The expression of miR-124 increases in aged skin to cause cell senescence and it decreases in squamous cell carcinoma

Role of non‑coding RNAs in UV‑induced radiation effects (Review)

Ultraviolet (UV) is divided into UVA (long-wave, 320-400 nm), UVB (middle-wave, 280-320 nm) and UVC (short-wave, 100-280 nm) based on wavelength. UV radiation (UVR) from sunlight (UVA + UVB) is a major cause of skin photodamage including skin inflammation, aging and pigmentation. Accidental exposure to UVC burns the skin and induces skin cancer. In addition to the skin, UV radiation can also impair visual function. Non-coding RNAs (ncRNAs) are a class of functional RNAs that do not have coding activity but can control cellular processes at the post-transcriptional level, including microRNA (miRNA), long non-coding RNA (lncRNA) and circulatory RNA (circRNA). Through a review of the literature, it was determined that UVR can affect the expression of various ncRNAs, and that this regulation may be wavelength specific. Functionally, ncRNAs participate in the regulation of photodamage through various pathways and play pathogenic or protective regulatory roles. In addition, ncRNAs that are upregulated or downregulated by UVR can serve as biomarkers for UV-induced diseases, aiding in diagnosis and prognosis assessment. Therapeutic strategies targeting ncRNAs, including the use of natural drugs and their extracts, have shown protective effects against UV-induced photodamage. In the present review, an extensive summarization of previous studies was performed and the role and mechanism of ncRNAs in UV-induced radiation effects was reviewed to aid in the diagnosis and treatment of UV-related diseases.

A hypothesis: MiRNA-124 mediated regulation of sirtuin 1 and vitamin D receptor gene expression accelerates aging

Objectives

Specific miRNAs are evident to be overexpressed with age, lifestyle, and environmental changes. Previous studies reported miR-124 overexpression in different scenarios in aged skin, age-related cognitive impairment, ischemic heart disease, muscle atrophy, and fractures. Thus miR-124 was considered to be a reliable miRNA target to establish a hypothesis on aging epigenome. Parallelly the hypothesis focuses on the expression of SIRT1 and VDR genes as a target for this specific miRNA expression as these genes were believed to be related to aging. This study aims to derive facts and evidence from past studies on aging. The objective was to establish a hypothetical linkage between miR-124 with age-related genes like SIRT1 and VDR.

Methods

An in silico search was performed in the TargetScan and miRbase databases to analyze the aging-associated miRNAs and their gene targets, the Python seaborn library was used, and the results were represented in terms of a bar plot.

Results

Based on an in silico analysis and studies available in the literature, we identified that miR-124-3p.1 and miR-124-3p.2 targets 3' UTR of VDR and SIRT1 genes, and hence thereby indicates that the miR-124 can regulate the expression of these genes. Further, few in vitro research studies have observed that miR-124 overexpression leads to the downregulation of VDR and SIRT1 gene expression. These results indicate that the suppression of these target genes accelerates early aging and age-related disorders.

Conclusions

Overall, this study hypothesizes that the overexpression of miR-124 diminishes the expression of VDR and SIRT1 genes, and thereby advances the process of aging, resulting in the development of age-associated complications.

MicroRNA-124 plays an inhibitory role in cutaneous squamous cell carcinoma cells via targeting SNAI2, an immunotherapy determinant

MicroRNAs (miRs) play multiple roles during cutaneous squamous cell carcinoma (CSCC) progression. Previous studies suggest miR-124 could inhibit cancer development in CSCC.

METHODS

Obtained 63 pairs of CSCC and adjacent tissues for analysis. Cultured HaCaT and two CSCC cell lines (A431 and SCL-1) in DMEM (10 % FBS). Transfected cells using Lipofectamine 2000 with various miR-124 mimics, inhibitors, or Snail family transcriptional repressor 2 (SNAI2) expression plasmid. Performed a series of assays, including real-time quantitative PCR, Western blot, CCK8, wound healing, transwell, and luciferase reporter gene assay, to examine the effects of miR-124 on CSCC cells.

RESULTS

An evident downregulation of miR-124 in CSCC tissues, which was related to advanced disease stage and nodal metastasis. Overexpressing miR-124 could reduce the proliferation, migration, and invasion abilities of CSCC cells. It was verified that miR-124 targets the SNAI2 in CSCC cells. Moreover, ectopic expression of SNAI2 rescued the suppressive effects on CSCC cells induced by miR-124 overexpression. Furthermore, miR-124 increased cell sensitivity to cisplatin. Besides, SNAI2 is a critical factor in the immune-related aspects of CSCC and its modulation may influence the response to immunotherapy.

CONCLUSION

We demonstrate that miR-124 inhibits CSCC progression through downregulating SNAI2, and thus it may be a molecular candidate for treating CSCC in the clinic.

Differential Expression of ATM, NF-KB, PINK1 and Foxo3a in Radiation-Induced Basal Cell Carcinoma

Research in normal tissue radiobiology is in continuous progress to assess cellular response following ionizing radiation exposure especially linked to carcinogenesis risk. This was observed among patients with a history of radiotherapy of the scalp for ringworm who developed basal cell carcinoma (BCC). However, the involved mechanisms remain largely undefined. We performed a gene expression analysis of tumor biopsies and blood of radiation-induced BCC and sporadic patients using reverse transcription-quantitative PCR. Differences across groups were assessed by statistical analysis. Bioinformatic analyses were conducted using miRNet. We showed a significant overexpression of the FOXO3a, ATM, P65, TNF-α and PINK1 genes among radiation-induced BCCs compared to BCCs in sporadic patients. ATM expression level was correlated with FOXO3a. Based on receiver-operating characteristic curves, the differentially expressed genes could significantly discriminate between the two groups. Nevertheless, TNF-α and PINK1 blood expression showed no statistical differences between BCC groups. Bioinformatic analysis revealed that the candidate genes may represent putative targets for microRNAs in the skin. Our findings may yield clues as to the molecular mechanism involved in radiation-induced BCC, suggesting that deregulation of ATM-NF-kB signaling and PINK1 gene expression may contribute to BCC radiation carcinogenesis and that the analyzed genes could represent candidate radiation biomarkers associated with radiation-induced BCC.

Epigenetic alterations-The silent indicator for early aging and age-associated health-risks

Aging is the process of gradual physiological deterioration till death and this process perpetually reduce the functionality of an individual. To address the rationale and provide geriatric care, the constant target of geroscience is to identify reliable biomarkers for aging. Over the past decades, diversified advancements in epigenetic studies crescively support the fact that the accumulation of epigenetic changes accompanies the process of aging. A growing number of studies have suggested that alterations occur through three fundamental mechanisms like methylation of DNA, histone protein modification, and production of non-coding microRNAs. Each of these changes occurs silently and provokes alterations in the circumstantial expression of genetic material without altering the underlying gene sequences. The changes in gene expression due to epigenetic alterations are suggested to be the cause of early aging and the onset of age-related health risks. This review would attempt to give an integrated overview of epigenetic changes related to aging and age-associated health risks. This review also discussed epigenomes influencing early aging and factors modulating it. Since epigenetic changes are reversible, early identification of epigenetic markers can be a hope for future geriatric medicine. Finally, this review emphasizes the identification of blood-based epigenetic biomarkers in order to enlighten the future scope for therapeutic intervention to slow down the aging process.

Progeria and Aging-Omics Based Comparative Analysis

Since ancient times aging has also been regarded as a disease, and humankind has always strived to extend the natural lifespan. Analyzing the genes involved in aging and disease allows for finding important indicators and biological markers for pathologies and possible therapeutic targets. An example of the use of omics technologies is the research regarding aging and the rare and fatal premature aging syndrome progeria (Hutchinson-Gilford progeria syndrome, HGPS). In our study, we focused on the in silico analysis of differentially expressed genes (DEGs) in progeria and aging, using a publicly available RNA-Seq dataset (GEO dataset GSE113957) and a variety of bioinformatics tools. Despite the GSE113957 RNA-Seq dataset being well-known and frequently analyzed, the RNA-Seq data shared by Fleischer et al. is far from exhausted and reusing and repurposing the data still reveals new insights. By analyzing the literature citing the use of the dataset and subsequently conducting a comparative analysis comparing the RNA-Seq data analyses of different subsets of the dataset (healthy children, nonagenarians and progeria patients), we identified several genes involved in both natural aging and progeria (KRT8, KRT18, ACKR4, CCL2, UCP2, ADAMTS15, ACTN4P1, WNT16, IGFBP2). Further analyzing these genes and the pathways involved indicated their possible roles in aging, suggesting the need for further in vitro and in vivo research. In this paper, we (1) compare "normal aging" (nonagenarians vs. healthy children) and progeria (HGPS patients vs. healthy children), (2) enlist genes possibly involved in both the natural aging process and progeria, including the first mention of IGFBP2 in progeria, (3) predict miRNAs and interactomes for WNT16 (hsa-mir-181a-5p), UCP2 (hsa-mir-26a-5p and hsa-mir-124-3p), and IGFBP2 (hsa-mir-124-3p, hsa-mir-126-3p, and hsa-mir-27b-3p), (4) demonstrate the compatibility of well-established R packages for RNA-Seq analysis for researchers interested but not yet familiar with this kind of analysis, and (5) present comparative proteomics analyses to show an association between our RNA-Seq data analyses and corresponding changes in protein expression.

Non-coding RNAs in photoaging-related mechanisms: a new paradigm in skin health

The aging of skin is a biological process affected by environmental or genetic factors. Exposure to ultraviolet (UV) radiation is the main environmental factor causing skin aging. Cumulative UV-induced photodamage of the skin tissue is associated with premature cellular senescence, extracellular degradation, and inflammatory responses in photoaging processes. Non-coding RNAs (ncRNAs) are untranslated transcripts and master regulators of protein-coding genes. ncRNAs have a critical regulatory role in maintaining skin structure, skin barrier function, morphogenesis, and development. Altered ncRNA expression has been reported in various skin disorders such as photoaging and skin cancers. ncRNAs contribute to the suppression and promotion of photoaging by modulating signaling pathways such as mitogen-activated protein kinase (MAPK) pathway and regulating inflammatory cytokines, matrix metalloproteinases (MMPs), and senescence-associated genes. Elucidation of the functions of ncRNAs will improve the identification of molecular mechanisms underlying photoaging, and can be used in the development of therapeutic approaches in skin health and prevention of sun-induced aging. This review summarized the currently described ncRNAs and their functions in photoaging.

Spectrum of microRNAs and their target genes in cancer: intervention in diagnosis and therapy

Till date, several groups have studied the mechanism of microRNA (miRNA) biogenesis, processing, stability, silencing, and their dysregulation in cancer. The miRNA coding genes recurrently go through abnormal amplification, deletion, transcription, and epigenetic regulation in cancer. Some miRNAs function as tumor promoters while few others are tumor suppressors based on the transcriptional regulation of target genes. A review of miRNAs and their target genes in a wide range of cancers is attempted in this article, which may help in the development of new diagnostic tools and intervention therapies. The contribution of miRNAs for drug sensitivity or resistance in cancer therapy and opportunities of miRNAs in cancer prognosis or diagnosis and therapy is also presented in detail.

Targeting microRNA for improved skin health

BACKGROUND

In human skin, miRNAs have important regulatory roles and are involved in the development, morphogenesis, and maintenance by influencing cell proliferation, differentiation, immune regulation, and wound healing. MiRNAs have been investigated for many years in various skin disorders such as atopic dermatitis, psoriasis, as well as malignant tumors. Only during recent times, cosmeceutical use of molecules/natural active ingredients to regulate miRNA expression for significant advances in skin health/care product development was recognized.

AIM

To review miRNAs with the potential to maintain and boost skin health and avoid premature aging by improving barrier function, preventing photoaging, hyperpigmentation, and chronological aging/senescence.

METHODS

Most of the cited articles were found through literature search on PubMed. The main search criteria was a keyword "skin" in combination with the following words: miRNA, photoaging, UV, barrier, aging, exposome, acne, wound healing, pigmentation, pollution, and senescence. Most of the articles reviewed for relevancy were published during the past 10 years.

RESULTS

All results are summarized in Figure 1, and they are based on cited references.

CONCLUSIONS

Thus, regulating miRNAs expression is a promising approach for novel therapy not only for targeting skin diseases but also for cosmeceutical interventions aiming to boost skin health.

Exosomes and Micro-RNAs in Aging Process

Exosomes are the main actors of intercellular communications and have gained great interest in the new cell-free regenerative medicine. These nanoparticles are secreted by almost all cell types and contain lipids, cytokines, growth factors, messenger RNA, and different non-coding RNA, especially micro-RNAs (mi-RNAs). Exosomes' cargo is released in the neighboring microenvironment but is also expected to act on distant tissues or organs. Different biological processes such as cell development, growth and repair, senescence, migration, immunomodulation, and aging, among others, are mediated by exosomes and principally exosome-derived mi-RNAs. Moreover, their therapeutic potential has been proved and reinforced by their use as biomarkers for disease diagnostics and progression. Evidence has increasingly shown that exosome-derived mi-RNAs are key regulators of age-related diseases, and their involvement in longevity is becoming a promising issue. For instance, mi-RNAs such as mi-RNA-21, mi-RNA-29, and mi-RNA-34 modulate tissue functionality and regeneration by targeting different tissues and involving different pathways but might also interfere with long life expectancy. Human mi-RNAs profiling is effectively related to the biological fluids that are reported differently between young and old individuals. However, their underlying mechanisms modulating cell senescence and aging are still not fully understood, and little was reported on the involvement of mi-RNAs in cell or tissue longevity. In this review, we summarize exosome biogenesis and mi-RNA synthesis and loading mechanism into exosomes' cargo. Additionally, we highlight the molecular mechanisms of exosomes and exosome-derived mi-RNA regulation in the different aging processes.

Skin Immunomodulation during Regeneration: Emerging New Targets

Adipose-Derived Stem Cells (ADSC) are present within the hypodermis and are also expected to play a pivotal role in wound healing, immunomodulation, and rejuvenation activities. They orchestrate, through their exosome, the mechanisms associated to cell differentiation, proliferation, and cell migration by upregulating genes implicated in different functions including skin barrier, immunomodulation, cell proliferation, and epidermal regeneration. ADSCs directly interact with their microenvironment and specifically the immune cells, including macrophages and T and B cells, resulting in differential inflammatory and anti-inflammatory mechanisms impacting, in return, ADSCs microenvironment and thus skin function. These useful features of ADSCs are involved in tissue repair, where the required cell proliferation, angiogenesis, and anti-inflammatory responses should occur rapidly in damaged sites. Different pathways involved have been reported such as Growth Differentiation Factor-11 (GDF11), Tumor Growth Factor (TGF)-β, Metalloproteinase (MMP), microRNA, and inflammatory cytokines that might serve as specific biomarkers of their immunomodulating capacity. In this review, we try to highlight ADSCs’ network and explore the potential indicators of their immunomodulatory effect in skin regeneration and aging. Assessment of these biomarkers might be useful and should be considered when designing new clinical therapies using ADSCs or their specific exosomes focusing on their immunomodulation activity.

The bright and dark side of skin senescence. Could skin rejuvenation anti-senescence interventions become a "bright" new strategy for the prevention of age-related skin pathologies?

The number of senescent cells in the skin is increasing with age. Numerous studies have attempted to elucidate the role of these cells in normal aging of the skin as well as in age-related skin conditions. In recent years, attempts have also been made to find treatments that aim either to cleanse the skin tissues of senescent cells or to neutralize their effects (referred to as senolytics and senomorphics respectively) and thus prevent the consequences, particularly on the skin's appearance in advanced age. Through this review, we have tried to gather data on the role of senescent cells in the skin, in treatments aimed at removing them, and we are asking a reasonable question as to whether anti-senescence treatments may contribute to the protection against age-related skin pathologies, including skin cancer, such as non-melanoma skin cancer, in addition to their involvement in skin rejuvenation.

Elevated miR-124-3p in the aging colon disrupts mucus barrier and increases susceptibility to colitis by targeting T-synthase

The risk of colitis and colorectal cancer increases markedly throughout adult life, endangering the health and lives of elderly individuals. Previous studies have proposed that bacterial translocation and infection are the main risk factors for these diseases. Therefore, in the present study, we aimed to identify the underlying mechanism by focusing on the mucus barrier function and mucin‐type O‐glycosylation. We evaluated alterations in the colon mucus layer in 2‐, 16‐, and 24‐month‐old mice and aged humans. Aged colons showed defective intestinal mucosal barrier and changed mucus properties. The miR‐124‐3p expression level was significantly increased in the aged distal colonic mucosa, which was accompanied by an increase in pathogens and bacterial translocation. Meanwhile, T‐synthase, the rate‐limiting enzyme in O‐glycosylation, displayed an age‐related decline in protein expression. Further experiments indicated that miR‐124‐3p modulated O‐glycosylation by directly targeting T‐synthase. Moreover, young mice overexpressing miR‐124‐3p exhibited abnormal glycosylation, early‐onset, and more severe colitis. These data suggest that miR‐124‐3p predisposes to senile colitis by reducing T‐synthase, and the miR‐124‐3p/T‐synthase/O‐glycans axis plays an essential role in maintaining the physiochemical properties of colonic mucus and intestinal homeostasis.

UV-type specific alteration of miRNA expression and its association with tumor progression and metastasis in SCC cell lines

PURPOSE

UV exposure is the main risk factor for development of cutaneous squamous cell carcinoma (cSCC). While early detection greatly improves cSCC prognosis, locally advanced or metastatic cSCC has a severely impaired prognosis. Notably, the mechanisms of progression to metastatic cSCC are not well understood. We hypothesized that UV exposure of already transformed epithelial cSCC cells further induces changes which might be involved in the progression to metastatic cSCCs and that UV-inducible microRNAs (miRNAs) might play an important role.

METHODS

Thus, we analyzed the impact of UV radiation of different quality (UVA, UVB, UVA + UVB) on the miRNA expression pattern in established cell lines generated from primary and metastatic cSCCs (Met-1, Met-4) using the NanoString nCounter platform.

RESULTS

This analysis revealed that the expression pattern of miRNAs depends on both the cell line used per se and on the quality of UV radiation. Comparison of UV-induced miRNAs in cSCC cell lines established from a primary tumor (Met-1) and the respective (un-irradiated) metastasis (Met-4) suggest that miR-7-5p, miR-29a-3p and miR-183-5p are involved in a UV-driven pathway of progression to metastasis. This notion is supported by the fact that these three miRNAs build up a network of 81 potential target genes involved e.g. in UVA/UVB-induced MAPK signaling and regulation of the epithelial-mesenchymal transition. As an example, PTEN, a target of UV-upregulated miRNAs (miR-29a-3p, miR-183-5p), could be shown to be down-regulated in response to UV radiation. We further identified CNOT8, the transcription complex subunit 8 of the CCR4-NOT complex, a deadenylase removing the poly(A) tail from miRNA-destabilized mRNAs, in the center of this network, targeted by all three miRNAs.

CONCLUSION

In summary, our results demonstrate that UV radiation induces an miRNA expression pattern in primary SCC cell line partly resembling those of metastatic cell line, thus suggesting that UV radiation impacts SCC progression beyond initiation.

Hopes and Limits of Adipose-Derived Stem Cells (ADSCs) and Mesenchymal Stem Cells (MSCs) in Wound Healing

Adipose tissue derived stem cells (ADSCs) are mesenchymal stem cells identified within subcutaneous tissue at the base of the hair follicle (dermal papilla cells), in the dermal sheets (dermal sheet cells), in interfollicular dermis, and in the hypodermis tissue. These cells are expected to play a major role in regulating skin regeneration and aging-associated morphologic disgraces and structural deficits. ADSCs are known to proliferate and differentiate into skin cells to repair damaged or dead cells, but also act by an autocrine and paracrine pathway to activate cell regeneration and the healing process. During wound healing, ADSCs have a great ability in migration to be recruited rapidly into wounded sites added to their differentiation towards dermal fibroblasts (DF), endothelial cells, and keratinocytes. Additionally, ADSCs and DFs are the major sources of the extracellular matrix (ECM) proteins involved in maintaining skin structure and function. Their interactions with skin cells are involved in regulating skin homeostasis and during healing. The evidence suggests that their secretomes ensure: (i) The change in macrophages inflammatory phenotype implicated in the inflammatory phase, (ii) the formation of new blood vessels, thus promoting angiogenesis by increasing endothelial cell differentiation and cell migration, and (iii) the formation of granulation tissues, skin cells, and ECM production, whereby proliferation and remodeling phases occur. These characteristics would be beneficial to therapeutic strategies in wound healing and skin aging and have driven more insights in many clinical investigations. Additionally, it was recently presented as the tool key in the new free-cell therapy in regenerative medicine. Nevertheless, ADSCs fulfill the general accepted criteria for cell-based therapies, but still need further investigations into their efficiency, taking into consideration the host-environment and patient-associated factors.

New Insights for Cellular and Molecular Mechanisms of Aging and Aging-Related Diseases: Herbal Medicine as Potential Therapeutic Approach

Aging is a progressive disease affecting around 900 million people worldwide, and in recent years, the mechanism of aging and aging-related diseases has been well studied. Treatments for aging-related diseases have also made progress. For the long-term treatment of aging-related diseases, herbal medicine is particularly suitable for drug discovery. In this review, we discuss cellular and molecular mechanisms of aging and aging-related diseases, including oxidative stress, inflammatory response, autophagy and exosome interactions, mitochondrial injury, and telomerase damage, and summarize commonly used herbals and compounds concerned with the development of aging-related diseases, including Ginkgo biloba, ginseng, Panax notoginseng, Radix astragali, Lycium barbarum, Rhodiola rosea, Angelica sinensis, Ligusticum chuanxiong, resveratrol, curcumin, and flavonoids. We also summarize key randomized controlled trials of herbal medicine for aging-related diseases during the past ten years. Adverse reactions of herbs were also described. It is expected to provide new insights for slowing aging and treating aging-related diseases with herbal medicine.

Royal jelly regulates the proliferation of human dermal microvascular endothelial cells through the down-regulation of a photoaging-related microRNA

Although royal jelly is believed to prevent skin aging, the underlying mechanism is not known in detail. In the present study, we investigated the plausibility of the involvement of microRNAs in the manifestation of this effect of royal jelly. The expression of microRNAs was determined by PCR array analysis and real-time PCR and the number of cells was counted with a cell counter. Using PCR array, we identified four microRNAs that were downregulated by royal jelly in cultured human dermal microvascular endothelial cells (HDMEC). Upon comparison of the expression of the four microRNAs between young and senescent facial skin, miR-129-5p was found to be significantly upregulated in senescent skin. Consistently, the expression of miR-129-5p in HDMEC was significantly increased by UVB radiation, suggesting that this microRNA is related to photoaging. The royal jelly treatment increased the number of HDMEC. Furthermore, forced overexpression of miR-129-5p resulted in significant decrease in the number of HDMEC, and its forced downregulation increased the number of cells. The number and density of vessels is reported to be decreased in aged skin. Our results indicate that miR-129-5p is induced in damaged endothelial cells upon exposure to UV radiation, which decreases the cell number. Furthermore, administration of royal jelly downregulated the expression of miR-129-5p in endothelial cells, and might prevent skin aging by maintaining the number of cells. The present study elucidates the mechanism of vessel aging caused by UV exposure and the anti-aging effects of royal jelly through the involvement of microRNA.

A potential significance of circ_0024169 down regulation in angiosarcoma tissue

Circular RNAs (circRNAs) are recently characterized non-coding RNAs that have a closed continuous loop. CircRNAs might play important roles in the oncogenesis of several cancers. However, little is known about association between circRNAs and skin tumors. In this study, we tried to demonstrate the expression change of circ_0024169 in angiosarcoma, and to elucidate correlations between circ_0024169 expression in angiosarcoma tissues and clinical manifestation. RNA expression was evaluated by quantitative real-time PCR with TaqMan systems for circ_0024169 and linear isoform CUL5. Both relative circRNA levels (corrected for EEF1A1 levels) and circRNA levels/linear RNA expression ratio were evaluated. We found that both relative circ_0024169 levels and circ_0024169/CUL5 ratio was decreased in normal human dermal microvascular endothelial cells (HDMEC) and angiosarcoma cell line in vitro, compared to squamous cell carcinoma line. circ_0024169/ CUL5 ratio was significantly reduced in angiosarcoma and pyogenic granuloma than other tumors in vivo, which were more evident than decreased relative circ_0024169 levels. On the other hand, relative circ_0024169 levels showed mild inverse correlation with the follow-up periods (duration between the first hospital visit and the last hospital visit/the date of death) of angiosarcoma patients. Taken together, circ_0024169/CUL5 ratio are likely to be useful as a diagnostic biomarker for vascular tumors, whereas circ_0024169 levels may have more potential as a prognostic marker of angiosarcoma. The future studies of the function of circRNAs may lead to the clarification of detailed mechanism of oncogenesis of angiosarcoma.

MicroRNA and Human Bone Health

The small non‐coding microRNAs (miRNAs) are post‐transcription regulators that modulate diverse cellular process in bone cells. Because optimal miRNA targeting is essential for their function, single‐nucleotide polymorphisms (SNPs) within or proximal to the loci of miRNA (miR‐SNPs) or mRNA (PolymiRTS) could potentially disrupt the miRNA‐mRNA interaction, leading to changes in bone metabolism and osteoporosis. Recent human studies of skeletal traits using miRNA profiling, genomewide association studies, and functional studies started to decipher the complex miRNA regulatory network. These studies have indicated that miRNAs may be a promising bone marker. This review focuses on human miRNA studies on bone traits and discusses how genetic variants affect bone metabolic pathways. Major ex vivo investigations using human samples supported with animal and in vitro models have shed light on the mechanistic role of miRNAs. Furthermore, studying the miRNAs’ signatures in secondary osteoporosis and osteoporotic medications such as teriparatide (TPTD) and denosumab (DMab) have provided valuable insight into clinical management of the disease. © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research

Identification of microRNA-124 in regulation of Hepatocellular carcinoma through BIRC3 and the NF-κB pathway

MicroRNAs (miRNAs) being proved to be involved in the carcinogenesis of numerous tumors. MicroRNA-124 (miR-124), identified as a tumor suppressor, has been demonstrated to exert pivotal roles in multiple processes of tumorigenesis. The present study demonstrated that miR-124 was low-expressed in human hepatocellular carcinoma (HCC) tissues and cell lines. In addition, overexpression of miR-124 through infected with miR-124 lentivirus inhibited the proliferation and migration of HCC in vitro and tumorigenesis in vivo, whereas inhibition of miR-124 expression can reverse the process. Moreover, Baculoviral IAP Repeat Containing 3 (BIRC3) was identified as a target gene of miR-124. The BIRC3 mRNA expression was increased in HCC tissues and negatively correlated with miR-124 expression. Knockdown of BIRC3 recovered the miR-124-induced inhibiting effect on HCC progression. Furthermore, we found that up-regulation of miR-124 significantly inhibited p-P65, p-IκBα and c-Myc proteins expression. However, the effect of miR-124 up-regulation on HCC development was partly reversed by BIRC3 restoration. In conclusion, our data proved that miR-124 inhibits the proliferation and migration of HCC at least partly through targeting BIRC3 and regulating NF-κB signaling pathway, and it may be a therapeutic target for HCC prognosis.

Towards topical microRNA-directed therapy for epidermal disorders

There remains an unmet dermatological need for innovative topical agents that achieve better longterm outcomes with fewer side effects. Modulation of the expression and activity of microRNA (miRNAs) represents an emerging translational framework for the development of such innovative therapies because changes in the expression of one miRNA can have wide-ranging effects on diverse cellular processes associated with disease. In this short review, the roles of miRNA in epidermal development, psoriasis, cutaneous squamous cell carcinoma and re-epithelisation are highlighted. Consideration is given to the delivery of oligonucleotides that mimic or inhibit miRNA function using vehicles such as cell penetrating peptides, spherical nucleic acids, deformable liposomes and liquid crystalline nanodispersions. Formulation of miRNA-directed oligonucleotides with such skin-penetrating epidermal agents will drive the development of RNA-based cutaneous therapeutics for deployment as primary or adjuvant therapies for epidermal disorders.

Transforming growth factor β-inhibitor Repsox downregulates collagen expression of scleroderma dermal fibroblasts and prevents bleomycin-induced mice skin fibrosis

Inhibition of transforming growth factor (TGF)-β1 signalling may be one of the most reliable approaches to treat skin fibrosis of scleroderma. Although there have been many basic researches of TGF-β blockade reagents, few of them were proved to have inhibitory effects on fibrosis both in vitro and in vivo. In this study, we randomly chose four commercially available low molecular weight compounds (Repsox, LY2109761, LY364947 and K02288) from TGF-β1 inhibitor library, and compared their antifibrotic effects in vitro and in vivo. We demonstrated that Repsox has the most potent inhibitory effects on TGF-β-induced expression of CTGF and collagen of cultured normal dermal fibroblasts in vitro and their constitutive overexpression of scleroderma fibroblast in vitro. In addition, Repsox could attenuate skin fibrosis by bleomycin in vivo, via the downregulation of CTGF or collagen. Our results may facilitate clinical trial of Repsox against fibrotic diseases in future.

NutrimiRAging: Micromanaging Nutrient Sensing Pathways through Nutrition to Promote Healthy Aging

Current sociodemographic predictions point to a demographic shift in developed and developing countries that will result in an unprecedented increase of the elderly population. This will be accompanied by an increase in age-related conditions that will strongly impair human health and quality of life. For this reason, aging is a major concern worldwide. Healthy aging depends on a combination of individual genetic factors and external environmental factors. Diet has been proved to be a powerful tool to modulate aging and caloric restriction has emerged as a valuable intervention in this regard. However, many questions about how a controlled caloric restriction intervention affects aging-related processes are still unanswered. Nutrient sensing pathways become deregulated with age and lose effectiveness with age. These pathways are a link between diet and aging. Thus, fully understanding this link is a mandatory step before bringing caloric restriction into practice. MicroRNAs have emerged as important regulators of cellular functions and can be modified by diet. Some microRNAs target genes encoding proteins and enzymes belonging to the nutrient sensing pathways and, therefore, may play key roles in the modulation of the aging process. In this review, we aimed to show the relationship between diet, nutrient sensing pathways and microRNAs in the context of aging.