Long Non-Coding RNA Signatures in the Ileum and Colon of Crohn's Disease Patients and Effect of Anti-TNF-α Treatment on Their Modulation.

Biological therapies only benefit one-third of patients with Crohn's disease (CD). For this reason, a deeper understanding of the mechanisms by which biologics elicit their effect on intestinal mucosa is needed. Increasing evidence points toward the involvement of long noncoding RNAs (lncRNAs) in the pathogenesis of CD, although their role remains poorly studied. We aimed to characterize lncRNA profiles in the ileum and colon from CD patients and evaluate the effect of anti-TNF-α treatment on their transcription. Terminal ileum and left colon samples from 30 patients (active CD = 10, quiescent CD = 10, and healthy controls (HCs) = 10) were collected for RNA-seq. The patients were classified according to endoscopic activity. Furthermore, biopsies were cultured with infliximab, and their transcriptome was determined by Illumina gene expression array. A total of 678 differentially expressed lncRNAs between the terminal ileum and left colon were identified in HCs, 438 in patients with quiescent CD, and 468 in patients with active CD. Additionally, we identified three new lncRNAs in the ileum associated with CD activity. No differences were observed when comparing the effect of infliximab according to intestinal location, presence of disease (CD vs. HC), and activity (active vs. quiescent). The expression profiles of lncRNAs are associated with the location of intestinal tissue, being very different in the ileum and colon. The presence of CD and disease activity are associated with the differential expression of lncRNAs. No modulatory effect of infliximab has been observed in the lncRNA transcriptome.

CCN2 Increases TGF-ß Receptor Type II Expression in Vascular Smooth Muscle Cells: Essential Role of CCN2 in the TGF-ß Pathway Regulation.

The cellular communication network factor 2 (CCN2/CTGF) has been traditionally described as a mediator of the fibrotic responses induced by other factors including the transforming growth factor ß (TGF-ß). However, several studies have defined a direct role of CCN2 acting as a growth factor inducing oxidative and proinflammatory responses. The presence of CCN2 and TGF-ß together in the cellular context has been described as a requisite to induce a persistent fibrotic response, but the precise mechanisms implicated in this relation are not described yet. Considering the main role of TGF-ß receptors (TßR) in the TGF-ß pathway activation, our aim was to investigate the effects of CCN2 in the regulation of TßRI and TßRII levels in vascular smooth muscle cells (VSMCs). While no differences were observed in TßRI levels, an increase in TßRII expression at both gene and protein level were found 48 h after stimulation with the C-terminal fragment of CCN2 (CCN2(IV)). Cell pretreatment with a TßRI inhibitor did not modify TßRII increment induced by CCN2(VI), demonstrating a TGF-ß-independent response. Secondly, CCN2(IV) rapidly activated the SMAD pathway in VSMCs, this being crucial in the upregulation of TßRII since the preincubation with an SMAD3 inhibitor prevented it. Similarly, pretreatment with the epidermal growth factor receptor (EGFR) inhibitor erlotinib abolished TßRII upregulation, indicating the participation of this receptor in the observed responses. Our findings suggest a direct role of CCN2 maintaining the TGF-ß pathway activation by increasing TßRII expression in an EGFR-SMAD dependent manner activation.

The C-terminal module IV of connective tissue growth factor, through EGFR/Nox1 signaling, activates the NF-κB pathway and proinflammatory factors in vascular smooth muscle cells.

AIMS: Connective tissue growth factor (CTGF/CCN2) is a developmental gene upregulated in pathological conditions, including cardiovascular diseases, whose product is a matricellular protein that can be degraded to biologically active fragments. Among them, the C-terminal module IV [CCN2(IV)] regulates many cellular functions, but there are no data about redox process. Therefore, we investigated whether CCN2(IV) through redox signaling regulates vascular responses. RESULTS: CCN2(IV) increased superoxide anion (O2(•-)) production in murine aorta (ex vivo and in vivo) and in cultured vascular smooth muscle cells (VSMCs). In isolated murine aorta, CCN2(IV), via O2(•-), increased phenylephrine-induced vascular contraction. CCN2(IV) in vivo regulated several redox-related processes in mice aorta, including increased nonphagocytic NAD(P)H oxidases (Nox)1 activity, protein nitrosylation, endothelial dysfunction, and activation of the nuclear factor-κB (NF-κB) pathway and its related proinflammatory factors. The role of Nox1 in CCN2(IV)-mediated vascular responses in vivo was investigated by gene silencing. The administration of a Nox1 morpholino diminished aortic O2(•-) production, endothelial dysfunction, NF-κB activation, and overexpression of proinflammatory genes in CCN2(IV)-injected mice. The link CCN2(IV)/Nox1/NF-κB/inflammation was confirmed in cultured VSMCs. Epidermal growth factor receptor (EGFR) is a known CCN2 receptor. In VSMCs, CCN2(IV) activates EGFR signaling. Moreover, EGFR kinase inhibition blocked vascular responses in CCN2(IV)-injected mice. INNOVATION AND CONCLUSION: CCN2(IV) is a novel prooxidant factor that in VSMCs induces O2(•-) production via EGFR/Nox1 activation. Our in vivo data demonstrate that CCN2(IV) through EGFR/Nox1 signaling pathway induces endothelial dysfunction and activation of the NF-κB inflammatory pathway. Therefore, CCN2(IV) could be considered a potential therapeutic target for redox-related cardiovascular diseases.