miR Profiles Research Articles

Ischemic-Preconditioning Induced Serum Exosomal miR-133a-3p Improved Post-Myocardial Infarction Repair via Targeting LTBP1 and PPP2CA.

Ischemic preconditioning-induced serum exosomes (IPC-exo) protected rat heart against myocardial ischemia/reperfusion injury. However, whether IPC-exo regulate replacement fibrosis after myocardial infarction (MI) and the underlying mechanisms remain unclear. MicroRNAs (miRs) are important cargos of exosomes and play an essential role in cardioprotection. We aim to investigate whether IPC-exo regulate post-MI replacement fibrosis by transferring cardioprotective miRs and its action mechanism. Exosomes obtained from serum of adult rats in control (Con-exo) and IPC groups were identified and analyzed, subsequently intracardially injected into MI rats following ligation. Their miRs profiles were identified using high-throughput miR sequencing to identify target miRs for bioinformatics analysis. Luciferase reporter assays confirmed target genes of selected miRs. IPC-exo transfected with selected miRs antagomir or NC were intracardially administered to MI rats post-ligation. Cardiac function and degree of replacement fibrosis were detected 4 weeks post-MI. IPC-exo exerted cardioprotective effects against excessive replacement fibrosis. MiR sequencing and RT-qPCR identified miR-133a-3p as most significantly different between IPC-exo and Con-exo. MiR-133a-3p directly targeted latent transforming growth factor beta binding protein 1 (LTBP1) and protein phosphatase 2, catalytic subunit, alpha isozyme (PPP2CA). KEGG analysis showed that transforming growth factor-β (TGF-β) was one of the most enriched signaling pathways with miR-133a-3p. Comparing to injection of IPC-exo transfected with miR-133a-3p antagomir NC, injecting IPC-exo transfected with miR-133a-3p antagomir abolished protective effects of IPC-exo on declining excessive replacement fibrosis and cardiac function enhancement, while increasing the messenger RNA and protein expression of LTBP1, PPP2CA, and TGF-β1in MI rats. IPC-exo inhibit excessive replacement fibrosis and improve cardiac function post-MI by transferring miR-133a-3p, the mechanism is associated with directly targeting LTBP1 and PPP2CA, and indirectly regulating TGF-β pathway in rats. Our finding provides potential therapeutic effect of IPC-induced exosomal miR-133a-3p for cardiac repair.

Plasma and Myocardial miRNomes Similarities and Differences during Cardiac Remodelling and Reverse Remodelling in a Murine Model of Heart Failure with Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome characterised by multiple risk factors touching various organs outside the heart. Using a murine HFpEF model, we studied cardiac reverse remodelling (RR) after stopping the causing metabolic-hypertensive stress (MHS; Angiotensin II [AngII] and a high-fat diet [HFD]) after 28 days and introducing voluntary exercise (VE) for four more weeks. We measured the effects of MHS and RR on the plasma and myocardial microRNA (miR) profile (miRNome) to characterise better cardiac and non-cardiac responses to HFpEF-inducing risk factors and their reversibility. AngII alone, the HFD or the MHS caused cardiac hypertrophy (CH), left ventricular (LV) concentric remodelling and left atrial enlargement in females. Only AngII and the MHS, but not HFD, did in males. After RR, CH, LV concentric remodelling and atrial enlargement were normalised. Among the 25 most abundant circulating miRs, 10 were modulated by MHS. Plasma miRNomes from AngII, HFD or MHS mice shared 31 common significantly modulated miRs (24 upregulated and 7 downregulated), suggesting that the response of organs producing the bulk of those circulating miRs was similar even for seemingly different stress. In the LV, 19 out of 25 most expressed miRs were modulated. RR restored normality for the plasma miRNome but not for the LV miRNome, which remained mostly unchanged. Our results suggest that abnormalities persist in the myocardium of the HFpEF mice and that the normalisation of circulatory markers may be falsely reassuring after recovery.

Circulating CXCL9, monocyte percentage, albumin, and C-reactive protein as a potential, non-invasive, molecular signature of carotid artery disease in 65+ patients with multimorbidity: a pilot study in Age.It.

Carotid endarterectomy (CEA) for the prevention of upcoming vascular and cerebral events is necessary in patients with high-grade stenosis (≥70%). In the framework of the Italian National project Age.It, a pilot study was proposed aiming at the discovery of a molecular signature with predictive potential of carotid stenosis comparing 65+ asymptomatic and symptomatic inpatients. A total of 42 inpatients have been enrolled, including 26 men and 16 women, with a mean age of 74 ± 6 years. Sixteen symptomatic and 26 asymptomatic inpatients with ≥70% carotid stenosis underwent CEA, according to the recommendations of the European Society for Vascular Surgery and the Society for Vascular Surgeons. Plaque biopsies and peripheral blood samples from the same individuals were obtained. Hematobiochemical analyses were conducted on all inpatients, and plasma cytokines/molecules, such as microRNAs (miRs), IL-6, sIL-6Ralpha, sgp130, myostatin (GDF8), follistatin, activin A, CXCL9, FGF21, and fibronectin, were measured using the ELISA standard technique. MiR profiles were obtained in the discovery phase including four symptomatic and four asymptomatic inpatients (both plasma and plaque samples), testing 734 miRs. MiRs emerging from the profiling comparison were validated through RT-qPCR analysis in the total cohort. The two groups of inpatients differ in the expression levels of blood c-miRs-126-5p and -1271-5p (but not in their plaques), which are more expressed in symptomatic subjects. Three cytokines were significant between the two groups: IL-6, GDF8, and CXCL9. Using receiver operating characteristic (ROC) analysis with a machine learning-based approach, the most significant blood molecular signature encompasses albumin, C-reactive protein (CRP), the percentage of monocytes, and CXCL9, allowing for the distinction of the two groups (AUC = 0.83, 95% c.i. [0.85, 0.81], p = 0.0028). The potential of the molecular signature will be tested in a second cohort of monitored patients, allowing the application of a predictive model and the final evaluation of cost/benefit for an assessable screening test.

Exosomal non-coding RNA exhibit sex-specific profiles in salt sensitive hypertension

Exosomes are secreted by various living cells and can be found in all body fluids, especially in cerebrospinal fluid (CSF) and plasma, thereby providing a source of biomarkers for cardiovascular diseases that can be used for patients’ diagnostic. Using high-throughput sequencing technologies, exosomes have been found to contain different RNA populations particularly non-coding RNA. Recently, many non-coding RNA have been recognized as key regulators in the progression of hypertension. In this study we hypothesized that female and male C57BI/6J mice exhibit different microRNA (miR) profiles after deoxycorticosterone acetate (DOCA)+salt hypertension treatment. CSF (10 μl) and plasma (100 μl) were collected from 3-month-old mice and again after 3 weeks of DOCA-salt treatment before exosomes isolation and processing for high throughput small RNA sequencing (Creative Biolabs). Analysis was performed using R language and RStudio ( https://rstudio.com/ ) as an integrated development environment. Global miRNA analysis of CSF exosomes shows different expression miRNA profiles in DOCA+salt male mice compared with their own baseline values. In addition, we observed a remarkable difference in global miRNA expression profile between DOCA+salt male mice and DOCA+salt females (p-value < 2.2e-16), while no significant difference was detected between DOCA+salt females and their baseline values (p-value = 0.6679). Moreover, we observed that there are three clusters of around 200 miR that have different expression levels in DOCA+salt males. Our analysis identified around 74 upregulated miRNA in DOCA+salt males compared to DOCA+salt females. The maximum level of expression belonged to the muscle-specific miRNA (myomiR) miR-1a-3p, miR-206-3p and miR-26a-5p which were highly accumulated in CSF derived exosomes. These top three upregulated miRNA were associated with 282 validated target genes among which, two pivotal genes, ACE2 and ADAM17, were identified in the PPI network, miRTargetLink, and by KEGG analysis. miR-26a-5p was mostly associated with ACE2 and ADAM17 and the mRNA expression of ADAM17 was associated with reduced miR-206-3p. In conclusion, our bioinformatic analysis identified three miRNA and associated them with two key molecules involved in salt sensitive hypertension. Further analysis is likely to highlight more diagnostic biomarkers and potential candidates for the development of new therapeutic approaches. This work was supported in part by a research grant from the National Institutes of Health (HL163588). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstract 2985: RXR agonist, 9cUAB30 impacts epigenetic regulations to achieve chemoprevention of UVB-induced Skin cancer by altering global miRNA profiling

Abstract Basal cell carcinoma (BCCs) and Squamous cell carcinoma (SCCs) are the most common skin neoplasms in the Caucasian population. UVB is considered as the most important etiologic factor for these cancers. The molecular mechanism regulating pathogenesis of these neoplasms is not well defined. Similar to humans Ptch+/−/SKH-1 mice develop both BCCs and SCCs, following chronic UVB-irradiation. We used TaqMan-based Open Array platform containing 796 miRNAs (miRs) to profile miRs associated with BCCs and SCCs. Pathway enrichment analysis was performed using miRPathDB databases at https://mpd.bioinf.uni-sb.de/. 81 miRNAs were differentially expressed in BCCs, of which 54 miRs had cumulative frequency of greater than 1 (FC>1) and 78 miRs were differentially expressed in SCCs, out of which 20 miRs had FC>1. miR-721 was highly induced (123.75 fold, P<0.0430) in BCCs followed by miR-2182, miR-21, miR-451, miR-124a, and miR-685 while downmodulated miRs includes miR-1, miR-133a, miR-133b, and miR-196b. Likewise, miR-21 had maximum fold induction (45.94, P<0.007) in SCCs followed by miR-2182, miR-685, miR-1938, miR-2138, and miR-451 while miR-196b, miR196c, and miR-1 were downmodulated. Kegg pathways analysis revealed that altered miRs belong to Hepatitis B, HIF-1, FoxO, chemokine, adipocytokine, NFκB, cholinergic and TLR signaling pathways. WikiPathway database showed alterations in miRs associated with neovascularization process, Notch Signaling, Pregnane X receptor, α6β4, and BDNF-TrkB signaling. To further investigate the importance of pathways associated with tumor progression, we profiled miRs in residual BCCs and SCCs procured from UAB30 treatment groups. The chemopreventive agent UAB30 is an RXR agonist. In BCCs, UAB30 treatment significantly downmodulated UVB-upregulated miRs. These miRs includes miR-210, miR-546, miR-324-3p, miR-706 and miR-1898. However, UAB30 treatment significantly upregulates miR-380-5p which was downmodulated by UVB-alone. These miRs were involved in immune regulation, Fanconi anemia pathways, FoxO signaling, prostate cancer and p53 signaling. In SCCs, UAB30 treatment significantly reversed the expression of various miRs which were downmodulated by UVB. These miRs were miR-24, miR-26a, miR-30c, miR-328, miR-30b, miR-495 and miR-2100. The expression of miR-21a-3p was downmodulated by UAB30 in SCCs of UVB-exposed group relative to SCCs of untreated but UVB-exposed group. These miRs belong to pathways involved in cell cycle progression, p53 signaling, viral carcinogenesis, Hepatitis B, Melanoma, Prostate cancer, FoxO and PI3K-AKT signaling. In summary, this profiling of miRs in UVB-induced BCC and SCC represents the underlying epigenetic mechanisms that regulate various signaling pathways in these cancers. Our data also show the critical role of miRs responsive to UAB30 treatment in cancer chemoprevention. Citation Format: Mahendra P. Kashyap, Rajesh Sinha, Craig A. Elmets, Venkatram R. Atigadda, Mohammad Athar. RXR agonist, 9cUAB30 impacts epigenetic regulations to achieve chemoprevention of UVB-induced Skin cancer by altering global miRNA profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2985.

MiRNA profiling of esophageal adenocarcinoma using transcriptome analysis.

Esophageal adenocarcinoma (EAC) occurs following a series of histological changes through epithelial-mesenchymal transition (EMT). A variable expression of normal and aberrant genes in the tissue can contribute to the development of EAC through the activation or inhibition of critical molecular signaling pathways. Gene expression is regulated by various regulatory factors, including transcription factors and microRNAs (miRs). The exact profile of miRs associated with the pathogenesis of EAC is largely unknown, though some candidate miRNAs have been reported in the literature. To identify the unique miR profile associated with EAC, we compared normal esophageal tissue to EAC tissue using bulk RNA sequencing. RNA sequence data was verified using qPCR of 18 selected genes. Fourteen were confirmed as being upregulated, which include CDH11, PCOLCE, SULF1, GJA4, LUM, CDH6, GNA12, F2RL2, CTSZ, TYROBP, and KDELR3 as well as the downregulation of UGT1A1. We then conducted Ingenuity Pathway Analysis (IPA) to analyze for novel miR-gene relationships through Causal Network Analysis and Upstream Regulator Analysis. We identified 46 miRs that were aberrantly expressed in EAC compared to control tissues. In EAC tissues, seven miRs were associated with activated networks, while 39 miRs were associated with inhibited networks. The miR-gene relationships identified provide novel insights into potentially oncogenic molecular pathways and genes associated with carcinogenesis in esophageal tissue. Our results revealed a distinct miR profile associated with dysregulated genes. The miRs and genes identified in this study may be used in the future as biomarkers and serve as potential therapeutic targets in EAC.

Left ventricle function and post-transcriptional events with exercise training in pigs.

Standardized exercise protocols have been shown to improve overall cardiovascular fitness, but direct effects on left ventricular (LV) function, particularly diastolic function and relation to post-transcriptional molecular pathways (microRNAs (miRs)) are poorly understood. This project tested the central hypothesis that adaptive LV remodeling resulting from a large animal exercise training protocol, would be directly associated with specific miRs responsible for regulating pathways relevant to LV myocardial stiffness and geometry. Pigs (n = 9; 25 Kg) underwent a 4 week exercise training protocol (10 degrees elevation, 2.5 mph, 10 min, 5 days/week) whereby LV chamber stiffness (KC) and regional myocardial stiffness (rKm) were measured by Doppler/speckle tracking echocardiography. Age and weight matched non-exercise pigs (n = 6) served as controls. LV KC fell by approximately 50% and rKm by 30% following exercise (both p < 0.05). Using an 84 miR array, 34 (40%) miRs changed with exercise, whereby 8 of the changed miRs (miR-19a, miR-22, miR-30e, miR-99a, miR-142, miR-144, miR-199a, and miR-497) were correlated to the change in KC (r ≥ 0.5 p < 0.05) and mapped to matrix and calcium handling processes. Additionally, miR-22 and miR-30e decreased with exercise and mapped to a localized inflammatory process, the inflammasome (NLRP-3, whereby a 2-fold decrease in NLRP-3 mRNA occurred with exercise (p < 0.05). Chronic exercise reduced LV chamber and myocardial stiffness and was correlated to miRs that map to myocardial relaxation processes as well as local inflammatory pathways. These unique findings set the stage for utilization of myocardial miR profiling to identify underlying mechanisms by which exercise causes changes in LV myocardial structure and function.

Abstract 15298: Epidemiology and microRNA Predictors of Infection After Heart Transplantation

Background: Infection rates are high in heart transplant (HT) patients due to the need for immunosuppressive medication. MicroRNAs (miR) are non-coding RNAs, that regulate gene expression and are promising biomarkers for identifying patients at risk for infection. Hypothesis: MiR profiles can identify HT patients who are at increased risk for developing an infection. Methods: HT patients who were prospectively enrolled from 2015-2018 had miR-sequencing performed. Incident infection after HT hospital discharge along with the epidemiologic characteristics of the infection were collected from the EMR. An opportunistic infection (OI) is an infection which is less virulent in a healthy host but can cause severe disease in those immunosuppressed. A time-to-event analysis was performed using miR expression at two weeks post-HT in multivariable modeling, and the Benjamini-Hochberg procedure was used to correct for false discovery. Results: The cohort included 46 patients with a median age of 56 years (IQR: 49, 62), 33% (N=15) were Female sex, 41% (N=19) were Black, and 80% (N=37) were supported with an LVAD prior to HT. Post-HT infection occurred in 59% of patients (N=27) and median time to infection was 341 days (IQR: 85, 859). Hospitalization was required in 56% (N=15) of infections. Respiratory tract and OIs were the most common infection type (Figure A). The most common microorganisms implicated were CMV (28%) and SARS-COV-2 (19%) (Figure B). After correction for false discovery, we identified 15 miRs associated with infection risk. The 5 miRs with strongest effect size and their corresponding hazard ratios include: miR-21 2.5(95% CI: 1.3, 4.7), miR-130b 8.6 (95%CI: 1.9, 39.3), miR-192 0.3 (95%CI: 0.1, 0.6), miR-218 2.6 (95%CI: 1.3, 5.1) and miR-484 0.3 (95%CI: 0.1, 0.7). Conclusion: While the burden of post-HT infections is high and contributes to patient morbidity, novel plasma miRs can potentially play a role in identifying patients at risk for infections after HT.

MicroRNA-30d-5p-A Potential New Therapeutic Target for Prevention of Ischemic Cardiomyopathy after Myocardial Infarction.

(1) Background and Objective: MicroRNAs (miRs) are biomarkers for assessing the extent of cardiac remodeling after myocardial infarction (MI) and important predictors of clinical outcome in heart failure. Overexpression of miR-30d-5p appears to have a cardioprotective effect. The aim of the present study was to demonstrate whether miR-30d-5p could be used as a potential therapeutic target to improve post-MI adverse remodeling. (2) Methods and Results: MiR profiling was performed by next-generation sequencing to assess different expression patterns in ischemic vs. healthy myocardium in a rat model of MI. MiR-30d-5p was significantly downregulated (p < 0.001) in ischemic myocardium and was selected as a promising target. A mimic of miR-30d-5p was administered in the treatment group, whereas the control group received non-functional, scrambled siRNA. To measure the effect of miR-30d-5p on infarct area size of the left ventricle, the rats were randomized and treated with miR-30d-5p or scrambled siRNA. Histological planimetry was performed 72 h and 6 weeks after induction of MI. Infarct area was significantly reduced at 72 h and at 6 weeks by using miR-30d-5p (72 h: 22.89 ± 7.66% vs. 35.96 ± 9.27%, p = 0.0136; 6 weeks: 6.93 ± 4.58% vs. 12.48 ± 7.09%, p = 0.0172). To gain insight into infarct healing, scratch assays were used to obtain information on cell migration in human umbilical vein endothelial cells (HUVECs). Gap closure was significantly faster in the mimic-treated cells 20 h post-scratching (12.4% more than the scrambled control after 20 h; p = 0.013). To analyze the anti-apoptotic quality of miR-30d-5p, the ratio between phosphorylated p53 and total p53 was evaluated in human cardiomyocytes using ELISA. Under the influence of the miR-30d-5p mimic, cardiomyocytes demonstrated a decreased pp53/total p53 ratio (0.66 ± 0.08 vs. 0.81 ± 0.17), showing a distinct tendency (p = 0.055) to decrease the apoptosis rate compared to the control group. (3) Conclusion: Using a mimic of miR-30d-5p underlines the cardioprotective effect of miR-30d-5p in MI and could reduce the risk for development of ischemic cardiomyopathy.

Circulating microRNAs improve bacterial infection diagnosis and overall survival prediction in acute decompensation of liver cirrhosis

Bacterial infections are the most frequent precipitating event in patients with acute decompensation of cirrhosis (AD) and are associated with high mortality. Early diagnosis is challenging due to cirrhosis-related systemic inflammation. Here we investigated the potential of circulating microRNAs to diagnose bacterial infections and predict survival in cirrhotic patients with AD. High throughput profiling of circulating microRNAs was performed using the Nanostring technology in 57 AD patients and 24 patients with compensated cirrhosis (CC). Circulating miRs profiling showed that: (a)miRs differentially detected in AD vs. CC were mostly down-regulated; (b)a composite score including absolute neutrophil count, C reactive protein and miR-362-3p could diagnose bacterial infection with an excellent performance (AUC of 0.825 [95% CI= 0.671-0.980; p<0.001]); (c)a composite score including miR-382-5p, miR-592 and MELD-Na improved 6-month survival prediction. Circulating miRs are strongly dysregulated in patients with AD and may help to improve bacterial infection diagnosis and survival prediction.

Expression of microRNAs and their target genes in melanomas originating from gynecologic sites.

Melanomas from gynecologic sites (MOGS) are rare and have poor survival. MicroRNAs (miRs) regulate gene expression and are dysregulated in cancer. We hypothesized that MOGS would display unique miR and mRNA expression profiles. The miR and mRNA expression profile in RNA from formalin fixed, paraffin embedded vaginal melanomas (relative to vaginal mucosa) and vulvar melanomas (relative to cutaneous melanoma) were measured with the Nanostring Human miRNA assay and Tumor Signaling mRNA assay. Differential patterns of expression were identified for 21 miRs in vaginal and 47 miRs in vulvar melanoma (fold change >2, p<0.01). In vaginal melanoma, miR-145-5p (tumor suppressor targeting TLR4, NRAS) was downregulated and miR-106a-5p, miR-17-5p, miR-20b-5p (members of miR-17-92 cluster) were upregulated. In vulvar melanoma, known tumor suppressors miR-200b-3p and miR-200a-3p were downregulated, and miR-20a-5p and miR-19b-3p, from the miR-17-92 cluster, were upregulated. Pathway analysis showed an enrichment of "proteoglycans in cancer". Among differentially expressed mRNAs, topoisomerase IIα (TOP2A) was upregulated in both MOGS. Gene targets of dysregulated miRs were identified using publicly available databases and Pearson correlations. In vaginal melanoma, suppressor of cytokine signaling 3 (SOCS3) was downregulated, was a validated target of miR-19b-3p and miR-20a-5p and trended toward a significant inverse Pearson correlation with miR-19b-3p (p = 0.093). In vulvar melanoma, cyclin dependent kinase inhibitor 1A (CDKN1A) was downregulated, was the validated target of 22 upregulated miRs, and had a significant inverse Pearson correlation with miR-503-5p, miR-130a-3p, and miR-20a-5p (0.005 < p < 0.026). These findings support microRNAs as mediators of gene expression in MOGS.

22-LB: MiRNA Profiling of Exosomes Derived from Perivascular Adipocyte Tissue in Type 2 Diabetic Mice

Background: Exosomes (EXs), a major type of extracellular vesicles, are emerging as a novel type of intercellular communicators. MicroRNAs (miRs) are one of the major executors of EXs. The previous study shows that lean and obesity adipocyte tissue EXs could elicit different effects in response to insulin sensitivity, the underlying mechanism is related to their carried miRs. Given EX cargoes and function vary on their cellular status, we speculate the miR profiling of EXs derived from the perivascular adipose tissue (PVAT) is altered in diabetic conditions. Methods: EXs were isolated from the PVAT tissue of type 2 diabetic db/db and control db/c mice. EX size and concentration were analyzed by nanoparticle tracking analysis. The miR profiling of PVAT-EXs was analyzed by mmu-miR miRome profiling kit. The miRs of interest were further validated by qRT-PCR. Results: 1) The PVAT-EXs level was higher in diabetic db/db mice than that in non-diabetic db/c mice; 2) In db/db mice, exosomal miRs profile was changed. The exosomal miRs, miR-223, miR-181a, miR-146a, miR-34a, and miR-210, were either down-regulated or up-regulated &amp;gt; 3-fold when comparing that in db/c mice. Among these candidate miRs, miR-181a, miR-223, miR-210, and miR-146a might be involved in modulating adipose tissue inflammation and/or vascular function. MiR-34a could participate in white adipose tissue browning, macrophage polarization, and glucose tolerance. Conclusion: Our data have demonstrated that the miR profiling of PVAT-derived EXs is changed in type 2 diabetic conditions, which suggests the functions of these EXs might be altered in diabetic conditions. Disclosure S. Chen: None. V. Polaki: None. J. Bihl: None. J. Wang: None.

Relation between left ventricular relaxation and post-transcriptional regulation with exercise in pigs

Background: Regular exercise has been shown to induce physiological adaptations such as improved left ventricle (LV) function, but LV diastolic function, particularly LV chamber stiffness (LV Kc) is rarely examined. In addition, the relation between changes in LV function, particularly LV Kc with regular exercise and post-transcriptional regulator checkpoints, the microRNAs (miRs), remains unexplored. This project tested the hypothesis that an exercise protocol in pigs will cause a shift in miR profiles which would affect pathways relevant to LV Kc. Methods and Results: Pigs (n=9; 3 months) underwent a chronic treadmill protocol (4 weeks, 10° elevation, 2.5 mph, 10 minutes) and two-dimensional speckle-tracking echocardiography was performed to obtain LV ejection fraction (LV EF) and to compute LV Kc. Age and weight matched non-exercised pigs (n=6) served as referent controls. All results are reported as mean ± SEM. LV EF increased with exercise (66.7 ± 1.9 vs 82.0 ± 0.7 %, p≤0.05) whereas LV Kc fell by approximately 50% (0.56 ± 0.04 vs 0.27 ± 0.02 kPa, p≤0.05). Using an 84 miR array (rt-PCR), a total of 34 (40%) miRs changed with exercise whereas 8 miRs (miR-19a, miR-22, miR-30e, miR-99a, miR-142, miR-144, miR-199a, and miR-497) correlated to LV Kc (r= 0.543, r=0.646, r=0.671, r=0.638, r=0.814, r=0.613, r=0.575, r=0.726 respectively, p≤0.05). Specifically, these miRs mapped to functional domains relevant to LV Kc such as calcium handling/active relaxation and extracellular matrix remodeling (i.e. metallopeptidases, heparin sulfate proteoglycans, and transforming growth factor-beta). Conclusion: Chronic exercise in pigs reduced LV chamber stiffness and correlated to miRs that mapped to regulatory processes which likely contributed to this reduction. Thus, utilization of miR profiling may provide insight into exercise training effectiveness. This work was supported in part by National Institutes of Health grant R01HL130972-01A1 (F.G.S.) &amp; R01HL5949 (F.G.S.) as well as a Merit Award from the Veterans Health Administration, BX000168-10A1 (F.G.S.) &amp; BX005320 (F.G.S.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

MicroRNA-494 augments fibrotic transformation of human retinal pigment epithelial cells and targets p27 with cell-type specificity.

Epiretinal membranes (ERMs) are the result of fibro-cellular proliferation that cause distortion and impairment of central vision. We hypothesized that select microRNAs (miRs) regulate retinal fibro-proliferation and ERM formation. Following IRB approval, a pilot study was performed in patients presenting for retina surgery with and without clinical ERMs. Total RNA was isolated from ERM tissue and controls from non-ERM vitreous and subjected to miR profiling via microarray analysis. MiR-494 was identified as the only miR selectively expressed at significantly greater levels, and in silico analysis identified p27 as a putative fibroproliferative gene target of miR-494. In vitro testing of miR-494 and p27 in fibrotic transformation was assessed in spontaneously immortalized human retinal pigment epithelial (RPE) and human Müller cell lines, stimulated to transform into a fibroproliferative state via transforming growth factor beta (TGFβ). Fibroproliferative transformation was characterized by de novo cellular expression of alpha smooth muscle actin (αSMA). In both RPE and Müller cells, both TGFβ and miR-494 mimic decreased p27 expression. In parallel experiments, transfection with p27 siRNA augmented TGFβ-induced αSMA expression, while only in RPE cells did co-transfection with miR-494 inhibitor decrease αSMA levels. These results demonstrate that miR-494 augments fibrotic transformation in both Müller cells and RPEs, however only in RPEs does miR-494 mediate fibrotic transformation via p27. As p27 is known to regulate cellular proliferation and differentiation, future studies should extend clinical testing of miR-494 and/or p27 as a potential novel non-surgical therapy for ERMs, as well as identify relevant miR-494 targets in Müller cells.

Abstract 3808: MicroRNA-206 drives antitumor immunity by disrupting the communication between Kupffer cells and Tregs

Abstract Kupffer cells (KCs) account for 15% of the total liver cells. However, their roles in hepatocellular carcinoma (HCC) is poorly described. Clec4fCre-tdTomato knock-in mice expressing Cre recombinase and tdTomato-NLS under the KC-specific Clec4f promoter were hydrodynamically injected with oncogenic AKT and Nras (AKT/Ras) to induce HCC. A LoxP-stop-LoxP (LSL) system was used to express miR-206 in KCs of mice. AKT activation was observed in hepatocytes and KCs of HCC patients. Hydrodynamic injection (HDI) of AKT/Ras led to activation of AKT signaling in KCs and hepatocytes. AKT/Ras mice developed lethal HCC within 6-8 weeks post injection. Activation of AKT signaling led to M2 polarization of KCs, increased hepatic Tregs and exhaustion of CTLs. MicroRNA (miR) profiling revealed that AKT/Ras impaired miR-206 biogenesis in KCs by driving translation of Yin Yang 1 (YY1), a transcription repressor of miR-206. HDI of miR-206 into AKT/Ras mice fully prevented HCC, while all control mice died of HCC 6-8 weeks post injection. However, HDI of miR-206 only transfected ~ 20% of hepatocytes, indicating that it is unreasonable to conclude that the full prevention of HCC in AKT/Ras/miR-206 mice is caused by inhibited proliferation of HCC cells. We, therefore, posited that miR-206-mediated recovery of immune surveillance, at least in part, accounted for the full prevention of HCC in AKT/Ras/miR-206 mice. We next used the LSL system to overexpress miR-206 in KCs of Clec4fCretdTomato mice injected with AKT/Ras. KC-specific expression of miR-206 fully prevented HCC in AKT/Ras mice, while 100% control mice died of HCC. Mechanistically, AKT signaling in KCs drove CCL22 (C-C motif chemokine ligand 22) production by phosphorylating β-catenin that activates transcription of Ccl22. In contrast, miR-206 disrupted β-catenin signaling by targeting LEF1 (lymphoid enhancer-binding factor 1), an “architectural” transcription factor of β-catenin. CCL22 recruits Tregs. Indeed, KC-specific expression of miR-206 led to elevated CCL22, M2 to M1 transition of KCs, reduced hepatic Tregs, and elevated CTLs. Depletion of CTLs in AKT/Ras mice fully offset the ability of miR-206 to prevent HCC. Conclusions: AKT-educated KCs initiate Treg recruitment via a regulatory loop consisting of YY1, β-catenin/LEF1, miR-206, and CCL22; once this loop is activated, AKT activates β-catenin axis, which drives CCL22 production, Treg recruitment and HCC growth; while KC-specific expression of miR-206 reversed this process by blocking β-catenin axis in KCs. miR-206 represents a novel immunotherapy against HCC. Citation Format: Guisheng Song, Ningning Liu. MicroRNA-206 drives antitumor immunity by disrupting the communication between Kupffer cells and Tregs. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3808.

Non-Coding RNA Investigations in Cutaneous Melanoma: A Step forward in Discovering Novel Biomarkers

Non-Coding RNA Investigations in Cutaneous Melanoma: A Step forward in Discovering Novel Biomarkers

Circulating miR-122-5p, miR-92a-3p, and miR-18a-5p as Potential Biomarkers in Human Liver Transplantation Follow-Up.

The requirement of blood-circulating sensitive biomarkers for monitoring liver transplant (LT) is currently a necessary step aiming at the reduction of standard invasive protocols, such as liver biopsy. In this respect, the main objective of this study is to assess circulating microRNA (c-miR) changes in recipients' blood before and after LT and to correlate their blood levels with gold standard biomarkers and with outcomes such as rejection or complications after graft. An miR profile was initially performed; then, the most deregulated miRs were validated by RT-qPCR in 14 recipients pre- and post-LT and compared to a control group of 24 nontransplanted healthy subjects. MiR-122-5p, miR-92a-3p, miR-18a-5p, and miR-30c-5p, identified in the validation phase, were also analyzed considering an additional 19 serum samples collected from LT recipients and focusing on different follow-up (FU) times. The results showed significant, FU-related changes in c-miRs. In particular, miR-122-5p, miR-92a-3p, and miR-18a-5p revealed the same trend after transplantation and an increase in their level was found in patients with complications, independently from FU times. Conversely, the variations in the standard haemato-biochemical parameters for liver function assessment were not significant in the same FU period, confirming the importance of c-miRs as potential noninvasive biomarkers for monitoring patients' outcomes.

MicroRNA Expression Profile in Mycosis Fungoides – Preliminary Findings

Dear Editor, Mycosis Fungoides (MF) is the commonest cutaneous lymphoma, comprising about 12% of all T-cell lymphomas in India.[1] MF presents as patches, plaques or tumors. While the diagnosis of tumor stage MF is easy, lesions of patch and plaque stages pose problems in diagnosis.[2] There is a clinicopathologic overlap with several inflammatory conditions. Currently, there is no single diagnostic standard for early MF. It rests on a combination of clinical findings, histopathology, immunohistochemistry and T-cell receptor clonality testing.[3] miRNAs(miR) have great potential as biomarkers as they are robust, tissue-specific and can be obtained from both blood and tissues. Their value as diagnostic markers have been shown in several cancer types but is still nascent in MF.[4] We attempted to explore the role of miRs in patch and plaque stage MF in Indian patients. We selected 24 MF samples whose diagnosis was established based on clinical features, histopathology and follow up. We chose a set of 7miRs namely miR 203, miR205, miR223, miR155, miR 93, miR 92a, miR 21 along with two controls RNU48 and RUN44. The first three miRs have a tumor suppressor function, while the rest serve as OncomiRs. RNU44, 48 served as controls. Primer sequences designed using Primer3Plus software and then validated on Ensemble & NCBI Blast. After deparaffinisation and overnight incubation with proteinase K, RNA was extracted using RNAwiz and estimated by Ribogreen fluorimetry, the yield ranged from 5.06 to 49.6 ng. Real time PCR was done on the 26 samples on LightCycler 480 (Roche). Pre-incubation and initial denaturation of the template was at - 95°C for 10 min and amplification was done for 45 cycles at 95°C for 15 sec and 60°C for 1 min and Ct values were obtained. There were 24 samples from 21 patients. Their age ranged from 24-83 years and were predominantly men (14:7). There were 8 patch stage MF, 9 plaque stage and 7 were recurrent MF. There was no significant difference in the expression of any of the 7 miRs between the patch and plaque stages (p-values ranged from 0.423-0.963). There was no difference between patch/plaque stages and recurrent lesions. (p-values ranged from 0.481-0.963). We compared the average Ct values of the 3 tumor suppressor miRs versus the 4 OncomiRs, to look for any difference between patch, plaque and recurrent lesions. There was no significant difference in these either. (p-value ranged from 0.877 to 1.484) A few studies have focussed on the differential expression of miRs in distinguishing MF from inflammatory diseases. van Kester et al studied 19 tumor stage MF and compared their miR expression patterns with 12 benign skin conditions.[5] They found that 49 miR were differentially expressed in the two groups and miR 93, which has an anti-apoptotic function, showed the highest discrimination.[5] Ralfkiaer et al showed that early MF displays a miR profile distinct from advanced T-cell lymphomas.[6] They were also able to demonstrate different profiles in patients with progressive vs. non-progressive disease. McGirt et al demonstrated that miR223, which targets TOX gene, needed for T-cell development is overexpressed in early MF and diminishes with progression to advanced disease.[7] There is only one study which has compared miR profiles in patch vs. plaque stages of MF. Sorensen et al found 11 miRNAs were overexpressed in plaques as compared to patches, most significantly miR-142, miR-21 and miR-22.[8] We did not find any difference in miR (including miR21) expression between patch and plaque stages or in patients who had recurrences. Variation in results could be due to the methodology used (whole tissue vs. microarray), quantity and quality of RNA and density of the infiltrate.[8] Nevertheless, it seems that although clinically distinct, patch and plaque stage MF are more similar biologically. We will expand the scope to compare miR expression profiles of MF with various inflammatory skin diseases in the next part of our ongoing study. To summarise, miR expression does not appear to be useful in distinguishing patch vs. plaque stage MF. Our findings need to be validated in larger samples in Indian patients. Financial support and sponsorship Rajiv Gandhi University of Health Sciences, Bangalore for funding the project Conflicts of interest There are no conflicts of interest.

Hypoxia-induced exosomes facilitate lung pre-metastatic niche formation in hepatocellular carcinoma through the miR-4508-RFX1-IL17A-p38 MAPK-NF-κB pathway.

Background: Hypoxia plays an important role in the lung metastasis of hepatocellular carcinoma (HCC). However, the process by which hypoxia promotes the formation of a pre-metastatic niche (PMN) and its underlying mechanism remain unclear. Methods: Exosomes derived from normoxic and hypoxic HCC cells were collected to induce fibroblast activation in vitro and PMN formation in vivo. The micro RNA (miR) profiles of the exosomes were sequenced to identify differentially expressed miRNAs. Gain- and loss-of-function analyses were performed to investigate miR-4508 function. Dual-luciferase, western blotting, and real-time reverse transcription-PCR analyses were used to identify the direct targets of miR-4508 and its downstream signaling pathways. To demonstrate the roles of hypoxic tumor-derived exosomes (H-TDEs) and miR-4508 in the lung metastasis of liver cancer, H22 tumor cells were injected through the tail vein of mice. Blood plasma-derived exosomes from patients with HCC who underwent transarterial chemoembolization (TACE) were applied to determine clinical correlations. Results: We demonstrated that H-TDEs activated lung fibroblasts and facilitated PMN formation, thereby promoting lung metastasis in mice. Screening for upregulated exosomal miRNAs revealed that miR-4508 and its target, regulatory factor X1 (RFX1), were involved in H-TDE-induced lung PMN formation. Moreover, miR-4508 was significantly upregulated in plasma exosomes derived from patients with HCC after TACE. We confirmed that the p38 MAPK-NF-κB signaling pathway is involved in RFX1 knockdown-induced fibroblast activation and PMN formation. In addition, IL17A, a downstream target of RFX1, was identified as a link between RFX1 knockdown and p38 MAPK activation in fibroblasts. Conclusion: Hypoxia enhances the release of TDEs enriched with miR-4508, thereby promoting lung PMN formation by targeting the RFX1-IL17A-p38 MAPK-NF-κB pathway. These findings highlight a novel mechanism underlying hypoxia-induced pulmonary metastasis of HCC.

Comparing tumor microRNA profiles of patients with long‑ and short‑term‑surviving glioblastoma

Glioblastoma is one of the most frequent primary brain tumors with a poor prognosis. Nevertheless, some patients show a prolonged survival. The aim of the present study was to compare the expression profiles of tumor derived microRNA (miR) of long‑term survivors with those of short‑term survivors in order to identify differentially expressed miRs as well as their target genes, which may elucidate mechanisms that play a role in varying tumor progression and, therefore, may influence survival. Formalin‑fixed paraffin‑embedded samples of 23patients with glioblastoma were classified according to overall survival. Profiles of miR expression were determined using Nanostring technology. Expression levels of potential target genes of differentially expressed miRs were assessed using immunohistochemistry. MiR profiles of long‑term survivors differed from those of short‑term survivors. A total of three prominent differentially expressed miRs were highlighted: MiR‑130b‑3p, which is downregulated in long‑term survivors, and miR‑146b‑5p and miR‑148a‑3p, which are upregulated in long‑term survivors. Known tumor suppressor genes are among targets potentially affected by miR‑130b‑3p, whereas targets of miR‑146b‑5p and miR‑148a‑3p consist of several genes known to have a role in tumor invasion and aggressiveness. In conclusion, it was revealed that a type of miR‑signature was associated with short‑ and long‑term survival, potentially serving as biomarker for disease progression and providing a base for further functional studies.