MicroRNA Let-7b inhibits keratinocyte migration in cutaneous wound healing by targeting IGF2BP2

Inhibition of Let-7b-5p maturation by LIN28A promotes thermal skin damage repair after burn injury

Burn injuries, especially severe ones, result in direct and indirect thermal damage to skin tissues, with a complex and slow wound healing process. Improper treatment can induce sustained inflammatory responses, causing systemic damage. Lin28A, a highly conserved RNA binding protein, was found to exert a significant effect on cell proliferation and wound repair. Lin28A exerts the functions through inhibiting the maturation of the let-7 family miRNAs. Herein, the roles of Lin28A and let-7b in thermal injury repair were investigated using a mouse thermal injury model and a human skin fibroblast (HSF) model for thermal injuries. Lin28A could inhibit the maturation of let-7b, thus participating in skin repair after burns. In the animal model, Lin28A was highly expressed after thermal injury. In the HSF model for thermal injuries, downregulation of Lin28A inhibited the proliferation, migration, and extracellular matrix (ECM) generation of fibroblasts. When let-7b was knocked down in HSFs, the impacts on fibroblast functions caused by downregulation of Lin28A were partially reversed. Moreover, let-7b overexpression might significantly attenuate the promotive effects of Lin28A upon thermal injury repair. Finally, AKT2 and IGF1R were the let-7b target genes within cells. These findings reveal that Lin28A might promote thermal injury repair in burn-injured skin by inhibiting the maturation of let-7b and improving HSF viability and functions, thus illustrating the critical effect of let-7b on burn wound healing and providing new therapeutic targets and strategies for burn treatment.

circ-Amotl1 in extracellular vesicles derived from ADSCs improves wound healing by upregulating SPARC translation

Aim

This study aims to explore the mechanism of circ- AMOT-like protein 1 (Amotl1) in extracellular vesicles (Evs) derived from adipose-derived stromal cells (ADSCs) regulating SPARC translation in wound healing process.

Methods

The morphology, wound healing rate of the wounds and Ki67 positive rate in mouse wound healing models were assessed by H&E staining and immunohistochemistry (IHC). The binding of IGF2BP2 and SPARC was verified by RNA pull-down. Adipose-derived stromal cells (ADSCs) were isolated and verified. The Evs from ADSCs (ADSC-Evs) were analyzed.

Results

Overexpression of SPARC can promote the wound healing process in mouse models. IGF2BP2 can elevate SPARC expression to promote the proliferation and migration of HSFs. circ-Amotl1 in ADSC-Evs can increase SPARC expression by binding IGF2BP2 to promote the proliferation and migration of HSFs.

Conclusion

ADSC-Evs derived circ-Amotl1 can bind IGF2BP2 to increase SPARC expression and further promote wound healing process.

Landscape of the epigenetic regulation in wound healing

Wound healing after skin injury is a dynamic and highly coordinated process involving a well-orchestrated series of phases, including hemostasis, inflammation, proliferation, and tissue remodeling. Epigenetic regulation refers to genome-wide molecular events, including DNA methylation, histone modification, and non-coding RNA regulation, represented by microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA). Epigenetic regulation is pervasively occurred in the genome and emerges as a new role in gene expression at the post-transcriptional level. Currently, it is well-recognized that epigenetic factors are determinants in regulating gene expression patterns, and may provide evolutionary mechanisms that influence the wound microenvironments and the entire healing course. Therefore, this review aims to comprehensively summarize the emerging roles and mechanisms of epigenetic remodeling in wound healing. Moreover, we also pose the challenges and future perspectives related to epigenetic modifications in wound healing, which would bring novel insights to accelerated wound healing.

The role of insulin-like growth factor 2 mRNA binding proteins in female reproductive pathophysiology

Insulin-like growth factor 2 (IGF2) mRNA binding proteins (IMPs) family belongs to a highly conserved family of RNA-binding proteins (RBPs) and is responsible for regulating RNA processing including localization, translation and stability. Mammalian IMPs (IMP1-3) take part in development, metabolism and tumorigenesis, where they are believed to play a major role in cell growth, metabolism, migration and invasion. IMPs have been identified that are expressed in ovary, placenta and embryo. The up-to-date evidence suggest that IMPs are involved in folliculogenesis, oocyte maturation, embryogenesis, implantation, and placentation. The dysregulation of IMPs not only contributes to carcinogenesis but also disturbs the female reproduction, and may participate in the pathogenesis of reproductive diseases and obstetric syndromes, such as polycystic ovary syndrome (PCOS), pre-eclampsia (PE), gestational diabetes mellitus (GDM) and gynecological tumors. In this review, we summarize the role of IMPs in female reproductive pathophysiology, and hope to provide new insights into the identification of potential therapeutic targets.

Beyond the Code: Noncoding RNAs in Skin Wound Healing

An increasing number of noncoding RNAs (ncRNAs) have been found to regulate gene expression and protein functions, playing important roles in diverse biological processes and diseases. Their crucial functions have been reported in almost every cell type and all stages of skin wound healing. Evidence of their pathogenetic roles in common wound complications, such as chronic nonhealing wounds and excessive scarring, is also accumulating. Given their unique expression and functional properties, ncRNAs are promising therapeutic and diagnostic entities. In this review, we discuss current knowledge about the functional roles of noncoding elements, such as microRNAs, long ncRNAs, and circular RNAs, in skin wound healing, focusing on in vivo evidence from studies of human wound samples and animal wound models. Finally, we provide a perspective on the outlook of ncRNA-based therapeutics in wound care.

Identification of the circ_PRKDC/miR-20a-3p/RASA1 axis in regulating HaCaT keratinocyte migration

Migration of keratinocytes plays a crucial role in the re-epithelialization phase during wound healing. Circular RNA (circRNA) protein kinase, DNA-activated, catalytic subunit (circ_PRKDC, hsa_circ_0084443) has been identified as a regulator of keratinocyte migration. However, the molecular basis governing it remains unclear. The levels of circ_PRKDC, microRNA (miR)-20a-3p, and RAS p21 protein activator 1 (RASA1) were assessed by quantitative real-time PCR (qRT-PCR) or western blot. Subcellular localization, Actinomycin D, and Ribonuclease (RNase) R assays were performed to characterise circ_PRKDC. Cell migration was gauged by transwell and wound-healing assays. A direct relationship between miR-20a-3p and circ_PRKDC or RASA1 was verified by dual-luciferase reporter and RNA pull-down assays. Circ_PRKDC expression was reduced in wound skin during wound healing. Circ_PRKDC modulated migration of HaCaT keratinocytes. Mechanistically, circ_PRKDC directly targeted miR-20a-3p. The regulation of circ_PRKDC on HaCaT keratinocyte migration was mediated by miR-20a-3p. RASA1 was identified as a direct and functional target of miR-20a-3p, and miR-20a-3p-mediated inhibition of RASA1 impacted HaCaT keratinocyte migration. Circ_PRKDC acted as a post-transcriptional modulator of RASA1 expression through miR-20a-3p. Moreover, circ_PRKDC modulated migration of HaCaT keratinocytes by RASA1. Our findings demonstrated a novel molecular basis, the miR-20a-3p/RASA1 axis, for the regulation of circ_PRKDC on HaCaT keratinocyte migration.

Insulin-like growth factor 2 mRNA binding protein 2 regulates proliferation, migration, and angiogenesis of keratinocytes by modulating heparanase stability

Wound healing is related to proliferation, migration, and angiogenesis of keratinocytes. Insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) is an important N6-methyladenosine (m6A) reader, which is involved in multiple processes, including wound healing. However, the function and mechanism of IGF2BP2 in keratinocyte processes are largely uncertain. In the present study, expression levels of IGF2BP2 and heparanase (HPSE) were detected by quantitative reverse transcription polymerase chain reaction and western blotting assays. Cell proliferation was investigated by cell counting kit-8 (CCK-8) analysis. Cell migration was determined through wound healing assay. Angiogenesis was measured by tube formation assay and vascular endothelial growth factor (VEGF) level using enzyme linked immunosorbent assay (ELISA). The interaction between IGF2BP2 and HPSE was analyzed by RNA immunoprecipitation, pull-down and luciferase reporter analyses. The results showed that IGF2BP2 expression was enhanced in wound healing. IGF2BP2 downregulation constrained HaCaT cell proliferation, migration, and angiogenesis. IGF2BP2 knockdown decreased HPSE expression. IGF2BP2 could regulate HPSE stability by binding with 3ʹ untranslated region (UTR) of HPSE. HPSE upregulation attenuated silencing IGF2BP2-mediated suppression of proliferation, migration, and angiogenesis. As a conclusion, IGF2BP2 knockdown repressed proliferation, migration, and angiogenesis of HaCaT cells by decreasing HPSE stability.

The role of microRNAs in the pathogenesis, grading and treatment of hepatic fibrosis in schistosomiasis

Schistosomiasis is a prevalent parasitic disease worldwide. The main pathological changes of hepatosplenic schistosomiasis are hepatic granuloma and fibrosis due to worm eggs. Portal hypertension and ascites induced by hepatic fibrosis are usually the main causes of death in patients with chronic hepatosplenic schistosomiasis. Currently, no effective vaccine exists for preventing schistosome infections. For quite a long time, praziquantel (PZQ) was widely used for the treatment of schistosomiasis and has shown benefit in treating liver fibrosis. However, drug resistance and chemical toxicity from PZQ are being increasingly reported in recent years; therefore, new and effective strategies for treating schistosomiasis-induced hepatic fibrosis are urgently needed. MicroRNA (miRNA), a non-coding RNA, has been proved to be associated with the development of many human diseases, including schistosomiasis. In this review, we present a balanced and comprehensive view of the role of miRNAs in the pathogenesis, grading, and treatment of schistosomiasis-associated hepatic fibrosis. The multiple regulatory roles of miRNAs, such as promoting or inhibiting the development of liver pathology in murine schistosomiasis are also discussed in depth. Additionally, miRNAs may serve as candidate biomarkers for diagnosing liver pathology of schistosomiasis and as novel therapeutic targets for treating schistosomiasis-associated hepatic fibrosis.

MicroRNAs in Ocular Infection

MicroRNAs (miRNAs) are small, non-coding, regulatory RNA molecules and constitute a newly recognized, important layer of gene-expression regulation at post-transcriptional levels. miRNAs quantitatively fine tune the expression of their downstream genes in a cell type- and developmental stage-specific fashion. miRNAs have been proven to play important roles in the normal development and function as well as in the pathogenesis of diseases in all tissues and organ systems. miRNAs have emerged as new therapeutic targets and biomarkers for treatment and diagnosis of various diseases. Although miRNA research in ocular infection remains in its early stages, a handful of pioneering studies have provided insight into the roles of miRNAs in the pathogenesis of parasitic, fungal, bacterial, and viral ocular infections. Here, we review the current status of research in miRNAs in several major ocular infectious diseases. We predict that the field of miRNAs in ocular infection will greatly expand with the discovery of novel miRNA-involved molecular mechanisms that will inform development of new therapies and identify novel diagnostic biomarkers.

Identification of Specific miRNAs in Neutrophils of Type 2 Diabetic Mice: Overexpression of miRNA-129-2-3p Accelerates Diabetic Wound Healing

Neutrophils are involved in the first stage of acute inflammation. After injury, they are mobilized and recruited to the injured tissue. In diabetes, wound healing is delayed and aberrant, leading to excessive recruitment and retention of neutrophils that fail to promote angiogenesis and prolong inflammation. However, the exact pathological mechanisms of diabetic-derived neutrophils in chronic inflammation remain unclear. Here, miRNA profiling of neutrophils from bone marrow in type 2 diabetic mice was performed using a microarray. miRNAs regulate the posttranscriptional expression of target mRNAs and are important in countering inflammation-related diseases. Our study revealed that miRNAs exhibit differential expression in diabetic-derived neutrophils compared with non-diabetic-derived neutrophils, especially miR-129 family members. miR-129-2-3p directly regulated the translation of Casp6 and Ccr2, which are involved in inflammatory responses and apoptosis. Furthermore, miR-129-2-3p overexpression at the wound site of type 2 diabetic mice accelerated wound healing. These results suggest possible involvement of miR-129-2-3p in diabetic-derived neutrophil dysfunction and that retention kinetics of neutrophils and chronic inflammation may be initiated through miR-129-2-3p-regulated genes. This study characterizes changes in global miRNA expression in diabetic-derived neutrophils and systematically identifies critical target genes involved in certain biological processes related to the pathology of diabetic wound healing.

MicroRNA let-7b inhibits keratinocyte differentiation by targeting IL-6 mediated ERK signaling in psoriasis

Background

The extensive involvement of microRNA (miRNA) in the pathophysiology of psoriasis is well documented. However, in order for this information to be useful in therapeutic manipulation of miRNA levels, it is essential that detailed functional mechanisms are elucidated. This study aimed to explore the effects of IL-6 targeting by let-7b and ERK1/2 mediated signaling on keratinocyte differentiation in psoriasis.

Methods

Following imiquimod cream (IMQ) application to let-7b^TG (keratinocyte-specific let-7b overexpression mouse) and control mice for 7 days, we analyzed erythema, scaling and thickening of skin. A dual luciferase reporter assay and bioinformatics was carried out to detect target gene of let-7b. Additionally, the differentiation markers were measured. Immunohistochemistry analyses demonstrate a relationship of let-7b with IL-6 and ERK signaling.

Results

we found let-7b^TG inhibits acanthosis and reduces the disease severity by treatment with IMQ compared to wild-type mice. Further study illustrated that let-7b promotes differentiation of keratinocytes in vivo and in vitro. Using bioinformatics and reporter gene assays, we found that IL-6 is a target gene of let-7b. In psoriasis, high expression levels of IL-6 lead to increased acivation of p-ERK1/2. High levels of let-7b^TG transgene expression suppresses IL-6 expression and leads to increased keratinocyte differentiation. Moreover, let-7b acts as an upstream negative regulator of the ERK signaling pathway in keratinocytes of psoriasis.

Conclusions

Our result reveals a previously unknown mechanism for regulation of IL-6 levels during psoriasis by let-7b and highlights a critical role for the ERK1/2 signaling pathway in epidermal differentiation during psoriasis.

Trial registration

The ethical approval for this study was from the Affiliated Hospital of Medical University of Anhui _ Fast_ PJ2017–11–14.

Electronic supplementary material

The online version of this article (10.1186/s12964-018-0271-9) contains supplementary material, which is available to authorized users.

Identification and functional analysis of inflammation-related miRNAs in skin wound repair

Inflammation at a wound site is essential for preventing infection. However, misregulated inflammation leads to pathologies of the healing process, including chronic non-healing wounds and scarring. MicroRNAs (miRNAs) are key regulators of the inflammatory response and tissue repair, acting by translational processing of target mRNAs. In the final step of miRNA processing, Argonaute 2 (Ago2)-bound mature miRNA complexes bind to target mRNAs and inhibit their translation. A variety of wound healing-related miRNAs have been identified and their misregulation likely contributes to wound pathologies, including scarring and chronic healing. Recently, we have developed an Ago2-bound mature miRNA purification system that uses Ago2 antibody to analyze the expression of miRNAs from wound tissues by microarray and next generation sequencing. We have identified several wound inflammation-related miRNAs via Ago2-target immunoprecipitation assays and next generation sequencing of wound tissues from wild-type and PU.1 knockout mice, which exhibit no inflammatory response because of a lack of immune cell lineages. We demonstrated that miR-142, an identified inflammation-related miRNA, is essential role for neutrophilic chemotaxis via inhibition of small GTPase translation; its misregulation leads to susceptibility to infection against Staphylococcus aureus at skin wound sites. In this review, we summarize recent advances of miRNA studies in skin wound healing, introduce our miRNA purification system using an immunoprecipitation assay method, and discuss the function of miR-142 in skin wound healing.

Regulation function of MMP-1 downregulated by siRNA on migration of heat-denatured dermal fibroblasts

Cutaneous wound healing is a complex physiological process that requires the efforts of various cell types and signaling pathways and often results in thickened collagen-enriched healed tissue called a scar. Therefore, the identification of the mechanism of cutaneous wound healing is necessary and has great value in providing better treatment. Here, we demonstrated that MMP-1 inhibition could promote cell proliferation in dermal fibroblasts via the MTT assay. Meanwhile, we investigated cell migration by flow cytometry and tested type I collagenase activity. We found that MMP-1 inhibition promoted cell proliferation and inhibited cell migration and type I collagenase activity. In conclusion, our study demonstrated that MMP-1 might be a potential therapeutic target in cutaneous wound healing.

Telomerase reverse transcriptase mediates EMT through NF-κB signaling in tongue squamous cell carcinoma

Locoregional lymph nodes metastasis in oral tongue squamous cell carcinoma represents one of important and common prognostic factors for poor clinical outcome. The human Telomerase Reverse Transcriptase (hTERT) is one of key players in cancer metastasis and stemness, but its exact function in tongue squamous cell carcinoma remains unknown. Here, we aim to understand the role of hTERT by utilizing the CRISPR/Cas9 gene editing system to deplete hTERT in the SCC-15 cell line. Functional comparison of SCC-15 control and knockout cells (hTERT^−/−) showed that loss of hTERT suppressed cell proliferation and migration/invasion. Furthermore, hTERT depletion significantly decreased tumorigenesis, including alterations in cellular morphology that areindicative for epithelial-mesenchymal transition (EMT). Mechanistically we demonstrated that the hTERT knockout attenuates NF-κB signaling via a negative feedback regulation in tumorprogression. From these results we propose a novel molecular mechanism of hTERT to promote SCC-15 invasion and metastasis via NF-κB activation. We conclude that targeting hTERT may represent a new therapeutic strategy to improve therapy and survival of tongue squamous cell carcinoma patients.