ADAM17 mediates MMP9 expression in lung epithelial cells

LncRNA NEAT1: A novel regulator associated with the inflammatory response in acute respiratory distress syndrome

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a life-threatening condition with an unfavorable prognosis. As the pathogenesis of ARDS remains unclear, we aimed to identify the core genes associated with ARDS and the mechanisms by which competing endogenous RNAs (ceRNAs) regulate the disease's progression.

METHODS

Three mRNA microarray datasets (GSE17355, GSE48787, and GSE130936), derived from the Gene Expression Omnibus (GEO) database, were selected. Common differentially expressed genes (DEGs) related to acute lung injury (ALI) were identified and subjected to enrichment analysis. Then, hub genes were figured out through the protein-protein interaction (PPI) network and functional analysis, and targeted miRNAs and lncRNAs were predicted. Finally, the ceRNA networks associated with ALI were constructed and validated experimentally.

RESULTS

A total of 155 upregulated and 93 downregulated DEGs were identified in the three datasets. The TNF signaling pathway and IL-17 signaling pathway were the most enriched pathways. Then, eleven DEGs enriched in the IL-17 signaling pathway were selected as the hub genes. Three miRNAs (mmu-mir-155-5p, mmu-mir-21a-5p, and mmu-mir-122-5p), which were located in the lung tissue and predicted to bind the hub genes at the same time, and two lncRNAs (Neat1 and Tug1), which have binding sites for the aforementioned miRNAs, were filtered. With qPCR verification, we identified a ceRNA network composed of NEAT1, miR-21-5p, MMP9, and CXCL5. NEAT1 knockdown promoted the migration and reduced the expression of pro-inflammatory factor and reactive oxygen species (ROS) in lung epithelial cells. We eventually confirmed that NEAT1/miR-21-5p/CXCL5/MMP9 played a pivotal role in regulating the inflammatory response in ALI.

CONCLUSION

The IL-17 signaling pathway is of great importance in the pathogenesis of ARDS. NEAT1/miR-21-5p is involved in the inflammation of ALI by regulating CXCL5 and MMP9.

The Biochemistry and Physiology of A Disintegrin and Metalloproteinases (ADAMs and ADAM-TSs) in Human Pathologies

Metalloproteinases are a group of proteinases that plays a substantial role in extracellular matrix remodeling and its molecular signaling. Among these metalloproteinases, ADAMs (a disintegrin and metalloproteinases) and ADAM-TSs (ADAMs with thrombospondin domains) have emerged as highly efficient contributors mediating proteolytic processing of various signaling molecules. ADAMs are transmembrane metalloenzymes that facilitate the extracellular domain shedding of membrane-anchored proteins, cytokines, growth factors, ligands, and their receptors and therefore modulate their biological functions. ADAM-TSs are secretory, and soluble extracellular proteinases that mediate the cleavage of non-fibrillar extracellular matrix proteins. ADAMs and ADAM-TSs possess pro-domain, metalloproteinase, disintegrin, and cysteine-rich domains in common, but ADAM-TSs have characteristic thrombospondin motifs instead of the transmembrane domain. Most ADAMs and ADAM-TSs are activated by cleavage of pro-domain via pro-protein convertases at their N-terminus, hence directing them to various signaling pathways. In this article, we are discussing not only the structure and regulation of ADAMs and ADAM-TSs, but also the importance of these metalloproteinases in various human pathophysiological conditions like cardiovascular diseases, colorectal cancer, autoinflammatory diseases (sepsis/rheumatoid arthritis), Alzheimer's disease, proliferative retinopathies, and infectious diseases. Therefore, based on the emerging role of ADAMs and ADAM-TSs in various human pathologies, as summarized in this review, these metalloproteases can be considered as critical therapeutic targets and diagnostic biomarkers.

Role of the LRP1-pPyk2-MMP9 pathway in hyperoxia-induced lung injury in neonatal rats

OBJECTIVES

To study the role of the low-density lipoprotein receptor-related protein 1 (LRP1)-proline-rich tyrosine kinase 2 phosphorylation (pPyk2)-matrix metalloproteinases 9 (MMP9) pathway in hyperoxia-induced lung injury in neonatal rats.

METHODS

A total of 16 neonatal rats were randomly placed in chambers containing room air (air group) or 95% medical oxygen (hyperoxia group) immediately after birth, with 8 rats in each group. All of the rats were sacrificed on day 8 of life. Hematoxylin and eosin staining was used to observe the pathological changes of lung tissue. ELISA was used to measure the levels of soluble LRP1 (sLRP1) and MMP9 in serum and bronchoalveolar lavage fluid (BALF). Western blot was used to measure the protein expression levels of LRP1, MMP9, Pyk2, and pPyk2 in lung tissue. RT-PCR was used to measure the mRNA expression levels of LRP1 and MMP9 in lung tissue.

RESULTS

The hyperoxia group had significantly higher levels of sLRP1 and MMP9 in serum and BALF than the air group (P<0.05). Compared with the air group, the hyperoxia group had significant increases in the protein expression levels of LRP1, MMP9, and pPyk2 in lung tissue (P<0.05). The hyperoxia group had significantly higher relative mRNA expression levels of LRP1 and MMP9 in lung tissue than the air group (P<0.05).

CONCLUSIONS

The activation of the LRP1-pPyk2-MMP9 pathway is enhanced in hyperoxia-induced lung injury in neonatal rats, which may be involved in the pathogenesis of bronchopulmonary dysplasia.

MiRNA-145 and Its Direct Downstream Targets in Digestive System Cancers: A Promising Therapeutic Target

MicroRNAs (miRNAs) play a vital role in the onset and development of many diseases, including cancers. Emerging evidence shows that numerous miRNAs have the potential to be used as diagnostic biomarkers for cancers, and miRNA-based therapy may be a promising therapy for the treatment of malignant neoplasm. MicroRNA-145 (miR-145) has been considered to play certain roles in various cellular processes, such as proliferation, differentiation and apoptosis, via modulating the expression of direct target genes. Recent reports show that miR-145 participates in the progression of digestive system cancers, and plays crucial and novel roles in cancer treatment. In this review, we summarize the recent knowledge concerning the function of miR-145 and its direct targets in digestive system cancers. We discuss the potential role of miR-145 as a valuable biomarker for digestive system cancers and how miR-145 regulates these digestive system cancers via different targets to explore the potential strategy of targeting miR-145.

ADAM17 and NF-κB p65 form a positive feedback loop that facilitates human esophageal squamous cell carcinoma cell viability

A Disintegrin and metalloproteinase 17 (ADAM17) was proposed to cooperate with NF-κB p65, promoting tumorigenesis and progression of several human cancers. However, the role of ADAM17 remains unknown in human esophageal squamous cell carcinoma (ESCC). In this study, gene expression analyses and cell viability assays suggested that knockdown of ADAM17 suppressed ESCC cell viability. Gene expression analyses and ChIP-qPCR revealed that NF-κB p65 positively regulated ADAM17 expression by binding to the ADAM17 promoter. Rescue experiments showed that overexpression of ADAM17 in NF-κB p65-depleted ESCC cells restored cell viability. In addition, western blot analyses and ChIP-qPCR indicated that ADAM17 was responsible for the persistent activation of NF-κB p65 and contributed to ADAM17 expression in ESCC cells. In conclusion, we propose that ADAM17-activated NF-κB p65 signaling positively regulates ADAM17 expression, and facilitates ESCC cell viability.

Comparative Analysis of Cytokine Expression in Oral Keratinocytes and THP-1 Macrophages in Response to the Most Prevalent Serotypes of Aggregatibacter actinomycetemcomitans

BACKGROUND

Periodontitis is a chronic inflammatory disease associated with a dysbiotic biofilm. Many pathogens have been related with its progression and severity, one of which is Aggregatibacter actinomycetemcomitans, a Gram-negative bacteria with seven serotypes (a-g) according with the structure of its LPS, with serotype b defined as the most virulent compared with the other serotypes. The aim of this study was to evaluate the response of oral keratinocytes and macrophages to A. actinomycetemcomitans.

METHODS

Oral keratinocytes (OKF6/TERT2) and macrophages (THP-1) were infected with A. actinomycetemcomitans serotypes a, b and c. The expression of IL-1β, IL-6, IL-8, IL-18, TNF-α, MMP-9, RANKL, TLR-2, TLR-4, TLR-6, thymic stromal lymphopoietin (TSLP), and ICAM-1 was evaluated by qPCR at 2 and 24 h after infection.

RESULTS

An increase in the expression of these molecules was induced by all serotypes at both times of infection, with macrophages showing higher levels of expression at 24 h compared to epithelial cells in which the highest levels were observed in the first hours after infection.

CONCLUSIONS

Keratinocytes and macrophages contribute to the inflammation in periodontitis from the early stages of infection, producing the first waves of cytokines, acting as the first signal for professional immune cell recruitment and modulation of more specific immune responses.

Long noncoding RNA SBF2-AS1 contributes to the growth and metastatic phenotypes of NSCLC via regulating miR-338-3p/ADAM17 axis

Non-small cell lung cancer (NSCLC) is a type of refractory malignant lung cancer with a high rate of metastasis and mortality. Currently, long non-coding RNA (lncRNA) SBF2 Antisense RNA 1 (SBF2-AS1) is considered as a biomarker for a variety of tumors. However, the function of SBF2-AS1 in the growth and metastasis of NSCLC needs to be further studied. In this study, we revealed that SBF2-AS1 was overexpressed in NSCLC tissues compared with that in normal tissues. SBF2-AS1 silencing restrained the growth and aggressive phenotypes of NSCLC cell in vitro. Consistently, SBF2-AS1 knockdown hindered the growth of NSCLC cell in nude mice. The following luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay suggested the relationship between miR-338-3p and SBF2-AS1. The rescue experiments showed that miR-338-3p inhibitor abolished SBF2-AS1 silencing caused inhibition on the growth, migration and invasiveness of NSCLC cell. The luciferase reporter assay and immunoblotting assay validated that A Disintegrin and Metalloprotease 17 (ADAM17) was a target of miR-338-3p. In addition, SBF2-AS1 positively regulated the level of ADAM17 through sponging for miR-338-3p. Finally, we revealed that SBF2-AS1 contributed to the proliferation and metastatic phenotypes of NSCLC cell via regulating miR-338-3p/ADAM17 axis.

Effects of rosuvastatin in combination with nimodipine in patients with mild cognitive impairment caused by cerebral small vessel disease

BACKGROUND

To investigate the clinical efficiency and safeness of the combination of rosuvastatin and nimodipine in treating mild cognitive impairment of cerebral small vessel disease (CSVD) patients.

METHODS

A total of 120 patients with mild cognitive impairment caused by CSVD were divided randomly into two groups: an observation group and a control group, each of which had 60 patients. In the observation group, patients were given rosuvastatin in combination with nimodipine, and other patients were given nimodipine in the control group. For the two groups, the course of treatment was six months. Before and after treatments, levels of total cholesterol (TC), triacylglycerol (TG), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), MMP-9 and high sensitivity C reactive protein (hs-CRP) were measured. Montreal Cognitive Assessment (MoCA) and activities of daily living (ADL) were also evaluated. Incidence of adverse reactions were compared between two groups.

RESULTS

The levels of TG, TC and LDL-C were decreased after treatment in the observation group (P<0.01), and these after-treatment levels were lower than the control group. Additionally, after treatment, the levels of MMP-9 and hs-CRP were significant lower in the observation group than the control group. The MoCA and ADL scores were higher in the observation group than the control group after treatment (P<0.05). Moreover, the overall effective rate were higher in the observation group (91.7%) than the control group (65.0%) (P<0.01), while there was no significant difference of the rate of adverse reactions between the observation group and the control one (10.0% vs. 8.3%) (P>0.05).

CONCLUSIONS

The combination of rosuvastatin and nimodipine was safe and effective in treating mild cognitive impairment of CSVD patients.

Anti-oxidative Fraction of Lycorma delicatula Alleviates Inflammatory Indicators

Lycorma delicatula is a reluctant pest capable of living in the stems of several tree species. The population has recently expanded in Korea due to several environmental factors including climate change. However, the precise reasons for this rapid and drastic increase in population size remain unknown. In order to examine the potential utility of this surplus biomass of Lycorma delicatula, we prepared an aqueous fraction from a dried imago, and tested its various anti-inflammatory activities and effects on cytokine levels in lipopolysaccharide (LPS)-activated RAW264.7 cells. The aqueous extract of Lycorma delicatula showed potent inhibitory activity on nitric oxide production, by more than 60% at a concentration of 300 μg/mL. We also evaluated interleukin (IL)-13 level using enzyme-linked immunosorbent assays (ELISAs). The anti-oxidative fraction of Lycorma delicatula inhibited LPS-induced IL-13 production in a dose-dependent manner, and T-bet promoter activity of cells treated with 300 μg/mL of Lycorma delicatula extract was also dramatically inhibited to 62% of that of LPS-treated cells. Furthermore, we compared matrix metalloproteinase-7 (MMP-7), -9, -14 and -17 expressions using reverse transcription-polymerase chain reaction (RT-PCR), which showed a drastic decrease in RNA levels in cells treated with the anti-oxidative fraction. Together, the present results suggest that the aqueous fraction of Lycorma delicatula has potential to ameliorate inflammatory characteristics during an inflammation event, supporting the idea that the fraction may be applied as a biomaterial to prevent inflammatory damage in skin tissues.

Lentivirus-mediated disintegrin and metalloproteinase 17 RNA interference reversed the acquired resistance to gefitinib in lung adenocarcinoma cells in vitro

Objective: The aim of the study is to evaluate the effects of silencing a disintegrin and metalloproteinase 17 (ADAM17) gene expression by lentivirus‐mediated RNA interference (RNAi) in the gefitinib‐resistant lung adenocarcinoma cells, and then to explore whether the recombinant lentivirus mediated ADAM17 RNAi reversed the acquired resistance of lung adenocarcinoma to gefitinib in vitro.

Methods: The gefitinib‐resistant RPC‐9 cells were established and the mutations of EGFR were detected by gene sequencing. The ADAM17 shRNA expression vectors were constructed and packaged to recombinant lentivirus. The cell proliferation viability was detected by MTT, and cellular apotosis was analyzed by flow cytometry assay. The expression levels of ADAM17, EGFR and the phosphorylated EGFR were respectively detected by reverse transcription polymerase chain reaction and western blot. TGF‐α production in the supernatant was detected by enzyme‐linked immunosorbent assay.

Results: The gefitinib‐resistant RPC‐9 cells in which mutated EGFR (exon 20) carried 790T > T/M mutation were established. When the concentrations of gefitinib were less than 10μmol/L, there were no significant changes in the apoptosis and cellular proliferation of RPC‐9 with the dose‐escalation of gefitinib. The cell proliferation viability of RPC‐9 was significantly decreased by lentivirus mediated ADAM17 RNAi (P < 0.05). Gefitinib did not inhibit ADAM17 expression in both the gefitinib‐sensitive PC‐9 and gefitinib‐resistant RPC‐9 cells (P > 0.05). Gefitinib had no significant effects on TGF alpha production in the supernatants (P > 0.05). Gefitinib did not inhibit EGFR expression in gefitinib‐sensitive PC‐9 and gefitinib‐resistant RPC‐9 cells (P > 0.05). The phosphorylation of EGFR in gefitinib‐sensitive PC‐9 cells was significantly inhibited by gefitinib (P < 0.05), but that in gefitinib‐resistant RPC‐9 could not be inhibited by gefitinib (P > 0.05). Lentivirus mediated ADAM17 RNAi significantly inhibited the mRNA and protein expression of ADAM17 in gefitinib‐resistant RPC‐9 cells (P < 0.05), as well as TGF alpha production in the supernatants (P < 0.05). Also, the phosphorylation of EGFR was significantly reduced in gefitinib‐resistant RPC‐9 cells by lentivirus mediated ADAM17 RNAi (P < 0.05); however, the mRNA and protein expression of EGFR could not be inhibited.

Conclusion: Lentivirus mediated ADAM17 RNAi may reverse the acquired resistance of lung adenocarcinoma to gefitinib via inhibiting the upstream of EGFR signal pathway, which may provide a new therapeutic target to solve the acquired resistance to EGFR tyrosine kinase inhibitors in lung adenocarcinoma. © 2017 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers Biotechnol. Prog., 34:196–205, 2018

TLR4-mediated galectin-1 production triggers epithelial-mesenchymal transition in colon cancer cells through ADAM10- and ADAM17-associated lactate production

Toll-like receptor 4 (TLR4) activation is a key contributor to the carcinogenesis of colon cancer. Overexpression of galectin-1 (Gal-1) also correlates with increased invasive activity of colorectal cancer. Lactate production is a critical predictive factor of risk of metastasis, but the functional relationship between intracellular lactate and Gal-1 expression in TLR4-activated colon cancer remains unknown. In this study, we investigated the underlying mechanism and role of Gal-1 in metastasis and invasion of colorectal cancer (CRC) cells after TLR4 stimulation. Exposure to the TLR4 ligand lipopolysaccharide (LPS) increased expression of Gal-1, induced EMT-related cytokines, triggered the activation of glycolysis-related enzymes, and promoted lactate production. Gene silencing of TLR4 and Gal-1 in CRC cells inhibited lactate-mediated epithelial-mesenchymal transition (EMT) after TLR4 stimulation. Gal-1-mediated activation of a disintegrin and metalloproteinase 10 (ADAM10) and ADAM 17 increased the invasion activity and expression of mesenchymal characteristics in LPS-activated CRC cells. Conversely, inhibition of ADAM10 or ADAM17 effectively blocked the generation of lactate and the migration capacity of LPS-treated CRC cells. Thus, the TLR4/Gal-1 signaling pathway regulates lactate-mediated EMT processes through the activation of ADAM10 and ADAM17 in CRC cells.

ADAMs family and relatives in cardiovascular physiology and pathology

A disintegrin and metalloproteinases (ADAMs) are a family of membrane-bound proteases. ADAM-TSs (ADAMs with thrombospondin domains) are a close relative of ADAMs that are present in soluble form in the extracellular space. Dysregulated production or function of these enzymes has been associated with pathologies such as cancer, asthma, Alzheimer's and cardiovascular diseases. ADAMs contribute to angiogenesis, hypertrophy and apoptosis in a stimulus- and cell type-dependent manner. Among the ADAMs identified so far (34 in mouse, 21 in human), ADAMs 8, 9, 10, 12, 17 and 19 have been shown to be involved in cardiovascular development or cardiomyopathies; and among the 19 ADAM-TSs, ADAM-TS1, 5, 7 and 9 are important in development of the cardiovascular system, while ADAM-TS13 can contribute to vascular disorders. Meanwhile, there remain a number of ADAMs and ADAM-TSs whose function in the cardiovascular system has not been yet explored. The current knowledge about the role of ADAMs and ADAM-TSs in the cardiovascular pathologies is still quite limited. The most detailed studies have been performed in other cell types (e.g. cancer cells) and organs (nervous system) which can provide valuable insight into the potential functions of ADAMs and ADAM-TSs, their mechanism of action and therapeutic potentials in cardiomyopathies. Here, we review what is currently known about the structure and function of ADAMs and ADAM-TSs, and their roles in development, physiology and pathology of the cardiovascular system.

Recombinant rat CC16 protein inhibits LPS-induced MMP-9 expression via NF-κB pathway in rat tracheal epithelial cells

Clara cell protein (CC16) is a well-known anti-inflammatory protein secreted by the epithelial Clara cells of the airways. It is involved in the development of airway inflammatory diseases such as chronic obstructive pulmonary disease and asthma. Previous studies suggest that CC16 gene transfer suppresses expression of interleukin (IL)-8 in bronchial epithelial cells. However, its role in the function of these cells during inflammation is not well understood. In this study, we evaluated the effect of CC16 on the expression of matrix metalloproteinase (MMP)-9 in lipopolysaccharide (LPS)-stimulated rat tracheal epithelial cells and its underlying molecular mechanisms. We generated recombinant rat CC16 protein (rCC16) which was bioactive in inhibiting the activity of phospholipase A2. rCC16 inhibited LPS-induced MMP-9 expression at both mRNA and protein levels in a concentration-dependent (0-2 µg/mL) manner, as demonstrated by real time RT-PCR, ELISA, and zymography assays. Gene transcription and DNA binding studies demonstrated that rCC16 suppressed LPS-induced NF-κB activation and its binding of gene promoters as identified by luciferase reporter and gel mobility shift assays, respectively. Western blotting and immunofluorescence staining analyses further revealed that rCC16 concentration dependently inhibited the effects of LPS on nuclear increase and cytosol reduction of NF-κB, on the phosphorylation and reduction of NF-κB inhibitory IκBα, and on p38 MAPK-dependent NF-κB activation by phosphorylation at Ser276 of its p65 subunit. These data indicate that inhibition of LPS-mediated NF-κB activation by rCC16 involves both translocation- and phosphorylation-dependent signaling pathways. When the tracheal epithelial cells were pretreated with chlorpromazine, an inhibitor of clathrin-mediated endocytosis, cellular uptake of rCC16 and its inhibition of LPS-induced NF-κB nuclear translocation and also MMP-9 production were significantly abolished. Taken together, our data suggest that clathrin-mediated uptake of rCC16 suppresses LPS-mediated inflammatory MMP-9 production through inactivation of NF-κB and p38 MAPK pathways in tracheal epithelial cells.

Therapeutic effects of amniotic fluid-derived mesenchymal stromal cells on lung injury in rats with emphysema

Background

In chronic obstructive pulmonary disease (COPD), two major pathological changes that occur are the loss of alveolar structure and airspace enlargement. To treat COPD, it is crucial to repair damaged lung tissue and regenerate the lost alveoli. Type II alveolar epithelial cells (AECII) play a vital role in maintaining lung tissue repair, and amniotic fluid-derived mesenchymal stromal cells (AFMSCs) possess the characteristics of regular mesenchymal stromal cells. However, it remains untested whether transplantation of rat AFMSCs (rAFMSCs) might alleviate lung injury caused by emphysema by increasing the expression of surfactant protein (SP)A and SPC and inhibiting AECII apoptosis.

Methods

We analyzed the phenotypic characteristics, differentiation potential, and karyotype of rAFMSCs, which were isolated from pregnant Sprague–Dawley rats. Moreover, we examined the lung morphology and the expression levels of SPA and SPC in rats with emphysema after cigarette-smoke exposure and intratracheal lipopolysaccharide instillation and rAFMSC transplantation. The ability of rAFMSCs to differentiate was measured, and the apoptosis of AECII was evaluated.

Results

In rAFMSCs, the surface antigens CD29, CD44, CD73, CD90, CD105, and CD166 were expressed, but CD14, CD19, CD34, and CD45 were not detected; rAFMSCs also strongly expressed the mRNA of octamer-binding transcription factor 4, and the cells could be induced to differentiate into adipocytes and osteocytes. Furthermore, rAFMSC treatment up-regulated the levels of SPA, SPC, and thyroid transcription factor 1 and inhibited AECII apoptosis, and rAFMSCs appeared to be capable of differentiating into AECII-like cells. Lung injury caused by emphysema was alleviated after rAFMSC treatment.

Conclusions

rAFMSCs might differentiate into AECII-like cells or induce local regeneration of the lung alveolar epithelium in vivo after transplantation and thus could be used in COPD treatment and lung regenerative therapy.

MicroRNA-145 inhibits cell proliferation by directly targeting ADAM17 in hepatocellular carcinoma

MicroRNAs (miRNAs) are key regulators in cell processes. Emerging evidence has suggested that there is a direct association between miRNAs and cancer. However, the exact regulatory mechanisms of miRNAs in tumorigenesis are poorly understood. In the present study, we showed that miR-145 is able to significantly reduce mRNA and protein expression levels of A disintegrin and metalloproteinase 17 (ADAM17) in liver cancer cells (SMMC-7721, BEL-7402 and Huh-7). Dual luciferase reporter assays confirmed that ADAM17 is a direct target of miR-145. Notably, we found that miR-145 inhibits cell proliferation and growth activity in SMMC-7721 cells. These results demonstrated that it may be exert the function of tumor suppression in a particular link of cancer cell growth. Further studies revealed that the silencing of ADAM17 decreased the proliferation and growth activity of SMMC-7721 cells. Moreover, it reduced the expression of MMP-9. In conclusion, miR-145 inhibits liver cancer cell proliferation by directly targeting ADAM17. Thus, it may become a promising biological target in the treatment strategy of hepatocellular carcinoma.

A disintegrin and metalloprotease (ADAM)10 is highly expressed in hepatocellular carcinoma and is associated with tumour progression

OBJECTIVE

A disintegrin and metalloprotease (ADAM)10 has been implicated in the progression of various solid tumours. Little is known, however, about its role in hepatocellular carcinoma (HCC). The aim of the present study was to evaluate the protein and transcript level expression of ADAM10 in HCC patients.

METHODS

Samples of HCC and adjacent noncancerous liver tissue were taken during liver resection surgery. Immunostaining was used to measure ADAM10 protein expression levels and quantitative reverse- transcription polymerase chain reaction was used to measure ADAM10 mRNA expression levels. Levels of ADAM10 were compared, and a survival analysis undertaken.

RESULTS

In total, 98 HCC patient samples were studied. There were significant associations between protein levels of ADAM10 and tumour grade, amount of tumour differentiation, tumour size and the presence of metastasis. Furthermore, ADAM10 protein expression was significantly associated with shortened patient survival.

CONCLUSIONS

ADAM10 is strongly expressed in a large proportion of HCC cases, which is in agreement with findings in other tumour entities. Expression of ADAM10 may serve as a useful molecular marker for HCC.

Rnh1 promotes differentiation and myelination via RhoA in oligodendrocytes

Increases in Rattus norvegicus ribonuclease/angiogenin inhibitor 1 (Rnh1) are observed in rat primary neuron injury and/or the regeneration process and in differentiated oligodendrocytes. However, the roles of Rnh1 in the central nervous system are still largely unexplored. RhoA is an important signaling protein that has been implicated in oligodendrocyte differentiation and myelination. We demonstrate enhanced differentiation and myelination of oligodendrocytes mediated by Rnh1 in vitro. We further show that Rnh1 is expressed in oligodendrocyte precursors and oligodendrocytes. Importantly, Rnh1 strongly affects oligodendrocyte differentiation through RhoA-ROCK signaling. Moreover, changes in Rnh1 expression in oligodendrocytes regulates the expression and phosphorylation of Fyn, a regulator of RhoA activity. Finally, Rnh1 promotes myelination in vitro. These results show that Rnh1-mediated RhoA inactivation enhances the differentiation and myelination in oligodendrocytes. Overall, Rnh1 might contribute to oligodendrocyte differentiation and myelination processes in vitro.