Calponin 3 regulates stress fiber formation in dermal fibroblasts during wound healing

Ketotifen directly modifies the fibrotic response of human skin fibroblasts

Fibrosis is a destructive, end-stage disease process. In the skin, it is associated with systemic sclerosis and scarring with considerable health burden. Ketotifen is a clinical antihistamine and mast cell stabilizer. Studies have demonstrated mast cell-dependent anti-fibrotic effects of ketotifen but direct effects on fibroblasts have not been determined. Human dermal fibroblasts were treated with pro-fibrotic transforming growth factor-β1 (TGFβ) followed by ketotifen or control treatments to determine direct effects on fibrotic fibroblasts. Ketotifen impaired TGFβ-induced α-smooth muscle actin gene and protein responses and decreased cytoskeletal- and contractility-associated gene responses associated with fibrosis. Ketotifen reduced Yes-associated protein phosphorylation, transcriptional coactivator with PDZ binding motif transcript and protein levels, and phosphorylation of protein kinase B. In a fibroblast-populated collagen gel contraction assay, ketotifen reduced the contractile activity of TGFβ-activated fibroblasts. In a murine model of bleomycin-induced skin fibrosis, collagen density and dermal thickness were significantly decreased in ketotifen-treated mice supporting in vitro findings. These results support a novel, direct anti-fibrotic activity of ketotifen, reducing pro-fibrotic phenotypic changes in fibroblasts and reducing collagen fibres in fibrotic mouse skin. Together, these findings suggest novel therapeutic potential and a novel mechanism of action for ketotifen in the context of fibrosis.

Mechanoregulation and function of calponin and transgelin

It is well known that chemical energy can be converted to mechanical force in biological systems by motor proteins such as myosin ATPase. It is also broadly observed that constant/static mechanical signals potently induce cellular responses. However, the mechanisms that cells sense and convert the mechanical force into biochemical signals are not well understood. Calponin and transgelin are a family of homologous proteins that participate in the regulation of actin-activated myosin motor activity. An isoform of calponin, calponin 2, has been shown to regulate cytoskeleton-based cell motility functions under mechanical signaling. The expression of the calponin 2 gene and the turnover of calponin 2 protein are both under mechanoregulation. The regulation and function of calponin 2 has physiological and pathological significance, as shown in platelet adhesion, inflammatory arthritis, arterial atherosclerosis, calcific aortic valve disease, post-surgical fibrotic peritoneal adhesion, chronic proteinuria, ovarian insufficiency, and tumor metastasis. The levels of calponin 2 vary in different cell types, reflecting adaptations to specific tissue environments and functional states. The present review focuses on the mechanoregulation of calponin and transgelin family proteins to explore how cells sense steady tension and convert the force signal to biochemical activities. Our objective is to present a current knowledge basis for further investigations to establish the function and mechanisms of calponin and transgelin in cellular mechanoregulation.

Role of Actin-Binding Proteins in Skeletal Myogenesis

Maintenance of skeletal muscle quantity and quality is essential to ensure various vital functions of the body. Muscle homeostasis is regulated by multiple cytoskeletal proteins and myogenic transcriptional programs responding to endogenous and exogenous signals influencing cell structure and function. Since actin is an essential component in cytoskeleton dynamics, actin-binding proteins (ABPs) have been recognized as crucial players in skeletal muscle health and diseases. Hence, dysregulation of ABPs leads to muscle atrophy characterized by loss of mass, strength, quality, and capacity for regeneration. This comprehensive review summarizes the recent studies that have unveiled the role of ABPs in actin cytoskeletal dynamics, with a particular focus on skeletal myogenesis and diseases. This provides insight into the molecular mechanisms that regulate skeletal myogenesis via ABPs as well as research avenues to identify potential therapeutic targets. Moreover, this review explores the implications of non-coding RNAs (ncRNAs) targeting ABPs in skeletal myogenesis and disorders based on recent achievements in ncRNA research. The studies presented here will enhance our understanding of the functional significance of ABPs and mechanotransduction-derived myogenic regulatory mechanisms. Furthermore, revealing how ncRNAs regulate ABPs will allow diverse therapeutic approaches for skeletal muscle disorders to be developed.

Evolution and function of calponin and transgelin

Calponin and transgelin (originally named SM22) are homologous cytoskeleton proteins that regulate actin-activated myosin motor functions in smooth muscle contraction and non-muscle cell motility during adhesion, migration, proliferation, phagocytosis, wound healing, and inflammatory responses. They are abundant cytoskeleton proteins present in multiple cell types whereas their physiological functions remain to be fully established. This focused review summarizes the evolution of genes encoding calponin and transgelin and their isoforms and discusses the structural similarity and divergence in vertebrate and invertebrate species in the context of functions in regulating cell motility. As the first literature review focusing on the evolution of the calponin-transgelin family of proteins in relevance to their structure-function relationship, the goal is to outline a foundation of current knowledge for continued investigations to understand the biological functions of calponin and transgelin in various cell types during physiological and pathological processes.

Single-Cell Profiling Uncovers the Roles of Endometrial Fibrosis and Microenvironmental Changes in Adenomyosis

Purpose

Adenomyosis (AM) is a common benign uterine disorder that has deleterious effects on women's health. However, the pathogenesis of AM is not clearly understood. We aimed to investigate the pathophysiological changes and molecular mechanism in AM.

Methods

Single-cell RNA sequencing (scRNA-seq) was employed to construct a transcriptomic atlas of various cell subsets from the ectopic endometrium (EC) and eutopic endometrium (EM) of one AM patient and evaluate differential expression. The Cell Ranger software pipeline (version 4.0.0) was applied to conduct sample demultiplexing, barcode processing and mapping reads to the reference genome (human GRCh38). Different cell types were classified with markers with the "FindAllMarkers" function, and differential gene expression analysis was performed with Seurat software in R. The findings were confirmed by Reverse Transcription Real-Time PCR using samples from three AM patients.

Results

We identified nine cell types: endothelial cells, epithelial cells, myoepithelial cells, smooth muscle cells, fibroblasts, lymphocytes, mast cells, macrophages and unknown cells. A number of differentially expressed genes, including CLO4A1, MMP1, TPM2 and CXCL8, were identified from all cell types. Functional enrichment showed that aberrant gene expression in fibroblasts and immune cells was related to fibrosis-associated terms, such as extracellular matrix dysregulation, focal adhesion and the PI3K-Akt signaling pathway. We also identified fibroblast subtypes and determined a potential developmental trajectory related to AM. In addition, we identified increased cell-cell communication patterns in EC, highlighting the imbalanced microenvironment in AM progression.

Conclusion

Our results support the theory of endometrial-myometrial interface disruption for AM, and repeated tissue injury and repair could lead to increased fibrosis in the endometrium. Therefore, the present study reveals the association between fibrosis, the microenvironment, and AM pathogenesis. This study provides insight into the molecular mechanisms regulating AM progression.

Promoting effects of calponin 3 on the growth of diffuse large B‑cell lymphoma cells

Diffuse large B‑cell lymphoma (DLBCL) is one of the most common types of lymphoma. Calponin 3 (CNN3) is a thin filament‑associated protein previously known to regulate smooth muscle contraction. Recent evidence illustrates its involvement in carcinogenesis; however, its roles in DLBCL remain unknown. CNN3 was found to be highly expressed in DLBCL specimens according to the online Gene Expression Profiling Interactive Analysis data. The aim of the present study was to investigate the roles of CNN3 in the progression of DLBCL. In vitro, the ectopic expression of CNN3 promoted the proliferation and G1/S transition of DLBCL cells, while its silencing led to opposite alterations. A similar tumor‑promoting role of CNN3 was also demonstrated by injecting nude mice with DLBCL cells over‑ or underexpressing CNN3. The results of dual‑luciferase reporter and chromatin immunoprecipitation assays revealed that forkhead box O3 (FOXO3), a known tumor suppressor in DLBCL, bound to the CNN3 promoter at ‑1955/‑1948 and ‑1190/‑1183, and suppressed the transcription of CNN3. The alterations induced by FOXO3 were partly blocked by CNN3 overexpression. On the whole, the present study demonstrates that CNN3, whose transcriptional activity is negatively regulated by FOXO3, contributes to the malignant behavior of DLBCL cells. The findings of the present study may provide novel diagnostic or therapeutic insight for DLBCL in clinical practice.

Single-cell RNA-seq uncovered hemocyte functional subtypes and their differentiational characteristics and connectivity with morphological subpopulations in Litopenaeus vannamei

Hemocytes play central roles in shrimp immune system, whereas whose subclasses have not yet been completely defined. At present, the morphological classification of hemocytes is inadequate to classify the complete hemocyte repertoire and elucidate the functions and differentiation and maturation processes. Based on single-cell RNA sequencing (scRNA-seq) of hemocytes in healthy Litopenaeus vannamei, combined with RNA-FISH and flow cytometric sorting, we identified three hemocyte clusters including TGase+ cells, CTL+ cells and Crustin+ cells, and further determined their functional properties, potential differentiation trajectory and correspondence with morphological subpopulations. The TGase+ cells were mainly responsible for the coagulation, exhibiting distinguishable characteristics of hyalinocyte, and appeared to be developmentally arrested at an early stage of hemocyte differentiation. The CTL+ cells and Crustin+ cells arrested at terminal stages of differentiation mainly participated in recognizing foreign pathogens and initiating immune defense responses, owning distinctive features of granule-containing hemocytes. Furthermore, we have revealed the functional sub-clusters of three hemocyte clusters and their potential differentiation pathways according to the expression of genes involved in cell cycle, cell differentiation and immune response, and the successive differentiation and maturation of hyalinocytes to granule-containing hemocytes have also mapped. The results revealed the diversity of shrimp hemocytes and provide new theoretical rationale for hemocyte classification, which also facilitate systematic research on crustacean immunity.

Proteomic profile analysis of pulmonary artery in a rat model under hypoxic pulmonary hypertensionc

Aim:

Proteomic profile analysis of pulmonary artery in a rat model under hypoxic pulmonary hypertension

Background:

Background: Hypoxic pulmonary hypertension (HPH) is a pathological condition exemplified by a constant rise in pulmonary artery pressure in high-altitudes.

Objective:

Objective: To investigated the proteome profile and response mechanisms of SD rats under hypoxia over a period of four-weeks.

Method:

Method: Proteomic profile analysis of pulmonary artery in a rat model under hypoxic pulmonary hypertension.

Results:

Results: With 3,204 proteins identified, 49 were up-regulated while 46 were down-regulated. Upregulated genes included Prolargin, Protein S100-A6 and Transgelin-2, whereas Nascent polypeptide-associated complex and Elongator complex protein 1 were down-regulated. KEGG enriched pathways had purine metabolism, cancer and lipolysis regulation as significantly enriched in hypoxic group.

Conclusion:

Conclusion: In conclusion, our findings submit basis for downstream studies on tissue hypoxia mechanisms alongside the associated physiological conditions. Hypoxic pulmonary hypertension (HPH) is a pathological condition exemplified by a constant rise in pulmonary artery pressure in high altitudes. Herein, we investigated the proteome profile and response mechanisms of Sprague-Dawley (SD) rats under hypoxia over a period of four weeks. Unbiased iTRAQ-based quantitative proteomics was utilized in proteome profile analysis of a rat model exposed to HPH. With 3,204 proteins identified, 49 were upregulated while 46 were downregulated. Upregulated genes included Prolargin, Protein, S100-A6 and Transgelin-2, whereas Nascent polypeptide-associated complex and Elongator complex protein 1 were downregulated. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enriched pathways had purine metabolism, cancer, and lipolysis regulation as significantly enriched in hypoxic group. In conclusion, the findings from this study submit a basis for downstream studies on tissue hypoxia mechanisms alongside the associated physiological conditions.

Profiling of plasma-derived exosomal RNA expression in patients with periodontitis: a pilot study

OBJECTIVE

This study aimed to profile differentially expressed (DE) exosomal RNAs in healthy subjects and periodontitis patients and compare their levels before and after treatment.

MATERIALS AND METHODS

Plasma samples from healthy subjects and patients with periodontitis (pre-/post-periodontal treatment) were collected for this case-control study. After isolation of exosomes from the plasma, the RNA was extracted and small RNA sequencing was performed (3 healthy samples, 4 pre-treatment samples, and 5 post-treatment samples). Two-way analyses were conducted according to the treatment status in the periodontitis group, unpaired analysis (grouping as pre-/post-treatment) and paired analysis (matching pre- and post-treatment in the same subject). The DE exosomal RNAs were screened by sequencing and visualized using the R software. Gene Ontology analysis was performed, and target genes were identified.

RESULTS

In both paired and unpaired analyses, two DE microRNAs (DEmiRs; miR-1304-3p and miR-200c-3p) and two DE small nucleolar RNAs (DEsnoRs; SNORD57 and SNODB1771) were common, and they were found to be downregulated during periodontitis and recovered to healthy levels after treatment. The top three target genes (NR3C1, GPR158, and CNN3) commonly regulated by DEmiRs were identified.

CONCLUSIONS

Plasma-derived exosomal miRs (miR-1304-3p and miR-200c-3p) and snoRs (SNORD57 and SNODB1771) could be valuable biomarkers for periodontitis.

The Role of Abnormal Uterine Junction Zone in the Occurrence and Development of Adenomyosis

Adenomyosis is a benign disease with a malignant behavior, bothering a lot of women at reproductive age who suffer from increased menstruation, prolonged menstruation, progressive dysmenorrhea, and infertility. At present, there is no effective treatment for adenomyosis. It seriously affects the life quality of these patients. However, the pathogenesis of adenomyosis is not yet clear. Recently, uterus junctional zone, defined as the inner 1/3 of myometrium between endometrium and myometrium, has gained broad attention. As is reported, the structure and function disorder of uterus junctional zone may play an important part in the occurrence and development of adenomyosis. In this issue, the present study generally reviews the role of uterine junction zone and the related mechanisms involved in adenomyosis, such as the local micro-damage, the formation of inflammatory and hypoxic microenvironment, changes of cytokines, and abnormalities of miRNA as well as signal pathways. It will provide new insights and potential therapeutic target strategies for clinical strategies in the management of adenomyosis.

Knockdown of CNN3 Impairs Myoblast Proliferation, Differentiation, and Protein Synthesis via the mTOR Pathway

Background

Myogenesis is a complex process that requires optimal outside–in substrate–cell signaling. Calponin 3 (CNN3) plays an important role in regulating myogenic differentiation and muscle regeneration; however, the precise function of CNN3 in myogenesis regulation remains poorly understood. Here, we investigated the role of CNN3 in a knockdown model in the mouse muscle cell line C2C12.

Methods

Myoblast proliferation, migration, differentiation, fusion, and protein synthesis were examined in CNN3 knockdown C2C12 mouse muscle cells. Involvement of the mTOR pathway in CNN3 signaling was explored by treating cells with the mTOR activator MHY1485. The regulatory mechanisms of CNN3 in myogenesis were further examined by RNA sequencing and subsequent gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene set enrichment analysis (GSEA).

Results

During proliferation, CNN3 knockdown caused a decrease in cell proliferation and migration. During differentiation, CNN3 knockdown inhibited myogenic differentiation, fusion, and protein synthesis in C2C12 cells via the AKT/mTOR and AMPK/mTOR pathways; this effect was reversed by MHY1485 treatment. Finally, KEGG and GSEA indicated that the NOD-like receptor signaling pathway is affected in CNN3 knockdown cell lines.

Conclusion

CNN3 may promote C2C12 cell growth by regulating AKT/mTOR and AMPK/mTOR signaling. The KEGG and GSEA indicated that inhibiting CNN3 may activate several pathways, including the NOD-like receptor pathway and pathways involved in necroptosis, apoptosis, and inflammation.

Calponin 3 suppresses proliferation, migration and invasion of non-small cell lung cancer cells

Calponin 3 (CNN3) is known to serve a role in certain types of cancer, such as gastric cancer and colorectal cancer. The present study investigated the clinical significance of CNN3 in non-small cell lung cancer (NSCLC) by evaluating its expression profile and relationship with disease prognosis using the Gene Expression Omnibus repository, Gene Expression Profiling Interactive Analysis 2 (GEPIA2) and Kaplan-Meier plotter analysis. CNN3 mRNA expression was measured using reverse transcription-quantitative PCR, while the protein expression level was measured using western blot analysis. Cell proliferation, cell cycle and apoptosis, and migration and invasion were analyzed using MTS assay, flow cytometry and Transwell assays, respectively. These results revealed that CNN3 mRNA expression was downregulated in NSCLC tissues compared with that in normal tissues. Additionally, CNN3 expression had a high diagnostic value based on the GSE2514 dataset and the data from The Cancer Genome Atlas and the Genotype Tissue Expression database, whereas it had a low diagnostic value based on the GSE10072 dataset. Furthermore, CNN3 expression was associated with survival in patients with lung adenocarcinoma (LUAD), whereas it was not associated with survival in patients with lung squamous cell carcinoma (LUSC) according to the Kaplan-Meier plotter results. According to the data from GEPIA2, and the GSE72094, GSE41271 and GSE31210 datasets, CNN3 expression was not associated with the prognosis of patients with LUAD and LUSC. The mRNA and protein expression levels of CNN3 were lower in two NSCLC cell lines (A549 and SK-MES-1) than in a human bronchial epithelial cell line (BEAS-2B). CNN3 overexpression suppressed cell proliferation, migration and invasion, induced G₁-phase arrest, promoted apoptosis and suppressed PI3K/AKT signaling pathway activation in the NSCLC cell lines, whereas CNN3 overexpression had no effect on cell morphology. In conclusion, CNN3 suppressed the proliferation and metastasis of NSCLC cells by downregulating the PI3K/AKT signaling pathway, making it a potential therapeutic target in this disease.

Serum Calponin 3 Levels in Patients with Systemic Sclerosis: Possible Association with Skin Sclerosis and Arthralgia

Systemic sclerosis (SSc) is a connective tissue disease characterized by tissue fibrosis and vasculopathy in various organs with a background of inflammation initiated by autoimmune abnormalities. Calponin 3 plays a role in the cell motility and contractibility of fibroblasts during wound healing in the skin. We aimed to evaluate serum calponin 3 levels in SSc patients and their association with clinical manifestations of SSc. Serum samples were collected from 68 patients with SSc and 20 healthy controls. Serum calponin 3 levels were examined using enzyme-linked immunosorbent assay kits, and their association with clinical features of SSc was statistically analyzed. The upper limit of the 95% confidence interval of serum calponin 3 levels in healthy controls was utilized as the cut-off value when dividing SSc patients into the elevated and normal groups. Serum calponin 3 levels were significantly higher in SSc patients than in healthy controls (mean (95% confidence interval), 15.38 (14.66–16.11) vs. 13.56 (12.75–14.38) ng/mL, p < 0.05). The modified Rodnan total skin thickness score was significantly higher in the elevated serum calponin 3 level group than in the normal level group (median (25–75th percentiles), 10.0 (2.0–16.0) vs. 6.5 (3.25–8.75), p < 0.05). Moreover, SSc patients with increased serum calponin 3 levels also had a higher frequency of arthralgia (40% vs. 9%, p < 0.05). Elevated serum calponin 3 levels were associated with skin sclerosis and arthralgia in SSc patients. Serum calponin 3 levels might be a biomarker that reflects the severity of skin sclerosis and joint involvement in SSc.

Calponin 3 is associated with poor prognosis and regulates proliferation and metastasis in osteosarcoma

Osteosarcoma is a malignant, life-threatening tumor that affects children and adolescents. In this study, we identified high levels of calponin 3 (CNN3) protein in osteosarcoma tissues and cell lines. The receiver operating characteristic curve analysis revealed that CNN3 has diagnostic value for patients with osteosarcoma. We also found that high CNN3 expression was associated with tumor size, tumor stage, and lymph node and distant metastases. Moreover, high levels of CNN3 mRNA were associated with a poor overall survival rate and a shorter disease-free survival period. CNN3 silencing inhibited cell proliferation, induced apoptosis and cell cycle arrest at the G1 stage, and inhibited cell migration and invasion in vitro. Furthermore, CNN3 silencing also inhibited subcutaneous tumor growth and lung metastasis in vivo. Western blotting revealed that silencing of CNN3 resulted in downregulated expression of MMP9, VEGF, and vimentin, and upregulation of E-cadherin. CNN3 silencing also resulted in downregulation of the ERK1/2 and p38 signaling pathways. In conclusion, high CNN3 expression was found to help in the diagnosis of osteosarcoma, and was found to be associated with poor prognosis in patients. Therefore, CNN3 may play an oncogenic role during the progression of osteosarcoma by activating the ERK1/2 and p38 pathways.

CNN3 acts as a potential oncogene in cervical cancer by affecting RPLP1 mRNA expression

The prognosis of advanced stage cervical cancer is poorer due to cancer invasion and metastasis. Exploring new factors and signalling pathways associated with invasiveness and metastasis would help to identify new therapeutic targets for advanced cervical cancer. We searched the cancer microarray database, Oncomine, and found elevated calponin 3 (CNN3) mRNA expression in cervical cancer tissues. QRT-PCR verified the increased CNN3 expression in cervical cancer compared to para-cancer tissues. Proliferation, migration and invasion assays showed that overexpressed CNN3 promoted the viability and motility of cervical cancer cells, the opposite was observed in CNN3-knockdown cells. In addition, xenografted tumours, established from SiHa cells with CNN3 knockdown, displayed decreased growth and metastasis in vivo. Furthermore, RNA-sequencing showed that ribosomal protein lateral stalk subunit P1 (RPLP1) was a potential downstream gene. Gene function experiments revealed that RPLP1 had the same biological effects as CNN3 did. Rescue experiments demonstrated that the phenotypes inhibited by CNN3 silencing were partly or completely reversed by RPLP1 overexpression. In conclusion, we verified that CNN3 acts as an oncogene to promote the viability and motility of cervical cancer cells in vitro and accelerate the growth and metastasis of xenografted tumours in vivo, by affecting RPLP1 expression.

Calponin-3 deficiency augments contractile activity, plasticity, fibrogenic response and Yap/Taz transcriptional activation in lens epithelial cells and explants

The transparent ocular lens plays a crucial role in vision by focusing light on to the retina with loss of lens transparency leading to impairment of vision. While maintenance of epithelial phenotype is recognized to be essential for lens development and function, knowledge of the identity of different molecular mechanisms regulating lens epithelial characteristics remains incomplete. This study reports that CNN-3, the acidic isoform of calponin, an actin binding contractile protein, is expressed preferentially and abundantly relative to the basic and neutral isoforms of calponin in the ocular lens, and distributes predominantly to the epithelium in both mouse and human lenses. Expression and MEKK1-mediated threonine 288 phosphorylation of CNN-3 is induced by extracellular cues including TGF-β2 and lysophosphatidic acid. Importantly, siRNA-induced deficiency of CNN3 in lens epithelial cell cultures and explants results in actin stress fiber reorganization, stimulation of focal adhesion formation, Yap activation, increases in the levels of α-smooth muscle actin, connective tissue growth factor and fibronectin, and decreases in E-cadherin expression. These results reveal that CNN3 plays a crucial role in regulating lens epithelial contractile activity and provide supporting evidence that CNN-3 deficiency is associated with the induction of epithelial plasticity, fibrogenic activity and mechanosensitive Yap/Taz transcriptional activation.

Calponin 3 promotes invasion and drug resistance of colon cancer cells

BACKGROUND

Calponin 3 (CNN3) is an actin-binding protein expressed in smooth muscle and non-smooth muscle cells. It is required for cytoskeletal rearrangement and wound healing.

AIM

To dissect the role of CNN3 in carcinogenesis with a focus on colon cancer.

METHODS

A total of 20 cancer cell lines (8 breast, 11 colon, and HeLa cervical cancer cell as a positive control for mesenchymal phenotype) and 57 formalin-fixed, paraffin-embedded sections from archived sporadic colorectal carcinomas were included in this study. CNN3 expression analysis by western blot or immunohistochemistry was followed by functional analyses. The CNN3 gene was silenced by specific small interfering RNA (commonly known as siRNA), followed by confirmation of the silencing efficiency by western blotting. Then, the silenced cells and control siRNA-transfected cells were analyzed for changes in epithelial and mesenchymal markers, invasion, and response to 5-fluoruracil treatment. We also performed proteomics analysis using a phospho-kinase array-based panel of 45 proteins.

RESULTS

CNN3 showed positive expression in 6/8 breast and 9/11 colon cancer lines and in HeLa cells. Interestingly, the colorectal adenocarcinoma line SW480 was negative, while the cell line developed from its matching lymph node metastasis (SW620) was positive for CNN3. CNN3 expression was fairly consistent with the metastatic phenotype in colon cancer because it was absent in one other colon cell line from a primary site and expressed in all others. We selected SW620 for subsequent functional analyses. CNN3-silenced SW620 cells showed a reduction in collagen invasion and loss of mesenchymal markers. CNN3 silencing caused an increase in the SW620 colon cancer cell sensitivity to 5-fluorouracil. Phospho-kinase array-based proteomics analysis showed that CNN3 silencing in SW620 reduced extracellular signal-regulated kinase, β-Catenin, mutant p53, c-Jun, and heat shock protein 60 activities but increased that of checkpoint kinase 2. CNN3 was expressed in 20/57 (35%) colon cancer cases as shown by immunohistochemistry. CNN3 was associated with a decrease in overall survival in colon cancer in silico.

CONCLUSION

These results show the involvement of CNN3 in lymph node metastasis and resistance to chemotherapy in colon cancer and suggest that significant oncogenic pathways are involved in these CNN3-related actions.

Establishment of a novel experimental model for muscle-invasive bladder cancer using a dog bladder cancer organoid culture

In human and dogs, bladder cancer (BC) is the most common neoplasm affecting the urinary tract. Dog BC resembles human muscle‐invasive BC in histopathological characteristics and gene expression profiles, and could be an important research model for this disease. Cancer patient‐derived organoid culture can recapitulate organ structures and maintains the gene expression profiles of original tumor tissues. In a previous study, we generated dog prostate cancer organoids using urine samples, however dog BC organoids had never been produced. Therefore we aimed to generate dog BC organoids using urine samples and check their histopathological characteristics, drug sensitivity, and gene expression profiles. Organoids from individual BC dogs were successfully generated, expressed urothelial cell markers (CK7, CK20, and UPK3A) and exhibited tumorigenesis in vivo. In a cell viability assay, the response to combined treatment with a range of anticancer drugs (cisplatin, vinblastine, gemcitabine or piroxicam) was markedly different in each BC organoid. In RNA‐sequencing analysis, expression levels of basal cell markers (CK5 and DSG3) and several novel genes (MMP28,CTSE,CNN3,TFPI2,COL17A1, and AGPAT4) were upregulated in BC organoids compared with normal bladder tissues or two‐dimensional (2D) BC cell lines. These established dog BC organoids might be a useful tool, not only to determine suitable chemotherapy for BC diseased dogs but also to identify novel biomarkers in human muscle‐invasive BC. In the present study, for the 1st time, dog BC organoids were generated and several specifically upregulated organoid genes were identified. Our data suggest that dog BC organoids might become a new tool to provide fresh insights into both dog BC therapy and diagnostic biomarkers.

Multi-dimensional immunoproteomics coupled with in vitro recapitulation of oncogenic NRASQ61R identifies diagnostically relevant autoantibody biomarkers in thyroid neoplasia

Tumor-associated antigen (TAA)-specific autoantibodies have been widely implicated in cancer diagnosis. However, cancer cell lines that are typically exploited as candidate TAA sources in immunoproteomic studies may fail to accurately represent the autoantigen-ome of lower-grade neoplasms. Here, we established an integrated strategy for the identification of disease-relevant TAAs in thyroid neoplasia, which combined NRAS^Q61R oncogene expression in non-tumorous thyroid Nthy-ori 3-1 cells with a multi-dimensional proteomic technique DISER that consisted of profiling NRAS^Q61R-induced proteins using 2-dimensional difference gel electrophoresis (2D-DIGE) coupled with serological proteome analysis (SERPA) of the TAA repertoire of patients with thyroid encapsulated follicular-patterned/RAS-like phenotype (EFP/RLP) tumors. We identified several candidate cell-based (nicotinamide phosphoribosyltransferase NAMPT, glutamate dehydrogenase GLUD1, and glutathione S-transferase omega-1 GSTO1) and autoantibody (fumarate hydratase FH, calponin-3 CNN3, and pyruvate kinase PKM autoantibodies) biomarkers, including NRAS^Q61R-induced TAA phosphoglycerate kinase 1 PGK1. Meta-profiling of the reactivity of the identified autoantibodies across an independent SERPA series implicated the PKM autoantibody as a histological phenotype-independent biomarker of thyroid malignancy (11/38 (29%) patients with overtly malignant and uncertain malignant potential (UMP) tumors vs 0/22 (p = 0.0046) and 0/20 (p = 0.011) patients with non-invasive EFP/RLP tumors and healthy controls, respectively). PGK1 and CNN3 autoantibodies were identified as EFP/RLP-specific biomarkers, potentially suitable for further discriminating tumors with different malignant potential (PGK1: 7/22 (32%) patients with non-invasive EFP/RLP tumors vs 0/38 (p = 0.00044) and 0/20 (p = 0.0092) patients with other tumors and healthy controls, respectively; СNN3: 9/29 (31%) patients with malignant and borderline EFP/RLP tumors vs 0/31 (p = 0.00068) and 0/20 (p = 0.0067) patients with other tumors and healthy controls, respectively). The combined use of PKM, CNN3, and PGK1 autoantibodies allowed the reclassification of malignant/UMP tumor risk in 19/41 (46%) of EFP/RLP tumor patients. Taken together, we established an experimental pipeline DISER for the concurrent identification of cell-based and TAA biomarkers. The combination of DISER with in vitro oncogene expression allows further targeted identification of oncogene-induced TAAs. Using this integrated approach, we identified candidate autoantibody biomarkers that might be of value for differential diagnostic purposes in thyroid neoplasia.

A chronic hypoxic response in photoreceptors alters the vitreous proteome in mice

Reduced oxygenation of the outer retina in the aging eye may activate a chronic hypoxic response in RPE and photoreceptor cells and is considered as a risk factor for the development of age-related macular degeneration (AMD). In mice, a chronically active hypoxic response in the retinal pigment epithelium (RPE) or photoreceptors leads to age-dependent retinal degeneration. To identify proteins that may serve as accessible markers for a chronic hypoxic insult to photoreceptors, we used proteomics to determine the protein composition of the vitreous humor in genetically engineered mice that lack the von Hippel-Lindau tumor suppressor (Vhl) specifically in rods (rod^ΔVhl) or cones (all-cone^ΔVhl). Absence of VHL leads to constitutively active hypoxia-inducible transcription factors (HIFs) and thus to a molecular response to hypoxia even in normal room air. To discriminate between the consequences of a local response in photoreceptors and systemic hypoxic effects, we also evaluated the vitreous proteome of wild type mice after exposure to acute hypoxia. 1'043 of the identified proteins were common to all three hypoxia models. 257, 258 and 356 proteins were significantly regulated after systemic hypoxia, in rod^ΔVhl and in all-cone^ΔVhl mice, respectively, at least at one of the analyzed time points. Only few of the regulated proteins were shared by the models indicating that the vitreous proteome is differentially affected by systemic hypoxia and the rod or cone-specific hypoxic response. Similarly, the distinct protein compositions in the individual genetic models at early and late time points suggest regulated, cell-specific and time-dependent processes. Among the proteins commonly regulated in the genetic models, guanylate binding protein 2 (GBP2) showed elevated levels in the vitreous that were accompanied by increased mRNA expression in the retina of both rod^ΔVhl and all-cone^ΔVhl mice. We hypothesize that some of the differentially regulated proteins at early time points may potentially be used as markers for the detection of a chronic hypoxic response of photoreceptors.

Calponin 3 Regulates Cell Invasion and Doxorubicin Resistance in Gastric Cancer

Calponin 3 (CNN3) is an F-actin-binding protein that regulates actin cytoskeletal rearrangement. However, the role of CNN3 in cancer cell invasion and resistance to chemotherapeutic agents has not yet been investigated. The present study was undertaken to investigate whether CNN3 influences cancer-related phenotypes in gastric cancer. We demonstrate that CNN3 contributes to cell invasion and resistance to doxorubicin in gastric cancer. CNN3 expression was markedly elevated in highly invasive cancer cell lines compared to less invasive or noninvasive cancer cell lines. Depletion of CNN3 protein suppressed the invasive ability of gastric cancer cells. The highly invasive MKN-28 gastric cancer cells were more resistant to doxorubicin than the noninvasive MKN-45 cells; however, knockdown of CNN3 expression in MKN-28 cells resensitized them to doxorubicin treatment. Taken together, our results suggest that CNN3 plays a key role in invasiveness and doxorubicin resistance in gastric cancer cells.

Arrangement of myofibroblastic and smooth muscle-like cells in superficial peritoneal endometriosis and a possible role of transforming growth factor beta 1 (TGFβ1) in myofibroblastic metaplasia

PURPOSE

Superficial peritoneal endometriotic (pEM) lesions are composed of endometrial glands and stroma, in addition to a third component-myofibroblasts and smooth muscles (SM)-like cells. The latter develops secondary to a metaplasia. In this study, we characterised the third component cells in pEM according to differentiation markers in different micro-compartments. Furthermore, a possible effect of TGFβ1 on myofibroblastic metaplasia in endometriotic epithelial cells was studied.

METHODS

Seventy-six premenopausal patients were included. Peritoneal biopsies were excised from EM patients (n = 23), unaffected peritoneum (peritoneum from EM patients but without EM components, n = 5/23) and non-EM patients (n = 10). All peritoneal biopsies were immunolabeled for ASMA, calponin, collagen I, desmin, TGFß receptor 1 (R1), R2 and R3 in addition to ultrastructure examination by transmission electron microscopy (TEM) (n = 1). TGFß1 level was measured in peritoneal fluid (PF) (EM, n = 19 and non-EM, n = 13) collected during laparoscopy. Furthermore, TGFß1 effect on myofibroblastic metaplasia was studied in vitro.

RESULTS

At the centre of pEM lesions, calponin immunolabeling outweighs the collagen I while in the periphery the reverse occurs. SM-like cells expressing desmin predominate at the periphery, while ASMA immunolabeling was detectable in all micro-compartments. Both indicate an abundance of myofibroblasts at the centre of pEM lesions and SM-like cells in the periphery. Although activated TGFß1 in PF did not differ between EM and non-EM, it inhibited the cell proliferation of the endometriotic epithelial cells and induced an upregulation in ASMA and collagen IA2 expression as well.

CONCLUSION

The abundance of the myofibroblasts and SM-like cells points to a myofibroblastic metaplasia in pEM. Both cells are differentially arranged in the different micro-compartments of pEM lesions, with increasing cell maturity towards the periphery of the lesion. Furthermore, TGFß1 may play a role in the myofibroblastic metaplasia of the endometriotic epithelial cells. These findings provide a better insight in the micro-milieu in EM lesions, where most of the disease dynamics occur.

Calponin-3 is critical for coordinated contractility of actin stress fibers

Contractile actomyosin bundles, stress fibers, contribute to morphogenesis, migration, and mechanosensing of non-muscle cells. In addition to actin and non-muscle myosin II (NMII), stress fibers contain a large array of proteins that control their assembly, turnover, and contractility. Calponin-3 (Cnn3) is an actin-binding protein that associates with stress fibers. However, whether Cnn3 promotes stress fiber assembly, or serves as either a positive or negative regulator of their contractility has remained obscure. Here, we applied U2OS osteosarcoma cells as a model system to study the function of Cnn3. We show that Cnn3 localizes to both NMII-containing contractile ventral stress fibers and transverse arcs, as well as to non-contractile dorsal stress fibers that do not contain NMII. Fluorescence-recovery-after-photobleaching experiments revealed that Cnn3 is a dynamic component of stress fibers. Importantly, CRISPR/Cas9 knockout and RNAi knockdown studies demonstrated that Cnn3 is not essential for stress fiber assembly. However, Cnn3 depletion resulted in increased and uncoordinated contractility of stress fibers that often led to breakage of individual actomyosin bundles within the stress fiber network. Collectively these results provide evidence that Cnn3 is dispensable for the assembly of actomyosin bundles, but that it is required for controlling proper contractility of the stress fiber network.

Establishment and Characterization of Paired Primary and Peritoneal Seeding Human Colorectal Cancer Cell Lines: Identification of Genes That Mediate Metastatic Potential

Peritoneal metastasis is one of the major patterns of unresectability in colorectal cancer (CRC) and a cause of death in advanced CRC. Identification of distinct gene expressions between primary CRC and peritoneal seeding metastasis is to predict the metastatic potential of primary human CRC. Three pairs of primary CRC (SNU-2335A, SNU-2404A, and SNU-2414A) and corresponding peritoneal seeding (SNU-2335D, SNU-2404B, and SNU-2414B) cell lines were established to determine the different gene expressions and resulting aberrated signaling pathways in peritoneal metastasis tumor using whole exome sequencing and microarray. Whole exome sequencing detected that mutation in CYP2A7 was exclusively shared in peritoneal seeding cell lines. Microarray identified that there were five upregulated genes (CNN3, SORBS1, BST2, EPSTI1, and KLHL5) and two downregulated genes (TRY6 and STYL5) in the peritoneal metastatic cell lines. CNN3 expression was highly augmented in both mRNA and protein levels in peritoneal metastasis cells. Knockdown of Calponin 3 resulted in augmented level of E-cadherin in peritoneal metastasis cells, and migration and invasiveness decreased accordingly. We suggest that CNN3 takes part in cell projection and movement, and the detection and distribution of CNN3 may render prognostic information for predicting peritoneal seeding metastasis from primary colorectal cancer.

Deletion of calponin 2 attenuates the development of calcific aortic valve disease in ApoE-/- mice

Calcific aortic valve disease (CAVD) is a leading cause of cardiovascular mortality and lacks non-surgical treatment. The pathogenesis of CAVD involves perturbation of valvular cells by mechanical stimuli, including shear stress, pressure load and leaflet stretch, of which the molecular mechanism requires further elucidation. We recently demonstrated that knockout (KO) of Cnn2 gene that encodes calponin isoform 2, a mechanoregulated cytoskeleton protein, attenuates atherosclerosis in ApoE KO mice. Here we report that Cnn2 KO also decreased calcification of the aortic valve in ApoE KO mice, an established model of CAVD. Although myeloid cell-specific Cnn2 KO highly effectively attenuated vascular atherosclerosis that shares many pathogenic processes with CAVD, it did not reduce aortic valve calcification in ApoE KO mice. Indicating a function in the pathogenesis of CAVD, calponin 2 participates in myofibroblast differentiation that is a leading step in the development of CAVD. The aortic valves of ApoE KO mice exhibited increased expression of calponin 2 and smooth muscle actin (SMA), a hallmark of myofibroblasts. The expression of calponin 2 increased during myofibroblast-like differentiation of primary sheep aortic valve interstitial cells and during the osteogenic differentiation of mouse myofibroblasts. Cnn2 KO attenuated TGFβ1-induced differentiation of myofibroblasts in culture as shown by the lower expression of SMA and less calcification than that of wild type (WT) cells. These findings present calponin 2 as a novel molecular target for the treatment and prevention of CAVD.

Morphology and contractile gene expression of adipose-derived mesenchymal stem cells in response to short-term cyclic uniaxial strain and TGF-β1

Previous studies have shown smooth muscle induction in adipose-derived mesenchymal stem cells (ASCs) caused by long-term cyclic stretch. Here we examined the capability of the short-term straining with time steps of 4, 8, 16 and 24 h alone or combined with TGF-β1 on smooth muscle induction of rabbit ASCs. Alterations in cell morphology were quantified through the cell shape index and orientation angle, and expression levels of α-SMA, SM22-α, h-caldesmon and calponin3 markers were examined using the real-time polymerase chain reaction (PCR) method. Moreover, F-actin cytoskeleton organization was observed by fluorescence staining. Mechanical strain either alone or combined with growth factor treatment caused significant up-regulation of both early and intermediate smooth muscle cells (SMCs) specific markers during the initial hours of stimulation peaking in 8 to 16 h. Furthermore, gradual alignment of cells perpendicular to the strain direction during loading time, and cell elongation resembling contractile SMC phenotype, together with alignment and reorganization of F-actin fibers were observed. Considering previously reported protein up-regulation in following days of straining, the effects of short-term cyclic stretch on smooth muscle induction of ASCs were revealed which can be helpful in achieving functional contractile SMCs through synergistic mechano-chemical regulation of ASCs as an appealing cell source for vascular tissue engineering.

Cnn3 regulates neural tube morphogenesis and neuronal stem cell properties

Calponin 3 (Cnn3) is a member of the Cnn family of actin-binding molecules that is highly expressed in the mammalian brain and has been shown to control dendritic spine morphology, density, and plasticity by regulating actin cytoskeletal reorganization and dynamics. However, little is known about the role of Cnn3 during embryonic development. In this study, we analyzed mutant animals deficient in Cnn3 to gain a better understanding of its role in brain morphogenesis. Embryos lacking Cnn3 exhibited massive malformation of the developing brain including exoencephaly, closure defects at the rostral neural tube, and strong enlargement of brain tissue. In wild-type animals, we found Cnn3 being localized to the apical lining of the neuroepithelium in close vicinity to beta-Catenin and N-cadherin. By performing immunohistochemistry on beta-Catenin and p-Smad, and furthermore taking advantage of Wnt-reporter animals, we provide evidence that the loss of Cnn3 during development can affect signaling pathways crucial for correct morphogenesis of the neural tube. In addition, we used embryonic neurosphere cultures to investigate the role of Cnn3 in embryonic neuronal stem cells (NSC). Here, we observed that Cnn3 deficiency in NSCs increased the number of newly formed neurospheres and increased neurosphere size without perturbing their differentiation potential. Together, our study provides evidence for an important role of Cnn3 during development of the embryonic brain and in regulating NSC function.

Regeneration of injured skin and peripheral nerves requires control of wound contraction, not scar formation

We review the mounting evidence that regeneration is induced in wounds in skin and peripheral nerves by a simple modification of the wound healing process. Here, the process of induced regeneration is compared to the other two well-known processes by which wounds close, i.e., contraction and scar formation. Direct evidence supports the hypothesis that the mechanical force of contraction (planar in skin wounds, circumferential in nerve wounds) is the driver guiding the orientation of assemblies of myofibroblasts (MFB) and collagen fibers during scar formation in untreated wounds. We conclude that scar formation depends critically on wound contraction and is, therefore, a healing process secondary to contraction. Wound contraction and regeneration did not coincide during healing in a number of experimental models of spontaneous (untreated) regeneration described in the literature. Furthermore, in other studies in which an efficient contraction-blocker, a collagen scaffold named dermis regeneration template (DRT), and variants of it, were grafted on skin wounds or peripheral nerve wounds, regeneration was systematically observed in the absence of contraction. We conclude that contraction and regeneration are mutually antagonistic processes. A dramatic change in the phenotype of MFB was observed when the contraction-blocking scaffold DRT was used to treat wounds in skin and peripheral nerves. The phenotype change was directly observed as drastic reduction in MFB density, dispersion of MFB assemblies and loss of alignment of the long MFB axes. These observations were explained by the evidence of a surface-biological interaction of MFB with the scaffold, specifically involving binding of MFB integrins α1 β1 and α2 β1 to ligands GFOGER and GLOGER naturally present on the surface of the collagen scaffold. In summary, we show that regeneration of wounded skin and peripheral nerves in the adult mammal can be induced simply by appropriate control of wound contraction, rather than of scar formation.

Characterization of the Molecular Mechanisms Underlying the Chronic Phase of Stroke in a Cynomolgus Monkey Model of Induced Cerebral Ischemia

Stroke is one of the main causes of mortality and long-term disability worldwide. The pathophysiological mechanisms underlying this disease are not well understood, particularly in the chronic phase after the initial ischemic episode. In this study, a Macaca fascicularis stroke model consisting of two sample groups, as determined by MRI-quantified infarct volumes as a measure of the stroke severity 28 days after the ischemic episode, was evaluated using qualitative and quantitative proteomics analyses. By using multiple online multidimensional liquid chromatography platforms, 8790 nonredundant proteins were identified that condensed to 5223 protein groups at 1% global false discovery rate (FDR). After the application of a conservative criterion (5% local FDR), 4906 protein groups were identified from the analysis of cerebral cortex. Of the 2068 quantified proteins, differential proteomic analyses revealed that 31 and 23 were dysregulated in the elevated- and low-infarct-volume groups, respectively. Neurogenesis, synaptogenesis, and inflammation featured prominently as the cellular processes associated with these dysregulated proteins. Protein interaction network analysis revealed that the dysregulated proteins for inflammation and neurogenesis were highly connected, suggesting potential cross-talk between these processes in modulating the cytoskeletal structure and dynamics in the chronic phase poststroke. Elucidating the long-term consequences of brain tissue injuries from a cellular prospective, as well as the molecular mechanisms that are involved, would provide a basis for the development of new potentially neurorestorative therapies.

MEKK1-dependent phosphorylation of calponin-3 tunes cell contractility

MEKK1 (also known as MAP3K1), which plays a major role in MAPK signaling, has been implicated in mechanical processes in cells, such as migration. Here, we identify the actin-binding protein calponin-3 as a new MEKK1 substrate in the signaling that regulates actomyosin-based cellular contractility. MEKK1 colocalizes with calponin-3 at the actin cytoskeleton and phosphorylates it, leading to an increase in the cell-generated traction stress. MEKK1-mediated calponin-3 phosphorylation is attenuated by the inhibition of myosin II activity, the disruption of actin cytoskeletal integrity and adhesion to soft extracellular substrates, whereas it is enhanced upon cell stretching. Our results reveal the importance of the MEKK1-calponin-3 signaling pathway to cell contractility.

Calponin isoforms CNN1, CNN2 and CNN3: Regulators for actin cytoskeleton functions in smooth muscle and non-muscle cells

Calponin is an actin filament-associated regulatory protein expressed in smooth muscle and many types of non-muscle cells. Three homologous genes, CNN1, CNN2 and CNN3, encoding calponin isoforms 1, 2, and 3, respectively, are present in vertebrate species. All three calponin isoforms are actin-binding proteins with functions in inhibiting actin-activated myosin ATPase and stabilizing the actin cytoskeleton, while each isoform executes different physiological roles based on their cell type-specific expressions. Calponin 1 is specifically expressed in smooth muscle cells and plays a role in fine-tuning smooth muscle contractility. Calponin 2 is expressed in both smooth muscle and non-muscle cells and regulates multiple actin cytoskeleton-based functions. Calponin 3 participates in actin cytoskeleton-based activities in embryonic development and myogenesis. Phosphorylation has been extensively studied for the regulation of calponin functions. Cytoskeleton tension regulates the transcription of CNN2 gene and the degradation of calponin 2 protein. This review summarizes our knowledge learned from studies over the past three decades, focusing on the evolutionary lineage of calponin isoform genes, their tissue- and cell type-specific expressions, structure-function relationships, and mechanoregulation.

Ixodes scapularis Tick Saliva Proteins Sequentially Secreted Every 24 h during Blood Feeding

Ixodes scapularis is the most medically important tick species and transmits five of the 14 reportable human tick borne disease (TBD) agents in the USA. This study describes LC-MS/MS identification of 582 tick- and 83 rabbit proteins in saliva of I. scapularis ticks that fed for 24, 48, 72, 96, and 120 h, as well as engorged but not detached (BD), and spontaneously detached (SD). The 582 tick proteins include proteases (5.7%), protease inhibitors (7.4%), unknown function proteins (22%), immunity/antimicrobial (2.6%), lipocalin (3.1%), heme/iron binding (2.6%), extracellular matrix/ cell adhesion (2.2%), oxidant metabolism/ detoxification (6%), transporter/ receptor related (3.2%), cytoskeletal (5.5%), and housekeeping-like (39.7%). Notable observations include: (i) tick saliva proteins of unknown function accounting for >33% of total protein content, (ii) 79% of proteases are metalloproteases, (iii) 13% (76/582) of proteins in this study were found in saliva of other tick species and, (iv) ticks apparently selectively inject functionally similar but unique proteins every 24 h, which we speculate is the tick's antigenic variation equivalent strategy to protect important tick feeding functions from host immune system. The host immune responses to proteins present in 24 h I. scapularis saliva will not be effective at later feeding stages. Rabbit proteins identified in our study suggest the tick's strategic use of host proteins to modulate the feeding site. Notably fibrinogen, which is central to blood clotting and wound healing, was detected in high abundance in BD and SD saliva, when the tick is preparing to terminate feeding and detach from the host. A remarkable tick adaptation is that the feeding lesion is completely healed when the tick detaches from the host. Does the tick concentrate fibrinogen at the feeding site to aide in promoting healing of the feeding lesion? Overall, these data provide broad insight into molecular mechanisms regulating different tick feeding phases. These data set the foundation for in depth I. scapularis tick feeding physiology and TBD transmission studies.

Surface biology of collagen scaffold explains blocking of wound contraction and regeneration of skin and peripheral nerves

We review the details of preparation and of the recently elucidated mechanism of biological (regenerative) activity of a collagen scaffold (dermis regeneration template, DRT) that has induced regeneration of skin and peripheral nerves (PN) in a variety of animal models and in the clinic. DRT is a 3D protein network with optimized pore size in the range 20-125 µm, degradation half-life 14 ± 7 d and ligand densities that exceed 200 µM α1β1 or α2β1 ligands. The pore has been optimized to allow migration of contractile cells (myofibroblasts, MFB) into the scaffold and to provide sufficient specific surface for cell-scaffold interaction; the degradation half-life provides the required time window for satisfactory binding interaction of MFB with the scaffold surface; and the ligand density supplies the appropriate ligands for specific binding of MFB on the scaffold surface. A dramatic change in MFB phenotype takes place following MFB-scaffold binding which has been shown to result in blocking of wound contraction. In both skin wounds and PN wounds the evidence has shown clearly that contraction blocking by DRT is followed by induction of regeneration of nearly perfect organs. The biologically active structure of DRT is required for contraction blocking; well-matched collagen scaffold controls of DRT, with structures that varied from that of DRT, have failed to induce regeneration. Careful processing of collagen scaffolds is required for adequate biological activity of the scaffold surface. The newly understood mechanism provides a relatively complete paradigm of regenerative medicine that can be used to prepare scaffolds that may induce regeneration of other organs in future studies.

SOST Inhibits Prostate Cancer Invasion

Inhibitors of Wnt signaling have been shown to be involved in prostate cancer (PC) metastasis; however the role of Sclerostin (Sost) has not yet been explored. Here we show that elevated Wnt signaling derived from Sost deficient osteoblasts promotes PC invasion, while rhSOST has an inhibitory effect. In contrast, rhDKK1 promotes PC elongation and filopodia formation, morphological changes characteristic of an invasive phenotype. Furthermore, rhDKK1 was found to activate canonical Wnt signaling in PC3 cells, suggesting that SOST and DKK1 have opposing roles on Wnt signaling in this context. Gene expression analysis of PC3 cells co-cultured with OBs exhibiting varying amounts of Wnt signaling identified CRIM1 as one of the transcripts upregulated under highly invasive conditions. We found CRIM1 overexpression to also promote cell-invasion. These findings suggest that bone-derived Wnt signaling may enhance PC tropism by promoting CRIM1 expression and facilitating cancer cell invasion and adhesion to bone. We concluded that SOST and DKK1 have opposing effects on PC3 cell invasion and that bone-derived Wnt signaling positively contributes to the invasive phenotypes of PC3 cells by activating CRIM1 expression and facilitating PC-OB physical interaction. As such, we investigated the effects of high concentrations of SOST in vivo. We found that PC3-cells overexpressing SOST injected via the tail vein in NSG mice did not readily metastasize, and those injected intrafemorally had significantly reduced osteolysis, suggesting that targeting the molecular bone environment may influence bone metastatic prognosis in clinical settings.

Proteomic comparison of the EWS-FLI1 expressing cells EF with NIH-3T3 and actin remodeling effect of (R/W)9 cell-penetrating peptide

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Comparison of tumoral EF versus non-tumoral 3T3 fibroblasts (SILAC).

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Characterization of EWS-FLI1 fusion protein impact on protein expression levels.

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Down-regulation of actin binding proteins responsible for passive dissemination.

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Investigation of (R/W)₉ cell-penetrating peptide actin remodeling activity.

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First proteomics study using a cell-penetrating peptide (R/W)_9.

EWS-FLI1 expression in NIH-3T3 fibroblasts has a profound impact on the phenotype, resulting in the cytoskeleton and adhesive capacity disorganization (EF cells). Besides this, (R/W)₉, a cell-penetrating peptide (CPP), has an intrinsic actin remodeling activity in EF cells. To evaluate the impact of the oncogenic protein EWS-FLI1 on proteins expression levels, a quantitative comparison of tumoral EF and non-tumoral 3T3 proteomes was performed. Then to see if we could link the EWS-FLI1 oncogenic transformation to the phenotype reversion induced by (R/W)₉, (R/W)₉ influence on EF cells proteome was assessed. To our knowledge no such ⿿CPPomic⿿ study has been performed before.

Biological significance

Up to now very few global quantitative proteomic studies have been published to help understand the oncogenic transformation induced by EWS-FLI1 fusion protein and leading to Ewing sarcoma development and dissemination. The comparison we did in this study between a model tumoral cell line EF and its non-tumoral counterpart (3T3) allowed us to highlight several features either common to most tumor types or specific to Ewing sarcoma. Particularly, lack of actin cytoskeleton organization could very likely be explained by the down-regulation of many important actin binding proteins. These results are in accordance with the hypothesis of a passive/stochastic mode of dissemination conferring Ewing sarcoma tumoral cell a high metastatic potential.

A Conditional Knockout Mouse Model Reveals That Calponin-3 Is Dispensable for Early B Cell Development

Calponins form an evolutionary highly conserved family of actin filament-associated proteins expressed in both smooth muscle and non-muscle cells. Whereas calponin-1 and calponin-2 have already been studied to some extent, little is known about the role of calponin-3 under physiological conditions due to the lack of an appropriate animal model. Here, we have used an unbiased screen to identify novel proteins implicated in signal transduction downstream of the precursor B cell receptor (pre-BCR) in B cells. We find that calponin-3 is expressed throughout early B cell development, localizes to the plasma membrane and is phosphorylated in a Syk-dependent manner, suggesting a putative role in pre-BCR signaling. To investigate this in vivo, we generated a floxed calponin-3-GFP knock-in mouse model that enables tracking of cells expressing calponin-3 from its endogenous promoter and allows its tissue-specific deletion. Using the knock-in allele as a reporter, we show that calponin-3 expression is initiated in early B cells and increases with their maturation, peaking in the periphery. Surprisingly, conditional deletion of the Cnn3 revealed no gross defects in B cell development despite this regulated expression pattern and the in vitro evidence, raising the question whether other components may compensate for its loss in lymphocytes. Together, our work identifies calponin-3 as a putative novel mediator downstream of the pre-BCR. Beyond B cells, the mouse model we generated will help to increase our understanding of calponin-3 in muscle and non-muscle cells under physiological conditions.

The effects of macrophage-stimulating protein on the migration, proliferation, and collagen synthesis of skin fibroblasts in vitro and in vivo

Macrophage-stimulating protein (MSP), an important cytokine with multiple functions, is highly expressed in adipose-derived stem cells-conditioned medium (ASC-CM). ASCs can effectively promote wound healing through paracrine mechanism, suggesting that MSP may play a critical role in wound healing. Through binding to its receptor, RON (Receptuerd'OrigineNantaise, also called macrophage stimulation 1 receptor; MST1R), it can activate epithelial cells and work as an inflammatory mediator. In this study, we found RON was also expressed on dermal fibroblasts and investigated the effects of MSP on proliferation, migration, and collagen synthesis of fibroblasts. With the treatment of different concentrations of MSP (0, 1, 10, 20, 50, and 100 ng/mL) on fibroblasts, proliferation, migration, and collagen synthesis were analyzed by Cell Counting Kit-8 (CCK-8), transwell and real-time polymerase chain reaction. Under the treatment of MSP, the migration, Collagen I, III synthesis, and matrix metalloproteinase-1 (MMP-1) mRNA expression of fibroblasts were upregulated significantly, although there was no effect on fibroblasts proliferation, and the optimal concentration of MSP for migration and collagen synthesis was 10 ng/mL. In the in vivo study, 10 ng/mL MSP was applied to full-thickness skin wound with bacterial cellulose membranes, and this treatment could accelerate the wound healing rate and increased the collagen synthesis of wound sites. This study suggested that MSP appears to promote the migration of fibroblasts, enhances collagen synthesis and remodeling, and effectively improves wound healing.

MicroRNA-7 protects against 1-methyl-4-phenylpyridinium-induced cell death by targeting RelA

Parkinson's disease (PD) is characterized by the progressive loss of dopaminergic neurons in the substantia nigra. Mitochondrial complex I impairment in PD is modeled in vitro by the susceptibility of dopaminergic neurons to the complex I inhibitor 1-methyl-4-phenylpyridinium (MPP+). In the present study, we demonstrate that microRNA-7 (miR-7), which is expressed in tyrosine hydroxylase-positive nigral neurons in mice and humans, protects cells from MPP+-induced toxicity in dopaminergic SH-SY5Y cells, differentiated human neural progenitor ReNcell VM cells, and primary mouse neurons. RelA, a component of nuclear factor-κB (NF-κB), was identified to be downregulated by miR-7 using quantitative proteomic analysis. Through a series of validation experiments, it was confirmed that RelA mRNA is a target of miR-7 and is required for cell death following MPP+ exposure. Further, RelA mediates MPP+-induced suppression of NF-κB activity, which is essential for MPP+-induced cell death. Accordingly, the protective effect of miR-7 is exerted through relieving NF-κB suppression by reducing RelA expression. These findings provide a novel mechanism by which NF-κB suppression, rather than activation, underlies the cell death mechanism following MPP+ toxicity, have implications for the pathogenesis of PD, and suggest miR-7 as a therapeutic target for this disease.

CNN3 regulates trophoblast invasion and is upregulated by hypoxia in BeWo cells

CNN3 is an ubiquitously expressed F-actin binding protein, shown to regulate trophoblast fusion and hence seems to play a role in the placentation process. In this study we demonstrate that CNN3 levels are upregulated under low oxygen conditions in the trophoblast cell line BeWo. Since hypoxia is discussed to be a pro-migratory stimulus for placental cells, we examined if CNN3 is involved in trophoblast invasion. Indeed, when performing a matrigel invasion assay we were able to show that CNN3 promotes BeWo cell invasion. Moreover, CNN3 activates the MAPKs ERK1/2 and p38 in trophoblast cells and interestingly, both kinases are involved in BeWo invasion. However, when we repeated the experiments under hypoxic conditions, CNN3 did neither promote cell invasion nor MAPK activation. These results indicate that CNN3 promotes invasive processes by the stimulation of ERK1/2 and/or p38 under normoxic conditions in BeWo cells, but seems to have different functions at low oxygen levels. We further speculated that CNN3 expression might be altered in human placentas derived from pregnancies complicated by IUGR and preeclampsia, since these placental disorders have been described to go along with impaired trophoblast invasion. Our studies show that, at least in our set of placenta samples, CNN3 expression is neither deregulated in IUGR nor in preeclampsia. In summary, we identified CNN3 as a new pro-invasive protein in trophoblast cells that is induced under low oxygen conditions.

Revelation of fibroblast protein commonalities and differences and their possible roles in wound healing and tumourigenesis using co-culture models of cells

BACKGROUND INFORMATION

The in vitro co-culture models of communication between normal fibroblasts and epithelial cells, such as keratinocytes or squamous cell carcinoma cells of FaDu line representing wound healing or cancer development, were established by non-direct contact between the cells and utilised in this study to examine epithelia-induced changes in overall fibroblast proteome patterns.

RESULTS

We were able to select the proteins co-regulated in both models in order to evaluate possible molecular commonalities between wound healing and tumour development. Amongst the most pronounced were the proteins implemented in contractile activity and formation of actin cytoskeleton such as caldesmon, calponin-2, myosin regulatory light-chain 12A and cofilin-1, which were expressed independently of the presence of α-smooth muscle actin. Additionally, proteins altered differently highlighted functional and cellular phenotypes during transition of fibroblasts towards myofibroblasts or cancer-associated fibroblasts. Results showed coordinated regulation of cytoskeleton proteins selective for wound healing which were lost in tumourigenesis model. Vimentin bridged this group of proteins with other regulated proteins in human fibroblasts involved in protein or RNA processing and metabolic regulation.

CONCLUSIONS

The findings provide strong support for crucial role of stromal microenvironment in wound healing and tumourigenesis. In particular, epithelia-induced protein changes in fibroblasts offer new potential targets which may lead to novel tailored cancer therapeutic strategies.

CNN3 is regulated by microRNA-1 during muscle development in pigs

The calponin 3 (CNN3) gene has important functions involved in skeletal muscle development. MicroRNAs (miRNAs) play critical role in myogenesis by influencing the mRNA stability or protein translation of target gene. Based on paired microRNA and mRNA profiling in the prenatal skeletal muscle of pigs, our previous study suggested that CNN3 was differentially expressed and a potential target for miR-1. To further understand the biological function and regulation mechanism of CNN3, we performed co-expression analysis of CNN3 and miR-1 in developmental skeletal muscle tissues (16 stages) from Tongcheng (a Chinese domestic breed, obese-type) and Landrace (a Western, lean-type) pigs, respectively. Subsequently, dual luciferase and western blot assays were carried out. During skeletal muscle development, we observe a significantly negative expression correlation between the miR-1 and CNN3 at mRNA level. Our dual luciferase and western blot results suggested that the CNN3 gene was regulated by miR-1. We identified four single nucleotide polymorphisms (SNPs) contained within the CNN3 gene. Association analysis indicated that these CNN3 SNPs are significantly associated with birth weight (BW) and the 21-day weaning weight of the piglets examined. These facts indicate that CNN3 is a candidate gene associated with growth traits and regulated by miR-1 during skeletal muscle development in pigs.

Mechanism of calponin stabilization of cross-linked actin networks

The actin-binding protein calponin has been previously implicated in actin cytoskeletal regulation and is thought to act as an actin stabilizer, but the mechanism of its function is poorly understood. To investigate this underlying physical mechanism, we studied an in vitro model system of cross-linked actin using bulk rheology. Networks with basic calponin exhibited a delayed onset of strain stiffening (10.0% without calponin, 14.9% with calponin) and were able to withstand a higher maximal strain before failing (35% without calponin, 56% with calponin). Using fluorescence microscopy to study the mechanics of single actin filaments, we found that calponin increased the flexibility of actin filaments, evident as a decrease in persistence length from 17.6 μm without to 7.7 μm with calponin. Our data are consistent with current models of affine strain behavior in semiflexible polymer networks, and suggest that calponin stabilization of actin networks can be explained purely by changes in single-filament mechanics. We propose a model in which calponin stabilizes actin networks against shear through a reduction of persistence length of individual filaments.