Epigenetics of the non-coding RNA nc886 across blood, adipose tissue and skeletal muscle in offspring exposed to diabetes in pregnancy.

BACKGROUND: Diabetes in pregnancy is associated with increased risk of long-term metabolic disease in the offspring, potentially mediated by in utero epigenetic variation. Previously, we identified multiple differentially methylated single CpG sites in offspring of women with gestational diabetes mellitus (GDM), but whether stretches of differentially methylated regions (DMRs) can also be identified in adolescent GDM offspring is unknown. Here, we investigate which DNA regions in adolescent offspring are differentially methylated in blood by exposure to diabetes in pregnancy. The secondary aim was to characterize the RNA expression of the identified DMR, which contained the nc886 non-coding RNA. METHODS: To identify DMRs, we employed the bump hunter method in samples from young (9-16 yr, n = 92) offspring of women with GDM (O-GDM) and control offspring (n = 94). Validation by pyrosequencing was performed in an adult offspring cohort (age 28-33 years) consisting of O-GDM (n = 82), offspring exposed to maternal type 1 diabetes (O-T1D, n = 67) and control offspring (O-BP, n = 57). RNA-expression was measured using RT-qPCR in subcutaneous adipose tissue and skeletal muscle. RESULTS: One significant DMR represented by 10 CpGs with a bimodal methylation pattern was identified, located in the nc886/VTRNA2-1 non-coding RNA gene. Low methylation status across all CpGs of the nc886 in the young offspring was associated with maternal GDM. While low methylation degree in adult offspring in blood, adipose tissue, and skeletal muscle was not associated with maternal GDM, adipose tissue nc886 expression was increased in O-GDM compared to O-BP, but not in O-T1D. In addition, adipose tissue nc886 expression levels were positively associated with maternal pre-pregnancy BMI (p = 0.006), but not with the offspring's own adiposity. CONCLUSIONS: Our results highlight that nc886 is a metastable epiallele, whose methylation in young offspring is negatively correlated with maternal obesity and GDM status. The physiological effect of nc886 may be more important in adipose tissue than in skeletal muscle. Further research should aim to investigate how nc886 regulation in adipose tissue by exposure to GDM may contribute to development of metabolic disease.

Systemic inflammation activates coagulation and immune cell infiltration pathways in brains with propagating α-synuclein fibril aggregates.

Synucleinopathies are a group of diseases characterized by brain aggregates of α-synuclein (α-syn). The gradual accumulation of α-syn and the role of inflammation in early-stage pathogenesis remain poorly understood. We explored this interaction by inducing chronic inflammation in a common pre-clinical synucleinopathy mouse model. Three weeks post unilateral intra-striatal injections of human α-syn pre-formed fibrils (PFF), mice underwent repeated intraperitoneal injections of 1 mg/ml lipopolysaccharide (LPS) for 3 weeks. Histological examinations of the ipsilateral site showed phospho-α-syn regional spread and LPS-induced neutrophil recruitment to the brain vasculature. Biochemical assessment of the contralateral site confirmed spreading of α-syn aggregation to frontal cortex and a rise in intracerebral TNF-α, IL-1ß, IL-10 and KC/GRO cytokines levels due to LPS. No LPS-induced exacerbation of α-syn pathology load was observed at this stage. Proteomic analysis was performed contralateral to the PFF injection site using LC-MS/MS. Subsequent downstream Reactome Gene-Set Analysis indicated that α-syn pathology alters mitochondrial metabolism and synaptic signaling. Chronic LPS-induced inflammation further lead to an overrepresentation of pathways related to fibrin clotting as well as integrin and B cell receptor signaling. Western blotting confirmed a PFF-induced increase in fibrinogen brain levels and a PFF + LPS increase in Iba1 levels, indicating activated microglia. Splenocyte profiling revealed changes in T and B cells, monocytes, and neutrophils populations due to LPS treatment in PFF injected animals. In summary, early α-syn pathology impacts energy homeostasis pathways, synaptic signaling and brain fibrinogen levels. Concurrent mild systemic inflammation may prime brain immune pathways in interaction with peripheral immunity.

Opportunities and barriers in omics-based biomarker discovery for steatotic liver diseases.

The rising prevalence of liver diseases related to obesity and excessive use of alcohol is fuelling an increasing demand for accurate biomarkers aimed at community screening, diagnosis of steatohepatitis and significant fibrosis, monitoring, prognostication and prediction of treatment efficacy. Breakthroughs in omics methodologies and the power of bioinformatics have created an excellent opportunity to apply technological advances to clinical needs, for instance in the development of precision biomarkers for personalised medicine. Via omics technologies, biological processes from the genes to circulating protein, as well as the microbiome - including bacteria, viruses and fungi, can be investigated on an axis. However, there are important barriers to omics-based biomarker discovery and validation, including the use of semi-quantitative measurements from untargeted platforms, which may exhibit high analytical, inter- and intra-individual variance. Standardising methods and the need to validate them across diverse populations presents a challenge, partly due to disease complexity and the dynamic nature of biomarker expression at different disease stages. Lack of validity causes lost opportunities when studies fail to provide the knowledge needed for regulatory approvals, all of which contributes to a delayed translation of these discoveries into clinical practice. While no omics-based biomarkers have matured to clinical implementation, the extent of data generated has enabled the hypothesis-free discovery of a plethora of candidate biomarkers that warrant further validation. To explore the many opportunities of omics technologies, hepatologists need detailed knowledge of commonalities and differences between the various omics layers, and both the barriers to and advantages of these approaches.

Advances in extracellular vesicles as mediators of cell-to-cell communication in pregnancy.

Cell-to-cell communication mediated by Extracellular Vesicles (EVs) is a novel and emerging area of research, especially during pregnancy, in which placenta derived EVs can facilitate the feto-maternal communication. EVs comprise a heterogeneous group of vesicle sub-populations with diverse physical and biochemical characteristics and originate by specific biogenesis mechanisms. EVs transfer molecular cargo (including proteins, nucleic acids, and lipids) between cells and are critical mediators of cell communication. There is growing interest among researchers to explore into the molecular cargo of EVs and their functions in a physiological and pathological context. For example, inflammatory mediators such as cytokines are shown to be released in EVs and EVs derived from immune cells play key roles in mediating the immune response as well as immunoregulatory pathways. Pregnancy complications such as gestational diabetes mellitus, preeclampsia, intrauterine growth restriction and preterm birth are associated with altered levels of circulating EVs, with differential EV cargo and bioactivity in target cells. This implicates the intriguing roles of EVs in reprogramming the maternal physiology during pregnancy. Moreover, the capacity of EVs to carry bioactive molecules makes them a promising tool for biomarker development and targeted therapies in pregnancy complications. This review summarizes the physiological and pathological roles played by EVs in pregnancy and pregnancy-related disorders and describes the potential of EVs to be translated into clinical applications in the diagnosis and treatment of pregnancy complications.

Tailed-Hoogsteen Triplex DNA Silver Nanoclusters Emit Red Fluorescence upon Target miRNA Sensing.

MicroRNAs (miRNAs) are small RNA molecules, typically 21‒22 nucleotides in size, which play a crucial role in regulating gene expression in most eukaryotes. Their significance in various biological processes and disease pathogenesis has led to considerable interest in their potential as biomarkers for diagnosis and therapeutic applications. In this study, a novel method for sensing target miRNAs using Tailed-Hoogsteen triplex DNA-encapsulated Silver Nanoclusters (DNA/AgNCs) is introduced. Upon hybridization of a miRNA with the tail, the Tailed-Hoogsteen triplex DNA/AgNCs exhibit a pronounced red fluorescence, effectively turning on the signal. It is successfully demonstrated that this miRNA sensor not only recognized target miRNAs in total RNA extracted from cells but also visualized target miRNAs when introduced into live cells, highlighting the advantages of the turn-on mechanism. Furthermore, through gel-fluorescence assays and small-angle X-ray scattering (SAXS) analysis, the turn-on mechanism is elucidated, revealing that the Tailed-Hoogsteen triplex DNA/AgNCs undergo a structural transition from a monomer to a dimer upon sensing the target miRNA. Overall, the findings suggest that Tailed-Hoogsteen triplex DNA/AgNCs hold great promise as practical sensors for small RNAs in both in vitro and cell imaging applications.

Analysis of the transcriptional pathways associated with the induction of quiescent embryonic arrest in the calanoid copepod Acartia tonsa.

The copepod species Acartia tonsa (Dana)(Crustacea) have the unique ability to induce quiescent embryonic dormancy if adverse environmental conditions occur; a characteristic shared by 41 other species belonging to the superfamily Centropagoida in the Calanoida order. However, the transcriptional changes characterizing this process are not known. Here, we compare the transcriptome of embryos in arrested quiescence with the normal development to identify pathways and differentially regulated transcripts involved in quiescent embryogenesis. Quiescence was induced by incubating eggs at 4 °C with anoxia for 26 h(hr), while eggs undergoing normal immediate development were incubated at 16.9 °C in normoxia for 7 h (where gastrulation occurs) or 14 h (where organogenesis occurs) before collecting for RNA extraction and analysis by RNA-sequencing. Results indicate that the expression profile of the quiescent embryo is not as different from the normal embryonic gastrulation as initially expected: None of the mapped transcripts is uniquely expressed in quiescence. Moreover, in quiescence a large proportion of the annotated transcripts display expression values halfway in-between the normal, immediate developmental stages of gastrulation and organogenesis. In depth comparison between the organogenesis stage and quiescent samples, reveal a high degree of divergence, confirming that a developmental arrest has been induced through quiescence. Specifically: Stress response transcripts are prominent in the quiescent phase with a transcript like the mammalian autophagy gene Sequestosome-1/p62 (SQSTM) being upregulated. The present analysis provides a better understanding of the molecular mechanisms characterizing the quiescent embryonic state of A. tonsa.

Circulating microRNAs for Early Diagnosis of Ovarian Cancer: A Systematic Review and Meta-Analysis.

In this study, we conducted a systematic review and meta-analysis to summarize and evaluate the global research potential of different circulating miRNAs as an early diagnostic biomarker for OC. A systematic literature search for relevant studies was conducted in June 2020 and followed up in November 2021. The search was conducted in English databases (PubMed, ScienceDirect). The primary search resulted in a total of 1887 articles, which were screened according to the prior established inclusion and exclusion criteria. We identified 44 relevant studies, of which 22 were eligible for the quantitative meta-analysis. Statistical analysis was performed using the Meta-package in Rstudio. Standardized mean differences (SMD) of relative levels between control subjects and OC patients were used to evaluate the differential expression. All studies were quality evaluated using a Newcastle-Ottawa Scale. Based on the meta-analysis, nine miRNAs were identified as dysregulated in OC patients compared to controls. Nine were upregulated in OC patients compared to controls (miR-21, -125, -141, -145, -205, -328, -200a, -200b, -200c). Furthermore, miR-26, -93, -106 and -200a were analyzed, but did not present an overall significant difference between OC patients and controls. These observations should be considered when performing future studies of circulating miRNAs in relation to OC: sufficient size of clinical cohorts, development of consensus guidelines for circulating miRNA measurements, and coverage of previously reported miRNAs.

Circulating microRNA as Biomarkers for Gestational Diabetes Mellitus-A Systematic Review and Meta-Analysis.

Gestational diabetes mellitus (GDM) is a severe pregnancy complication for both the woman and the child. Women who suffer from GDM have a greater risk of developing Type 2 diabetes mellitus (T2DM) later in life. Identification of any potential biomarkers for the early prediction of gestational diabetes can help prevent the disease in women with a high risk. Studies show microRNA (miRNA) as a potential biomarker for the early discovery of GDM, but there is a lack of clarity as to which miRNAs are consistently altered in GDM. This study aimed to perform a systematic review and meta-analysis to investigate miRNAs associated with GDM by comparing GDM cases with normoglycemic controls. The systematic review was performed according to PRISMA guidelines with searches in PubMed, Web of Science, and ScienceDirect. The primary search resulted in a total of 849 articles, which were screened according to the prior established inclusion and exclusion criteria. Following the screening of articles, the review was based on the inclusion of 35 full-text articles, which were evaluated for risk of bias and estimates of quality, after which data were extracted and relative values for miRNAs were calculated. A meta-analysis was performed for the miRNA species investigated in three or more studies: MiR-29a, miR-330, miR-134, miR-132, miR-16, miR-223, miR-155, miR-122, miR-17, miR-103, miR-125, miR-210, and miR-222. While some miRNAs showed considerable between-study variability, miR-29a, miR-330, miR-134, miR-16, miR-223, and miR-17 showed significant overall upregulation in GDM, while circulating levels of miR-132 and miR-155 were decreased among GDM patients, suggesting further studies of these as biomarkers for early GDM discovery.

Circulating miRNAs associated with nonalcoholic fatty liver disease.

MicroRNAs (miRNAs) are secreted from cells as either protein-bound or enclosed in extracellular vesicles. Circulating liver-derived miRNAs are modifiable by weight-loss or insulin-sensitizing treatments, indicating that they could be important biomarker candidates for diagnosis, monitoring, and prognosis in nonalcoholic liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Unfortunately, the noninvasive diagnosis of NASH and fibrosis remains a key challenge, which limits case finding. Current diagnostic guidelines, therefore, recommend liver biopsies, with risks of pain and bleeding for the patient and substantial healthcare costs. Here, we summarize mechanisms of RNA secretion and review circulating RNAs associated with NAFLD and NASH for their biomarker potential. Few circulating miRNAs are consistently associated with NAFLD/NASH: miR-122, miR-21, miR-34a, miR-192, miR-193, and the miR-17-92 miRNA-cluster. The hepatocyte-enriched miRNA-122 is consistently increased in NAFLD and NASH but decreased in liver cirrhosis. Circulating miR-34a, part of an existing diagnostic algorithm for NAFLD, and miR-21 are consistently increased in NAFLD and NASH. MiR-192 appears to be prominently upregulated in NASH compared with NAFDL, whereas miR-193 was reported to distinguish NASH from fibrosis. Various members of miRNA cluster miR-17-92 are reported to be associated with NAFLD and NASH, although with less consistency. Several other circulating miRNAs have been reported to be associated with fatty liver in a few studies, indicating the existence of more circulating miRNAs with relevant as diagnostic markers for NAFLD or NASH. Thus, circulating miRNAs show potential as biomarkers of fatty liver disease, but more information about phenotype specificity and longitudinal regulation is needed.

Embryogenesis of a calanoid copepod analyzed by transcriptomics.

The calanoid copepod Acartia tonsa (Dana) has attracted interest because of its use as a copepod model organism as well as its potential economic role as live fish larval feed. While the adult genome and transcriptome of A. tonsa has been investigated, no studies have been performed investigating the genome-wide transcriptional changes during the normal subitaneous embryogenesis. Thus, the aim of the current study was to investigate said transcriptional changes throughout A. tonsa embryonic development. RNA extraction and de novo transcriptome assembly for the subitaneous embryogenesis of the copepod was conducted. The assembly includes for the first-time samples describing quiescent development and overall helps establishing a framework for future studies on the molecular biology of our species of interest. Among the findings reported, sequences annotated to well-known developmental genes, were identified. At the same time are described the molecular changes and gene expression levels throughout the entire 42 h the embryonic development lasts. In conclusion, here we present the most complete genome-wide transcriptional map of early copepod embryonic development to date, enabling further use of A. tonsa as a model organism for crustacean development. Keywords: enrichment of pathways; subitaneous embryogenesis, comparative genomics; transcriptome assembly; invertebrate genomics.

Development of circulating microRNA-based biomarkers for medical decision-making: a friendly reminder of what should NOT be done.

Circulating cell-free microRNAs (miRNAs) represent a major reservoir for biomarker discovery. Unfortunately, their implementation in clinical practice is limited due to a profound lack of reproducibility. The great technical variability linked to major pre-analytical and analytical caveats makes the interpretation of circulating cell-free miRNA data challenging and leads to inconsistent findings. Additional efforts directed to standardization are fundamental. Several well-established protocols are currently used by independent groups worldwide. Nonetheless, there are some specific aspects in specimen collection and processing, sample handling, miRNA quantification, and data analysis that should be considered to ensure reproducibility of results. Here, we have addressed this challenge using an alternative approach. We have highlighted and discussed common pitfalls that negatively impact the robustness of circulating miRNA quantification and their application for clinical decision-making. Furthermore, we provide a checklist usable by investigators to facilitate and ensure the control of the whole miRNA quantification and analytical process. We expect that these recommendations improve the reproducibility of findings, and ultimately, facilitate the incorporation of circulating miRNA profiles into clinical practice as the next generation of disease biomarkers.

Circulating microRNA levels differ in the early stages of insulin resistance in prepubertal children with obesity.

AIMS: The increasing prevalence of childhood obesity escalates the risk for related complications. Circulating microRNAs (miRNAs) have been suggested as good predictive markers of insulin resistance in those with obesity. The aim was to identify a circulating miRNA profile that reflects insulin resistance in prepubertal children with obesity. MATERIAL AND METHODS: Plasma miRNAs were measured in prepubertal children (n = 63, 5-9 years) using TaqMan Advanced miRNA Human Serum/Plasma plates and then were validated by RT-qPCR. Subjects were divided into normal weight (n = 20, NW) and overweight or obese (n = 43, OW/OB) groups according to their BMI z-scores. The OW/OB group was further subdivided into insulin sensitive or metabolically healthy obese (n = 26, MHO) and insulin resistant or metabolically unhealthy obese (n = 17, MUO) according to HOMA-IR. KEY FINDINGS: While no differences were observed in the fasting plasma glucose levels, serum insulin levels were significantly elevated in the OW/OB compared to the NW group. Of 188 screened miRNAs, eleven were differentially expressed between the NW and OW/OB groups. Validation confirmed increased circulating levels of miR-146a-5p and miR-18a-5p in the OW/OB group, which correlated with BMI z-score. Interestingly, miR-146a-5p was also correlated with HOMA-IR index. While only miR-18a-5p was upregulated in the OW/OB children, independently of their degree of insulin sensitivity, miR-146-5p, miR-423-3p and miR-152-3p were associated with insulin resistance. SIGNIFICANCE: The present study provides evidence of molecular alterations that occur early in life in prepubertal obesity. These alterations may potentially be crucial for targeted prevention or prompt precision therapeutic development and subsequent interventions.

Consensus guidelines for the validation of qRT-PCR assays in clinical research by the CardioRNA consortium.

Despite promising findings, quantitative PCR (qPCR)-based tests for RNA quantification have experienced serious limitations in their clinical application. The noticeable lack of technical standardization remains a huge obstacle in the translation of qPCR-based tests. The incorporation of qPCR-based tests into the clinic will benefit from guidelines for clinical research assay validation. This will ultimately impact the clinical management of the patient, including diagnosis, prognosis, prediction, monitoring of the therapeutic response, and evaluation of toxicity. However, clear assay validation protocols for biomarker investigation in clinical trials using molecular assays are currently lacking. Here, we will focus on the necessary steps, including sample acquisition, processing and storage, RNA purification, target selection, assay design, and experimental design, that need to be taken toward the appropriate validation of qRT-PCR assays in clinical research. These recommendations can fill the gap between research use only (RUO) and in vitro diagnostics (IVD). Our contribution provides a tool for basic and clinical research for the development of validated assays in the intermediate steps of biomarker research. These guidelines are based on the current understanding and consensus within the EU-CardioRNA COST Action consortium (www.cardiorna.eu). Their applicability encompasses all clinical areas.

The Temporal Profile of Circulating miRNAs during Gestation in Overweight and Obese Women with or without Gestational Diabetes Mellitus.

Circulating non-coding microRNAs (miRNAs) are important for placentation, but their expression profiles across gestation in pregnancies, which are complicated by gestational diabetes mellitus (GDM), have not been fully established. Investigating a single time point is insufficient, as pregnancy is dynamic, involving several processes, including placenta development, trophoblast proliferation and differentiation and oxygen sensing. Thus, the aim of this study was to compare the temporal expression of serum miRNAs in pregnant women with and without GDM. This is a nested case-control study of longitudinal data obtained from a multicentric European study (the 'DALI' study). All women (n = 82) were overweight/obese (BMI ≥ 29 kg/m2) and were normal glucose tolerant (NGT) at baseline (before 20 weeks of gestation). We selected women (n = 41) who were diagnosed with GDM at 24-28 weeks, according to the IADPSG/WHO2013 criteria. They were matched with 41 women who remained NGT in their pregnancy. miRNA (miR-16-5p, -29a-3p, -103-3p, -134-5p, -122-5p, -223-3p, -330-3p and miR-433-3p) were selected based on their suggested importance for placentation, and measurements were performed at baseline and at 24-28 and 35-37 weeks of gestation. Women with GDM presented with overall miRNA levels above those observed for women remaining NGT. In both groups, levels of miR-29a-3p and miR-134-5p increased consistently with progressing gestation. The change over time only differed for miR-29a-3p when comparing women with GDM with those remaining NGT (p = 0.044). Our findings indicate that among overweight/obese women who later develop GDM, miRNA levels are already elevated early in pregnancy and remain above those of women who remain NGT during their pregnancy. Maternal circulating miRNAs may provide further insight into placentation and the cross talk between the maternal and fetal compartments.

The Predictive Value of miR-16, -29a and -134 for Early Identification of Gestational Diabetes: A Nested Analysis of the DALI Cohort.

Early identification of gestational diabetes mellitus (GDM) aims to reduce the risk of adverse maternal and perinatal outcomes. Currently, no circulating biomarker has proven clinically useful for accurate prediction of GDM. In this study, we tested if a panel of small non-coding circulating RNAs could improve early prediction of GDM. We performed a nested case-control study of participants from the European multicenter 'Vitamin D and lifestyle intervention for GDM prevention (DALI)' trial using serum samples from obese pregnant women (BMI ≥ 29 kg/m2) entailing 82 GDM cases (early- and late- GDM), and 41 age- and BMI-matched women with normal glucose tolerance (NGT) throughout pregnancy (controls). Anthropometric, clinical and biochemical characteristics were obtained at baseline (<20 weeks of gestation) and throughout gestation. Baseline serum microRNAs (miRNAs) were measured using quantitative real time PCR (qPCR). Elevated miR-16-5p, -29a-3p, and -134-5p levels were observed in women, who were NGT at baseline and later developed GDM, compared with controls who remained NGT. A combination of the three miRNAs could distinguish later GDM from NGT cases (AUC 0.717, p = 0.001, compared with fasting plasma glucose (AUC 0.687, p = 0.004)) as evaluated by area under the curves (AUCs) using Receiver Operator Characteristics (ROC) analysis. Elevated levels of individual miRNAs or a combination hereof were associated with higher odds ratios of GDM. Conclusively, circulating miRNAs early in pregnancy could serve as valuable predictive biomarkers of GDM.

Mechanistic Actions of microRNAs in Diabetic Wound Healing.

Wound healing is a complex biological process that is impaired under diabetes conditions. Chronic non-healing wounds in diabetes are some of the most expensive healthcare expenditures worldwide. Early diagnosis and efficacious treatment strategies are needed. microRNAs (miRNAs), a class of 18-25 nucleotide long RNAs, are important regulatory molecules involved in gene expression regulation and in the repression of translation, controlling protein expression in health and disease. Recently, miRNAs have emerged as critical players in impaired wound healing and could be targets for potential therapies for non-healing wounds. Here, we review and discuss the mechanistic background of miRNA actions in chronic wounds that can shed the light on their utilization as specific wound healing biomarkers.

Metformin decreases miR-122, miR-223 and miR-29a in women with polycystic ovary syndrome.

Metformin is associated with increased insulin sensitivity, whereas oral contraceptive pills (OCP) could increase the risk for type 2 diabetes (T2D) in women with polycystic ovary syndrome (PCOS). Certain miRNAs might serve as biomarkers for the risk of T2D. The aim of this study was to investigate changes in circulating miRNA levels during treatment with metformin and OCP in women with PCOS. Sixty-five women with PCOS according to Rotterdam criteria were randomized to metformin (2 g/day), metformin + OCP (150 mg desogestrel + 30 µg ethinylestradiol) or OCP alone for 12 months. Serum miRNA analysis was performed with individual RT-qPCR or Taqman low density array cards of 22 selected miRNAs previously related to PCOS, glucose and/or lipid metabolism. miR-122 and miR-29a levels were decreased after treatment with metformin compared with metformin + OCP and OCP group: miR-122: log2 difference -0.7 (P = 0.01) and -0.7 (P = 0.02), miR-29a: log2 difference -0.5 (P = 0.01) and -0.4 (P = 0.04), while miR-223 levels were decreased in the metformin + OCP group after treatment: log2 difference -0.5 (P = 0.02). During the treatment period, a significant weight loss was observed in the metformin group compared with the OCP group. In the OCP group, miRNA levels were unchanged during the treatment period. Levels of circulating miRNAs associated with lipid and glucose metabolism decreased during metformin treatment. Changes in miRNA levels in the metformin group could be explained by the simultaneous weight loss in the same group. These results support the notion that metformin treatment alone may be superior for metabolic health compared with OCP.

Levels of Circulating miR-122 are Associated with Weight Loss and Metabolic Syndrome.

OBJECTIVE: This study investigated whether the levels of specific serum microRNAs (miRNAs) were altered following diet-induced weight loss and whether the serum miRNAs differed in the presence of the metabolic syndrome. METHODS: The study was a weight loss intervention trial with a prescribed energy deficit of approximately 500 kcal/d. Levels of 22 miRNAs were determined in serum samples from 85 participants with overweight or obesity. miRNAs were analyzed using TaqMan Array miRNA Cards and normalized to the geometric mean of spiked-in ath-miR-159a and U6 small nuclear RNA using the ΔCT method. RESULTS: The average weight loss was 5.7 kg (P < 0.001). miR-122-5p (-0.18 ± 0.06 log fold relative to initial, P < 0.01) and miR-193a-5p (-0.12 ± 0.04, P < 0.01) levels decreased in response to weight loss. miR-126a-3p (0.11 ± 0.04, P = 0.01) and miR-222-3p (1.51 ± 0.12, P < 0.001) levels increased. Furthermore, a higher level of miR-122-5p was observed at baseline in participants with the metabolic syndrome compared with participants without (0.28 ± 0.08, P < 0.01). CONCLUSIONS: Changes in circulating miR-122-5p, miR-126a-3p, miR-193a-5p, and miR-222-3p in response to diet-induced weight loss are demonstrated. Furthermore, assessment of miR-122-5p could be an indicator of an adverse metabolic health status independent of obesity.

microRNA-155 inhibition restores Fibroblast Growth Factor 7 expression in diabetic skin and decreases wound inflammation.

Treatment for chronic diabetic foot ulcers is limited by the inability to simultaneously address the excessive inflammation and impaired re-epithelization and remodeling. Impaired re-epithelization leads to significantly delayed wound closure and excessive inflammation causes tissue destruction, both enhancing wound pathogen colonization. Among many differentially expressed microRNAs, miR-155 is significantly upregulated and fibroblast growth factor 7 (FGF7) mRNA (target of miR-155) and protein are suppressed in diabetic skin, when compared to controls, leading us to hypothesize that topical miR-155 inhibition would improve diabetic wound healing by restoring FGF7 expression. In vitro inhibition of miR-155 increased human keratinocyte scratch closure and topical inhibition of miR-155 in vivo in wounds increased murine FGF7 protein expression and significantly enhanced diabetic wound healing. Moreover, we show that miR-155 inhibition leads to a reduction in wound inflammation, in accordance with known pro-inflammatory actions of miR-155. Our results demonstrate, for the first time, that topical miR-155 inhibition increases diabetic wound fibroblast growth factor 7 expression in diabetic wounds, which, in turn, increases re-epithelization and, consequently, accelerates wound closure. Topical miR-155 inhibition targets both excessive inflammation and impaired re-epithelization and remodeling, being a potentially new and effective treatment for chronic diabetic foot ulcers.