Suppression of cell proliferation and collagen production in cultured human hypertrophic scar fibroblasts by Sp1 decoy oligodeoxynucleotide

Effectiveness of fractional carbon dioxide laser combined with botulinum toxin type A in a rabbit ear model with the underlying mechanism

BACKGROUND

Hypertrophic scar (HS) is a common disease in plastic and cosmetic surgery, with limited treatment options, and is a challenge for clinicians.

OBJECTIVES

This study aimed to evaluate the efficacy of fractional carbon dioxide (CO₂ ) laser combined with botulinum toxin type A (BTXA) in treating HSs in rabbit ears and to provide new strategies for treating HS.

METHODS

Twenty-four New Zealand white rabbits with induced HSs were randomly divided into one control and three treatment groups. After 4 weeks of modeling, BTXA (2.0 U) was injected into the HS of the BTXA and combination groups, whereas a fractional CO₂ laser (combo mode, deep energy: 12.5 mJ; super energy: 90 mJ) was used in the fractional CO₂ laser and combination groups. The laser treatments were repeated after 2 weeks. The HSs in the rabbit ears were observed and photographed 5 weeks after the first treatment. The scar thickness in each group was measured and compared, and the scar elevation index (SEI) was determined using hematoxylin and eosin staining. Collagen content and alignment were observed using Masson's trichrome staining. Western blotting and immunohistochemistry were performed to analyze scar-related protein levels.

RESULTS

Hypertrophic scars were reduced in all treatment groups compared with the control group. The combination group had lower scar thickness, SEI, and expression of scar-related proteins in HSs, with an appearance similar to that of normal rabbit ear skin. Furthermore, the fibroblast content and collagen deposition decreased significantly in the combination group (p < 0.001).

CONCLUSIONS

Fractional CO₂ laser combined with BTXA more effectively reduced HSs by inhibiting fibroblast proliferation, decreasing transforming growth factor-β1 and α- smooth muscle actin expression, and causing collagen remodeling.

MicroRNA-365a/b-3p as a Potential Biomarker for Hypertrophic Scars

The clinical aspects of hypertrophic scarring vary according to personal constitution and body part. However, the mechanism of hypertrophic scar (HS) formation remains unclear. MicroRNAs (miRNAs) are known to contribute to HS formation, however, their detailed role remains unknown. In this study, candidate miRNAs were identified and analyzed as biomarkers of hypertrophic scarring for future clinical applications. HSfibroblasts and normal skin fibroblasts from patients were used for profiling and validation of miRNAs. An HS mouse model with xenografted human skin on nude mice was established. The miRNA expression between normal human, normal mouse, and mouse HS skin tissues was compared. Circulating miRNA expression levels in the serum of normal mice and mice with HSs were also analyzed. Ten upregulated and twenty-one downregulated miRNAs were detected. Among these, miR-365a/b-3p and miR-16-5p were identified as candidate miRNAs with statistically significant differences; miR-365a/b-3p was significantly upregulated (p = 0.0244). In mouse studies, miR-365a/b-3p expression levels in skin tissue and serum were higher in mice with HSs than in the control group. These results indicate that miRNAs contribute to hypertrophic scarring and that miR-365a/b-3p may be considered a potential biomarker for HS formation.

MicroRNA‑181 exerts an inhibitory role during renal fibrosis by targeting early growth response factor‑1 and attenuating the expression of profibrotic markers

Progressive renal fibrosis is a common complication of chronic kidney disease that results in end‑stage renal disorder. It is well established that several microRNAs (miRs) function as critical regulators implicated in fibrotic diseases. However, the role of miR‑181 in the development and progression of renal fibrosis remains unclear, and the precise mechanism has not yet been fully defined. The present study identified the functional implications of miR‑181 expression during renal fibrosis. miR‑181 exhibited significantly reduced expression in the serum of renal fibrosis patients and in the kidneys of mice with unilateral ureteral obstruction (UUO). In addition, miR‑181 downregulated the expression of human α‑smooth muscle actin (α‑SMA) in response to angiotensin II stimulation. Transfection with miR‑181 mimics significantly suppressed the expression levels of α‑SMA, connective tissue growth factor, collagen type I α1 (COL1A1) and collagen type III α1 (COL3A1) in NRK49F cells. Notably, early growth response factor‑1 (Egr1) was identified as a direct target gene of miR‑181. Furthermore, in vivo experiments revealed that treatment with miR‑181 agonist strongly rescued kidney impairment induced by UUO, as supported by Masson's trichrome staining of kidney tissues and reverse transcription‑quantitative polymerase chain reaction analysis of COL1A1 and COL3A1 mRNA levels. Therefore, miR‑181 may be regarded as an important mediator in the control of profibrotic markers during renal fibrosis via binding to Egr1, and may be a promising new target in the diagnosis and therapy of renal fibrosis.

The miRNA-184 drives renal fibrosis by targeting HIF1AN in vitro and in vivo

Progressive renal fibrosis is the last phase of chronic kidney disease and results in renal failure. Micro-RNA has been demonstrated as important agent to drive organ fibrosis. However, the precise mechanisms are not fully understood. Here, we found miRNA-184 as a critical mediator to promote the renal fibrosis by targeting HIF1AN. In Vivo, miRNA-184 expression levels remarkably increased both in patients’ serum and in unilateral ureteral obstruction kidneys, as well as induced the expression of COL1A1 and COL3A1. Furthermore, transfection of NRK49F cells with miRNA-184 mimics down-regulated HIF1AN, transfection of NRK49F cells with miRNA-184 inhibitor up-regulated HIF1AN, while the cells transfected with miRNA-184 inhibitor exerted the opposite effect. When the cells were co-transfected with miRNA-184 mimics and HIF1AN, the expression of α-SMA, GTGF, COL1A1, and COL3A1 at mRNA level was apparently decreased when compared with miRNA-184 mimic-transfected cells, which was strengthened when transfected with miRNA-184 inhibitor. Thus, miRNA-184 is an important agent to promote the fibrosis though binding to HIF1AN, and may be a promising novel target in treatment of renal fibrosis.

Simultaneous targeted inhibition of Sox2-Oct4 transcription factors using decoy oligodeoxynucleotides to repress stemness properties in mouse embryonic stem cells

Transcriptional master regulators like Sox2 and Oct4, which are expressed in various human tumors, have been shown to cause tumor growth promotion as well as epithelial dysplasia by means of interfering with progenitor cell differentiation. In order to investigate the potential of Sox2-Oct4 transcription factor decoy (TFD) strategy for differentiation therapy, mouse embryonic stem cells (mESCs) were used in this study as a model of cancer stem cells (CSCs). Sox2-Oct4 complex decoy ODNs (cd-ODNs) were designed according to their elements in the promoter region of Sox2 gene. DNA-protein interactions between decoy ODNs and their corresponding proteins were examined by electrophoretic mobility shift assay (EMSA). Then, decoy and scrambled ODNs were transfected into mESCs with lipofectamine under 2 inhibitors (2i) conditions. Fluorescence and confocal microscopy, cell viability, cell cycle and apoptosis analysis, alkaline phosphatase, embryoid body formation assay, and real-time PCR were used to conduct further investigations. EMSA data showed that Sox2-Oct4 decoy ODNs bound specifically to their recombinant proteins. The results revealed that the synthesized complex decoy can concomitantly target Sox2 and Oct4, which subsequently represses the stemness properties of mESCs compared to controls through decreasing cell viability, arresting cell cycle in G₀ /G₁ phases, inducing apoptosis, and modulating differentiation in mESCs despite the presence of 2i/LIF in cell culture. While cd-ODN strategy seems to offer great promise for cancer therapy, further studies are still required to put this powerful investigative tool in practice for a wide range of human cancers.

MicroRNA-98 inhibits the cell proliferation of human hypertrophic scar fibroblasts via targeting Col1A1

Background

Hypertrophic scarring (HS) is a severe disease, and results from unusual wound healing. Col1A1 could promote the hypertrophic scar formation, and the expression of Col1A1 in HS tissue was markedly higher than that in the normal. In present study, we aimed to identify miRNAs as post-transcriptional regulators of Col1A1 in HS.

Methods

MicroRNA-98 was selected as the key miRNA comprised in HS. The mRNA levels of miR-98 in HS tissues and the matched normal skin tissues were determined by qRT-PCR. MTT and flow cytometry were used to determine the influence of miR-98 on cell proliferation and apoptosis of HSFBs, respectively. Col1A1 was found to be the target gene of miR-98 using luciferase reporter assay. Luciferase assay was performed to determine the relative luciferase activity in mimic NC, miR-98 mimic, inhibitor NC and miR-98 inhibitor with Col1A13′-UTR wt or Col1A13′-UTR mt reporter plasmids. The protein expression of Col1A1 in HSFBs after transfection with mimic NC, miR-98 mimic, inhibitor NC and miR-98 inhibitor were determined by western blotting.

Results

The mRNA level of miR-98 in HS tissues was much higher than that in the control. Transfection of HSFBs with a miR-98 mimic reduced the cell viability of HSFBs and increased the apoptosis portion of HSFBs, while inhibition of miR-98 increased cell viability and decreased apoptosis portion of HSFBs. miR-98 inhibitor increased the relative luciferase activity significantly when cotransfected with the Col1A1-UTR reporter plasmid, while the mutant reporter plasmid abolished the miR-98 inhibitor-mediated increase in luciferase activity. Western blotting revealed that overexpression of miR-98 decreased the expression of Col1A1.

Conclusions

Overexpression of miR-98 repressed the proliferation of HSFBs by targeting Col1A1.

SP1 and UTE1 Decoy ODNs inhibit activation and proliferation of hepatic stellate cells by targeting tissue inhibitors of metalloproteinase 1

Background

The excessive accumulation of extracellular matrix of hepatic fibrosis is positively correlated with tissue inhibitors of metalloproteinase 1 (TIMP1). Here we aimed to investigate whether TIMP1 may be down-regulated by Decoy ODNs strategy to capture transcriptional factor upstream TIMP1 element 1 (UTE1) and specificity protein 1(SP1).

Results

By luciferase reporter assays, we confirmed that these Decoy ODNs could influence the promoter activation of TIMP-1, α-SMA and Collagen Iα2 (COLΙα2) genes as well as the enhancer activation of TRE in HSC-T6 cells, and the combination tended to be more effective than SP1 or UTE1 Decoy ODN alone. Western blot analysis also demonstrated down-regulation of the expression of those target genes except for TGF-β. Furthermore, we observed that the viability of HSC-T6 cells at 72 h was significantly in decline in combination group.

Conclusion

The combination of SP1 and UTE1 Decoy ODNs treatments inhibit the activation and proliferation of HSCs more effectively than one of the Decoy ODNs through co-regulation of TIMP1 and TGF-β signal pathway but not the expression of TGF-β itself.

Investigating the potential of Shikonin as a novel hypertrophic scar treatment

Background

Hypertrophic scarring is a highly prevalent condition clinically and results from a decreased number of apoptotic fibroblasts and over-abundant production of collagen during scar formation following wound healing. Our previous studies indicated that Shikonin, an active component extracted from Radix Arnebiae, induces apoptosis and reduces collagen production in hypertrophic scar-derived fibroblasts. In the study reported here, we further evaluate the potential use of Shikonin as a novel scar remediation therapy by examining the effects of Shikonin on both keratinocytes and fibroblasts using Transwell® co-culture techniques. The underlying mechanisms were also revealed. In addition, effects of Shikonin on the expression of cytokines in Transwell co-culture “conditioned” medium were investigated.

Results

Our results indicate that Shikonin preferentially inhibits cell proliferation and induces apoptosis in fibroblasts without affecting keratinocyte function. In addition, we found that the proliferation-inhibiting and apoptosis-inducing abilities of SHI might be triggered via MAPK and Bcl-2/Caspase 3 signalling pathways. Furthermore, SHI has been found to attenuate the expression of TGF-β1 in Transwell co-cultured “conditioned” medium.

Conclusions

The data generated from this study provides further evidence that supports the potential use of Shikonin as a novel scar remediation therapy.