miR Profiles Research Articles

Abstract 14936: Profiling of Microrna Expression in Extracellular Vesicles Released From Ischemic Skeletal Muscles in Hypercholesterolemic Conditions

Introduction: Hypercholesterolemia (HC) is an important cardiovascular risk factor associated with impaired neovascularization in response to ischemia. We found that specific microRNAs (miRs) whose levels are reduced in ischemic skeletal muscles of mice exposed to HC can rescue endothelial cell function and neovascularization. miRs can be transferred between cells via extracellular vesicles (EVs). EVs are involved in several biological functions including the response to ischemia and angiogenesis. Hypothesis: Here we tested the hypothesis that HC causes alterations in the miR content of EVs related to ischemia/neovascularization. Methods: We used a mouse model of peripheral artery disease to induce severe ischemia in the hindlimbs of hypercholesterolemic ApoE -/- and control C57Bl/6J mice. Microvesicles (MVs) and exosomes (exo) were isolated from ischemic skeletal muscles by differential centrifugation. Total RNA was extracted from these 2 types of EVs, and the miR content was analyzed using next generation sequencing. Results: Bioinformatic analysis of the 100 most expressed miRs in EVs showed an enrichment of 38 miRs in MVs compared to ischemic skeletal muscles, and an enrichment of 44 miRs in exo compared to ischemic skeletal muscles. Among enriched miRs, 27 are common to both MVs and exo. We identified specific miRs enriched in EVs that are known to modulate angiogenesis, including several miRs that were altered by HC. For example, among enriched miRs downregulated by HC in EVs, the let-7 family and miR-29a are known to be pro-angiogenic via inhibition of members of the TIMP family. On the other hand, among enriched miRs upregulated by HC in EVs, miR-199a and miR-16-5p are known to be anti-angiogenic via inhibition of VEGF. Conclusions: This study describes for the first time the effect of HC on the modulation of miR profile in EVs following skeletal muscle ischemia. We found that several angiogenesis-modulating miRs are enriched in EVs and altered by HC. Our findings constitute a solid framework for the identification of miRs that could be targeted to modify EV content in atherosclerotic conditions. Eventually these engineered EVs could serve as vectors to promote neovascularization and reduce ischemic damages in severe vascular diseases.

Abstract 14074: Unique Circulating microRNA Profile in Pediatric Heart Transplant Recipients

Introduction: MicroRNAs (miRs) are small noncoding RNAs capable of modulating the expression of many genes. Hypothesis: Our hypothesis was that circulating miRs would be a biomarker of acute cellular rejection (ACR) in pediatric heart transplant recipients (PHTR). Methods: An array for 381 miRs was performed using serum from 52 PHTR and 21 healthy pediatric controls (HC). ACR was defined as ISHLT biopsy score ≥2R. Patients with antibody mediated rejection were excluded. RNA was extracted using the miRNeasy Mini Kit (Qiagen), and arrays were performed using the TaqMan Open Array miR panel (Thermo Fisher Scientific). Statistical analysis included Random Forest (RF) with area under the receiver operator curve (AUC) based on the top 3 differentiating miRs by RF, and Wilcoxon rank-sum t-test (significant q-value < 0.05). Results: Of the 52 PHTR, median age 8.5 years, 44% female, race/ethnicity white in 83%, 12% African American, 13% Asian/other, and 13% Hispanic; 22 PHTR had ACR at time of serum collection. There were 21 HC, median age 5.6 years, 38% female, race/ethnicity white in 76%, 24% Asian/other, and 19% Hispanic. There were 66 miRs significantly different between HC and all PHTR (AUC of 0.91). For HC vs PHTR without ACR there were 50 differential miRs (AUC of 0.94), and for HC vs PHTR with ACR there were 51 differential miRs (AUC 0.96). Table 1 demonstrates miRs that are differentially expressed compared to HC based on the presence or absence of ACR. Circulating miRs were not different between PHTR with (n=22) and without ACR (n=30). Conclusions: The circulating miR profile of PHTR is unique compared to HC, suggesting a strong influence of the transplant mileu on miR expression. There were 17 miRs with differential expression compared to HC based on the presence or absence of ACR. These results support future investigations in larger populations to determine if circulating miRs could serve as biomarkers of ACR in PHTR, and whether these miRs contribute to the pathophysiology of ACR.

Abstract 15061: Role of Exosomal Microrna-21a-5p in the Modulation of Ischemia-Induced Angiogenesis in Hypercholesterolemic Conditions

Introduction: Extracellular vesicles (EVs) and their MicroRNA (miR) content are involved in several physiological processes, including the response to ischemia and angiogenesis. Hypercholesterolemia (HC) is an important cardiovascular risk factor associated with impaired angiogenesis and ischemia-induced neovascularization. However, the effect of HC on the modulation of miR content in EVs in the setting of tissue ischemia is unknown. Hypothesis: We tested the hypothesis that HC causes alterations in the miR content of EVs related to ischemia/neovascularization, and that engineered EVs can be harnessed as angiogenic vectors to promote angiogenesis and therapeutic neovascularization in this situation. Methods: We used a mouse model of peripheral artery disease to induce severe ischemia in the hindlimbs of hypercholesterolemic ApoE -/- and control C57Bl/6J mice. Microvesicles (MVs) and exosomes (exo) were isolated from ischemic skeletal muscles by differential centrifugation. Total RNA was extracted from these 2 types of EVs, and the miR content was analyzed using next generation sequencing. Selected miRs were transfected in EVs and the angiogenic capacity of the engineered EVs was assessed in vitro using a Matrigel assay. Results:: Bioinformatic analysis of the 100 most expressed miRs in EVs showed an enrichment of several miRs in EVs compared to ischemic skeletal muscles. Interestingly the highly expressed miR-21a-5p, which has previously been shown to have angiogenic properties, is specifically enriched in exo. Moreover, we found that miR-21a-5p expression is reduced in exo isolated from ischemic skeletal muscles in hypercholesterolemic conditions. We next forced miR-21a-5p expression in exo, and found that these engineered exo significantly increase tube formation in HUVECs. Conclusions: We show that several angiogenic miRs are enriched in EVs in the setting of tissue ischemia, and that HC can alter EV miR profile in this situation. miR-21a-5p, which expression is reduced by HC, was identified as an important modulator of exo angiogenic activity. Exo engineered to overexpress miR-21a-5p could eventually constitute a novel therapeutic strategy to promote neovascularization and reduce ischemic damages in severe vascular diseases.

MircoRNA in Extracellular Vesicles from Patients with Pulmonary Arterial Hypertension Alters Endothelial Angiogenic Response.

Pulmonary arterial hypertension (PAH) is characterized by a progressive elevation of pulmonary pressure leading to right ventricular dysfunction and is associated with a poor prognosis. Patients with PAH have increased numbers of circulating extracellular vesicles (EVs) and altered expression of circulating microRNAs (miRs). The study aimed to evaluate the miR profile contained within purified EVs derived from the plasma of PAH patients as compared to healthy controls (HC). Circulating EVs, purified from platelet-free plasma were analyzed using flow cytometry, western blot, and electron microscopy. Total RNA isolated from EVs was subjected to Microarray analysis using GeneChip miRNA 4.0 Array and bioinformatics tools. Overexpression and inhibition of miRs were conducted in human pulmonary artery endothelial cells (hPAECs) that had been incubated previously with either PAH- or HC-derived EVs. Cell proliferation (MTT assay) and angiogenesis (tube formation assay) were tested in hPAECs to determine miR functionality. MiR profiling revealed 370 heats while comparing PAH and HC groups, 22 of which were found to be down-regulated and 6 were up-regulated in the PAH EVs. Among the altered miRs, miR-486-5p was overexpressed, while miR-26a-5p was downregulated in PAH EVs compared to HC EVs. Inhibition of mir-486-5p or overexpression of miR-26a-5p in hPAECs post-exposure of PAH EVs abrogated proangiogenic and proliferative effects posed by PAH EVs contrary to HC EVs. The angiogenic and proliferative effects of the miRs from PAH EVs were observed to be mediated through nuclear factor (NF)-κB activation. PAH EVs carry and present an altered miR profile that can be targeted to restrict angiogenesis and reduce pulmonary endothelium activation. Further studies concerning miRs from circulating heterogeneous EVs in PAH patients are warranted to understand their potential as targets for treatment in PAH.

Expression Patterns of microRNAs and Associated Target Genes in Ulcerated Primary Cutaneous Melanoma

Ulcerated cutaneous melanoma carries a poor prognosis, and the underlying biology driving its aggressive behavior is largely unexplored. MicroRNAs (miRs) are small, noncoding RNAs that inhibit the expression of specific genes and exhibit dysregulated expression patterns in cancer. We hypothesized that a unique miR profile exists in ulcerated relative to nonulcerated melanoma and that miR expression inversely correlates with target genes of biologic importance. Expression of miRs and mRNAs was assessed in ulcerated and nonulcerated cutaneous melanomas using the NanoString Human miRNA and Tumor Signaling 360 mRNA assays and validated in an independent cohort. Pathway enrichment and functional annotations for differentially expressed miRs and mRNAs were determined using publicly available databases. Pearson correlations were employed to predict potential miR‒mRNA binding pairs. Ulcerated melanoma tissue showed at least 1.5-fold change in relative expression of 24 miRs, including miR-206, miR-1-3p, and miR-4286 (>2.25-fold decrease, P< 0.048) and miR-146a-5p, miR-196b-5p, and miR-363-3p (>2.5-fold increase, P < 0.014). Ulcerated melanomas also had 21 differentially expressed mRNAs relative to nonulcerated tumors (P < 0.01), among which two had an inverse correlation in expression with regulatory miRs (SOCS3 and miR-218-5p and IL7R and miR-376c-5p). This miR expression profile adds to the molecular characterization of the poorly understood histopathologic phenotype of ulcerated melanoma.

Cellular responses and microRNA profiling in bovine spermatozoa under heat shock.

Elevated temperatures disturbed sperm physiology. Bovine sperm cells exposed to heat shock led to diminished mitochondrial activity, fertilizing ability, increased oxidative stress and caspase activity concomitant with a delay in embryonic developmental kinetics and modulation of sperm-borne microRNAsmiRNAs. Sperm function is susceptible to adverse environmental conditions. It has been demonstrated that in vivo and in vitro exposure of bovine sperm to elevated temperature reduces sperm motility and fertilizing potential. However, the cascade of functional, cellular, and molecular events triggered by elevated temperature in the mature sperm cell remains not fully understood. Therefore, the aim of this study was to determine the effect of heat shock on mature sperm cells. Frozen-thawed Holstein sperm were evaluated immediately after Percoll purification (0 h non-incubation control) or after incubation at 35, 38.5, and 41°C for 4 h. Heat shock reduced sperm motility after 3-4 h at 41°C while mitochondrial activity was reduced by 38.5 and 41°C when compared to the control. Heat shock also increased sperm reactive oxygen species production and caspase activity. Heat-shocked sperm had lower fertilizing ability, which led to diminished cleavage and blastocyst rates. Preimplantation embryo developmental kinetics was also slowed and reduced by sperm heat shock. The microRNA (miR) profiling identified >300 miRs in bovine sperm. Among these, three and seven miRs were exclusively identified in sperm cells exposed to 35 and 41°C, respectively. Moreover, miR-181d was enriched in sperm cells exposed to higher temperatures. Hence, elevated temperature altered the physiology of mature sperm cells by perturbing cellular processes and the miR profile, which collectively led to lower fertilizing ability and preimplantation development.

Sex-specific analysis of microRNA profiles in HBV-associated cirrhosis by small RNA-sequencing.

Liver cirrhosis represents an advanced stage of chronic liver disease and is associated with significant morbidity, mortality, and risk of cancer development. While sex disparity of liver diseases has been observed, understanding at a genetic level awaits more thorough investigation. In this study, we performed a sex-specific analysis of the microRNA (miR) profiles in hepatitis B virus (HBV)-associated cirrhosis by small RNA-sequencing using clinical tissue samples. Potential associated signaling pathways, downstream gene targets, and upstream regulators were highlighted by computational prediction analyses based on the differentially expressed miRs (DEmiRs). From our results, deregulation of miRs in cirrhosis showed a marked difference between males and females by the degree and pattern. Sixty-five (64 up-regulated, 1 down-regulated) and 12 (6 up-regulated, 6 down-regulated) DEmiRs were found in males and females, respectively, when compared with their respective control group. A number of DEmiRs were only observed in one sex but not the other. In addition, 26 DEmiRs were identified between cirrhosis female and cirrhosis male groups. Fatty acid biosynthesis pathway, extracellular matrix-receptor interaction, p53 signaling, Hippo signaling, tumor necrosis factor signaling, the forkhead box O signaling, as well as gene targets ribosomal protein S27 like, methyl CpG binding protein 2, and estrogen receptor 1, may contribute to the pathogenesis and biological behavior of cirrhosis in a sex-specific manner. Analysis of the Cancer Genome Atlas data set suggested a role of sex-specific DEmiRs in multistep hepatocarcinogenesis. Conclusion: Our findings illustrate that miR profiles in HBV-associated cirrhosis are distinct between the males and females and suggest a potential role of sex-specific biomarkers and molecular mechanisms in disease development and progression.

MiR Profile of Chronic Right Ventricular Pacing: a Pilot Study in Children with Congenital Complete Atrioventricular Block

Chronic ventricular pacing can lead to pacing-induced cardiomyopathy (PICM). Clinical data alone is insufficient to predict who will develop PICM. Our study aimed to evaluate the circulating miR profile associated with chronic right ventricular pacing in children with congenital complete AV block (CCAVB) and to identify candidate miRs for longitudinal monitoring. Clinical data and blood were collected from chronically paced children (N = 9) and compared with non-paced controls (N = 13). miR microarrays from the buffy coat revealed 488 differentially regulated miRs between groups. Pathway analysis predicted both adaptive and maladaptive miR signaling associated with chronic pacing despite preserved ventricular function. Greater profibrotic signaling (miRs-92a, 130, 27, 29) and sodium and calcium channel dysregulation (let-7) were seen in those paced > 10 years with the most dyregulation seen in a patient with sudden death vs. those paced < 10 years. These miRs may help to identify early adverse remodeling in this population.Graphical abstract

Expression analysis of miRNA-155 level in Helicobacter pylori related inflammation and chronic gastritis.

Helicobacter pylori, is a major etiologic agent associated with gastritis. There is more evidence of noncoding microRNAs (miRs) dysregulation in gastrointestinal diseases, including inflammation caused by Helicobacter pylori. Also, the classification of gastrointestinal malignancies using the miRs profile is better than the protein profile. MiRNA-155(miRNA-155) among other miRs plays an important role in control of inflammation and gastric malignancy, so it can be remarkable prognosis marker of gastric cancer in the phase of chronic gastritis. The aim of this study was to compare the expression of miRNA-155 in gastric biopsy and serum samples of adult patients with chronic gastritis. Biopsy and blood samples were collected from endoscopy candidates at Taleghani hospital, Tehran, during 2019. H. pylori infection was detected using histology, culture and molecular PCR methods. Based on cagA and vacA genotyping, the toxicity of H. pylori isolates were determined. After RNA extraction, the expression rate of miRNA-155 was evaluated by real-time polymerase chain reaction (RT-PCR) in gastric tissue and serum of adults infected by H. pylori (n = 30) compared with control group without infection (n = 20). RNU6 housekeeping miRNA were used as endogenous control and statistical analyses were performed using SPSS, ANOVA and Student's t-test. miRNA-155 expression in H. pylori infected adult patients increased significantly by 5.61 and 10.11 fold in serum and tissue respectively, compared to that observed in the control group. Evaluation of miRNA-155 expression pattern in relation to bacterial virulence factors showed that the increase in miRNA-155 expression is independent of CagA and VacA toxins. According to the differential expression patterns of miRNA-155 in serum samples of the infected adult patients, miRNA-155 has the potential to evaluate as chronic gastritis marker.

Urine Cell-Free MicroRNAs in Localized Prostate Cancer Patients.

Simple SummaryUrine cell-free microRNAs (cfmiRs) are promising biomarkers for the detection of prostate cancer (PCa) and may replace or complement prostate-specific antigen screening. This pilot study aims to demonstrate the diagnostic utility of urine cfmiRs for early-stage PCa using a robust microRNA (miR) panel based on next-generation sequencing. We assessed urine, plasma, and formalin-fixed paraffin-embedded tumor tissue samples obtained from patients diagnosed with pT2 PCa. Differentially expressed miRs were found in urine, plasma, and tumor samples obtained from PCa patients. Through bioinformatic analysis, several miRs were found as potential cfmiRs with utility for the detection of PCa. Our results showed that specific cfmiRs in urine samples from PCa patients may have potential utility in the detection of early-stage PCa.Prostate cancer (PCa) is the most common cancer in men. Prostate-specific antigen screening is recommended for the detection of PCa. However, its specificity is limited. Thus, there is a need to find more reliable biomarkers that allow non-invasive screening for early-stage PCa. This study aims to explore urine microRNAs (miRs) as diagnostic biomarkers for PCa. We assessed cell-free miR (cfmiR) profiles of urine and plasma samples from pre- and post-operative PCa patients (n = 11) and normal healthy donors (16 urine and 24 plasma) using HTG EdgeSeq miRNA Whole Transcriptome Assay based on next-generation sequencing. Furthermore, tumor-related miRs were detected in formalin-fixed paraffin-embedded tumor tissues obtained from patients with localized PCa. Specific cfmiRs signatures were found in urine samples of localized PCa patients using differential expression analysis. Forty-two cfmiRs that were detected were common to urine, plasma, and tumor samples. These urine cfmiRs may have potential utility in diagnosing early-stage PCa and complementing or improving currently available PCa screening assays. Future studies may validate the findings.

Chronic binge alcohol‐mediated alterations in myotube EV profile affect recipient myotube miRNA expression

The average age of people living with HIV (PLWH) is now over 50 years, and this increased life expectancy is associated with increased prevalence of comorbid conditions including myopathy. At‐risk alcohol use is twice as prevalent in PLWH as the general population, and loss of muscle mass is a concern in PLWH and those with at‐risk alcohol use. Our group has previously shown that chronic binge alcohol (CBA) in SIV‐infected macaques decreases myoblast differentiation and is partly mediated by altered microRNA (miR) profile. miRs transported between cells in extracellular vesicles (EVs) mediate numerous physiologic and pathologic cellular responses and can alter the function of target cells through miR delivery. We tested the hypothesis that EVs derived from myotubes isolated from CBA‐administered female macaques would alter miR expression in recipient myotubes. Seven SIV‐infected female rhesus macaques received either CBA (2.5 g/kg/day, N=4) or water (VEH, N=3) for 14.5 months. Three months following the initiation of CBA or VEH, the animals were vaginally inoculated with SIVmac251. Antiretroviral therapy was initiated 2.5 months later. Animals were sacrificed 9 months later, and primary cells were derived from skeletal muscle tissue 24 hours following the last dose of alcohol (blood alcohol=0 mM). EVs were isolated by ultracentrifugation from the conditioned cell culture supernatant of three 10 cm plates of differentiated primary myoblasts (i.e. myotubes). EVs were transferred to naïve (prior to SIV or CBA) recipient macaque myotubes in serum‐free media and incubated for 48 hours. Following incubation, cells were washed, and RNA extracted to determine relative expression of miRs 133a, 133b, 206, 16, and 23a. EVs derived from CBA myotubes increased expression of miR‐206 in target myotubes (p&lt;0.05, Cohen d=2.68). There was no difference in the expression of other measured miRs; however, there were large effect sizes for CBA‐derived EVs to increase miR‐133a and miR‐23a expression (Cohen d=1.13 and 1.51, respectively) in recipient myotubes. These results indicate that CBA‐mediated alterations in myotube EV profile affect recipient myotube miRNA expression. Ongoing studies will determine if this altered recipient miR expression reflects altered EV miR expression and/or host cell miR expression and determine the functional relevance of increased miR‐206 on myotube differentiation and hypertrophy.

The miR-183/96/182 cluster is upregulated in glioblastoma carrying EGFR amplification

Glioblastoma (GBM) is one of the most frequent primary brain tumors. Limited therapeutic options and high recurrency rates lead to a dismal prognosis. One frequent, putative driver mutation is the genomic amplification of the oncogenic receptor tyrosine kinase EGFR. Often accompanied by variants like EGFRvIII, heterogenous expression and ligand independent signaling render this tumor subtype even more difficult to treat, as EGFR-directed therapeutics show only weak effects at best. So EGFR-amplified GBM is considered to have an even worse prognosis, and therefore, deeper understanding of molecular mechanisms and detection of potential targets for novel therapeutic strategies is urgently needed. In this study, we looked at the level of microRNAs (miRs), small non-coding RNAs frequently deregulated in cancer, both acting as oncogenes and tumor suppressors. Comparative analysis of GBM with and without EGFR amplification should give insight into the expression profiles of miRs, which are considered both as potential targets for directed therapies or as therapeutic reagents. Comparison of miR profiles of EGFR-amplified and EGFR-normal GBM revealed an upregulation of the miR-183/96/182 cluster, which is associated with oncogenic properties in several tumor entities. One prominent target of this miR cluster is FOXO1, a pro-apoptotic factor. By observing FOXO1 downregulation in EGFR-amplified tumors, we can see a significant correlation of EGFR amplification, miR-183/96/182 cluster upregulation, and repression of FOXO1. Although no significant difference in overall survival is shown, these data may contribute to the molecular understanding of this tumor subtype and offer potential targets for miR-based therapies.

Emerging Evidence of Noncoding RNAs in Bleb Scarring after Glaucoma Filtration Surgery.

Purpose: To conduct a narrative review of research articles on the potential anti- and pro-fibrotic mechanisms of noncoding RNAs following glaucoma filtration surgery. Methods: Keyword searches of PubMed, and Medline databases were conducted for articles discussing post-glaucoma filtration surgeries and noncoding RNA. Additional manual searches of reference lists of primary articles were performed. Results: Fifteen primary research articles were identified. Four of the included papers used microarrays and qRT-PCR to identify up- or down-regulated microRNA (miRNA, miR) profiles and direct further study, with the remainder focusing on miRNAs or long noncoding RNAs (lncRNAs) based on previous work in other organs or disease processes. The results of the reviewed papers identified miR-26a, -29b, -139, -155, and -200a as having anti-fibrotic effects. In contrast, miRs-200b and -216b may play pro-fibrotic roles in filtration surgery fibrosis. lncRNAs including H19, NR003923, and 00028 have demonstrated pro-fibrotic effects. Conclusions: Noncoding RNAs including miRNAs and lncRNAs are emerging and promising therapeutic targets in the prevention of post-glaucoma filtration surgery fibrosis.

Distinct Response of Circulating microRNAs to the Treatment of Pancreatic Cancer Xenografts with FGFR and ALK Kinase Inhibitors.

Simple SummaryPancreatic cancer is among the top three leading causes of cancer-related death in the United States, mainly due to late diagnosis after the disease has already spread to other organs. Hence, timely and efficient treatments are necessary to improve outcomes. In this study, we explored the use of circulating microRNAs (miRs) collected from the peripheral blood of pancreatic cancer-bearing mice for assessment of treatment efficacy early in the treatment schedule. MicroRNA changes in serum samples precede histologic changes during the treatments, suggesting the use of circulating microRNA as early indicators of response to treatment. These easily-accessible biomarkers can be sampled repeatedly and could guide timely treatment decisions.Pancreatic adenocarcinoma is typically detected at a late stage and thus shows only limited sensitivity to treatment, making it one of the deadliest malignancies. In this study, we evaluate changes in microRNA (miR) patterns in peripheral blood as a potential readout of treatment responses of pancreatic cancer to inhibitors that target tumor–stroma interactions. Mice with pancreatic cancer cell (COLO357PL) xenografts were treated with inhibitors of either fibroblast growth factor receptor kinase (FGFR; PD173074) or anaplastic lymphoma kinase receptor (ALK; TAE684). While both treatments inhibited tumor angiogenesis, signal transduction, and mitogenesis to a similar extent, they resulted in distinct changes in circulating miR signatures. Comparison of the miR pattern in the tumor versus that in circulation showed that the inhibitors can be distinguished by their differential impact on tumor-derived miRs as well as host-derived circulating miRs. Distinct signatures that include circulating miR-1 and miR-22 are associated with the efficacy of ALK and FGFR inhibition, respectively. We propose that monitoring changes in circulating miR profiles can provide an early signature of treatment response or resistance to pathway-targeted drugs, and thus provide a non-invasive measurement to rapidly assess the efficacy of candidate therapies.

Influence of age and sex on microRNA response and recovery in the hippocampus following sepsis.

Sepsis, defined as a dysregulated host immune response to infection, is a common and dangerous clinical syndrome. The excessive host inflammatory response can induce immediate and persistent cognitive decline, which can be worse in older individuals. Sex-specific differences in the outcome of infectious diseases and sepsis appear to favor females. We employed a murine model to examine the influence of age and sex on the brain's microRNA (miR) response following sepsis. Young and old mice of both sexes underwent cecal ligation and puncture (CLP) with daily restraint stress. Expression of hippocampal miR was examined in age- and sex-matched controls at 1 and 4 days post-CLP. Few miR were modified in a similar manner across age or sex and these few miR were generally associated with neuroprotection against inflammation. Similar to previous work examining transcription, young females exhibited a better recovery of the miR profile from day 1 to day 4, relative to young males and old females. For young males and all female groups, the initial response mainly involved a decrease in miR expression. In contrast, old males exhibited only upregulated miR on day 1 and day 4 and many of the miR upregulated on day 1 and day 4 were linked to neurodegeneration, increased neuroinflammation, and cognitive impairment. The results emphasize age and sex differences in epigenetic mechanisms that likely contribute to susceptibility or resilience to cognitive impairment due to sepsis.

Myeloma cells regulate miRNA transfer from fibroblast-derived exosomes by expression of lncRNAs.

Multiple myeloma (MM) progression and drug resistance depend on the crosstalk between MM cells and bone marrow (BM) fibroblasts (FBs). During monoclonal gammopathy of undetermined significance (MGUS) to MM transition, MM cell-derived exosomes (EXOs) reprogram the miRNA (miR) profile of FBs, inducing the overexpression miR-23b-3p, miR-27b-3p, miR-125b-5p, miR-214-3p, and miR-5100. Here, we demonstrate that the miR content of MM FB-derived EXOs (FB-EXOs) overlaps the miR profile of parental FBs by overexpressing comparable levels of miR-23b-3p, miR-27b-3p, miR-125b-5p, miR-214-3p, and miR-5100. Recipient MM cells co-cultured with MM FB-EXOs selectively overexpress only miR-214-3p and miR-5100 but not miR-23b-3p, miR-27b-3p, and miR-125b-5p, suggesting a putative selective transfer. MM cells express HOTAIR, TOB1-AS1, and MALAT1 lncRNAs. Transient transfection of MM cells with lnc·siRNAs demonstrates that HOTAIR, TOB1-AS1, and MALAT1 lncRNAs are sponges for miR-23b-3p, miR-27b-3p, and miR-125b-5p. Indeed, lncRNA knockdown significantly increased miR levels in U266 MM cells co-cultured with MM FB-EXOs. Selective miR-214-3p and miR-5100 overexpression modulates MAPK, PI3K/AKT/mTOR, and p53 pathways in MM cells. Interrogation using the DIANA tools algorithm and transient overexpression using miR mimic probes confirmed the involvement of miR-214-3p and miR-5100 and their target genes, PTEN and DUSP16, respectively, in the modulation of these intracellular pathways. Finally, the uptake of EXOs as well as miR-214-3p and miR-5100 overexpression increase MM cell proliferation and resistance to bortezomib-induced apoptosis by switching the balance between pro-/anti-apoptotic proteins. Overall, these data show that MM cells are not simply a container into which EXOs empty their cargo. On the contrary, tumour cells finely neutralize exosomal miRs via lncRNA expression to ensure their survival. © 2021 The Pathological Society of Great Britain and Ireland.

Extracellular vesicles derived from tumour cells as a trigger of energy crisis in the skeletal muscle.

BackgroundCachexia, a syndrome frequently occurring in cancer patients, is characterized by muscle wasting, altered energy and protein metabolism and impaired myogenesis. Tumour‐derived microvesicles (TMVs) containing proteins, messenger RNAs (mRNAs), and non‐coding RNAs could contribute to cancer‐induced muscle wasting.MethodsDifferential ultracentrifugation was used to isolate TMVs from the conditioned medium of Lewis lung carcinoma and C26 colon carcinoma cell cultures. TMVs were added to the culture medium of C2C12 myoblasts and myotubes for 24–48–72 h, and the effects on protein and energy metabolism were assessed. TMVs were also isolated from the blood of C26‐bearing mice. MicroRNA (miR) profile of TMVs was obtained by RNA‐seq and validated by digital drop PCR. Selected miRs were overexpressed in C2C12 myoblasts to assess the effects on myogenic differentiation.ResultsDifferentiation was delayed in C2C12 myoblasts exposed to TMVs, according to reduced expression of myosin heavy chain (MyHC; about 62% of controls at Day 4) and myogenin (about 68% of controls at Day 4). As for myotubes, TMVs did not affect the expression of MyHC, while revealed able to modulate mitochondria and oxidative metabolism. Indeed, reduced mRNA levels of PGC‐1α (C = 1 ± 0.2, TMV = 0.57 ± 0.06, normalized fold change, P < 0.05) and Cytochrome C (C = 1 ± 0.2, TMV = 0.65 ± 0.04, normalized fold change, P < 0.05), associated with increased BNIP3 expression (C = 1 ± 0.1, TMV = 1.29 ± 0.2, normalized fold change, P < 0.05), were observed, suggesting reduced mitochondrial biogenesis/amount and enhanced mitophagy. These changes were paralleled by decreased oxygen consumption (C = 686.9 ± 44 pmol/min, TMV = 552.25 ± 24 pmol/min, P < 0.01) and increased lactate levels (C = 0.0063 ± 0.00045 nmol/μL, TMV = 0.0094 ± 0.00087 nmol/μL, P < 0.01). A total of 118 miRs were found in MVs derived from the plasma of the C26 hosts; however, only three of them were down‐regulated (RNA‐seq): miR‐181a‐5p (−1.46 fold change), miR‐375‐3p (−2.52 fold change), and miR‐455‐5p (−3.87 fold change). No correlation could be observed among miRs in the MVs obtained from the blood of the C26 host and those released by C26 cells in the culture medium. Overexpression of miR‐148a‐3p and miR‐181a‐5p in C2C12 myoblasts revealed the ability to impinge on the mRNA levels of Myf5, Myog, and MyHC (Myh4 and Myh7).ConclusionsThese results show that in C2C12 cultures, TMVs are able to affect both differentiation and the mitochondrial system. Such effects could be related to TMV‐contained miRs.

Identification of a Distinct miRNA Regulatory Network in the Tumor Microenvironment of Transformed Mycosis Fungoides.

Simple SummaryTransformed mycosis fungoides (LCT-MF) is a histopathological marker of poor prognosis and associated with worse survival. We compared miRNA and mRNA expression profiles of LCT-MF with classic MF and found a distinct miRNA regulatory network modulated immunosuppressive tumor microenvironment in LCT-MF. Our findings provide novel insights and therapeutic targets for LCT-MF.Large cell transformation of mycosis fungoides (LCT-MF) occurs in 20–50% of advanced MF and is generally associated with poor response and dismal prognosis. Although different mechanisms have been proposed to explain the pathogenesis, little is known about the role of microRNAs (miRs) in transcriptional regulation of LCT-MF. Here, we investigated the miR and mRNA expression profile in lesional skin samples of patients with LCT-MF and non-LCT MF using RNA-seq analysis. We found miR-146a and miR-21 to be significantly upregulated, and miR-708 the most significantly downregulated miR in LCT-MF. Integration of miR and mRNA expression profiles revealed the miR-regulated networks in LCT-MF. Ingenuity pathway analysis (IPA) demonstrated the involvement of genes for ICOS-ICOSL, PD1-PDL1, NF-κB, E2F transcription, and molecular mechanisms of cancer signaling pathways. Quantitative real time (qRT)-PCR results of target genes were consistent with the RNA-seq data. We further identified the immunosuppressive tumor microenvironment (TME) in LCT-MF. Moreover, our data indicated that miR-146a, -21 and -708 are associated with the immunosuppressive TME in LCT-MF. Collectively, our results suggest that the key LCT-MF associated miRs and their regulated networks may provide insights into its pathogenesis and identify promising targets for novel therapeutic strategies.

Vascular Tissue Specific miRNA Profiles Reveal Novel Correlations with Risk Factors in Coronary Artery Disease.

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Non-coding RNAs have already been linked to CVD development and progression. While microRNAs (miRs) have been well studied in blood samples, there is little data on tissue-specific miRs in cardiovascular relevant tissues and their relation to cardiovascular risk factors. Tissue-specific miRs derived from Arteria mammaria interna (IMA) from 192 coronary artery disease (CAD) patients undergoing coronary artery bypass grafting (CABG) were analyzed. The aims of the study were 1) to establish a reference atlas which can be utilized for identification of novel diagnostic biomarkers and potential therapeutic targets, and 2) to relate these miRs to cardiovascular risk factors. Overall, 393 individual miRs showed sufficient expression levels and passed quality control for further analysis. We identified 17 miRs–miR-10b-3p, miR-10-5p, miR-17-3p, miR-21-5p, miR-151a-5p, miR-181a-5p, miR-185-5p, miR-194-5p, miR-199a-3p, miR-199b-3p, miR-212-3p, miR-363-3p, miR-548d-5p, miR-744-5p, miR-3117-3p, miR-5683 and miR-5701–significantly correlated with cardiovascular risk factors (correlation coefficient >0.2 in both directions, p-value (p < 0.006, false discovery rate (FDR) <0.05). Of particular interest, miR-5701 was positively correlated with hypertension, hypercholesterolemia, and diabetes. In addition, we found that miR-629-5p and miR-98-5p were significantly correlated with acute myocardial infarction. We provide a first atlas of miR profiles in IMA samples from CAD patients. In perspective, these miRs might play an important role in improved risk assessment, mechanistic disease understanding and local therapy of CAD.

Restoration of aged hematopoietic cells by their young counterparts through instructive microvesicles release.

This study addresses the potential to reverse age-associated morbidity by establishing methods to restore the aged hematopoietic system. Parabiotic animal models indicated that young secretome could restore aged tissues, leading us to establish a heterochronic transwell system with aged mobilized peripheral blood (MPB), co-cultured with young MPB or umbilical cord blood (UCB) cells. Functional studies and omics approaches indicate that the miRNA cargo of microvesicles (MVs) restores the aged hematopoietic system. The in vitro findings were validated in immune deficient (NSG) mice carrying an aged hematopoietic system, improving aged hallmarks such as increased lymphoid:myeloid ratio, decreased inflammation and cellular senescence. Elevated MYC and E2F pathways, and decreased p53 were key to hematopoietic restoration. These processes require four restorative miRs that target the genes for transcription/differentiation, namely PAX and phosphatase PPMIF. These miRs when introduced in aged cells were sufficient to restore the aged hematopoietic system in NSG mice. The aged MPBs were the drivers of their own restoration, as evidenced by the changes from distinct baseline miR profiles in MPBs and UCB to comparable expressions after exposure to aged MPBs. Restorative natural killer cells eliminated dormant breast cancer cells in vivo, indicating the broad relevance of this cellular paradigm - preventing and reversing age-associated disorders such as clearance of early malignancies and enhanced responses to vaccine and infection.