miR-141-3p inhibits fibroblast proliferation and migration by targeting GAB1 in keloids

MiR-141-3p-Functionalized Exosomes Loaded in Dissolvable Microneedle Arrays for Hypertrophic Scar Treatment

Hypertrophic scar (HS) is a common fibroproliferative disease caused by abnormal wound healing after deep skin injury. However, the existing approaches have unsatisfactory therapeutic effects, which promote the exploration of newer and more effective strategies. MiRNA-modified functional exosomes delivered by dissolvable microneedle arrays (DMNAs) are expected to provide new hope for HS treatment. In this study, a miRNA, miR-141-3p, which is downregulated in skin scar tissues and in hypertrophic scar fibroblasts (HSFs), is identified. MiR-141-3p mimics inhibit the proliferation, migration, and myofibroblast transdifferentiation of HSFs in vitro by targeting TGF-β2 to suppress the TGF-β2/Smad pathway. Subsequently, the engineered exosomes encapsulating miR-141-3p (miR-141-3pOE -Exos) are isolated from adipose-derived mesenchymal stem cells transfected with Lv-miR-141-3p. MiR-141-3pOE -Exos show the same inhibitive effects as miR-141-3p mimics on the pathological behaviors of HSFs in vitro. The DMNAs for sustained release of miR-141-3pOE -Exos are further fabricated in vivo. MiR-141OE -Exos@DMNAs effectively decrease the thickness of HS and improve fibroblast distribution and collagen fiber arrangement, and downregulate the expression of α-SMA, COL-1, FN, TGF-β2, and p-Smad2/3 in the HS tissue. Overall, a promising, effective, and convenient exosome@DMNA-based miRNA delivery strategy for HS treatment is provided.

Upregulation of miR-200a improves ureteral obstruction-induced renal fibrosis via GAB1/Wnt/β-catenin signaling

BACKGROUND

Renal fibrosis is a basic pathological change of almost all chronic kidney disorders. Epithelial-mesenchymal transition (EMT) and excessive extracellular matrix (ECM) accumulation play a crucial role in the process of fibrosis.

METHODS

Western blot and qRT-PCR were accomplished to analyze the expression levels of target proteins and genes, respectively. The fibrotic levels in the renal tissues of rats were confirmed utilizing Masson staining. Expression of ECM-related α-SMA in the renal tissues was determined by immunohistochemistry assay. The combination of GRB2 associated binding protein 1 (GAB1) and miR-200a was ensured by starBase database and luciferase reporter assay.

RESULTS

Our data uncovered that miR-200a was downregulated, but GAB1 was upregulated in the renal tissues of the rat experienced unilateral ureteral obstruction (UUO). Overexpression of miR-200a improved tissues fibrosis, suppressed GAB1 expression and ECM deposition, and inactivated Wnt/β-catenin in UUO rats. Moreover, miR-200a expression was inhibited, while GAB1 expression was facilitated in the TGF-β1-induced HK-2 cells. In TGF-β1-induced HK-2 cells, miR-200a overexpression inhibited GAB1 expression, also declined ECM-related proteins and mesenchymal markers expression. Oppositely, miR-200a overexpression facilitated epithelial marker expression in the TGF-β1-induced HK-2 cells. Next, the data revealed that miR-200a inhibited GAB1 expression through binding to the mRNA 3'-UTR of GAB1. Increasing of GAB1 reversed the regulation of miR-200a to GAB1 expression, Wnt/β-catenin signaling activation, EMT and ECM accumulation.

CONCLUSION

Overall, miR-200a increasing improved renal fibrosis through attenuating EMT and ECM accumulation by limiting Wnt/β-catenin signaling via sponging GAB1, indicating miR-200a may be a promising objective for renal disease therapy.

Mechanisms underlying pathological scarring by fibroblasts during wound healing

Pathological scarring is an abnormal outcome of wound healing, which often manifests as excessive proliferation and transdifferentiation of fibroblasts (FBs), and excessive deposition of the extracellular matrix. FBs are the most important effector cells involved in wound healing and scar formation. The factors that promote pathological scar formation often act on the proliferation and function of FB. In this study, we describe the factors that lead to abnormal FB formation in pathological scarring in terms of the microenvironment, signalling pathways, epigenetics, and autophagy. These findings suggest that understanding the causes of abnormal FB formation may aid in the development of precise and effective preventive and treatment strategies for pathological scarring that are associated with improved quality of life of patients.

Circ_0057452 sponges miR-7-5p to promote keloid progression through upregulating GAB1

Increasing evidence has shown that circular RNAs (circRNAs) play critical roles in various diseases, including keloid. The purpose of this study was to investigate the role of circ_0057452 and related action mechanisms during the development of keloid. The expression levels of circ_0057452, microRNA-7-5p (miR-7-5p) and GRB2 associated binding protein 1 (GAB1) mRNA were determined by quantitative real-time PCR (qRT-PCR). Cell proliferation was evaluated using methylthiazolyldiphenyl-tetrazolium bromide (MTT) and 5-Ethynyl-2'-deoxyuridine (Edu) assays. Flow cytometry analysis was utilized to determine cell cycle distribution and cell apoptosis. Western blot assay was used to measure apoptosis-related, collagen synthesis-related, and GAB1 protein levels. Cell migration and invasion were detected by wound healing assay and transwell assay. The interaction between miR-7-5p and circ_0057452 or GAB1 was confirmed by dual-luciferase reporter, RNA pull-down, and RNA Immunoprecipitation (RIP) assays. Circ_0057452 and GAB1 were upregulated in keloid tissues and keloid fibroblasts (KFs), while miR-7-5p was downregulated. Circ_0057452 knockdown or miR-7-5p overexpression inhibited the proliferation, migration, invasion, and collagen synthesis and induced cell cycle arrest and apoptosis of KFs. MiR-7-5p was targeted by circ_0057452, and its inhibition overturned the effects of circ_0057452 knockdown. In addition, GAB1 was a target of miR-7-5p, and GAB1 upregulation abolished the role of miR-7-5p overexpression and circ_0057452 knockdown in KFs. Circ_0057452 regulated the expression of GAB1 by adsorbing miR-7-5p in KFs. Circ_0057452 knockdown suppressed keloid development by regulating miR-7-5p/GAB1 axis, which might provide a promising therapeutic target for keloid.

Comprehensive Analysis of Chromatin Accessibility and Transcriptional Landscape Identified BRCA1 Repression as a Potential Pathological Factor for Keloid

Keloid is a poorly understood fibrotic skin disease that commonly occurs during wound-healing. As a polymer composed of nucleic acid and proteins, the structure of chromatin could be dynamically regulated in the nucleus. In this study, we explored the dynamics of chromatin accessibility and the transcriptome in dermal fibroblasts (DFs) in keloid formation. Compared to normal samples, chromatin accessibility and transcriptome were extensively altered in keloid DFs. In addition, changes in chromatin accessibility were closely associated with changes in gene expression in DFs. Breast cancer type 1 (BRCA1) was significantly downregulated in keloid DFs, and its knockdown promoted the proliferation and attenuated the migration ability of normal DF cells. Mechanistically, BRCA1 suppression significantly reduced the expression of neuronal pentraxin 2 (NPTX2), a cell viability-related gene. BRCA1 binding affinity at the NPTX2 enhancer and the chromatin accessibility in the same region were significantly lower in keloid DFs than in normal DFs, which might contribute to NPTX2 inhibition. In conclusion, this study identified BRCA1 inhibition in DFs as a novel pathological factor in keloids and preliminarily explored its potential mechanisms, which will help us understand the formation of keloids.

Advances in the pathogenesis and clinical application prospects of tumor biomolecules in keloid

Keloid scarring is a kind of pathological healing manifestation after skin injury and possesses various tumor properties, such as the Warburg effect, epithelial-mesenchymal transition (EMT), expression imbalances of apoptosis-related genes and the presence of stem cells. Abnormal expression of tumor signatures is critical to the initiation and operation of these effects. Although previous experimental studies have recognized the potential value of a single or several tumor biomolecules in keloids, a comprehensive evaluation system for multiple tumor signatures in keloid scarring is still lacking. This paper aims to summarize tumor biomolecules in keloids from the perspectives of liquid biopsy, genetics, proteomics and epigenetics and to investigate their mechanisms of action and feasibility from bench to bedside. Liquid biopsy is suitable for the early screening of people with keloids due to its noninvasive and accurate performance. Epigenetic biomarkers do not require changes in the gene sequence and their reversibility and tissue specificity make them ideal therapeutic targets. Nonetheless, given the ethnic specificity and genetic predisposition of keloids, more large-sample multicenter studies are indispensable for determining the prevalence of these signatures and for establishing diagnostic criteria and therapeutic efficacy estimations based on these molecules.

Aberrantly Expressed Small Noncoding RNAome in Keloid Skin Tissue

The skin is an organ that protects against injury and infection but can be damaged easily. Wound healing is a subtle balance which, if broken, can lead to keloid formation. Small noncoding (nc) RNAs can be of “housekeeping,” for example, ribosomal RNAs and transfer RNAs, or “regulatory,” for example, microRNAs (miRNAs or miRs), small nucleolar RNAs (snoRNAs), and P-element–induced Wimpy testis (PIWI)-interacting RNA (piRNA) types. We examined five types of small ncRNAs [miR, piRNA, snoRNA, small nuclear (sn) RNA, and repeat-associated small interfering RNA (rasiRNA)] in keloid skin tissue (KST) using sequencing and real-time reverse transcription-quantitative polymerase chain reaction. All comparisons were made in relation to expression in normal skin tissue (obtained by abdominoplasty). The expression of three piRNAs was upregulated, and the expression of six piRNAs was downregulated in KST. The expression of 12 snoRNAs was upregulated, and the expression of two snoRNAs was downregulated in KST. The expression of two snRNAs was downregulated in KST. The expression of 18 miRs was upregulated, and the expression of three miRNAs was downregulated in KST. The expression of one rasiRNA was upregulated, and the expression of one rasiRNA was downregulated in KST. We revealed the differential expression of small ncRNAs in KST, which may aid the development of new treatment for keloids.

Use of Adipose Stem Cells Against Hypertrophic Scarring or Keloid

Hypertrophic scars or keloid form as part of the wound healing reaction process, and its formation mechanism is complex and diverse, involving multi-stage synergistic action of multiple cells and factors. Adipose stem cells (ASCs) have become an emerging approach for the treatment of many diseases, including hypertrophic scarring or keloid, owing to their various advantages and potential. Herein, we analyzed the molecular mechanism of hypertrophic scar or keloid formation and explored the role and prospects of stem cell therapy, in the treatment of this condition.

Long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) regulates fibroblast growth factor receptor substrate 2 (FRS2) by targeting microRNA (miR)-29-3p in hypertrophic scar fibroblasts

Long non-coding RNAs (lncRNAs) play crucial roles in human diseases. However, the detailed role of lncRNAs in hypertrophic scar fibroblasts (HSFs) is inadequately understood. This study aimed to investigate the potential role of lncRNA nuclear enriched abundant transcript 1 (NEAT1) in hypertrophic scarring. Expression of lncRNAs, miRNAs, and genes were detected by polymerase chain reaction; protein expression was evaluated using western blotting. Cellular function was determined using the CCK-8 assay. The interaction between microRNA (miR)-29-3p and NEAT1 or fibroblast growth factor receptor substrate 2 (FRS2) was verified by luciferase and RNA pull-down assays. The results showed that NEAT1 was overexpressed in the hypertrophic dermis and in HSFs. However, knockdown of NEAT1 suppressed the proliferation and extracellular matrix (ECM) production of HSFs. Moreover, NEAT1 functioned as a competing endogenous RNA to upregulate FRS2 by sponging miR-29-3p. Downregulation of miR-29-3p or overexpression of FRS2 antagonized the effects of NEAT1 knockdown and promoted HSF proliferation and ECM release. In conclusion, NEAT1 knockdown protected against hypertrophic scarring by modulating the miR-29-3p/FRS2 axis, which is a viable target in scar treatment.

The epigenetics of keloids

Keloid scarring is a fibroproliferative disorder of the skin with unknown pathophysiology, characterised by fibrotic tissue that extends beyond the boundaries of the original wound. Therapeutic options are few and commonly ineffective, with keloids very commonly recurring even after surgery and adjunct treatments. Epigenetics, defined as alterations to the DNA not involving the base-pair sequence, is a key regulator of cell functions, and aberrant epigenetic modifications have been found to contribute to many pathologies. Multiple studies have examined many different epigenetic modifications in keloids, including DNA methylation, histone modification, microRNAs and long non-coding RNAs. These studies have established that epigenetic dysregulation exists in keloid scars, and successful future treatment of keloids may involve reverting these aberrant modifications back to those found in normal skin. Here we summarise the clinical and experimental studies available on the epigenetics of keloids, discuss the major open questions and future perspectives on the treatment of this disease.

Epigenetic modification mechanisms involved in keloid: current status and prospect

Keloid, a common dermal fibroproliferative disorder, is benign skin tumors characterized by the aggressive fibroblasts proliferation and excessive accumulation of extracellular matrix. However, common therapeutic approaches of keloid have limited effectiveness, emphasizing the momentousness of developing innovative mechanisms and therapeutic strategies. Epigenetics, representing the potential link of complex interactions between genetics and external risk factors, is currently under intense scrutiny. Accumulating evidence has demonstrated that multiple diverse and reversible epigenetic modifications, represented by DNA methylation, histone modification, and non-coding RNAs (ncRNAs), play a critical role in gene regulation and downstream fibroblastic function in keloid. Importantly, abnormal epigenetic modification manipulates multiple behaviors of keloid-derived fibroblasts, which served as the main cellular components in keloid skin tissue, including proliferation, migration, apoptosis, and differentiation. Here, we have reviewed and summarized the present available clinical and experimental studies to deeply investigate the expression profiles and clarify the mechanisms of epigenetic modification in the progression of keloid, mainly including DNA methylation, histone modification, and ncRNAs (miRNA, lncRNA, and circRNA). Besides, we also provide the challenges and future perspectives associated with epigenetics modification in keloid. Deciphering the complicated epigenetic modification in keloid is hopeful to bring novel insights into the pathogenesis etiology and diagnostic/therapeutic targets in keloid, laying a foundation for optimal keloid ending.

NEAT1 Knockdown Inhibits Keloid Fibroblast Progression by miR-196b-5p/FGF2 Axis

BACKGROUND

Keloid is a benign fibroproliferative tumor of the skin caused by abnormal wound healing process after skin injury. Long noncoding RNAs have been reported to be involved in the development of keloid. However, the role and mechanism of nuclear enriched abundant transcript 1 (NEAT1) in keloid are still unknown.

METHODS

Quantitative real-time polymerase chain reaction was performed to detect the expression of NEAT1, miR-196b-5p, and fibroblast growth factor 2 (FGF2). Western blot was conducted to measure the levels of collagen I, α-smooth muscle actin, fibronectin, and FGF2. Cell Counting Kit-8 assay and transwell assay were used to evaluate cell viability and migration, respectively. Dual-luciferase reporter assay was conducted to verify the targeting relationship between miR-196b-5p and NEAT1 or FGF2.

RESULTS

NEAT1 was increased and miR-196b-5p was decreased in keloid tissues and fibroblasts. NEAT1 knockdown or miR-196b-5p overexpression suppressed cell viability, migration, and extracellular matrix (ECM) component production in keloid fibroblasts. MiR-196 b-5p was a target of NEAT1, and NEAT1 overexpression reversed the effect of miR-196b-5p on keloid fibroblast progression. Moreover, we found that miR-196b-5p directly targeted FGF2. FGF2 knockdown suppressed keloid fibroblast viability, migration, and ECM protein production. FGF2 overexpression abolished the effect of miR-196b-5p overexpression on keloid fibroblast development.

CONCLUSIONS

NEAT1 silencing suppressed cell viability, migration, and ECM expression in keloid fibroblasts by regulating miR-196b-5p/FGF2 axis, indicating a promising strategy for keloid treatment.

Drug delivery to optimize angiogenesis imbalance in keloid: A review

The wound healing process involves three continuous stages. Where, any imbalance can lead to the formation of unwanted keloids, hypertrophic scar, or tumors. Keloids are any unpleasant, non-compliant comorbidity affecting a major section of people around the globe who acquire it either genetically or by pathological means as a result of a skin injury. Angiogenesis is unavoidable in the healing process after an injury or disruption of skin to promote tissue regeneration. Uncontrolled angiogenesis during the healing process can initiate the unwanted response in the wound that facilitate keloid. Angiogenic therapy is adapted to accelerate healing after an injury. Else ways, there exists a risk of keloid formation due to excessive angiogenesis during the wound healing process. There are numerous strategies to treat keloid. Anti-angiogenic factors are provided to patients post-surgery to prevent the keloid formation; however, they come into the picture after the formation of keloid. The available strategies to treat keloids are steroidal injections, surgical excision of the keloid, radiotherapy, pressure therapy, the use of cryosurgery, and many more. The available treatments are not promising in reducing the recurrent rate of keloids as there are chances of high re-occurrences with similar/larger lesions on the removed keloid site. In this review, we are discussing the importance of controlled angiogenesis with the help of controlled drug delivery strategies enabling the wound healing process without the induction of keloid.

LncRNA MALAT1 promotes wound healing via regulating miR-141-3p/ZNF217 axis

Background

The process of wound healing is complex. Increasing evidences have shown that lncRNA MALAT1 is abundant in fibroblasts and may be engaged in wound healing process. Therefore, we explored the mechanism of MALAT1 affecting wound healing.

Methods

The expression levels of MALAT1, miR-141-3p as well as ZNF217 in human fibroblast cells (HFF-1) were quantified by qRT-PCR. HFF-1 proliferation was measured by MTT, while migration was detected by wound healing assay. SMAD2 activation and matrix proteins expression were detected by western blotting. The interaction between miR-141-3p and MALAT1 or ZNF217 was further confirmed using the luciferase reporter gene assay. In vivo wound healing was assessed by full-thickness wound healing model on C57BL/6 mice.

Result

Knockdown of MALAT1 as well as overexpression miR-141-3p remarkably inhibited the proliferation, migration and matrix protein expression in HFF-1 cells. MALAT1 directly targeted and inhibited the expression of miR-141-3p. MiR-141-3p suppressed the activation of TGF-β2/SMAD2 signaling pathway by targeting ZNF217. Knockdown of MALAT1 inhibited wound healing process in mice.

Conclusions

MALAT1 up-regulates ZNF217 expression by targeting miR-141-3p, thus enhances the activity of TGF-β2/SMAD2 signaling pathway and promotes wound healing process. This investigation shed new light on the understanding of the role of MALAT1 in wound healing, and may provide potential target for the diagnosis or therapy of chronic wounds.

BTXA regulates the epithelial-mesenchymal transition and autophagy of keloid fibroblasts via modulating miR-1587/miR-2392 targeted ZEB2

Keloids are very resistant to treatment in dermatology and plastic surgical practice. The present study aimed to explore the underlying mechanism of botulinum toxin A (BTXA) treated human skin keloid fibroblasts (HSFBs) proving some new insights into keloids treatment. Expression of miR-1587 and miR-2392 were significantly down-regulated in keloid tissues and HSFBs, while the ZEB2 was a target of both and up-regulated in keloid tissues and HSFBs compared with the normal controls. BTXA could significantly increase the expression of miR-1587 and miR-2392 but decrease the expression of ZEB2. BTXA could significantly inhibit the proliferation, cell cycle, and migration and promote apoptosis and autophagy of HSFBs; however, miR-1587 and miR-2392 inhibitors could reverse these effects of BTXA on HSFBs. Silencing ZEB2 could significantly attenuate the effects of miR-1587 and miR-2392 inhibitors in promoting cell proliferation and migration and suppressing apoptosis and autophagy of HSFBs after treating with BTXA. BTXA could suppress the proliferation and migration and promote apoptosis and autophagy of HSFBs via modulating miR-1587/miR-2392 targeted ZEB2.

Long non-coding RNA H19 promotes the proliferation, migration and invasion while inhibits apoptosis of hypertrophic scarring fibroblasts by targeting miR-3187-3p/GAB1 axis

BACKGROUND

It had been reported that long non-coding RNA (lncRNA) H19 was associated with the proliferation of fibroblasts. However, the regulatory mechanism of H19 remains unclear. Thus, the study was designed to explore the underlying mechanism of H19 in the process of Hypertrophic scarring (HS).

METHODS

The expression levels of H19, miR-3187-3p, and growth factor receptor binding 2-associated binding protein 1 (GAB1) in HS tissues and HS fibroblasts were measured by real-time quantitative polymerase chain reaction (RT-qPCR) assay. The biological behaviors of HS fibroblasts, such as cell proliferation, apoptosis, migration, and invasion were assessed by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT), colony formation, flow cytometry, and transwell assays, respectively. The protein expression level was quantified by western blot assay. The interaction association between miR-3187-3p and H19 or GAB1 was predicted by Starbase database analysis and confirmed by dual-luciferase reporter assay, respectively.

RESULTS

H19 was significantly increased in HS tissues and HS fibroblasts. Loss-of-functional experiments revealed that knockdown of H19 inhibited the development of HS. Moreover, silencing of H19 impeded the proliferation, migration, and invasion, while enhanced apoptosis of HS fibroblasts by increasing miR-3187-3p expression. In addition, overexpression of GAB1 could abolish miR-3187-3p overexpression-induced effects on cell proliferation, apoptosis, migration, and invasion of HS fibroblasts. Mechanistically, H19 could act as a sponge of miR-3187-3p to upregulate the expression of GAB1 in HS fibroblasts.

CONCLUSION

Collectively, our results revealed that H19 promoted the proliferation, migration, and invasion, while impeded apoptosis of HS fibroblasts by targeting miR-3187-3p/GAB1 axis.

Human Cytomegalovirus miR-US5-2 Downregulation of GAB1 Regulates Cellular Proliferation and UL138 Expression through Modulation of Epidermal Growth Factor Receptor Signaling Pathways

Human cytomegalovirus (HCMV) causes significant disease in immunocompromised individuals, including transplant patients. HCMV establishes latency in hematopoietic stem cells in the bone marrow. The mechanisms governing latency and reactivation of viral replication are complex and not fully understood. HCMV-encoded miRNAs are small regulatory RNAs that reduce protein expression. In this study, we found that the HCMV miRNA miR-US5-2 targets the epidermal growth factor receptor (EGFR) adaptor protein GAB1 which directly affects downstream cellular signaling pathways activated by EGF. Consequently, miR-US5-2 blocks the EGF-mediated proliferation of human fibroblasts. Early growth response gene 1 (EGR1) is a transcription factor activated by EGFR signaling that regulates expression of HCMV UL138. We show that miR-US5-2 regulates UL138 expression through GAB1-mediated downregulation of the signaling pathways that lead to EGR1 expression. These data suggest that miR-US5-2, through downregulation of GAB1, could play a critical role during reactivation from latency by reducing proliferation and UL138 expression.

Regulation of epidermal growth factor (EGF) receptor (EGFR) signaling is critical for the replication of human cytomegalovirus (HCMV) as well as latency and reactivation in CD34⁺ hematopoietic progenitor cells. HCMV microRNAs (miRNAs) provide a means to modulate the signaling activated by EGF through targeting components of the EGFR signaling pathways. Here, we demonstrate that HCMV miR-US5-2 directly downregulates the critical EGFR adaptor protein GAB1 that mediates activation and sustained signaling through the phosphatidylinositol 3-kinase (PI3K) and MEK/extracellular signal-regulated kinase (ERK) pathways and cellular proliferation in response to EGF. Expression of HCMV UL138 is regulated by the transcription factor early growth response gene 1 (EGR1) downstream of EGFR-induced MEK/ERK signaling. We show that by targeting GAB1 and attenuating MEK/ERK signaling, miR-US5-2 indirectly regulates EGR1 and UL138 expression, which implicates the miRNA in critical regulation of HCMV latency.

IMPORTANCE Human cytomegalovirus (HCMV) causes significant disease in immunocompromised individuals, including transplant patients. HCMV establishes latency in hematopoietic stem cells in the bone marrow. The mechanisms governing latency and reactivation of viral replication are complex and not fully understood. HCMV-encoded miRNAs are small regulatory RNAs that reduce protein expression. In this study, we found that the HCMV miRNA miR-US5-2 targets the epidermal growth factor receptor (EGFR) adaptor protein GAB1 which directly affects downstream cellular signaling pathways activated by EGF. Consequently, miR-US5-2 blocks the EGF-mediated proliferation of human fibroblasts. Early growth response gene 1 (EGR1) is a transcription factor activated by EGFR signaling that regulates expression of HCMV UL138. We show that miR-US5-2 regulates UL138 expression through GAB1-mediated downregulation of the signaling pathways that lead to EGR1 expression. These data suggest that miR-US5-2, through downregulation of GAB1, could play a critical role during reactivation from latency by reducing proliferation and UL138 expression.

Increased Expression of microRNA-141-3p Improves Necrotizing Enterocolitis of Neonates Through Targeting MNX1

Objective: MicroRNA-141-3p (miR-141-3p) has been investigated in various kinds of cancers. This research delves into the functions and regulatory mechanisms of miR-141-3p in necrotizing enterocolitis (NEC) of neonates. Methods: NEC tissues were obtained from neonatal mice, and subsequently, expression of miR-141-3p and motor neuron and pancreas homeobox 1 (MNX1) was assayed via RT-qPCR. Moreover, the intestinal histopathological changes and histiocytic apoptosis were observed via hematoxylin and eosin (H&E) and TUNEL staining. The correlative inflammatory factors and oxidative stress markers were evaluated to uncover the influence of miR-141-3p in NEC tissue damage. Further, the relation between MNX1 and miR-141-3p was predicated, and the functions of MNX1 in inflammatory response and cell growth of IEC-6 cells were investigated. Results: Downregulated miR-141-3p and upregulated MNX1 were discovered in NEC tissues. Moreover, miR-141-3p clearly alleviated inflammation response and oxidative stress damage in NEC, which was achieved through regulating inflammatory cytokines (IL-1β, IL-6, and TNF-α) and oxidative stress markers (MPO, MDA, and SOD) expression. MNX1 was forecasted as a target gene of miR-141-3p; meanwhile, MNX1 overexpression overturned the influence of miR-141-3p in the inflammatory response and cell growth process of IEC-6 cells. Conclusion: These explorations reveal that increased expression of miR-141-3p could improve the damage to intestinal tissues in NEC through targeting MNX1. The research might exhibit a neoteric therapeutic strategy for NEC.

MiR-152-3p regulates cell proliferation, invasion and extracellular matrix expression through by targeting FOXF1 in keloid fibroblasts

Emerging evidence has revealed that microRNAs (miRNAs) play critical roles in keloid pathogenesis. However, potential molecular mechanism of keloid formation remains unclear. In the present study, our findings showed that miR-152-3p mRNA expression level was notably up-regulated in keloid tissues and keloid fibroblasts compared with that of normal skin tissues and normal skin fibroblasts, respectively. Furthermore, miR-152-3p inhibition remarkably suppressed cell proliferation, which was increased by miR-152-3p overexpression. Cell invasion was also significantly decreased by miR-152-3p inhibition, whereas was increased by miR-152-3p overexpression. The mRNA and protein expression levels of extracellular matrix components including type I collagen, type III collagen and fibronectin were decreased by miR-152-3p inhibition, but were increased by miR-152-3p overexpression. In addition, results of dual-luciferase reporter assay indicated that FOXF1 is a direct target of miR-152-3p. FOXF1 overexpression significantly inhibits cell proliferation, invasion, and extracellular matrix in keloid fibroblasts, and the suppressive effects of miR-152-3p mimic on these functions were notably partly reversed by FOXF1 overexpression. Taken together, these findings indicated that miR-152-3p regulates cell proliferation, invasion and extracellular matrix expression through targeting FOXF1 in keloid fibroblasts, suggesting that miR-152-3p is a novel and promising molecular target for keloid treatment.

TRAF4 Promotes Fibroblast Proliferation in Keloids by Destabilizing p53 via Interacting with the Deubiquitinase USP10

Keloids represent one extreme of aberrant dermal wound healing. One of the important characteristics of keloids is uncontrolled fibroblasts proliferation. However, the mechanism of excessive proliferation of fibroblasts in keloids remains elusive. In this study, we demonstrated that TRAF4 was highly expressed in keloid fibroblasts and promoted fibroproliferation. We investigated the underlying molecular mechanism and found that TRAF4 suppressed the p53 pathway independent of its E3 ubiquitin ligase activity. Specifically, TRAF4 interacted with the deubiquitinase USP10 and blocked the access of p53 to USP10, resulting in p53 destabilization. Knockdown of p53 rescued cell proliferation in TRAF4-knockdown keloid fibroblasts, suggesting that the regulation of proliferation by TRAF4 in keloids relied on p53. Furthermore, in keloid patient samples, TRAF4 expression was inversely correlated with p53-p21 signaling activity. These findings help to elucidate the mechanisms underlying keloid development and indicate that blocking TRAF4 could represent a potential strategy for keloid therapy in the future.

Identification of Novel Genes in Osteoarthritic Fibroblast-Like Synoviocytes Using Next-Generation Sequencing and Bioinformatics Approaches

Synovitis in osteoarthritis (OA) the consequence of low grade inflammatory process caused by cartilage breakdown products that stimulated the production of pro-inflammatory mediators by fibroblast-like synoviocytes (FLS). FLS participate in joint homeostasis and low grade inflammation in the joint microenvironment triggers FLS transformation. In the current study, we aimed to identify differentially expressed genes and potential miRNA regulations in human OA FLS through deep sequencing and bioinformatics approaches. The 245 differentially expressed genes in OA FLS were identified, and pathway analysis using various bioinformatics databases indicated their enrichment in functions related to altered extracellular matrix organization, cell adhesion and cellular movement. Moreover, among the 14 dysregulated genes with potential miRNA regulations identified, src kinase associated phosphoprotein 2 (SKAP2), adaptor related protein complex 1 sigma 2 subunit (AP1S2), PHD finger protein 21A (PHF21A), lipoma preferred partner (LPP), and transcription factor AP-2 alpha (TFAP2A) showed similar expression patterns in OA FLS and OA synovial tissue datasets in Gene Expression Omnibus database. Ingenuity Pathway Analysis identified the dysregulated LPP participated in cell migration and cell spreading of OA FLS, which was potentially regulated by miR-141-3p. The current findings suggested new perspectives into understanding the novel molecular signatures of FLS involved in the pathogenesis of OA, which may be potential therapeutic targets.

Integrated analysis of microRNA and mRNA expression profiles in splenomegaly induced by non-cirrhotic portal hypertension in rats

The spleen plays an important role in the immune and hematopoietic systems. Splenomegaly is a frequent consequence of portal hypertension, but the underlying molecular and cellular mechanisms remain to be fully elucidated. In this study, we have performed a whole-genome microarray analysis combined with histological examination in enlarged spleens isolated from rats with partial portal vein ligation (PPVL) surgery to provide comprehensive profiles of microRNAs and their target mRNAs with a focus on their potential biological functions. A total of 964 mRNAs and 30 microRNAs showed significant differential expression in the spleens of PPVL rats compared to rats undergoing a sham procedure. Twenty-two down-regulated microRNAs were associated with significantly increased genes highly involved in fibrogenic activity and cell proliferation/migration (e.g., Ctgf, Serpine1, Col1a1). Consistently, histological analyses demonstrated increased splenic fibrosis and cell proliferation in the spleens of PPVL rats. Eight up-regulated microRNAs were associated with suppression of genes that are related to interferon-mediated antiviral activity in innate immune responses (e.g., Irf7, Dhx58). In conclusion, we determined a specific microRNA-mRNA network potentially implicated in the tissue fibrosis and cell proliferation in portal hypertension-induced splenomegaly. Our findings provide new insight into the mechanisms for regulation of spleen structure and function.

Identification of transcription factor-miRNA-lncRNA feed-forward loops in breast cancer subtypes

Previous studies have demonstrated that transcription factor-miRNA-gene feed-forward loops (FFLs) played important roles in tumorigenesis. However, the lncRNA-involved FFLs have not been explored very well. Understanding the characteristics of lncRNA-involved FFLs in breast cancer subtypes may be a key question with clinical implications. In this study, we firstly constructed an integrated background regulatory network. Then, based on mRNA, miRNA, and lncRNA differential expression, we identified 147, 140, 284, 1031 dysregulated FFLs for luminal A, luminal B, HER2+ and basal-like subtype of breast cancer, respectively. Importantly, the known breast cancer-associated lncRNAs and miRNAs were enriched in the identified dysregulated FFLs. Through merging the dysregulated FFLs, we constructed the regulatory sub-network for each subtype. We found that all sub-networks were enriched in the well-known cancer-related pathways, such as cell cycle, pathways in cancer. Next, we also identified potential prognostic FFLs for subtypes of breast cancer, such as the hsa-miR-182-5p_JUN_XIST in basal-like subtype. Finally, we also discussed the potential application of inferring the candidate drugs for breast cancer treatment through modulating the lncRNA expression in the dysregulated FFLs. Collectively, this study elucidated the roles of lncRNA-involved FFLs in breast cancer subtypes, which could contribute to understanding breast cancer pathogenesis and improving the treatment.

MicroRNAs as biological regulators in skin disorders

microRNAs are being investigated as promising therapeutic targets and biomarkers for different disease conditions. miRNAs serve as essential regulators of cell differentiation, proliferation and survival. The involvement of miRNAs in the functioning and regulation of the skin cells and skin diseases is a rapidly advancing area in dermatological research. miRNAs have been identified to play a key role in the pathogenesis, diagnosis, and treatment of the skin diseases. Skin is one of the largest organs of the body, primarily functioning as the first line of defence against external insults including bacteria, virus and other pathogens. Various miRNAs have been identified to demonstrate significant effects in various skin inflammatory conditions such as wounds, cancer, psoriasis, scleroderma, dermatomyositis. The current review explores the possible roles of the miRNAs in skin disorders and reports relating to the clinical trials involving skin diseases and miRNAs. The review has also compiled the information of the databases available, which correlates the miRNAs with different diseases and give details about targeting interactions of miRNA.

Survey of miRNA-miRNA cooperative regulation principles across cancer types

Cooperative regulation among multiple microRNAs (miRNAs) is a complex type of posttranscriptional regulation in human; however, the global view of the system-level regulatory principles across cancers is still unclear. Here, we investigated miRNA-miRNA cooperative regulatory landscape across 18 cancer types and summarized the regulatory principles of miRNAs. The miRNA-miRNA cooperative pan-cancer network exhibited a scale-free and modular architecture. Cancer types with similar tissue origins had high similarity in cooperative network structure and expression of cooperative miRNA pairs. In addition, cooperative miRNAs showed divergent properties, including higher expression, greater expression variation and a stronger regulatory strength towards targets and were likely to regulate cancer hallmark-related functions. We found a marked rewiring of miRNA-miRNA cooperation between various cancers and revealed conserved and rewired network miRNA hubs. We further identified the common hubs, cancer-specific hubs and other hubs, which tend to target known anticancer drug targets. Finally, miRNA cooperative modules were found to be associated with patient survival in several cancer types. Our study highlights the potential of pan-cancer miRNA-miRNA cooperative regulation as a novel paradigm that may aid in the discovery of tumorigenesis mechanisms and development of anticancer drugs.

Predicting Potential Drugs for Breast Cancer based on miRNA and Tissue Specificity

Network-based computational method, with the emphasis on biomolecular interactions and biological data integration, has succeeded in drug development and created new directions, such as drug repositioning and drug combination. Drug repositioning, that is finding new uses for existing drugs to treat more patients, offers time, cost and efficiency benefits in drug development, especially when in silico techniques are used. MicroRNAs (miRNAs) play important roles in multiple biological processes and have attracted much scientific attention recently. Moreover, cumulative studies demonstrate that the mature miRNAs as well as their precursors can be targeted by small molecular drugs. At the same time, human diseases result from the disordered interplay of tissue- and cell lineage-specific processes. However, few computational researches predict drug-disease potential relationships based on miRNA data and tissue specificity. Therefore, based on miRNA data and the tissue specificity of diseases, we propose a new method named as miTS to predict the potential treatments for diseases. Firstly, based on miRNAs data, target genes and information of FDA (Food and Drug Administration) approved drugs, we evaluate the relationships between miRNAs and drugs in the tissue-specific PPI (protein-protein) network. Then, we construct a tripartite network: drug-miRNA-disease Finally, we obtain the potential drug-disease associations based on the tripartite network. In this paper, we take breast cancer as case study and focus on the top-30 predicted drugs. 25 of them (83.3%) are found having known connections with breast cancer in CTD (Comparative Toxicogenomics Database) benchmark and the other 5 drugs are potential drugs for breast cancer. We further evaluate the 5 newly predicted drugs from clinical records, literature mining, KEGG pathways enrichment analysis and overlapping genes between enriched pathways. For each of the 5 new drugs, strongly supported evidences can be found in three or more aspects. In particular, Regorafenib (DB08896) has 15 overlapping KEGG pathways with breast cancer and their p-values are all very small. In addition, whether in the literature curation or clinical validation, Regorafenib has a strong correlation with breast cancer. All the facts show that Regorafenib is likely to be a truly effective drug, worthy of our further study. It further follows that our method miTS is effective and practical for predicting new drug indications, which will provide potential values for treatments of complex diseases.

AMF siRNA treatment of keloid through inhibition signaling pathway of RhoA/ROCK1

A keloid (KD) is a benign dermal fibrotic tumor. Treatment of KDs is challenging and the recurrence rate is high; thus, there is an unmet need to explore new target sites and new treatment methods. As a tumor-associated cytokine, autocrine motility factor (AMF) can effectively stimulate the random and directional movement of cells. We first found that AMF was overexpressed in keloid fibroblasts (KFs) and the proliferation and migration of KFs were promoted by AMF stimulation. After treatment with Y-27632, RhoA kinase inhibitor, the proliferation and migration capacity of KFs declined significantly, and type I collagen protein, active RhoA and ROCK1 also were downregulated. In addition, a KD transplantation model was established under the skin of nude mice, with KD intramural injection AMF siRNA, we found that the weight of the KD was smaller than in the control group (P < 0.05), KD tissue sections stained by HE and Masson showed that fibers became loose and the blood vessels were visibly reduced. In conclusion, AMF siRNA is expected to be a novel strategy to treat KD by inhibiting signaling pathway of RhoA/ROCK1.

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.