Analysis of Argonaute 2-microRNA complexes in ex vivo stored red blood cells

Differences in serum and plasma levels of microRNAs and their time-course changes after blood collection

Background

Serum and plasma are used for measurements of microRNAs (miRNAs) as biomarkers of various diseases. However, no consistent findings have been obtained regarding differences in serum and plasma levels of miRNAs. The purpose of this study was to clarify differences in serum and plasma levels of total miRNAs and their time-course changes after blood collection.

Methods

Venous blood was collected from healthy men, and samples were prepared at the time points of 0, 15, 30, 60 and 180 min after blood collection for plasma and after clot formation for serum. Levels of total miRNAs were analyzed by the hybridization method using the 3D-Gene miRNA Oligo chip.

Results

About one third of 2632 miRNAs tested showed levels high enough for comparison of serum and plasma levels and for investigation of their time-course changes. Levels of 299 miRNAs at time 0 were significantly different in serum and plasma. Levels of representative platelet-derived miRNAs including miR-185-5p, -22-3p and -320b were significantly higher in plasma than in serum, while levels of representative erythrocyte-derived miRNAs including miR-451a, -486-5p and -92a-3p were not significantly different in serum and plasma. Plasma levels of 173 miRNAs and 6 miRNAs showed significant decreasing and increasing tendencies, respectively, while there were no miRNAs in serum that showed significant time-course changes.

Conclusion

The results suggest that careful attention should be paid when comparing serum and plasma levels of miRNAs and that plasma samples should be prepared early after blood collection.

Plasmodium falciparum infection reshapes the human microRNA profiles of red blood cells and their extracellular vesicles

Plasmodium falciparum, a human malaria parasite, develops in red blood cells (RBCs), which represent approximately 70% of all human blood cells. Additionally, RBC-derived extracellular vesicles (RBC-EVs) represent 7.3% of the total EV population. The roles of microRNAs (miRNAs) in the consequences of P. falciparum infection are unclear. Here, we analyzed the miRNA profiles of non-infected human RBCs (niRBCs), ring-infected RBCs (riRBCs), and trophozoite-infected RBCs (trRBCs), as well as those of EVs secreted from these cells. Hsa-miR-451a was the most abundant miRNA in all RBC and RBC-EV populations, but its expression level was not affected by P. falciparum infection. Overall, the miRNA profiles of RBCs and their EVs were altered significantly after infection. Most of the differentially expressed miRNAs were shared between RBCs and their EVs. A target prediction analysis of the miRNAs revealed the possible identity of the genes targeted by these miRNAs (CXCL10, OAS1, IL7, and CCL5) involved in immunomodulation.

MicroRNAs as Quality Assessment Tool in Stored Packed Red Blood Cell in Blood Banks

Micro-ribonucleic acids are control gene expression in cells. They represent the changed cellular states that occur can be employed as biomarkers. Red blood cells alter biochemically and morphologically while they are being stored, which could be detrimental to transfusion. The effect of storage on the erythrocyte transcriptome is not mostly investigated. Because adult erythrocytes lack a nucleus, it has long been assumed that they lack deoxyribonucleic acid and ribonucleic acid. On the other hand, erythrocytes contain a diverse range of ribonucleic acids, of which micro-ribonucleic acids are key component. Changes in this micro-ribonucleic acid protect cells from death and adenine triphosphate depletion, and they are linked to specific storage lesions. As a result, changes in micro-ribonucleic acid in stored erythrocytes may be used as a marker to assess the quality and safety of stored erythrocytes. Therefore, this review ams to review the role of microRNA in stored packed red blood cells as quality indicator. Google Scholar, PubMed, Scopus, and Z-libraries are used for searching articles and books. The article included in this paper was written in the English language and had the full article. During long storage of RBCs, miR-16-2-3p, miR-1260a, miR-1260b, miR-4443, miR-4695-3p, miR-5100, let-7b, miR-16, miRNA-1246, MiR-31-5p, miR-203a, miR-654-3p, miR-769-3p, miR-4454, miR-451a and miR-125b- 5p are up regulated. However, miR-96, miR-150, miR-196a, miR-197, miR-381 and miR-1245a are down regulated after long storage of RBCs. The changes of this microRNAs are linked to red blood cell lesions. Therefore, micro-ribonucleic acids are the potential quality indicator in stored packed red blood cells in the blood bank. Particularly, micro-ribonucleic acid-96 is the most suitable biomarker for monitoring red blood cell quality in stored packed red blood units.

Differential Effect of Extracellular Vesicles Derived from Plasmodium falciparum-Infected Red Blood Cells on Monocyte Polarization

Malaria is a life-threatening tropical arthropod-borne disease caused by Plasmodium spp. Monocytes are the primary immune cells to eliminate malaria-infected red blood cells. Thus, the monocyte's functions are one of the crucial factors in controlling parasite growth. It is reasoned that the activation or modulation of monocyte function by parasite products might dictate the rate of disease progression. Extracellular vesicles (EVs), microvesicles, and exosomes, released from infected red blood cells, mediate intercellular communication and control the recipient cell function. This study aimed to investigate the physical characteristics of EVs derived from culture-adapted P. falciparum isolates (Pf-EVs) from different clinical malaria outcomes and their impact on monocyte polarization. The results showed that all P. falciparum strains released similar amounts of EVs with some variation in size characteristics. The effect of Pf-EV stimulation on M1/M2 monocyte polarization revealed a more pronounced effect on CD14⁺CD16⁺ intermediate monocytes than the CD14⁺CD16^- classical monocytes with a marked induction of Pf-EVs from a severe malaria strain. However, no difference in the levels of microRNAs (miR), miR-451a, miR-486, and miR-92a among Pf-EVs derived from virulent and nonvirulent strains was found, suggesting that miR in Pf-EVs might not be a significant factor in driving M2-like monocyte polarization. Future studies on other biomolecules in Pf-EVs derived from the P. falciparum strain with high virulence that induce M2-like polarization are therefore recommended.

Differentially Expressed Extracellular Vesicle-Contained microRNAs before and after Transurethral Resection of Bladder Tumors

Bladder cancer (BC) is currently diagnosed and monitored by cystoscopy, a costly and invasive procedure. Potential biomarkers in urine, blood, and, more recently, extracellular vesicles (EVs), have been explored as non-invasive alternatives for diagnosis and surveillance of BC. EVs are nanovesicles secreted by most cell types containing diverse molecular cargo, including different types of small RNAs, such as microRNA (miRNA). In this study, we performed next-generation sequencing of EV-contained miRNA isolated from urine and serum of 41 patients with non-muscle invasive BC (27 stage Ta, 14 stage T1) and 15 non-cancer patients (NCP) with benign cystoscopy findings. MiRNA sequencing was also performed on serum supernatant samples for T1 patients. To identify potential BC-specific biomarkers, expression levels of miRNA in presurgery samples were compared to those at postsurgery check-ups, and to NCPs. Results showed that two miRNAs, urinary EV-contained miR-451a and miR-486-5p, were significantly upregulated in presurgery samples from T1 patients compared to postsurgery check-up samples. This was confirmed in a replica EV/RNA isolation and sequencing run of 10 T1 patients from the primary run; however, analyses revealed no differential expression of miRNAs in serum EVs, serum supernatant, or when comparing BC patients to NCPs. This is the first study to investigate EV-containing miRNA sequencing in pre- and postsurgery BC patient samples and our findings suggest that urinary EV-contained miR-451a and miR-486-5p may be potential biomarkers for recurrence-free survival of BC patients with stage T1 disease.

Proteome of Stored RBC Membrane and Vesicles from Heterozygous Beta Thalassemia Donors

Genetic characteristics of blood donors may impact the storability of blood products. Despite higher basal stress, red blood cells (RBCs) from eligible donors that are heterozygous for beta-thalassemia traits (βThal⁺) possess a differential nitrogen-related metabolism, and cope better with storage stress compared to the control. Nevertheless, not much is known about how storage impacts the proteome of membrane and extracellular vesicles (EVs) in βThal⁺. For this purpose, RBC units from twelve βThal⁺ donors were studied through proteomics, immunoblotting, electron microscopy, and functional ELISA assays, versus units from sex- and aged-matched controls. βThal⁺ RBCs exhibited less irreversible shape modifications. Their membrane proteome was characterized by different levels of structural, lipid raft, transport, chaperoning, redox, and enzyme components. The most prominent findings include the upregulation of myosin proteoforms, arginase-1, heat shock proteins, and protein kinases, but the downregulation of nitrogen-related transporters. The unique membrane proteome was also mirrored, in part, to that of βThal⁺ EVs. Network analysis revealed interesting connections of membrane vesiculation with storage and stress hemolysis, along with proteome control modulators of the RBC membrane. Our findings, which are in line with the mild but consistent oxidative stress these cells experience in vivo, provide insight into the physiology and aging of stored βThal⁺ RBCs.

Blood levels of microRNAs associated with ischemic heart disease differ between Austrians and Japanese: a pilot study

Mortality from ischemic heart disease (IHD) is significantly lower in Japan than in Western countries. The purpose of this study was to investigate differences in circulating microRNA (miRNA) levels related to IHD in Austrians and Japanese. Participants were middle-aged healthy male Austrians (n = 20) and Japanese (n = 20). Total miRNAs in serum from each participant were analyzed using the 3D-Gene miRNA Oligo chip. Twenty-one miRNAs, previously reported as associated with IHD, were compared between Austrians and Japanese. The expression levels of miR-106a-5p, miR-135a-3p, miR-150-3p, miR-16-5p, miR-17-5p. miR-191-5p, miR-320b, miR-451a, miR-486-5p, miR-663b, and miR-92a-3p were significantly higher, while the miR-2861 expression level was significantly lower in Austrians as compared to Japanese. Both in Austrians and Japanese, there were significant positive correlations between serum expression levels of each pair of the above miRNAs except for miR-2861. The expression level of miR-2861 showed significant positive correlations with the expression levels of miR-106a-5p, miR-150-3p, miR-17-5p, miR-486-5p, miR-663b and miR-92a-3p in Austrians but not in Japanese. In pathway analysis, proinflammatory cytokine production in foam cells and collagen synthesis in vascular smooth muscle cells were associated with differentially expressed miRNAs. Difference in miRNA levels may contribute to lower cardiovascular risk in Japan than in Western countries.

Red Blood Cells as Potential Repositories of MicroRNAs in the Circulatory System

The amount of erythrocyte-derived microRNAs (miRNAs) represents the majority of miRNAs expressed in whole blood. miR-451, miR-144, and miR-486, which are abundant in red blood cells (RBCs), are involved in the process of erythropoiesis and disease occurrence. Moreover, erythrocyte-derived miRNAs have been reported to be potential biomarkers of specific diseases. However, the function and underlying mechanisms of miRNAs derived from erythrocytes remain unclear. Based on a review of previously published literature, we discuss several possible pathways by which RBC miRNAs may function and propose that RBCs may serve as repositories of miRNAs in the circulatory system and participate in the regulation of gene expression mainly via the transfer of miRNAs from erythrocyte extracellular vesicles (EVs). In the whole blood, there are still other important cell types such as leukocytes and platelets harboring functional miRNAs, and hemolysis also exists, which limit the abundance of miRNAs as disease biomarkers, and thus, miRNA studies on RBCs may be impacted. In the future, the role of RBCs in the regulation of normal physiological functions of the body and the entire circulatory system under pathological states, if any, remains to be determined.

Effects of Cardiac Sympathetic Neurodegeneration and PPARγ Activation on Rhesus Macaque Whole Blood miRNA and mRNA Expression Profiles

Degeneration of sympathetic innervation of the heart occurs in numerous diseases, including diabetes, idiopathic REM sleep disorder, and Parkinson's disease (PD). In PD, cardiac sympathetic denervation occurs in 80-90% of patients and can begin before the onset of motor symptoms. Today, there are no disease-modifying therapies for cardiac sympathetic neurodegeneration, and biomarkers are limited to radioimaging techniques. Analysis of expression levels of coding mRNA and noncoding RNAs, such as microRNAs (miRNAs), can uncover pathways involved in disease, leading to the discovery of biomarkers, pathological mechanisms, and potential drug targets. Whole blood in particular is a clinically relevant source of biomarkers, as blood sampling is inexpensive and simple to perform. Our research group has previously developed a nonhuman primate model of cardiac sympathetic denervation by intravenous administration of the catecholaminergic neurotoxin 6-hydroxydopamine (6-OHDA). In this rhesus macaque (Macaca mulatta) model, imaging with positron emission tomography showed that oral administration of the peroxisome proliferator-activated receptor gamma (PPARγ) agonist pioglitazone (n = 5; 5 mg/kg daily) significantly decreased cardiac inflammation and oxidative stress compared to placebo (n = 5). Here, we report our analysis of miRNA and mRNA expression levels over time in the whole blood of these monkeys. Differential expression of three miRNAs was induced by 6-OHDA (mml-miR-16-2-3p, mml-miR-133d-3p, and mml-miR-1262-5p) and two miRNAs by pioglitazone (mml-miR-204-5p and mml-miR-146b-5p) at 12 weeks posttoxin, while expression of mRNAs involved in inflammatory cytokines and receptors was not significantly affected. Overall, this study contributes to the characterization of rhesus coding and noncoding RNA profiles in normal and disease-like conditions, which may facilitate the identification and clinical translation of biomarkers of cardiac neurodegeneration and neuroprotection.

Relationships among erythrocyte-derived microRNAs in serum of healthy donors

BACKGROUND

Circulating microRNAs (miRNAs) have recently been proposed to be biomarkers for various diseases including cancer and cardiovascular disease. Erythrocytes are a major source of miRNAs in blood. However, it remains unknown how miRNA levels in serum are influenced by miRNAs in erythrocytes. In this study, we investigated the relationships among serum levels of miRNAs that are contained in erythrocytes.

METHODS

Participants were middle-aged healthy Japanese men. Total miRNAs in serum from each participant were analyzed using the 3D-Gene miRNA Oligo chip. Relationships among the levels of eleven miRNAs (miR-103a-3p, -144-3p, -15a-5p, -16--5p, -26a-5p, -423-5p, -451a, -484, -486-5p, -92a-3p, and -93-5p) that have been reported to exist in erythrocytes were investigated by using correlation analysis.

RESULTS

Among 55 pairs prepared by the above 11 miRNAs, there were significant correlations between miRNA levels of 31 pairs. In principal component analysis, 4 major erythrocyte-derived miRNAs, miR-16-5p, -451a, -486-5p and -92a-3p, were included in the first principal component. There were strong correlations between miR-16-5p and -451a levels (Spearman's rank correlation coefficient: 0.920) and between miR-486-5p and -92a-3p levels (Spearman's rank correlation coefficient: 0.863).

CONCLUSION

There are significant associations among serum levels of erythrocyte-derived miRNAs, and these associations should be taken into account when considering the miRNAs as disease biomarkers.

microRNA-196a Overexpression Inhibits Apoptosis in Hemin-Induced K562 Cells

microRNAs (miRNAs) have a crucial role in erythropoiesis. However, the understanding of the apoptosis of erythroid lineage remains poorly understood. Hence, an additional examination is required. K562 cell lines can be differentiated into early erythrocytes by hemin and the model of early erythrocytes can be established, consequently. miR-196a has been proven to take part in antiapoptosis in many cell lines. However, the role of miR-196a associated with the apoptosis in hemin-induced K562 cells remains unclear. To study the potential function of miR-196a involved in the common progenitor of erythroblasts, miR-196a mimics and microRNA-small hairpin negative control (miRNA-ShNC) were transfected into hemin-induced K562 cells with lentiviruses. After that, the viability of the transfected hemin-induced K562 cells was tested by CCK-8 assay, and the alteration of cell cycle and apoptosis rate were detected by flow cytometry. Furthermore, bioinformatics and dual-luciferase report system verified that p27^kip1 is a target gene of miR-196a. Additionally, the expression of some proteins associated with cell cycle and apoptosis was tested by Western blotting assays. It was found that after overexpressing miR-196a, the proliferation of hemin-induced K562 cells was promoted while the apoptosis inhibited. Furthermore, miR-196a combines with the 3'UTR of p27^kip1 directly. Additionally, the relationship between miR-196a and the protein level of p27^kip1 is negative. After restoring the expression of p27^kip1, the growth rate of hemin-induced K562 cells was not as high as before and the inhibition of apoptosis was alleviated. The present study validates that miR-196a overexpression inhibits apoptosis in hemin-induced K562 cells through downregulating p27^kip1.

Stored red blood cells enhance in vivo migration of dendritic cells by promoting reactive oxygen species-induced cytoskeletal rearrangement

BACKGROUND

A complex array of physicochemical changes occurs in red blood cells (RBCs) during storage, leading to enhanced posttransfusion clearance. Dendritic cells (DCs) play crucial roles in the engulfment of aged RBCs; however, it is unclear how stored RBCs (sRBCs) modulate their responses to inflammatory stimuli and DC migration ability.

STUDY DESIGN AND METHODS

In this study, we examined whether sRBCs affect the migration ability of DCs and elucidated the detailed mechanisms mediating this process. Murine RBCs were incubated with marrow DCs after removing the storage supernatant. The effects of sRBCs on cytokine secretion from DCs, surface marker expression, and homing ability were examined.

RESULTS

More sRBCs were internalized by DCs than fresh RBCs (fRBCs), and RBC accumulation significantly promoted the expression of allostimulatory molecules and the secretion of Th1-type cytokines in the presence of lipopolysaccharide (LPS). In particular, the lymphoid-tissue homing ability of transfused DCs treated with sRBCs (sRBC-DCs) was also significantly greater than that of fRBCs. Up regulation of CCR7 and improved organization of the cytoskeleton were observed in sRBC-DCs, and blocking Rho/Rho-associated protein kinase (ROCK), PI3K/Akt, and NF-κB pathways greatly hindered cytoskeletal rearrangement. Moreover, high levels of reactive oxygen species (ROS) were detected in sRBC-DCs, and treatment with N-acetylcysteine simultaneously decreased the lymph node-homing ability of DCs and phosphorylation of RhoA, ROCK1, and cortactin.

CONCLUSIONS

sRBCs initiated differential immune responses compared to fRBCs, and the presence of LPS augmented this phenomenon. Up regulation of CCR7 and ROS production promotes cytoskeletal reorganization and contributes to the increased homing of sRBCs-DCs.

Different Erythrocyte MicroRNA Profiles in Low- and High-Altitude Individuals

Background: The number of red blood cells (RBCs) increases significantly in response to high-altitude hypoxic environments, and the RBC microRNA (miRNA) expression pattern is similar to that in whole blood. Studies have shown that miRNA in plasma can act as a circulating hypoxia-associated marker, but the effect of a high-altitude hypoxic environment on RBC-derived miRNAs has not yet been reported.

Methods: Blood samples were collected from 20 Han Chinese individuals residing at 500 m (Sichuan Han), 10 migrant Han Chinese citizens residing at 3,658 m (Tibet Han) and 12 native Tibetans, and RBC indices measurements and miRNA sequencing analyses were performed for the three sample groups. The levels of some markedly altered miRNAs at high altitude were subsequently measured from 5 randomly selected samples of each group by real-time PCR. Bioinformatic analyses was performed to determine the potential target genes of selected hypoxia-associated miRNAs.

Results: Marked changes of several RBC indices were observed among the Tibet Han population, the Tibetan population and the Sichuan Han population. A total of 516 miRNAs derived from RBCs were initially identified by miRNA sequencing in the three sample groups. Compared with the Sichuan Han population, 49 miRNAs were differentially expressed in the Tibet Han population (17 upregulated and 32 downregulated). 12 upregulated and 21 downregulated miRNAs were observed in the Tibetan population compared with the Sichuan Han population. A total of 40 RBC miRNAs were differentially expressed in the Tibetan population (15 upregulated and 25 downregulated) compared with the Tibet Han population. Two significantly altered miRNAs with the highest expression levels (miRNA-144-5p and miR-30b-5p) were selected for real-time PCR analysis, and the results were consistent with those of miRNA sequencing. Furthermore, bioinformatic analyses showed that some potential target genes of miR-144-5p and miR-30b-5p are involved in the erythroid- hypoxia-, and nitric oxide (NO)-related signaling pathways in response to hypoxia.

Conclusion: Our findings provide clear evidence, for the first time, that a high-altitude hypoxic environment significantly affects human RBC miRNA profiles.

Temporal expression of circulating miRNA after severe injury

BACKGROUND

Severe injury can lead to immune dysfunction and predispose patients to infection and death. Micro-RNAs regulate gene expression and may act as biomarkers for susceptibility to infection. The aim of this study was to examine the temporal and differential expression of previously identified dysregulated micro-RNAs in patients with severe injury.

METHODS

Fourteen severely injured patients requiring transfusion were enrolled prospectively in this study approved by our institutional review board. Inclusion criteria consisted of adult patients deemed clinically to be in hemorrhagic shock necessitating transfusion in the acute phase of their injury care. Peripheral blood samples were obtained after admission to the surgical intensive care unit and again at 6, 12, 24, and 48 hours after admission. The samples obtained at arrival to the intensive care unit and 24 and 48 hours later were analyzed in this data set. Fourteen healthy volunteers served as controls. The 10 dysregulated micro-RNAs identified in a prior study at the 12-hour time point and important genes in innate immunity were measured using quantitative reverse transcription-polymerase chain reaction.

RESULTS

The participants were 21-77 years old (median, 42), 78% were male, and their Injury Severity Score ranged from 11 to 43 (median, 27); 11 had blunt and 3 had penetrating injuries. Three were intubated and 5 had received blood products before arrival at the hospital. Base deficit on hospital admission was 3-20 (median, 9). All patients required blood transfusion secondary to blood loss sustained during injury. Eleven of the 14 patients went directly to the operating room from the emergency department for control of the source of hemorrhage. Survival to discharge was 93%. Seven patients developed infection. Compared with healthy controls, miR-106a was downregulated at all time points compared with controls (P < .05). miR-618 was upregulated in initial blood draws (P < .05) and at 24 and 48 hours (P < .06). Tumor necrosis factor α and human leukocyte antigen-DR (HLA-DR) were downregulated, and interleukin-10 and PD-L1 were upregulated (P < .05). In patients who developed infection, miR-106a levels appeared more downregulated than those who did not develop infection.

CONCLUSION

miR-106a was downregulated in trauma patients after major injury for up to 48 hours after intensive care unit admission. Tumor necrosis factor α and interleukin-10 are targeted by miR-106a, which are regulators of the immune response. Manipulation of micro-RNA expression may be a therapeutic target for immune dysfunction.