Versican 3′-untranslated region (3′UTR) promotes dermal wound repair and fibroblast migration by regulating miRNA activity

Comparison Study on the Effect of Mesenchymal Stem Cells-Conditioned Medium Derived from Adipose and Wharton’s Jelly on Versican Gene Expression in Hypoxia

Background:

Mesenchymal stem cells enhance tissue repair through paracrine effects following transplantation. The versican protein is one of the important factors contributing to this repair mechanism. Using MSC conditioned medium for cultivating monocytes may increase versican protein production and could be a good alternative for transplantation of MSCs. This study investigates the effect of culture medium conditioned by human MSCs on the expression of the versican gene in PBMCs under hypoxia-mimetic and normoxic conditions.

Methods:

The conditioned media used were derived from either adipose tissue or from WJ. Flow cytometry for surface markers (CD105, CD73, and CD90) was used to confirm MSCs. The PBMCs were isolated and cultured with the culture media of the MSC derived from either the adipose tissue or WJ. Desferrioxamine and cobalt chloride (200 and 300 µM final concentrations, respectively) were added to monocytes media to induce hypoxia-mimetic conditions. Western blotting was applied to detect HIF-1α protein and confirm hypoxia-mimetic conditions in PBMC. Versican gene expression was assessed in PBMC using RT-PCR. Western blotting showed that the expression of HIF-1α in PBMC increased significantly (p < 0.01).

Results:

RT-PCR results demonstrated that the expression of the versican and VEGF genes in PBMC increased significantly (p < 0.01) in hypoxia-mimetic conditions as compared to normoxia.

Conclusion:

Based on the findings in the present study, the secreted factors of MSCs can be replaced by direct use of MSCs to improve damaged tissues.

Inhibition of miR-144/199 promote myeloma pathogenesis via upregulation of versican and FAK/STAT3 signaling

The continuous rise in relapse rate and mortality for multiple myeloma (MM) demands an effective treatment option. The microRNAs are emerging nowadays for their promising therapeutic potential. Earlier, we reported involvement of Versican (VCAN) in myeloma pathogenesis which could be inhibited by miR-144 and miR-199 in stroma. However, there is dearth of literature showcasing the direct effect of these miRs in association with VCAN in MM. Expression of miR-144 and miR-199 was determined in myeloma cell lines (RPMI8226 & U266). These miRs were inhibited by small oligos to elucidate changes in expression of VCAN along with variation in parameters such as proliferation, apoptosis, migration and invasion in vitro. Moreover, effect on certain downstream signaling cascades was also evaluated. Lastly, interaction of miRs with VCAN was assessed by reporter luciferase assay. microRNAs expression were found significantly elevated in myeloma cells in comparison to stromal levels reported previously. The antagomirs-mediated inhibition of miR-144 and miR-199 significantly induced VCAN expression in myeloma cells along with alteration in myeloma-associated parameters in favor of myeloma pathogenesis with downstream activation of FAK/STAT3 signaling. Interestingly, miR-144 found to have direct binding with VCAN 3' UTR while miR-199 possess different mechanism. The inhibition of miR-144 and miR-199 contributed in myeloma progression via upregulation of VCAN in vitro affirming the translational significance of VCAN and associated microRNAs in MM. These miRs, hence might be employed for targeting VCAN and might emerge as an effective therapy for the better outcome of MM in clinical settings in future.

MicroRNA-185 inhibits the proliferation and migration of HaCaT keratinocytes by targeting peroxisome proliferator-activated receptor β

Proliferation and migration of keratinocytes are major processes of skin wound repair after injury. It has been indicated that microRNAs (miRNAs/miRs) are associated with the proliferation and migration of keratinocytes. However, the mechanism by which miR-185 affects these processes in keratinocytes remains unclear. In the present study, the expression level of miR-185 and peroxisome proliferator-activated receptor β (PPARβ) was examined by reverse transcription-quantitative PCR in HaCaT keratinocytes. Cell proliferation was evaluated using Cell Counting Kit-8 and colony formation assays. Western blot analysis was used to detect the levels of cell proliferation, migration and PI3K/AKT signaling pathway-associated proteins. In addition, the migratory capacity of the cells was determined using Transwell assay. The target gene of miR-185 was verified using dual-luciferase reporter assay. The results indicated that overexpression of miR-185 inhibited proliferation, migration and activation of the PI3K/AKT signaling pathway in HaCaT keratinocytes. PPARβ was indicated to be a target of miR-185 and its overexpression promoted the proliferation and migration of HaCaT keratinocytes, while its knockdown exhibited the adverse effects. Furthermore, PI3K inhibitor LY294002 inhibited activation of the PI3K/AKT signaling pathway and decreased the proliferation and migration of HaCaT keratinocytes. In addition, overexpressed PPARβ reversed the suppressive effects of miR-185 overexpression on proliferation, migration and activation of the PI3K/AKT signaling pathway. In conclusion, the results of the present study demonstrated that miR-185 suppressed activation of the PI3K/AKT signaling pathway via targeting PPARβ, thereby regulating proliferation and migration in HaCaT keratinocytes. The present study provided a novel theoretical basis for the use of miR-185 as a target in wound repair.

Interplay between C-type lectin receptors and microRNAs in cellular homeostasis and immune response

C-type lectin receptors (CLRs) belong to the family of pattern recognition receptors (PRRs). They have a critical role to play in the regulation of a range of physiological functions including development, respiration, angiogenesis, inflammation, and immunity. CLRs can recognize distinct and conserved exogenous pathogen-associated as well as endogenous damage-associated molecular patterns. These interactions set off downstream signaling cascades, leading to the production of inflammatory mediators, activation of effector immune cells as well as regulation of the developmental and physiological homeostasis. CLR signaling must be tightly controlled to circumvent the excessive inflammatory burden and to maintain the cellular homeostasis. Recently, MicroRNAs (miRNAs) have been shown to be important regulators of expression of CLRs and their downstream signaling. The delicate balance between miRNAs and CLRs seems crucial in almost all aspects of multicellular life. Any dysregulations in the miRNA-CLR axes may lead to tumorigenesis or inflammatory diseases. Here, we present an overview of the current understanding of the central role of miRNAs in the regulation of CLR expression, profoundly impacting upon homeostasis and immunity, and thus, development of therapeutics against immune disorders.

Accumulation of versican facilitates wound healing: Implication of its initial ADAMTS-cleavage site

Versican is a large chondroitin sulfate/dermatan sulfate proteoglycan in the extracellular matrix, and is expressed at high levels in tissues during development and remodeling in pathological conditions. Its core protein is cleaved at a region close to the N-terminal end of CSβ domain by several members of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) family, i.e., ADAMTS-1, 4, 5, 9, 15, and 20. Here, using a CRISPR/Cas9 system, we generated knock-in mice (V1R), which express an ADAMTS cleavage-resistant versican. Some V1R homozygote mice, termed R/R, exhibit syndactyly and organ hemorrhage. In wound healing experiments, R/R wound shows accumulation of versican and activated TGFβ-signaling in the early stage, leading to faster healing than wild type wound. Immunostaining for Ki67, CD31, smooth muscle α-actin, periostin demonstrates higher levels of overall cell proliferation and an increased number of endothelial cells and myofibroblasts. Immunostaining for CD11b and qRT-PCR for macrophage markers revealed increased levels of inflammatory cell infiltration, especially those of M1 macrophages. Cultured R/R dermal fibroblasts revealed increased deposition of versican, type I and III collagens, and hyaluronan, and upregulation of Smad2/3 signaling. Taken together, these results demonstrate that the cleavage site determines versican turnover and that versican plays a central role in the provisional matrix during the wound repair.

Targeting of stromal versican by miR-144/199 inhibits multiple myeloma by downregulating FAK/STAT3 signalling

The abnormal growth of malignant plasma cells in Multiple Myeloma (MM) requires bone marrow (BM) niche consisting of proteoglycans, cytokines, etc. Versican (VCAN), a chondroitin sulphate proteoglycan promotes progression in solid tumours but there is dearth of literature in MM. Hence, we studied the involvement of VCAN in MM and its regulation by microRNAs as a therapeutic approach. Thirty MM patients and 20 controls were recruited and BM stromal cells (BMSCs) were isolated by primary culture. Molecular levels of VCAN, miR-144, miR-199 & miR-203 were determined in study subjects and cell lines. The involvement of VCAN in myeloma pathogenesis was studied using BMSCs-conditioned medium (BMSCs-CM) and VCAN-neutralizing antibody or microRNA mimics. Elevated expression of VCAN was observed in patients especially in BM stroma while microRNA expression was significantly lower and showed negative correlation with VCAN. Moreover, BMSCs-CM showed the presence of VCAN which upon supplementing to MM cells alter parameters in favour of myeloma progression, however, this effect was neutralized by VCAN antibody or miR (miR-144 and miR-199) mimics. The downstream signalling of VCAN was found to activate FAK and STAT3 which subsides by using VCAN antibody or miR mimics. The neutralization of oncogenic effect of BMSCs-CM by VCAN blockage affirms its plausible role in progression of MM. VCAN was observed as a paracrine mediator in the cross-talk of BMSCs and myeloma cells in BM microenvironment. Therefore, these findings suggest exploring VCAN as novel therapeutic target and utilization of microRNAs as a therapy to regulate VCAN for better management of MM.

Versican is crucial for the initiation of cardiovascular lumen development in medaka (Oryzias latipes)

Versican is an evolutionary conserved extracellular matrix proteoglycan, and versican expression loss in mice results in embryonic lethality owing to cardiovascular defects. However, the in utero development of mammals limits our understanding of the precise role of versican during cardiovascular development. Therefore, the use of evolutionarily distant species that develop ex utero is more suitable for studying the mechanistic basis of versican activity. We performed ENU mutagenesis screening to identify medaka mutants with defects in embryonic cardiovascular development. In this study, we described a recessive point mutation in the versican 3'UTR resulting in reduced versican protein expression. The fully penetrant homozygous mutant showed termination of cardiac development at the linear heart tube stage and exhibited absence of cardiac looping, a constricted outflow tract, and no cardiac jelly. Additionally, progenitor cells did not migrate from the secondary source towards the arterial pole of the linear heart tube, resulting in a constricted outflow tract. Furthermore, mutants lacked blood flow and vascular lumen despite continuous peristaltic heartbeats. These results enhance our understanding of the mechanistic basis of versican in cardiac development, and this mutant represents a novel genetic model to investigate the mechanisms of vascular tubulogenesis.

Effect of Preparation Method on the Protein Profile of Equine Amnion Dressings

The protein content of amnion is thought to be the primary contributor to its efficacy as a biological dressing for wounds. Protein elution into antibiotic processing media has been reported, but the effect of antiseptic-based processing methods is unknown. Amniotic membranes were collected from eight healthy mares. Samples were collected after removal of gross debris. Tissues were subsequently divided and processed with either 0.05% chlorhexidine or 2% iodine/0.25% acetic acid. After protein extraction and trypsin digestion, the proteins were labeled with 8-plex iTRAQ tags, combined, and analyzed by high-resolution liquid chromatography-mass spectrometry. The MaxQuant-Perseus software suite was used to identify and quantify sample proteins, with functional annotation performed in PANTHER. There were 220 unique proteins identified, of which 144 were found in all individuals and across all conditions, several with a known role in wound healing. Contrary to expectations, processing did not significantly alter the protein content of the amnion tissue. Limitations include the small sample size and single time point. These results suggest that either processing method is acceptable for use in the preparation of equine amnion dressings. The role of expressed proteins in the biological activity of amnion dressings remains to be elucidated.

MiR-889 promotes cell growth in human non-small cell lung cancer by regulating KLF9

Currently, non-small cell lung cancer (NSCLC) is still the most common malignancy worldwide. Although miR-889 has been reported to play an important role in various malignancies, the physiological function of miR-889 in NSCLC remains unknown. This paper places emphasis on the influence of miR-889 on the development and progression of non-small cell lung cancer. To detect the expression level of miR-889 in NSCLC tissues and cell lines, quantitative real-time polymerase chain reaction (qRT-PCR) assay and In Situ Hybridization (ISH) were adopted in this study. Cell proliferation and colony forming ability were examined by Cell Counting Kit-8 (CCK-8) and colony formation assays. Furthermore, transwell experiments were conducted to determine the influence of miR-889 on migration. KLF9 expression was evaluated by qRT-PCR and Western blotting. First, miR-889 expression was increased in the cancer tissues of non-small cell lung cancer patients (n = 40) compared with adjacent tissues. Subsequently, knockdown of miR-889 significantly inhibited cell proliferation and migration, while overexpression of miR-889 had the opposite effect. KLF9 may be a potential target of miR-889. In addition, upregulation of miR-889 promotes tumorigenesis in vitro, and KLF9 protein levels are also reduced. The current study suggests that miR-889 may play a potential therapeutic role for NSCLC by targeting KLF9 to control NSCLC proliferation and migration.

Insights into the key roles of epigenetics in matrix macromolecules-associated wound healing

Extracellular matrix (ECM) is a dynamic network of macromolecules, playing a regulatory role in cell functions, tissue regeneration and remodeling. Wound healing is a tissue repair process necessary for the maintenance of the functionality of tissues and organs. This highly orchestrated process is divided into four temporally overlapping phases, including hemostasis, inflammation, proliferation and tissue remodeling. The dynamic interplay between ECM and resident cells exerts its critical role in many aspects of wound healing, including cell proliferation, migration, differentiation, survival, matrix degradation and biosynthesis. Several epigenetic regulatory factors, such as the endogenous non-coding microRNAs (miRNAs), are the drivers of the wound healing response. microRNAs have pivotal roles in regulating ECM composition during wound healing and dermal regeneration. Their expression is associated with the distinct phases of wound healing and they serve as target biomarkers and targets for systematic regulation of wound repair. In this article we critically present the importance of epigenetics with particular emphasis on miRNAs regulating ECM components (i.e. glycoproteins, proteoglycans and matrix proteases) that are key players in wound healing. The clinical relevance of miRNA targeting as well as the delivery strategies designed for clinical applications are also presented and discussed.

Role of MicroRNA in Proliferation Phase of Wound Healing

Wound healing is a complex biological process that is generally composed of four phases: hemostasis, inflammation, proliferation, and remodeling. The proliferation phase is crucial for effective healing compared to other phases. Many critical events occur during this phase, i.e., migration of fibroblasts, re-epithelialization, angiogenesis and wound contraction. Chronic wounds are common and are considered a major public health problem. Therefore, there is the increasing need to discover new therapeutic strategies. MicroRNA (miRNA) research in the field of wound healing is in its early phase, but the knowledge of the recent discoveries is essential for developing effective therapies for the treatment of chronic wounds. In this review, we focused on recently discovered miRNAs which are involved in the proliferation phase of wound healing in the past few years and their role in wound healing.

microRNA inhibitors: Natural and artificial sequestration of microRNA

MicroRNA (miRNAs) is post-transcriptional regulator of mRNA. However, the prevalence and activity of miRNA are regulated by other regulators. miRNA inhibitors are natural or artificial RNA transcripts that sequestrate miRNAs and decrease or even eliminate miRNA activity. Competing endogenous RNAs (ceRNAs) are natural and intracellular miRNA inhibitors that compete to bind to shared miRNA recognition elements (MREs) to decrease microRNA availability and relieve the repression of target RNAs. In recent years, studies have revealed that ceRNA crosstalk is involved in many pathophysiological processes and adds a new dimension to miRNA regulation. Artificial miRNA inhibitors are RNA transcripts that are synthesized via chemical and genetic methods. Artificial miRNA inhibitors can be used in miRNA loss-of-function research and gene therapies for certain diseases. In this review, we summarize the recent advances in the two different types of miRNA inhibitors.

MicroRNA‑185 regulates transforming growth factor‑β1 and collagen‑1 in hypertrophic scar fibroblasts

Transforming growth factor-β1 (TGF-β1) and collagen type I (Col-1) serve a critical role in the development and progression of hypertrophic scarring (HS). The present study hypothesized that a post‑translational mechanism of microRNAs (miR) regulated the expression of TGF‑β1 and Col‑1 in HS fibroblasts (HSFBs). A collection of 20 HS tissues was compared with corresponding normal tissues from clinical patients, and the expression of miR‑185 was measured. Using PicTar, TargetScan and miRBase databases, it was identified that miR‑185 may be a regulator of TGF‑β1 and Col‑1 in humans. Based on these hypotheses, the expression of miR‑185, TGF‑β1 and Col‑1 in HS tissues was investigated. The results demonstrated that the expression of miR‑185 was markedly suppressed, and TGF‑β1 and Col‑1 levels were increased, in HS tissues. The expression levels of endogenous miR‑185 negatively correlated with the TGF‑β1 and Col‑1 mRNA levels (Pearson's correlation coefficient r=‑0.674, P<0.01 and r=‑0.590, P<0.01, respectively). In vitro, miR‑185 can regulate TGF‑β1 and Col‑1 through the predicted binding sites in its 3'‑untranslated region. miR‑185 had an effect on cell proliferation and apoptosis, thereby regulating HSFBs growth. In addition, miR‑185 gain‑of‑function decreased TGF‑β1 and Col‑1 protein expression, and miR‑185 loss‑of‑function increased TGF‑β1 and Col‑1 protein expression in HSFBs. In conclusion, overexpressed miR‑185 could inhibit HSFBs growth, and the underlying mechanism was mediated, at least partly, through the suppression of TGF‑β1 and Col‑1 expression. However, above all, miR‑185 might serve as a potential therapeutic approach for the treatment of HS.

MiR-690, a Runx2-targeted miRNA, regulates osteogenic differentiation of C2C12 myogenic progenitor cells by targeting NF-kappaB p65

BACKGROUND

The runt-related transcription factor 2 (Runx2) is a cell-fate-determining factor that controls osteoblast differentiation and bone formation. It has been previously demonstrated that microRNAs (miRNAs) play important roles in osteogenesis. However, the Runx2-regulated miRNAs that have been reported thus far are limited. In this study, we pursued to identify these miRNAs in Tet-on stable C2C12 cell line (C2C12/Runx2(Dox) subline).

RESULTS

Microarray analysis revealed that alterations in miRNA expression occur with 54 miRNAs. Among these miRNAs, miR-690 was identified as a positive regulator of Runx2-induced osteogenic differentiation of C2C12 cells through gain- and loss-of-function assays. Expression of miR-690 is induced by Runx2, which binds directly to the putative promoter of mir-690 (Mirn690). The miR-690 proceeds to inhibit translation of the messenger RNA encoding the nuclear factor kappa B (NF-κB) subunit p65 whose overexpression inhibits Runx2-induced osteogenic differentiation of C2C12 cells. Interleukin-6 (IL-6), a downstream target of NF-κB pathway, is upregulated by p65 overexpression but significantly downregulated during this differentiation process. Furthermore, overexpression of IL-6 impedes the expression of osteocalcin, a defined marker of late osteoblast differentiation.

CONCLUSIONS

Together, our results suggest that the miR-690 transactivated by Runx2 acts as a positive regulator of Runx2-induced osteogenic differentiation by inactivating the NF-κB pathway via the downregulation of the subunit p65.

Mechanisms of Hypoxic Up-Regulation of Versican Gene Expression in Macrophages

Hypoxia is a hallmark of many pathological tissues. Macrophages accumulate in hypoxic sites and up-regulate a range of hypoxia-inducible genes. The matrix proteoglycan versican has been identified as one such gene, but the mechanisms responsible for hypoxic induction are not fully characterised. Here we investigate the up-regulation of versican by hypoxia in primary human monocyte-derived macrophages (HMDM), and, intriguingly, show that versican mRNA is up-regulated much more highly (>600 fold) by long term hypoxia (5 days) than by 1 day of hypoxia (48 fold). We report that versican mRNA decay rates are not affected by hypoxia, demonstrating that hypoxic induction of versican mRNA is mediated by increased transcription. Deletion analysis of the promoter identified two regions required for high level promoter activity of luciferase reporter constructs in human macrophages. The hypoxia-inducible transcription factor HIF-1 has previously been implicated as a key potential regulator of versican expression in hypoxia, however our data suggest that HIF-1 up-regulation is unlikely to be principally responsible for the high levels of induction observed in HMDM. Treatment of HMDM with two distinct specific inhibitors of Phosphoinositide 3-kinase (PI3K), LY290042 and wortmannin, significantly reduced induction of versican mRNA by hypoxia and provides evidence of a role for PI3K in hypoxic up-regulation of versican expression.

AEG-1 3'-untranslated region functions as a ceRNA in inducing epithelial-mesenchymal transition of human non-small cell lung cancer by regulating miR-30a activity

Competitive endogenous messenger RNA regulates the transcription of other RNA moleculars through competing for the shared microRNAs. This study was carried out to explore the regulation of AEG-1 messenger RNA as a competitive endogenous RNA in the epithelial-mesenchymal transition and metastasis of lung tumor cells. It is shown that the epithelial-mesenchymal transition was associated with the down-regulation of miR-30a, up-regulation of AEG-1 and mesenchymal markers (Snail and Vimentin); miR-30a inhibited the metastasis of lung tumor A549 cells in vitro, whereas AEG-1 promoted it. These results suggested the potential linkage between miR-30a and genes (AEG-1, Snail and Vimentin) in the epithelial-mesenchymal transition and metastasis of lung tumor cell. It was verified later that the 3'-untranslated regions of AEG-1, Snail and Vimentin bind to miR-30a in A549 cells. Therefore, a competitive endogenous RNAs regulatory network among AEG-1, Snail and Vimentin mediated via competitive binding to miR-30a was proved. That is, the 3'-untranslated region of AEG-1, functioning as the competitive endogenous RNAs, indirectly regulated the expression of Vimentin and Snail in inducing epithelial-mesenchymal transition of human non-small cell lung cancer. In conclusion, our findings demonstrated a competitive endogenous RNAs regulatory network which will help understand the metastasis mechanisms of lung cancer and improve the prevention and treatment of lung cancer.