The ITGB6 gene: its role in experimental and clinical biology

Targeting circFOXO3 to Modulate Integrin β6 Expression in Periodontitis: A Potential Therapeutic Approach

AIMS

Circular RNA forkhead box O3 (circFOXO3) is crucial in regulating inflammation in lung and heart injuries. However, its role in periodontitis remains unclear. We sought to elucidate the effects of circFOXO3 on periodontitis progression and related molecular mechanisms.

METHODS

Reverse-transcription quantitative polymerase chain reaction and fluorescence in situ hybridization were used to quantify and localize circFOXO3 expression. The mechanism by which circFOXO3 promotes inflammation in periodontitis was investigated using epithelial cells, human gingival epithelium and a rat model of ligature-induced periodontitis.

RESULTS

circFOXO3 expression was abnormally high in the gingival epithelial tissues of patients with periodontitis. Elevated circFOXO3 levels down-regulated microRNA (miR)-141-3p, leading to increased FOXO3 expression. FOXO3 interacted with JunB to form a transcriptional-repression complex that inhibited the integrin β6 (ITGβ6)-mediated activation of transforming growth factor β (TGF-β) in epithelial cells. Through the miR-141-3p/FOXO3/JunB axis, circFOXO3 suppressed TGF-β signalling, thereby exacerbating periodontal inflammation. Finally, circFOXO3 inhibition hindered disease progression and restored TGF-β activity in vivo via the FOXO3/JunB/ITGβ6 pathway.

CONCLUSION

Our study identified a novel mechanism by which circFOXO3 contributes to periodontal inflammation through a complex transcriptional regulatory network involving miR-141-3p, FOXO3, JunB and ITGβ6. These findings highlight potential therapeutic targets for the development of effective treatments for this debilitating disease.

Pulmonary exposure to renewable diesel exhaust particles alters protein expression and toxicity profiles in bronchoalveolar lavage fluid and plasma of mice

Exposure to diesel exhaust is associated with increased risk of cardiovascular and lung disease. Substituting petroleum diesel with renewable diesel can alter emission properties but the potential health effects remain unclear. This study aimed to explore toxicity and underlying mechanisms of diesel exhaust from renewable fuels. Using proximity extension assay (Olink), 92 proteins linked to inflammation, cardiovascular function, and cancer were analyzed in bronchoalveolar lavage fluid (BALF) and plasma in mice 1 day after pulmonary exposure to exhaust particles at doses of 6, 18, and 54 µg/mouse. Particles were generated from combustion of renewable (rapeseed methyl ester, RME13, hydrogen-treated vegetable oil, HVO13; both at 13% O2 engine intake) and petroleum diesel (MK1 ultra-low-sulfur diesel at 13% and 17% O2 intake; DEP13 and DEP17). We identified positive dose-response relationships between exposure and proteins in BALF using linear models: 33 proteins for HVO13, 24 for DEP17, 22 for DEP13, and 12 for RME13 (p value < 0.05). In BALF, 11 proteins indicating cytokine signaling and inflammation (CCL2, CXCL1, CCL3L3, CSF2, IL1A, CCL20, TPP1, GDNF, LGMN, ITGB6, PDGFB) were common for all exposures. Several proteins in BALF (e.g., CCL2, CXCL1, CCL3L3, CSF2, IL1A) correlated (rs ≥ 0.5) with neutrophil cell count and DNA damage in BAL cells. Interestingly, plasma protein profiles were only affected by RME13 and, to lesser extent, by DEP13. Overall, we identified inflammation-related changes in the BALF as a common toxic mechanism for the combustion particles. Our protein-based approach enables sensitive detection of inflammatory protein changes across different matrices enhancing understanding of exhaust particle toxicity.

A comparative analysis of paxillin and Hic-5 proximity interactomes

Focal adhesions serve as structural and signaling hubs, facilitating bidirectional communication at the cell-extracellular matrix interface. Paxillin and the related Hic-5 (TGFβ1i1) are adaptor/scaffold proteins that recruit numerous structural and regulatory proteins to focal adhesions, where they perform both overlapping and discrete functions. In this study, paxillin and Hic-5 were expressed in U2OS osteosarcoma cells as biotin ligase (BioID2) fusion proteins and used as bait proteins for proximity-dependent biotinylation in order to directly compare their respective interactomes. The fusion proteins localized to both focal adhesions and the centrosome, resulting in biotinylation of components of each of these structures. Biotinylated proteins were purified and analyzed by mass spectrometry. The list of proximity interactors for paxillin and Hic-5 comprised numerous shared core focal adhesion proteins that likely contribute to their similar functions in cell adhesion and migration, as well as proteins unique to paxillin and Hic-5 that have been previously localized to focal adhesions, the centrosome, or the nucleus. Western blotting confirmed biotinylation and enrichment of FAK and vinculin, known interactors of Hic-5 and paxillin, as well as several potentially unique proximity interactors of Hic-5 and paxillin, including septin 7 and ponsin, respectively. Further investigation into the functional relationship between the unique interactors and Hic-5 or paxillin may yield novel insights into their distinct roles in cell migration.

The αvβ6 integrin specific virotherapy, Ad5NULL-A20.FCU1, selectively delivers potent "in-tumour" chemotherapy to pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) represent an unmet clinical need. Approximately 90% of PDACs express high levels of αvβ6 integrin. We have previously described Ad5NULL-A20, an adenovirus vector with ablated native means of cell entry and retargeted to αvβ6 integrin by incorporation of an A20 peptide.

METHODS

Here, we incorporate suicide genes FCY1 and FCU1 encoding for cytosine deaminase (CDase) or a combination of CDase and UPRTase, capable of catalysing a non-toxic prodrug, 5-FC into the chemotherapeutic 5-FU and downstream metabolites, into replication-deficient Ad5 and Ad5NULL-A20.

RESULTS

We show that Ad5NULL-A20 enables the transfer of suicide genes to αvβ6 integrin-positive PDAC cells which, in combination with 5-FC, results in cell death in vitro which is further mediated by a bystander effect in non-transduced cells. Intratumoural delivery of Ad5NULL-A20.FCU1 in combination with intraperitoneal delivery of 5-FC further results in tumour growth inhibition in a cell line xenograft in vivo. Using clinically-relevant 3D organoid models, we show selective transduction and therapeutic efficacy of FCU1 transgenes in combination with 5-FC.

CONCLUSION

Taken together these data provide the preclinical rationale for combined Ad5NULL-A20.FCU1 plus 5-FC as a promising targeted therapy to mediate "in-tumour chemotherapy" and merits further investigation for the treatment of PDAC patients.

Transcriptome analysis reveals the effects of Schizochytrium sp. on the meat quality attributes of Tan lambs

Schizochytrium sp., a feed additive, positively affects the quality of animal meat. In this study, the molecular mechanisms through which dietary Schizochytrium sp. affects the meat quality characteristics of Tan lambs were investigated using transcriptomic techniques. The findings demonstrate that the lambs supplemented with Schizochytrium sp. had a larger loin eye area and a higher average daily gain and intramuscular fat content (P < 0.05). They also had lower drip loss (at 24 and 48 h) and shear force (P < 0.05). Further, 745 genes were differentially expressed between lambs supplemented with Schizochytrium and the control group. Moreover, KEGG pathway analysis showed that the ECM-receptor interaction pathway, which is related to muscle generation and intramuscular fat deposition, was significantly enriched in the lambs administered a diet containing Schizochytrium sp. Herein, we identified some pivotal genes linked to muscular system development and lipid metabolism. Thus, using Schizochytrium sp. may boost the meat quality of Tan lambs by modifying the expression of genes related to hub pathways. The results supply a new basis to determine the molecular mechanisms through which Schizochytrium sp. supplementation regulates the meat quality characteristics of sheep.

Loss of tolerance to dietary proteins: From mouse models to human model diseases

The critical importance of the immunoregulatory mechanisms, which prevent adverse responses to dietary proteins is demonstrated by the consequences of their failure in two common but distinct human pathological conditions, food allergy and celiac disease. The mechanisms of tolerance to dietary proteins have been extensively studied in mouse models but the extent to which the results in mice can be extrapolated to humans remains unclear. Here, after summarizing the mechanisms known to control oral tolerance in mouse models, we discuss how the monogenic immune disorders associated with food allergy on the one hand, and celiac disease, on the other hand, represent model diseases to gain insight into the key immunoregulatory pathways that control immune responses to food antigens in humans. The spectrum of monogenic disorders, in which the dysfunction of a single gene, is strongly associated with TH2-mediated food allergy suggests an important overlap between the mechanisms that regulate TH2 and IgE responses to food antigens in humans and mice. In contrast, celiac disease provides a unique example of the link between autoimmunity and loss of tolerance to a food antigen.

Proteomics identifies potential immunological drivers of postinfection brain atrophy and cognitive decline

Infections have been associated with the incidence of Alzheimer disease and related dementias, but the mechanisms responsible for these associations remain unclear. Using a multicohort approach, we found that influenza, viral, respiratory, and skin and subcutaneous infections were associated with increased long-term dementia risk. These infections were also associated with region-specific brain volume loss, most commonly in the temporal lobe. We identified 260 out of 942 immunologically relevant proteins in plasma that were differentially expressed in individuals with an infection history. Of the infection-related proteins, 35 predicted volumetric changes in brain regions vulnerable to infection-specific atrophy. Several of these proteins, including PIK3CG, PACSIN2, and PRKCB, were related to cognitive decline and plasma biomarkers of dementia (Aβ42/40, GFAP, NfL, pTau-181). Genetic variants that influenced expression of immunologically relevant infection-related proteins, including ITGB6 and TLR5, predicted brain volume loss. Our findings support the role of infections in dementia risk and identify molecular mediators by which infections may contribute to neurodegeneration.

CRISPR/Cas9-mediated knock out of ITGB6 in human OSCC cells reduced migration and proliferation ability

BACKGROUND

The treatment of oral squamous cell carcinoma (OSCC) remains challenging and survival rates have not been improved significantly over the past decades. Integrins have been recognized driving the cancer progression and high expression levels cause poor outcomes in patients afflicted with OSCC. Integrin αvβ6 and its subunit integrin beta 6 (ITGB6) were discovered to enhance the invasiveness by providing beneficial effects on downstream pathways promoting the cancer progression. The objective of this study was to establish a CRISPR/Cas9-mediated knock out of ITGB6 in the human OSCC cell line HN and investigate the effects on the migration and proliferation ability.

METHODS

ITGB6 knock out was performed using the CRISPR/Cas9-system, RNPs, and lipofection. Monoclonal cell clones were achieved by limiting dilution and knock out verification was carried out by sanger sequencing and FACS on protein level. The effects of the knock out on the proliferation and migration ability were evaluated by using MTT and scratch assays. In addition, in silico TCGA analysis was utilized regarding the effects of ITGB6 on overall survival and perineural invasion.

RESULTS

In silico analysis revealed a significant impact of ITGB6 mRNA expression levels on the overall survival of patients afflicted with OSCC. Additionally, a significantly higher rate of perineural invasion was discovered. CRISPR/Cas9-mediated knock out of ITGB6 was performed in the OSCC cell line HN, resulting in the generation of a monoclonal knock out clone. The knock out clone exhibited a significantly reduced migration and proliferation ability when compared to the wildtype.

CONCLUSIONS

ITGB6 is a relevant factor in the progression of OSCC and can be used for the development of novel treatment strategies. The present study is the first to establish a monoclonal CRISPR/Cas9-mediated ITGB6 knockout cell clone derived from an OSCC cell line. It suggests that ITGB6 has a significant impact on the proliferative and migratory capacity in vitro.

Exploring the role of ITGB6: fibrosis, cancer, and other diseases

Integrin β6 (ITGB6), a member of the integrin family of proteins, is only present in epithelial tissues and frequently associates with integrin subunit αv to form transmembrane heterodimers named integrin αvβ6. Importantly, ITGB6 determines αvβ6 expression and availability. In addition to being engaged in organ fibrosis, ITGB6 is also directly linked to the emergence of cancer, periodontitis, and several potential genetic diseases. Therefore, it is of great significance to study the molecular-biological mechanism of ITGB6, which could provide novel insights for future clinical diagnosis and therapy. This review introduces the structure, distribution, and biological function of ITGB6. This review also expounds on ITGB6-related diseases, detailing the known biological effects of ITGB6.

Insights on the molecular mechanisms of cytotoxicity induced by AS1411 linked to folate-functionalized DNA nanocages in cancer cells

Self-assembled multivalent DNA nanocages are an emerging class of molecules useful for biomedicine applications. Here, we investigated the molecular mechanisms of cytotoxicity induced by AS1411 free aptamer, AS1411-linked nanocages (Apt-NCs) and nanocages harboring both folate and AS1411 functionalization (Fol-Apt-NCs) in HeLa and MDA-MB-231 cancer cell lines. The three treatments showed different cytotoxic efficacy and Fol-Apt-NCs resulted the most effective in inhibiting cell proliferation and inducing apoptotic pathways and ROS activation in both HeLa and MDA-MB-231 cells. RNA-seq analysis allowed to identify biological functions and genes altered by the various treatments, depending on the AS1411 route of intracellular entry, highlighting the different behavior of the two cancer cell lines. Notably, Fol-Apt-NCs altered the expression of a subset of genes associated to cancer chemoresistance in MDA-MB-231, but not in HeLa cells, and this may explain the increased chemosensitivity to drugs delivered through DNA nanocages of the triple-negative breast cancer cells.

Prognostic value and potential molecular mechanism of ITGB superfamily members in hepatocellular carcinoma

We analyzed the prognostic value and potential molecular mechanisms of the members of integrin β (ITGB)superfamily in hepatocellular carcinoma (HCC) using data from The Cancer Genome Atlas (TCGA), cBioPortal, Gene Expression Profiling Interactive Analysis (GEPIA), Human Protein Atlas (HPA) HPA, Search Tool for the Retrieval of Interacting Genes/Proteins, GeneMANIA, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), TIMER and Gene set enrichment analysis (GSEA) databases. ITGB4/5 mRNA was upregulated in HCC tissues in contrast to the normal liver tissues, whereas ITGB2/3/8 levels were lower in the former. ITGB4 was the most frequently mutated ITGB gene in HCC. Receiver operating characteristic curve (ROC) analysis showed that the expression levels of ITGB2/3/4/5/7/8 had significant diagnostic value in distinguishing HCC tissues from healthy liver tissues, ITGB8 had the highest diagnostic efficacy. The ITGB1/3/6/8 were also upregulated in the HCC tissues in contrast to healthy liver tissues. The expression of ITGB8 was verified by immunohistochemistry (IHC). Furthermore, ITGB6 and ITGB7 expression levels were strongly associated with the overall survival (OS) of HCC patients. The ITGB superfamily members exhibited homology and interactions in protein structure. In addition, ITGB6 together with ITGB7 were negatively related to the infiltration of multiple immune cell populations. GSEA results showed that ITGB6 was enriched in HCC migration and recurrence, whereas ITGB7 was significantly enriched in HIPPO, TOLL and JAK-STAT signaling pathways. In conclusion, ITGB6 and ITGB7 genes are possible to be prognostic biomarkers for HCC.

PANoptosis-related molecular subtype and prognostic model associated with the immune microenvironment and individualized therapy in pancreatic cancer

Background

PANoptosis is an inflammatory type of programmed cell death regulated by PANopotosome. Mounting evidence has shown that PANoptosis could be involved in cancer pathogenesis and the tumor immune microenvironment. Nevertheless, there have been no studies on the mechanism of PANoptosis on pancreatic cancer (PC) pathogenesis.

Methods

We downloaded the data on transcriptomic and clinical features of PC patients from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus databases. Additionally, the data on copy number variation (CNV), methylation and somatic mutations of genes in 33 types of cancers were obtained from TCGA. Next, we identified the PANoptosis-related molecular subtype using the consensus clustering analysis, and constructed and validated the PANoptosis-related prognostic model using LASSO and Cox regression analyses. Moreover, RT-qPCR was performed to determine the expression of genes involved in the model.

Results

We obtained 66 PANoptosis-related genes (PANRGs) from published studies. Of these, 24 PC-specific prognosis-related genes were identified. Pan-cancer analysis revealed complex genetic changes, including CNV, methylation, and mutation in PANRGs were identified in various cancers. By consensus clustering analysis, PC patients were classified into two PANoptosis-related patterns: PANcluster A and B. In PANcluster A, the patient prognosis was significantly worse compared to PANcluster B. The CIBERSORT algorithm showed a significant increase in the infiltration of CD8⁺ T cells, monocytes, and naïve B cells, in patients in PANcluster B. Additionally, the infiltration of macrophages, activated mast cells, and dendritic cells were higher in patients in PANcluster A. Patients in PANcluster A were more sensitive to erlotinib, selumetinib and trametinib, whereas patients in PANcluster B were highly sensitive to irinotecan, oxaliplatin and sorafenib. Moreover, we constructed and validated the PANoptosis-related prognostic model to predict the patient's survival. Finally, the GEPIA and Human Protein Atlas databases were analyzed, and RT-qPCR was performed. Compared to normal tissues, a significant increase in CXCL10 and ITGB6 (associated with the model) expression was observed in PC tissues.

Conclusion

We first identified the PANoptosis-related molecular subtypes and established a PANoptosis-related prognostic model for predicting the survival of patients with PC. These results would aid in exploring the mechanisms of PANoptosis in PC pathogenesis.

An atlas of healthy and injured cell states and niches in the human kidney

Understanding kidney disease relies on defining the complexity of cell types and states, their associated molecular profiles and interactions within tissue neighbourhoods1. Here we applied multiple single-cell and single-nucleus assays (>400,000 nuclei or cells) and spatial imaging technologies to a broad spectrum of healthy reference kidneys (45 donors) and diseased kidneys (48 patients). This has provided a high-resolution cellular atlas of 51 main cell types, which include rare and previously undescribed cell populations. The multi-omic approach provides detailed transcriptomic profiles, regulatory factors and spatial localizations spanning the entire kidney. We also define 28 cellular states across nephron segments and interstitium that were altered in kidney injury, encompassing cycling, adaptive (successful or maladaptive repair), transitioning and degenerative states. Molecular signatures permitted the localization of these states within injury neighbourhoods using spatial transcriptomics, while large-scale 3D imaging analysis (around 1.2 million neighbourhoods) provided corresponding linkages to active immune responses. These analyses defined biological pathways that are relevant to injury time-course and niches, including signatures underlying epithelial repair that predicted maladaptive states associated with a decline in kidney function. This integrated multimodal spatial cell atlas of healthy and diseased human kidneys represents a comprehensive benchmark of cellular states, neighbourhoods, outcome-associated signatures and publicly available interactive visualizations.

Integrin β6 deficiency protects mice from experimental colitis and colitis-associated carcinoma by altering macrophage polarization

Background

Given the key role of integrins in maintaining intestinal homeostasis, anti-integrin biologics in inflammatory bowel disease (IBD) are being investigated in full swing. However, the unsatisfactory efficacy and safety of current anti-integrin biologics in clinical trials limit their widespread use in clinic. Therefore, it is particularly important to find a target that is highly and specifically expressed in the intestinal epithelium of patients with IBD.

Methods

The function of integrin αvβ6 in IBD and colitis-associated carcinoma (CAC) with the underlying mechanisms has been less studied. In the present study, we detected the level of integrin β6 within inflammation including colitis tissues in human and mouse. To investigate the role of integrin β6 in IBD and CAC, integrin β6 deficient mice were hence generated based on the construction of colitis and CAC model.

Results

We noted that integrin β6 was significantly upregulated in inflammatory epithelium of patients with IBD. Integrin β6 deletion not only reduced infiltration of pro-inflammatory cytokines, but also attenuated disruption of tight junctions between colonic epithelial cells. Meanwhile, lack of integrin β6 affected macrophage infiltration in mice with colitis. This study further revealed that lack of integrin β6 could inhibit tumorigenesis and tumor progression in CAC model by influencing macrophage polarization, which was also involved in attenuating the degree of intestinal symptoms and inflammatory responses in mice suffering from colitis.

Conclusions

The present research provides a potentially new perspective and option for the treatment of IBD and CAC.

Novel ITGB6 variants cause hypoplastic-hypomineralized amelogenesis imperfecta and taurodontism: characterization of tooth phenotype and review of literature

OBJECTIVES

To characterize phenotype and genotype of amelogenesis imperfecta (AI) in a Thai patient, and review of literature.

MATERIALS AND METHODS

Variants were identified using trio-exome and Sanger sequencing. The ITGB6 protein level in patient's gingival cells was measured. The patient's deciduous first molar was investigated for surface roughness, mineral density, microhardness, mineral composition, and ultrastructure.

RESULTS

The patient exhibited hypoplastic-hypomineralized AI, taurodontism, and periodontal inflammation. Exome sequencing identified the novel compound heterozygous ITGB6 mutation, a nonsense c.625 G > T, p.(Gly209*) inherited from mother and a splicing c.1661-3 C > G from father, indicating AI type IH. The ITGB6 level in patient cells was significantly reduced, compared with controls. Analyses of a patient's tooth showed a significant increase in roughness while mineral density of enamel and microhardness of enamel and dentin were significantly reduced. In dentin, carbon was significantly decreased while calcium, phosphorus, and oxygen levels were significantly increased. Severely collapsed enamel rods and a gap in dentinoenamel junction were observed. Of six affected families and eight ITGB6 variants that have been reported, our patient was the only one with taurodontism.

CONCLUSION

We report the hypoplasia/hypomineralization/taurodontism AI patient with disturbed tooth characteristics associated with the novel ITGB6 variants and reduced ITGB6 expression, expanding genotype, phenotype, and understanding of autosomal recessive AI.

Prognostic assessment capability of a five-gene signature in pancreatic cancer: a machine learning based-study

BACKGROUND

A prognostic assessment method with good sensitivity and specificity plays an important role in the treatment of pancreatic cancer patients. Finding a way to evaluate the prognosis of pancreatic cancer is of great significance for the treatment of pancreatic cancer.

METHODS

In this study, GTEx dataset and TCGA dataset were merged together for differential gene expression analysis. Univariate Cox regression and Lasso regression were used to screen variables in the TCGA dataset. Screening the optimal prognostic assessment model is then performed by gaussian finite mixture model. Receiver operating characteristic (ROC) curves were used as an indicator to assess the predictive ability of the prognostic model, the validation process was performed on the GEO datasets.

RESULTS

Gaussian finite mixture model was then used to build 5-gene signature (ANKRD22, ARNTL2, DSG3, KRT7, PRSS3). Receiver operating characteristic (ROC) curves suggested the 5-gene signature performed well on both the training and validation datasets.

CONCLUSIONS

This 5-gene signature performed well on both our chosen training dataset and validation dataset and provided a new way to predict the prognosis of pancreatic cancer patients.

TGFβ-mediated MMP13 secretion drives myoepithelial cell dependent breast cancer progression

Ductal carcinoma in situ (DCIS) is a non-obligate precursor of invasive breast cancer. Virtually all women with DCIS are treated, despite evidence suggesting up to half would remain with stable, non-threatening, disease. Overtreatment thus presents a pressing issue in DCIS management. To understand the role of the normally tumour suppressive myoepithelial cell in disease progression we present a 3D in vitro model incorporating both luminal and myoepithelial cells in physiomimetic conditions. We demonstrate that DCIS-associated myoepithelial cells promote striking myoepithelial-led invasion of luminal cells, mediated by the collagenase MMP13 through a non-canonical TGFβ - EP300 pathway. In vivo, MMP13 expression is associated with stromal invasion in a murine model of DCIS progression and is elevated in myoepithelial cells of clinical high-grade DCIS cases. Our data identify a key role for myoepithelial-derived MMP13 in facilitating DCIS progression and point the way towards a robust marker for risk stratification in DCIS patients.

FOXO1 inhibits FSL-1 regulation of integrin β6 by blocking STAT3 binding to the integrin β6 gene promoter

Integrin β6 (ITGB6), an epithelial-specific receptor, is downregulated in the gingival epithelium of periodontitis and is associated with inflammation response and periodontitis development. However, the transcriptional regulatory mechanism of ITGB6 downregulation in the human gingival epithelium remains unclear. Fibroblast-stimulating lipopeptide-1 (FSL-1), an oral biofilm component, promotes an epithelial cell-driven proinflammatory response in periodontitis partially by suppressing ITGB6 expression. The aim of the current study was to investigate the transcriptional regulatory mechanism of ITGB6 inhibition by FSL-1 in human epithelial cells (HaCaT and primary human gingival epithelial cells), and to delineate the transcriptional mechanism of ITGB6 suppression in periodontitis. We found that FSL-1 inhibited ITGB6 transcription through increasing forkhead box protein O1 (FOXO1) expression and inhibiting signal transducer and activator of transcription 3 (STAT3) activation. Furthermore, FOXO1 bound to STAT3 directly, leading to decreased STAT3 phosphorylation induced by FSL-1. Consequently, the binding of phosphorylated STAT3 to the ITGB6 promoter was decreased, and ITGB6 transcription was therefore downregulated following FSL-1 stimulation. The reciprocal action of STAT3 and FOXO1 on ITGB6 downregulation was also confirmed by the immunostaining of the inflammatory epithelium associated with periodontitis. Our findings suggest that the interaction of FOXO1-STAT3 may be a useful signal target for the treatment of periodontitis.

Ligand-bound integrin αvβ6 internalisation and trafficking

The integrin αvβ6 is expressed at low levels in most normal healthy tissue but is very often upregulated in a disease context including cancer and fibrosis. Integrins use endocytosis and trafficking as a means of regulating their surface expression and thus their functions, however little is known of how this process is regulated in the context of αvβ6. As αvβ6 is a major target for the development of therapeutics in cancer and fibrosis, understanding these dynamics is critical in the development of αvβ6-targeted therapies. Following development of a flow cytometry-based assay to measure ligand (A20FMDV2 or LAP)-bound αvβ6 endocytosis, an siRNA screen was performed to identify which genes were responsible for internalising αvβ6. These data identified 15 genes (DNM2, CBLB, DNM3, CBL, EEA1, CLTC, ARFGAP3, CAV1, CYTH2, CAV3, CAV2, IQSEC1, AP2M1, TSG101) which significantly decreased endocytosis, predominantly within dynamin-dependent pathways. Inhibition of these dynamin-dependent pathways significantly reduced αvβ6-dependent migration (αvβ6-specific migration was 547 ± 128 under control conditions, reduced to 225 ± 73 with clathrin inhibition, and 280 ± 51 with caveolin inhibition). Colocalization studies of αvβ6 with endosome markers revealed that up to 6 h post-internalisation of ligand, αvβ6 remains in Rab11-positive endosomes in a perinuclear location, with no evidence of αvβ6 degradation up to 48 h post exposure to A20FMDV2. Additionally, 60% of ligand-bound αvβ6 was recycled back to the surface by 6 h. With studies ongoing using conjugated A20FMDV2 to therapeutically target αvβ6 in cancer and fibrosis, these data have important implications. Binding of A20FMDV2 seemingly removes much of the αvβ6 from the cell membrane, and upon its recycling, a large fraction appears to still be in the ligand-bound state. While these results are observed with A20FMDV2, these data will be of value in the design of αvβ6-specific therapeutics and potentially the types of therapeutic load.

Intranasal immunization with a vaccinia virus vaccine vector expressing pre-fusion stabilized SARS-CoV-2 spike fully protected mice against lethal challenge with the heavily mutated mouse-adapted SARS2-N501Y MA30 strain of SARS-CoV-2

The Omicron SARS-CoV-2 variant has been designated a variant of concern because its spike protein is heavily mutated. In particular, Omicron spike is mutated at 5 positions (K417, N440, E484, Q493 and N501) that have been associated with escape from neutralizing antibodies induced by either infection with or immunization against the early Washington strain of SARS-CoV-2. The mouse-adapted strain of SARS-CoV-2, SARS2-N501Y _MA30 , contains a spike that is also heavily mutated, with mutations at 4 of the 5 positions in Omicron spike associated with neutralizing antibody escape (K417, E484, Q493 and N501). In this manuscript we show that intranasal immunization with a pre-fusion stabilized Washington strain spike, expressed from a highly attenuated, replication-competent vaccinia virus construct, NYVAC-KC, fully protected mice against disease and death from SARS2-N501Y _MA30 . Similarly, immunization by scarification on the skin fully protected against death, but not from mild disease. This data demonstrates that Washington strain spike, when expressed from a highly attenuated, replication-competent poxvirus, administered without parenteral injection can fully protect against the heavily mutated mouse-adapted SARS2-N501Y _MA30 .

Identification of Therapeutic Targets and Prognostic Biomarkers Among Integrin Subunits in the Skin Cutaneous Melanoma Microenvironment

The roles of different integrin alpha/beta (ITGA/ITGB) subunits in skin cutaneous melanoma (SKCM) and their underlying mechanisms of action remain unclear. Oncomine, UALCAN, GEPIA, STRING, GeneMANIA, cBioPortal, TIMER, TRRUST, and Webgestalt analysis tools were used. The expression levels of ITGA3, ITGA4, ITGA6, ITGA10, ITGB1, ITGB2, ITGB3, ITGB4, and ITGB7 were significantly increased in SKCM tissues. The expression levels of ITGA1, ITGA4, ITGA5, ITGA8, ITGA9, ITGA10, ITGB1, ITGB2, ITGB3, ITGB5, ITGB6 and ITGB7 were closely associated with SKCM metastasis. The expression levels of ITGA1, ITGA4, ITGB1, ITGB2, ITGB6, and ITGB7 were closely associated with the pathological stage of SKCM. The expression levels of ITGA6 and ITGB7 were closely associated with disease-free survival time in SKCM, and the expression levels of ITGA6, ITGA10, ITGB2, ITGB3, ITGB6, ITGB7, and ITGB8 were markedly associated with overall survival in SKCM. We also found significant correlations between the expression of integrin subunits and the infiltration of six types of immune cells (B cells, CD8+ T cells, CD4+T cells, macrophages, neutrophils, and dendritic cells). Finally, Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed, and protein-protein interaction (PPI) networks were constructed. We have identified abnormally-expressed genes and gene regulatory networks associated with SKCM, improving understanding of the underlying pathogenesis of SKCM.

ITGB6 inhibits the proliferation of porcine skeletal muscle satellite cells

The formation of embryonic muscle fibers determines the amount of postnatal muscles and is regulated by a variety of signaling pathways and transcription factors. Previously, by using chromatin immunoprecipitation-sequencing and RNA-Seq techniques, we identified a large number of genes that are regulated by H3K27me3 in porcine embryonic skeletal muscles. Among these genes, we found that ITGB6 is regulated by H3K27me3. However, its function in muscle development is unknown. In this study, we first verified that ITGB6 was differentially regulated by H3K27me3 and that its expression levels were upregulated in porcine skeletal muscles at embryonic Days 33, 65, and 90. Then, we performed gain- or loss-of-function studies on porcine skeletal muscle satellite cells to study the role of ITGB6 in porcine skeletal muscle development. The proliferation of porcine skeletal muscle satellite cells was studied through real-time polymerase chain reaction, Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine staining, Western blot, and flow cytometry analyses. We found that the ITGB6 gene was regulated by H3K27me3 during muscle development and had an inhibitory effect on the proliferation of porcine skeletal muscle satellite cells.

Chronic lung diseases are associated with gene expression programs favoring SARS-CoV-2 entry and severity

Patients with chronic lung disease (CLD) have an increased risk for severe coronavirus disease-19 (COVID-19) and poor outcomes. Here, we analyze the transcriptomes of 611,398 single cells isolated from healthy and CLD lungs to identify molecular characteristics of lung cells that may account for worse COVID-19 outcomes in patients with chronic lung diseases. We observe a similar cellular distribution and relative expression of SARS-CoV-2 entry factors in control and CLD lungs. CLD AT2 cells express higher levels of genes linked directly to the efficiency of viral replication and the innate immune response. Additionally, we identify basal differences in inflammatory gene expression programs that highlight how CLD alters the inflammatory microenvironment encountered upon viral exposure to the peripheral lung. Our study indicates that CLD is accompanied by changes in cell-type-specific gene expression programs that prime the lung epithelium for and influence the innate and adaptive immune responses to SARS-CoV-2 infection.

Gene Expression in Pancreatic Cancer-Like Cells and Induced Pancreatic Stem Cells Generated by Transient Overexpression of Reprogramming Factors

We previously reported that transient overexpression of reprogramming factors can be used to generate induced pluripotent stem (iPS) cells, induced tissue-specific stem (iTS) cells, and fibroblast-like (iF) cells from pancreatic tissue. iF cells have tumorigenic ability and behave similarly to pancreatic cancer cells. In this study, we analyzed gene expression in iF cells and iTS-P cells (iTS cells from pancreatic tissue) via microarray analysis and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The expression levels of the Mybl2 and Lyn genes, which are reported to be oncogenes, were significantly higher in iF cells than in iTS-P cells. The expression level of Nestin, which is expressed in not only pancreatic progenitor cells but also pancreatic ductal adenocarcinomas, was also higher in iF cells than in iTS-P cells. Itgb6 and Fgf13, which are involved in the pathogenesis of diseases such as cancer, exhibited higher expression levels in iF cells than in iTS-P cells. Unexpectedly, the expression levels of genes related to epithelial-mesenchymal transition (EMT), except Bmp4, were lower in iF cells than in iTS-P cells. These data suggest that the Mybl2, Lyn, Nestin, Itgb6, and Fgf13 genes could be important biomarkers to distinguish iTS-P cells from iF cells.

Chronic lung diseases are associated with gene expression programs favoring SARS-CoV-2 entry and severity

Patients with chronic lung disease (CLD) have an increased risk for severe coronavirus disease-19 (COVID-19) and poor outcomes. Here, we analyzed the transcriptomes of 605,904 single cells isolated from healthy and CLD lungs to identify molecular characteristics of lung cells that may account for worse COVID-19 outcomes in patients with chronic lung diseases. We observed a similar cellular distribution and relative expression of SARS-CoV-2 entry factors in control and CLD lungs. CLD epithelial cells expressed higher levels of genes linked directly to the efficiency of viral replication and innate immune response. Additionally, we identified basal differences in inflammatory gene expression programs that highlight how CLD alters the inflammatory microenvironment encountered upon viral exposure to the peripheral lung. Our study indicates that CLD is accompanied by changes in cell-type-specific gene expression programs that prime the lung epithelium for and influence the innate and adaptive immune responses to SARS-CoV-2 infection.

Role of Flt4 in Skin Protection against UVB Radiation: A System Biology Approach

Background: Although the application of ultraviolet B (UVB) in phototherapy of human skin is a common therapeutic method, it is known as a risk factor for skin cancer. This study aims to assess the role of differentially expressed genes (DEGs) to find the critical one that is mainly responsible for skin protection against UVB radiation. Methods: The gene expression profiles of irradiated mice by UVB that issued skin protection against exposure are extracted from Gene Expression Omnibus (GEO) and analyzed by GEO2R. The significant DEGs are assessed via gene ontology (GO) analysis and the critical individuals are investigated via action mapping. Results: Thirty-eight significant DEGs that provide skin resistance against UVB irradiation were determined. Among the query DEGs, 26 individuals were related to 43 biological terms. Flt4, F3, Tspan6, Cblb, and Itgb6 were highlighted as the critical DEGs to promote skin protection against UVB irradiation. Conclusion: The finding indicates that Flt4 is the key DEG that is mainly responsible for protecting skin from UVB exposure.

αvβ6-Targeted Molecular PET/CT Imaging of the Lungs After SARS-CoV-2 Infection

The true impact and long-term damage to organs such as the lungs after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remain to be determined. Noninvasive molecularly targeted imaging may play a critical role in aiding visualization and understanding of the systemic damage. We have identified α_vβ₆ as a molecular target; an epithelium-specific cell surface receptor that is low or undetectable in healthy adult epithelium but upregulated in select injured tissues, including fibrotic lung. Herein we report the first human PET/CT images using the integrin α_vβ₆-binding peptide (¹⁸F-α_vβ₆-BP) in a patient 2 mo after the acute phase of infection. Minimal uptake of ¹⁸F-α_vβ₆-BP was noted in normal lung parenchyma, with uptake being elevated in areas corresponding to opacities on CT. This case suggests that ¹⁸F-α_vβ₆-BP PET/CT is a promising noninvasive approach to identify the presence and potentially monitor the persistence and progression of lung damage.

Impact of Human Cytomegalovirus and Human Herpesvirus 6 Infection on the Expression of Factors Associated with Cell Fibrosis and Apoptosis: Clues for Implication in Systemic Sclerosis Development

Systemic sclerosis (SSc) is a severe autoimmune disorder characterized by vasculopathy and multi-organ fibrosis; its etiology and pathogenesis are still largely unknown. Herpesvirus infections, particularly by human cytomegalovirus (HCMV) and human herpesvirus 6 (HHV-6), have been suggested among triggers of the disease based on virological and immunological observations. However, the direct impact of HCMV and/or HHV-6 infection on cell fibrosis and apoptosis at the cell microenvironment level has not yet been clarified. Thus, this study aimed to investigate the effects of HCMV and HHV-6 infection on the induction of pro-fibrosis or pro-apoptosis conditions in primary human dermal fibroblasts, one of the relevant SSc target cells. The analysis, performed by microarray in in vitro HCMV- or HHV-6-infected vs. uninfected cells, using specific panels for the detection of the main cellular factors associated with fibrosis or apoptosis, showed that both viruses significantly modified the expression of at least 30 pro-fibrotic and 20 pro-apoptotic factors. Notably, several recognized pro-fibrotic factors were highly induced, and most of them were reported to be involved in vivo in the multifactorial and multistep pathogenic process of SSc, thus suggesting a potential role of both HCMV and HHV-6.

Lily steroidal glycoalkaloid promotes early inflammatory resolution in wounded human fibroblasts

ETHNOPHARMACOLOGICAL RELEVANCE

The bulbs and flowers of plants from the Lilium genus have historically been used in Asian and Greco-Roman medicine to treat burns and promote skin healing.

AIM OF THE STUDY

To evaluate a steroidal glycoalkaloid isolated from Easter lily bulbs for its potential wound healing promoting properties.

MATERIALS AND METHODS

A lily-derived steroidal glycoalkaloid (LSGA), (22R, 25R)-spirosol-5-en-3β-yl O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-glucopyranoside, was isolated from Easter lily bulbs, and its structure was confirmed by LC-MS and NMR spectrometry. LSGA effects on wound scratch closure were evaluated in a primary human dermal fibroblast cell culture, and the changes in gene expression profiles were quantitated using an 84 wound-related gene qPCR microarray.

RESULTS

LSGA promoted migration of dermal fibroblasts into the wounded area. The treatment was associated with a rapid upregulation of early inflammatory (CD40LG, CXCL11, IFNG, IL10, IL2 and IL4), cell growth (CSF3 and TNF) and remodeling (CTSG, F13A1, FGA, MMP and PLG) genes both in the wounded and unwounded cells treated with LSGA. A selective decrease in gene expression profiles associated with inflammatory (CXCL2 and CCL7) and remodeling (MMP7 and PLAT) phases was observed in wounded cells treated with LSGA, in contrast to the wounded cells (control).

CONCLUSION

This study demonstrates that a glycoalkaloid present in lilies promoted fibroblast migration in vitro and affected inflammatory, remodeling and growth factor gene expression. The decreases in expression of key genes may impact the wound healing process, possibly contributing to an earlier end of the inflammatory response and shortening the early phases of model tissue reconstitution. The results of this preliminary investigation may provide a basis for the historical use of lily bulbs to promote dermal healing after injury.