups: control, MCT water gavage (MCT-water), and MCT Lactobacillus rhamnosus (4x10 7 CFU/day) gavage (MCT- Lactobacillus ) with treatments starting 2 weeks after MCT injection. Next-generation sequencing evaluated the composition of the bacterial and fungal components of the microbiome. SomaScan proteomics quantified levels of serum GP130 ligands. Immunoblots probed RV microtubule and JPH2 expression. Echocardiography and closed-chest pressure-volume (PV) loops determined RV function. Results: Lactobacillus supplementation restructured the micro/mycobiome, and concomitantly improved jejunal epithelial cell morphology. Serum proteomics revealed Lactobacillus treatment decreased circulating GP130 ligand levels which normalized RV microtubule and JPH2 protein expression. Finally, Lactobacillus reduced RV hypertrophy and fibrosis and enhanced RV function without changing PAH severity. Conclusions: Lactobacillus supplementation restructured the microbiome, dampened GP130 activation, normalized RV microtubule and JPH2 expression, and augmented RV function. Thus, Lactobacillus treatment could be a readily translatable approach to combat RVD in PAH.

Analysis of phellinus igniarius effects on gastric cancer cells by atomic force microscopy

Gastric cancer is one of the common malignant tumors in the world, which originates from the gene mutation of human cells. In this work, an atomic force microscope was used to quantitatively detect the changes of multiple physical parameters such as the cell morphology, surface roughness, elasticity modulus and adhesion force before and after Phellinus linteus stimulation. The experimental results show that Phellinus linteus can change the shape of gastric cancer cells (SGC-7901) from flat to spherical, and increase their height and surface roughness values.The adhesion force of cells is reduced and the elasticity modulus is increased. But there are no significant differences in the morphology and mechanical properties of gastric epithelial cells (GES-1). The results indicate that Phellinus linteus has a high anticancer effect on the gastric cancer cells, but has less toxic side effects on the gastric epithelial cells. This work proves that Phellinus linteus can be used as a preferred anticancer drug for the treatment of gastric cancer cells.

Corneal epithelial dendritic cells, tear neuropeptides and corneal nerves continue to be affected more than 12 months after LASIK.

LASIK causes corneal nerve damage and may affect the neuro-immune crosstalk. This study examined the effects of LASIK on corneal epithelial dendritic cells (CEDC) density and morphology and explored their relationships with corneal nerves and tear neuropeptides. A grading system was developed to assess CEDC morphology. Intra- and inter-observer repeatability of the CEDC morphology grading system was established using kappa (κ). In vivo confocal microscope images of the central cornea were captured from 20 participants who had undergone LASIK 12-16 months earlier and 20 controls (age 18-32 years, 55%F). CEDC density was counted manually, and CEDC morphology was assessed using a new grading system. CEDC sub-types (contacting nerves [CEDCc] and not contacting nerves [CEDCnc]) were also assessed. Differences in CEDC density and morphology were examined using mixed models and chi-squared test. Relationships between CEDC and corneal nerve parameters and tear substance P were explored using Spearman's correlation. Excellent intra- and inter-observer repeatability was demonstrated for the grading system (κ=0.82-0.97). In post-LASIK participants, CEDC density was lower compared with controls (5 [0-34] vs. 21 [7-77] cells/mm2 ; p= 0.01), and the proportion of CEDC with thick dendrites was higher (55%-73% vs. 11%-21%, p< 0.003). Higher tear substance P levels were associated with higher CEDC density (rho=0.48, p= 0.003). Fewer nerve interconnections were observed in participants in whom CEDC had dendrites (p= 0.03). CEDC sub-types followed a similar pattern to CEDC. The findings suggest that CEDC may remain altered more than 12 months post-LASIK. The association with substance P suggests a role for CEDC in corneal neurogenic inflammation.

Organ-specific extracellular matrix directs trans-differentiation of mesenchymal stem cells and formation of salivary gland-like organoids in vivo

BackgroundCurrent treatments for salivary gland (SG) hypofunction are palliative and do not address the underlying cause or progression of the disease. SG-derived stem cells have the potential to treat SG hypofunction, but their isolation is challenging, especially when the tissue has been damaged by disease or irradiation for head and neck cancer. In the current study, we test the hypothesis that multipotent bone marrow-derived mesenchymal stem cells (BM-MSCs) in a rat model are capable of trans-differentiating to the SG epithelial cell lineage when induced by a native SG-specific extracellular matrix (SG-ECM) and thus may be a viable substitute for repairing damaged SGs.MethodsRat BM-MSCs were treated with homogenates of decellularized rat SG-ECM for one hour in cell suspension and then cultured in tissue culture plates for 7 days in growth media. By day 7, the cultures contained cell aggregates and a cell monolayer. The cell aggregates were hand-selected under a dissecting microscope, transferred to a new tissue culture dish, and cultured for an additional 7 days in epithelial cell differentiation media. Cell aggregates and cells isolated from the monolayer were evaluated for expression of SG progenitor and epithelial cell specific markers, cell morphology and ultrastructure, and ability to form SG-like organoids in vivo.ResultsThe results showed that this approach was very effective and guided the trans-differentiation of a subpopulation of CD133-positive BM-MSCs to the SG epithelial cell lineage. These cells expressed amylase, tight junction proteins (Cldn 3 and 10), and markers for SG acinar (Aqp5 and Mist 1) and ductal (Krt 14) cells at both the transcript and protein levels, produced intracellular secretory granules which were morphologically identical to those found in submandibular gland, and formed SG-like organoids when implanted in the renal capsule in vivo.ConclusionsThe results of this study suggest the feasibility of using autologous BM-MSCs as an abundant source of stem cells for treating SG hypofunction and restoring the production of saliva in these patients.

Microcarrier-Based Culture of Human Pluripotent Stem-Cell-Derived Retinal Pigmented Epithelium.

Dry age-related macular degeneration (AMD) is estimated to impact nearly 300 million individuals globally by 2040. While no treatment options are currently available, multiple clinical trials investigating retinal pigmented epithelial cells derived from human pluripotent stem cells (hPSC-RPE) as a cellular replacement therapeutic are currently underway. It has been estimated that a production capacity of >109 RPE cells annually would be required to treat the afflicted population, but current manufacturing protocols are limited, being labor-intensive and time-consuming. Microcarrier technology has enabled high-density propagation of many adherent mammalian cell types via monolayer culture on surfaces of uM-diameter matrix spheres; however, few studies have explored microcarrier-based culture of RPE cells. Here, we provide an approach to the growth, maturation, and differentiation of hPSC-RPE cells on Cytodex 1 (C1) and Cytodex 3 (C3) microcarriers. We demonstrate that hPSC-RPE cells adhere to microcarriers coated with Matrigel, vitronectin or collagen, and mature in vitro to exhibit characteristic epithelial cell morphology and pigmentation. Microcarrier-grown hPSC-RPE cells (mcRPE) are viable; metabolically active; express RPE signature genes including BEST1, RPE65, TYRP1, and PMEL17; secrete the trophic factors PEDF and VEGF; and demonstrate phagocytosis of photoreceptor outer segments. Furthermore, we show that undifferentiated hESCs also adhere to Matrigel-coated microcarriers and are amenable to directed RPE differentiation. The capacity to support hPSC-RPE cell cultures using microcarriers enables efficient large-scale production of therapeutic RPE cells sufficient to meet the treatment demands of a large AMD patient population.

P-170 Comparison of the effect of human polarized and non-polarized Granulosa cells co-culture on mouse embryo development

Abstract Study question Do human polarized Granulosa cells (GCs), improve the development of mouse embryos after co-culture, compared to human non-polarized GCs and standard culture? Summary answer Yes, human polarized GCs improve blastulation and hatching rate and also embryos quality after co-culture, compared to human non-polarized GCs and standard embryo culture. What is known already Co-culture embryo with the cells of the female reproductive tract is one of the methods that, in addition to meeting the metabolic needs of the embryo, compensate for the lack of interactions between the embryo and the female reproductive tract during in vitro culture. Various studies have shown that co-culturing of embryos with GCs improves embryo quality and clinical outcomes. However, GCs morphology is essential for proper function changes during in vitro culture to fibroblast-like appearance. Matrigel can effectively maintain epithelial cells' physiology, morphology, and polarity like GCs in vitro and provide more efficient feeder cells. Study design, size, duration GCs were cultured on Matrigel to maintain epithelial nature. The effect of Matrigel on GCs morphology, ultrastructure, and the transcription level of specific and apoptotic genes was studied following one and six days of culture and compared to culturing without Matrigel. Then Polarized and non-polarized GCs were applied for co-culturing with embryos. Blastulation and hatching rate, cell count in the blastocyst stage, and expansion were compared between two co-culture groups and standard embryo culture. Participants/materials, setting, methods GCs were enzymatically isolated from oocyte surroundings of fertile women who had undergone IVF treatment due to male factors and cultured with or without Matrigel overnight. Pronucleus embryos were extracted from adult female NMRI mice and cultured randomly for up to five days in three groups: standard culture, co-culture with non-polarized GCs, and co-culture with polarized GCs. Main results and the role of chance Histological results showed that Matrigel maintains the round shape of GCs, but in the group without Matrigel, GCs were slender and spindle-shaped. Ultrastructure sections showed in culture on Matrigel, Multiple cell junctions connected GCs, lipid droplets were homogeneously spread on the cytoplasm, and Cylinder- shape mitochondria were also detected. GCs culture without Matrigel showed thick cell extensions and gaps between cells and also clustered lipid droplets on one side of the cytoplasm. Gene expression studies indicated culturing GCs on Matrigel is associated with maintaining function and greater cell viability, which had a positive effect on co-culture with embryos; In the co-culture group with polarized GCs, the blastulation rate, as well as hatching or hatched blastocyst, was significantly higher compared to the control group (P-value&amp;lt;0.05). Also, the number of blastomeres increased dramatically in both co-culture groups compared to the standard culture (P-value&amp;lt;0.05). The approximate ratio of the area of inner cell mass to the total area of blastocytes was also significantly lower in the co-culture group with polarized GCs compared to the control group and culture with non-polarized GCs (P-value&amp;lt;0.05), indicating more blastocyst expansion in the co-culture group with polarized GCs. Limitations, reasons for caution Because of ethical issues, mice embryos were used in this study instead of human embryos. Wider implications of the findings In the presence of polarized granulosa cells, the number of embryonic cells, especially trophectoderm cells, blastocyst expansion, blastulation, and hatching rate increase. It seems that granulosa cell culture on Matrigel can effectively simulate the in vivo environment for the embryo and lead to more successful assisted reproductive techniques. Trial registration number 98000112

Toxicity of Amphotericin B in Rabbit Corneal Epithelial Cells Stored in Optisol™-GS: Corneal Epithelial Cell Morphology and Migration

Purpose To evaluate the toxicity of Amphotericin B (AmB) in Optisol™-GS Corneal Storage Media (Bausch & Lomb) on corneal epithelial cell (CEC) morphology and migration ability. Methods Sclerocorneal strips were removed from male Japanese white rabbits, and then stored at 4 °C in Optisol™-GS containing 0 µg/ml of AmB (control group) and 2.5, 5, 25, and 50 µg/ml of AmB (AmB groups; four eyes per group). After 7 days of storage, CEC morphology was evaluated by hematoxylin-eosin staining, immunohistochemical staining (ZO-1), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Moreover, to evaluate CEC migration ability, three corneal blocks (6–8 × 3 mm each) from one preserved cornea were cultured for 24 h, and the area of CEC migration (2 mm at the central region) onto the stromal surface was then measured. Results At 5, 25, and 50 µg/ml of AmB, deformation and vacuolation of CECs were observed in all preserved corneas. ZO-1 expression was significantly reduced in corneas preserved at AmB concentrations of 25 and 50 µg/ml. TUNEL Labeling Index was significantly increased at AmB concentrations of ≥5 µg/ml. CEC migration was inhibited in a dose-dependent manner at AmB concentrations of 25 and 50 µg/ml compared to the control group. Conclusions The addition of AmB to Optisol™-GS can be toxic to CECs and inhibit their migration at a concentration of ≥5 µg/ml. AmB at a concentration of 2.5 µg/ml can be considered safe for the preservation of donor corneal tissue used in corneal epithelial transplantation surgery.

Opioid Use in Murine Model Results in Severe Gastric Pathology that May Be Attenuated by Proton Pump Inhibition

Opioids are the gold standard for chronic and acute pain management; however, their consequence on gastric function is relatively understudied. Opioid users have a higher incidence of gastric dysfunction, worse quality of life, increased hospitalizations, and increased use of antiemetic and pain modulator medications. The current study shows that morphine treatment in the murine model results in greater disruption of gastric epithelial cell morphology, increased gastric cell apoptosis, elevated inflammatory cytokines, and matrix metallopeptidase-9 secretion. Morphine treatment also increases gastric acid secretion and causes delays in gastric emptying. Moreover, morphine treatment causes an increase in systemic IL-6 level, which plays an important role in morphine-induced delayed gastric emptying and gastric damage. IL-6 knockout mice show a significant level of reduction in morphine-induced gastric delaying, acid retention, and gastric damage. Thus, morphine-mediated gastric damage is a consequence of the accumulation of acid in the stomach due to increased gastric acid secretion and delayed gastric emptying. Treatment with a proton pump inhibitor resulted in a significant reduction in morphine-induced gastric inflammation, gastric delaying, and improved morphine tolerance. Hence, these studies attribute morphine-mediated induction in gastric acidity and inflammatory cytokines as drivers for morphine-associated gastric pathology and show the therapeutic use of proton pump inhibitors as an inexpensive approach for clinical management of morphine-associated pathophysiology and analgesic tolerance.

M070 Urine sediment external quality assessment program in Brazil reveals the need for more education on epithelial cells morphology and clinical significance

M070 Urine sediment external quality assessment program in Brazil reveals the need for more education on epithelial cells morphology and clinical significance

NUTM1-fusion positive malignant neoplasms of the genitourinary tract: A report of six cases highlighting involvement of unusual anatomic locations and histologic heterogeneity.

Tumors with NUTM1 fusions occur predominantly in the thoracic cavity and head and neck region. However, recent literature expanded the location of NUTM1-translocated malignancy to soft tissue, brain, and visceral organs. In this study, we describe the first series of six NUTM1-translocated carcinomas and sarcomas occurring in the genitourinary tract. The sites of origin were kidney (n= 2), bladder (n= 3), and penis (n= 1). All tumors occurred in adulthood (range: 30-78 years). The histologic features were heterogeneous, showing epithelial, spindle cell, or primitive small blue round cell morphology. Glandular architecture, keratinization, rhabdoid cells, or myxoid-to-edematous stromal component were also noted. In three cases, features were in keeping with a carcinoma (two from kidney and one from bladder), whereas the remaining three were classified as malignant undifferentiated neoplasm (MUN)/sarcoma. Fusion partners detected in four cases tested by either FISH and/or RNA sequencing were BRD4 in two kidney tumors, MXD1 in a bladder sarcoma, and MXD4 in a penile sarcoma. NUT immunostain showed diffuse spiculated positivity in five cases. Immunopositivity for various cytokeratins was noted in two tumors. The outcome of NUTM1-rearranged genitourinary malignancy was dismal: four of five cases with follow-up developed distant metastasis, and three suffered disease-specific death. In conclusion, NUTM1-rearranged carcinoma and sarcoma can affect the genitourinary tract, including kidney, bladder, and penis. Histologic features and keratin immunoexpression are highly variable. A NUTM1-fusion positive malignancy may be included in the differential diagnosis of a MUN of the genitourinary tract given the dismal outcome and the existing BET-targeted therapy for tumors with BRD3/4::NUTM1 fusion.

Actomyosin fibers DApPLE epithelial apical junctions.

Epithelial cell morphology is essential for cellular homeostasis, but the mechanisms by which cell shape is established remain unclear. In this study, Marivin et al. (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202111002) identify DAPLE as a linker between polarity complexes and the actomyosin network at apical junctions. By recruiting CD2P and activating Gαβγ-mediated RhoA signaling, DAPLE ensures proper cell shape and function.

DAPLE orchestrates apical actomyosin assembly from junctional polarity complexes.

Establishment of apicobasal polarity and the organization of the cytoskeleton must operate coordinately to ensure proper epithelial cell shape and function. However, the precise molecular mechanisms by which polarity complexes directly instruct the cytoskeletal machinery to determine cell shape are poorly understood. Here, we define a mechanism by which the PAR polarity complex (PAR3-PAR6-aPKC) at apical cell junctions leads to efficient assembly of the apical actomyosin network to maintain epithelial cell morphology. We found that the PAR polarity complex recruits the protein DAPLE to apical cell junctions, which in turn triggers a two-pronged mechanism that converges upon assembly of apical actomyosin. More specifically, DAPLE directly recruits the actin-stabilizing protein CD2AP to apical junctions and, concomitantly, activates heterotrimeric G protein signaling in a GPCR-independent manner to favor RhoA-myosin activation. These observations establish DAPLE as a direct molecular link between junctional polarity complexes and the formation of apical cytoskeletal assemblies that support epithelial cell shape.

Coordinated activities of Myosin Vb isoforms and mTOR signaling regulate epithelial cell morphology during development.

The maintenance of epithelial architecture necessitates tight regulation of cell size and shape. However, mechanisms underlying epithelial cell size regulation remain poorly understood. We show that the interaction of Myosin Vb with Rab11 prevents the accumulation of apically derived endosomes to maintain cell-size, whereas that with Rab10 regulates vesicular transport from the trans-Golgi. These interactions are required for the fine-tuning of the epithelial cell morphology during zebrafish development. Furthermore, the compensatory cell growth upon cell-proliferation inhibition involves a preferential expansion of the apical domain, leading to flatter epithelial cells, an efficient strategy to cover the surface with fewer cells. This apical domain growth requires post-trans-Golgi transport mediated by the Rab10-interacting Myosin Vb isoform, downstream of the mTOR-Fatty Acid Synthase (FASN) axis. Changes in trans-Golgi morphology indicate that the Golgi synchronizes mTOR-FASN-regulated biosynthetic input and Myosin Vb-Rab10 dependent output. Our study unravels the mechanism of polarized growth in epithelial cells and delineates functions of Myosin Vb isoforms in cell size regulation during development.

Effect of F11R Gene Knockdown on Malignant Biological Behaviors of Pancreatic Cancer Cells.

F11R receptor (F11R/junctional adhesion molecule-A/F11R-A) is preferentially concentrated at tight junctions and influences epithelial cell morphology and migration. Numerous studies have shown that the aberrant expression of F11R contributes to tumor progression including pancreatic cancer. However, the significance of F11R in various tumors is controversial, and the role of F11R in regulating the malignant behaviors of human pancreatic cancer is unknown. To investigate the role of F11R in the carcinogenesis of pancreatic cancer and the potential targets of F11R as a therapeutic target for pancreatic cancer, we knocked down F11R in the pancreatic cancer cell line PANC-1 using lentiviral approaches. We found that F11R silencing led to decreased cell proliferation, a loss of cell invasiveness, cell cycle arrest in the G1 phase, and enhanced cell apoptosis. The present results suggest that F11R may be a promising therapeutic target for pancreatic cancer.