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Background: Cardiac-abundant microRNA-378a (miR-378a) is associated with postnatal repression of insulin-like growth factor 1 receptor (IGF-1R) controlling physiological hypertrophy and survival pathways. IGF-1/IGF-1R axis has been proposed as a therapeutic candidate against the pathophysiological progress of diabetic cardiomyopathy (DCM). We ask whether hyperglycemia-driven changes in miR-378a expression could mediate DCM progression., Methods: Diabetes mellitus was induced by streptozotocin (STZ) (55 mg/kg i.p. for 5 days) in male C57BL/6 wild type (miR-378a+/+) and miR-378a knockout (miR-378a-/-) mice. As a parallel human model, we harnessed human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM miR378a+/+ vs. hiPSC-CM miR378a-/-) subjected to high glucose (HG) treatment., Results: We reported miR-378a upregulation in cardiac diabetic milieu arising upon STZ administration to wild-type mice and in HG-treated hiPSC-CMs. Pro-hypertrophic IGF-1R/ERK1/2 pathway and hypertrophic marker expression were activated in miR-378a deficiency and upon STZ/HG treatment of miR-378a+/+ specimens in vivo and in vitro suggesting miR-378a-independent hyperglycemia-promoted hypertrophy. A synergistic upregulation of IGF-1R signaling in diabetic conditions was detected in miR-378a-/- hiPSC-CMs, but not in miR-378a-/- hearts that showed attenuation of this pathway, pointing to the involvement of compensatory mechanisms in the absence of miR-378a. Although STZ administration did not cause pro-inflammatory or pro-fibrotic effects that were detected in miR-378a-/- mice, the compromised diabetic heart function observed in vivo by high-resolution ultrasound imaging upon STZ treatment was not affected by miR-378a presence., Conclusions: Overall, data underline the role of miR-378a in maintaining basal cardiac structural integrity while pointing to miR-378a-independent hyperglycemia-driven cardiac hypertrophy and associated dysfunction., (© 2023. The Author(s).)

Skeletal muscle regeneration relies on the reciprocal interaction between many types of cells. Regenerative capacity may be altered in different disorders. In our study, we investigated whether the deletion of miR-378a (miR-378) affects muscle regeneration. We subjected 6-week-old wild-type (WT) and miR-378 knockout (miR-378 -/- ) animals to the glycerol-induced muscle injury and performed analyses in various time-points. In miR-378 -/- animals, an elevated abundance of muscle satellite cells (mSCs) on day 3 was found. Furthermore, fibro-adipogenic progenitors (FAPs) isolated from the muscle of miR-378 -/- mice exhibited enhanced adipogenic potential. At the same time, lack of miR-378 did not affect inflammation, fibrosis, adipose tissue deposition, centrally nucleated fiber count, muscle fiber size, FAP abundance, and muscle contractility at any time point analyzed. To conclude, our study revealed that miR-378 deletion influences the abundance of mSCs and the adipogenic potential of FAPs, but does not affect overall regeneration upon acute, glycerol-induced muscle injury., (© 2023. Springer Nature Limited.)

miR-15a/16-1 cluster, composed of MIR15A and MIR16-1 genes located in close proximity on chromosome 13 was described to regulate post-natal cell cycle withdrawal of cardiomyocytes in mice. In humans, on the other hand, the level of miR-15a-5p and miR-16-p was negatively associated with the severity of cardiac hypertrophy. Therefore, to better understand the role of these microRNAs in human cardiomyocytes in regard to their proliferative potential and hypertrophic growth, we generated hiPSC line with complete deletion of miR-15a/16-1 cluster using CRISPR/Cas9 gene editing. Obtained cells demonstrate expression of pluripotency markers, differentiation capacity into all three germ layers and normal karyotype., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Impaired muscle regeneration is a hallmark of Duchenne muscular dystrophy (DMD), a neuromuscular disorder caused by mutations in the DMD gene encoding dystrophin. The lack of heme oxygenase-1 (HO-1, Hmox1), a known anti-inflammatory and cytoprotective enzyme, was shown to aggravate DMD pathology., Methods: We evaluated the role of HO-1 overexpression in human induced pluripotent stem cell (hiPSC)-derived skeletal muscle cells (hiPSC-SkM) in vitro and in the regeneration process in vivo in wild-type mice. Furthermore, the effect of cobalt protoporphyrin IX (CoPP), a pharmacological inducer of HO-1 expression, on regeneration markers during myogenic hiPSC differentiation and progression of the dystrophic phenotype was analysed in the mdx mouse DMD model., Results: HO-1 has an impact on hiPSC-SkM generation by decreasing cell fusion capacity and the expression of myogenic regulatory factors and muscle-specific microRNAs (myomiRs). Also, strong induction of HO-1 by CoPP totally abolished hiPSC-SkM differentiation. Injection of HO-1-overexpressing hiPSC-SkM into the cardiotoxin (CTX)-injured muscle of immunodeficient wild-type mice was associated with decreased expression of miR-206 and Myh3 and lower number of regenerating fibers, suggesting some advanced regeneration. However, the very potent induction of HO-1 by CoPP did not exert any protective effect on necrosis, leukocyte infiltration, fibrosis, myofiber regeneration biomarkers, and exercise capacity of mdx mice., Conclusions: In summary, HO-1 inhibits the expression of differentiation markers in human iPSC-derived myoblasts. Although moderate overexpression of HO-1 in the injected myoblast was associated with partially advanced muscle regeneration, the high systemic induction of HO-1 did not improve muscle regeneration. The appropriate threshold of HO-1 expression must be established for the therapeutic effect of HO-1 on muscle regeneration., (© 2023. The Author(s).)

Increased oxidative stress can slow down the regeneration of skeletal muscle and affect the activity of muscle satellite cells (mSCs). Therefore, we evaluated the role of the NRF2 transcription factor (encoded by the Nfe2l2 gene), the main regulator of the antioxidant response, in muscle cell biology. We used (i) an immortalized murine myoblast cell line (C2C12) with stable overexpression of NRF2 and (ii) primary mSCs isolated from wild-type and Nfe2l2 (transcriptionally)-deficient mice ( Nfe2l2 ). NRF2 promoted myoblast proliferation and viability under oxidative stress conditions and decreased the production of reactive oxygen species. Furthermore, NRF2 overexpression inhibited C2C12 cell differentiation by down-regulating the expression of myogenic regulatory factors (MRFs) and muscle-specific microRNAs. We also showed that NRF2 is indispensable for the viability of mSCs since the lack of its transcriptional activity caused high mortality of cells cultured in vitro under normoxic conditions. Concomitantly, tKO ). NRF2 promoted myoblast proliferation and viability under oxidative stress conditions and decreased the production of reactive oxygen species. Furthermore, NRF2 overexpression inhibited C2C12 cell differentiation by down-regulating the expression of myogenic regulatory factors (MRFs) and muscle-specific microRNAs. We also showed that NRF2 is indispensable for the viability of mSCs since the lack of its transcriptional activity caused high mortality of cells cultured in vitro under normoxic conditions. Concomitantly, Nfe2l2 tKO mSCs grown and differentiated under hypoxic conditions were viable and much more differentiated compared to cells isolated from wild-type mice. Taken together, NRF2 significantly influences the properties of myoblasts and muscle satellite cells. This effect might be modulated by the muscle microenvironment.

Duchenne muscular dystrophy (DMD) is an X-linked genetic disease affecting approximately 1 in 5,000 born boys. It is caused by mutations in the DMD gene encoding dystrophin, which protects muscle fibers upon contraction. Its absence leads to muscle weakening and premature death mostly due to cardio-respiratory failure. Many experimental therapies have been developed to restore functional dystrophin or counteract processes contributing to disease progression. Nonetheless, DMD remains an incurable disease, and glucocorticoids, exerting many side effects, still serve as the “gold standard” of treatment. Hence, there is a need to develop innovative therapeutic options that will at least alleviate the symptoms of DMD. Among them, targeting specific microRNAs (miRs), e.g. miR-378a, restoring normal angiogenesis and the use of cytoprotective factors such as heme oxygenase-1 (HO-1) or hydrogen sulfide (H2S) might be of special interest. In this review, we describe both the pathology of the disease and the aforementioned new therapeutic options in DMD.

Although Duchenne muscular dystrophy (DMD) primarily affects muscle tissues, the alterations to systemic metabolism manifested in DMD patients contribute to the severe phenotype of this fatal disorder. We propose that microRNA-378a (miR-378) alters carbohydrate and lipid metabolism in dystrophic mdx mice. In our study, we utilized double knockout animals which lacked both dystrophin and miR-378 (mdx/miR-378 -/- ). RNA sequencing of the liver identified 561 and 194 differentially expressed genes that distinguished mdx versus wild-type (WT) and mdx/miR-378 -/- versus mdx counterparts, respectively. Bioinformatics analysis predicted, among others, carbohydrate metabolism disorder in dystrophic mice, as functionally proven by impaired glucose tolerance and insulin sensitivity. The lack of miR-378 in mdx animals mitigated those effects with a faster glucose clearance in a glucose tolerance test (GTT) and normalization of liver glycogen levels. The absence of miR-378 also restored the expression of genes regulating lipid homeostasis, such as Acly, Fasn, Gpam, Pnpla3, and Scd1. In conclusion, we report for the first time that miR-378 loss results in increased systemic metabolism of mdx mice. Together with our previous finding, demonstrating alleviation of the muscle-related symptoms of DMD, we propose that the inhibition of miR-378 may represent a new strategy to attenuate the multifaceted symptoms of DMD., (© 2022. The Author(s).)

microRNA-378a (miR-378a) is one of the most highly expressed microRNAs in the heart. However, its role in the human cardiac tissue has not been fully understood. It was observed that miR-378a protects cardiomyocytes from hypertrophic growth by regulation of IGF1R and the expression of downstream kinases. Increased levels of miR-378a were reported in the serum of Duchenne muscular dystrophy (DMD) patients and female carriers of DMD gene-associated mutations with developed cardiomyopathy. In order to shed more light on the role of miR-378a in human cardiomyocytes and its potential involvement in DMD-related cardiomyopathy, we generated two human induced pluripotent stem cell (hiPSC) models; one with deletion of miR-378a and the second one with deletion of DMD exon 50 leading to the DMD phenotype. Our results indicate that lack of miR-378a does not influence the pluripotency of hiPSC and their ability to differentiate into cardiomyocytes (hiPSC-CM). miR-378a-deficient hiPSC-CM exhibited, however, significantly bigger size compared to the isogenic control cells, indicating the role of this miRNA in the hypertrophic growth of human cardiomyocytes. In accordance, the level of NFATc3, phosphoAKT, phosphoERK and ERK was higher in these cells compared to the control counterparts. A similar effect was achieved by silencing miR-378a with antagomirs. Of note, the percentage of cells with nuclear localization of NFATc3 was higher in miR-378a-deficient hiPSC-CM. Analysis of electrophysiological properties and Ca 2+ oscillations revealed the decrease in the spike slope velocity and lower frequency of calcium spikes in miR-378a-deficient hiPSC-CM. Interestingly, the level of miR-378a increased gradually during cardiac differentiation of hiPSC. Of note, it was low until day 15 in differentiating DMD-deficient hiPSC-CM and then rose to a similar level as in the isogenic control counterparts. In summary, our findings confirmed the utility of hiPSC-based models for deciphering the role of miR-378a in the control and diseased human cardiomyocytes., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The severity of Duchenne muscular dystrophy (DMD), an incurable disease caused by the lack of dystrophin, might be modulated by different factors, including miRNAs. Among them, miR-378 is considered of high importance for muscle biology, but intriguingly, its role in DMD and its murine model (mdx mice) has not been thoroughly addressed so far. Here, we demonstrate that dystrophic mice additionally globally lacking miR-378 (double-KO [dKO] animals) exhibited better physical performance and improved absolute muscle force compared with mdx mice. Accordingly, markers of muscle damage in serum were significantly decreased in dKO mice, accompanied by diminished inflammation, fibrosis, and reduced abundance of regenerating fibers within muscles. The lack of miR-378 also normalized the aggravated fusion of dystrophin-deficient muscle satellite cells (mSCs). RNA sequencing of gastrocnemius muscle transcriptome revealed fibroblast growth factor 1 (Fgf1) as one of the most significantly downregulated genes in mice devoid of miR-378, indicating FGF1 as one of the mediators of changes driven by the lack of miR-378. In conclusion, we suggest that targeting miR-378 has the potential to ameliorate DMD pathology.

Aims: MicroRNA-378a, highly expressed in skeletal muscles, was demonstrated to affect myoblasts differentiation and to promote tumour angiogenesis. We hypothesized that miR-378a could play a pro-angiogenic role in skeletal muscle and may be involved in regeneration after ischaemic injury in mice., Methods and Results: Silencing of miR-378a in murine C2C12 myoblasts did not affect differentiation but impaired their secretory angiogenic potential towards endothelial cells. miR-378a knockout (miR-378a-/-) in mice resulted in a decreased number of CD31-positive blood vessels and arterioles in gastrocnemius muscle. In addition, diminished endothelial sprouting from miR-378a-/- aortic rings was shown. Interestingly, although fibroblast growth factor 1 (Fgf1) expression was decreased in miR-378a-/- muscles, this growth factor did not mediate the angiogenic effects exerted by miR-378a. In vivo, miR-378a knockout did not affect the revascularization of the ischaemic muscles in both normo- and hyperglycaemic mice subjected to femoral artery ligation (FAL). No difference in regenerating muscle fibres was detected between miR-378a-/- and miR-378+/+ mice. miR-378a expression temporarily declined in ischaemic skeletal muscles of miR-378+/+ mice already on Day 3 after FAL. At the same time, in the plasma, the level of miR-378a-3p was enhanced. Similar elevation of miR-378a-3p was reported in the plasma of patients with intermittent claudication in comparison to healthy donors. Local adeno-associated viral vectors-based miR-378a overexpression was enough to improve the revascularization of the ischaemic limb of wild-type mice on Day 7 after FAL, what was not reported after systemic delivery of vectors. In addition, the number of infiltrating CD45+ cells and macrophages (CD45+ CD11b+ F4/80+ Ly6G-) was higher in the ischaemic muscles of miR-378a-/- mice, suggesting an anti-inflammatory action of miR-378a., Conclusions: Data indicate miR-378a role in the pro-angiogenic effect of myoblasts and vascularization of skeletal muscle. After the ischaemic insult, the anti-angiogenic effect of miR-378a deficiency might be compensated by enhanced inflammation., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2019. For permissions, please email: journals.permissions@oup.com.)

Objective: Perivascular adipose tissue (PVAT) plays a vital role in maintaining vascular homeostasis. However, most studies ascribed the function of PVAT in vascular remodeling to adipokines secreted by the perivascular adipocytes. Whether mesenchymal stem cells exist in PVAT and play a role in vascular regeneration remain unknown. Approach and Results: Single-cell RNA-sequencing allowed direct visualization of the heterogeneous PVAT-derived mesenchymal stem cells (PV-ADSCs) at a high resolution and revealed 2 distinct subpopulations, among which one featured signaling pathways crucial for smooth muscle differentiation. Pseudotime analysis of cultured PV-ADSCs unraveled their smooth muscle differentiation trajectory. Transplantation of cultured PV-ADSCs in mouse vein graft model suggested the contribution of PV-ADSCs to vascular remodeling through smooth muscle differentiation. Mechanistically, treatment with TGF-β1 (transforming growth factor β1) and transfection of microRNA (miR)-378a-3p mimics induced a similar metabolic reprogramming of PV-ADSCs, including upregulated mitochondrial potential and altered lipid levels, such as increased cholesterol and promoted smooth muscle differentiation., Conclusions: Single-cell RNA-sequencing allows direct visualization of PV-ADSC heterogeneity at a single-cell level and uncovers 2 subpopulations with distinct signature genes and signaling pathways. The function of PVAT in vascular regeneration is partly attributed to PV-ADSCs and their differentiation towards smooth muscle lineage. Mechanistic study presents miR-378a-3p which is a potent regulator of metabolic reprogramming as a potential therapeutic target for vascular regeneration.

Duchenne muscular dystrophy (DMD) is a genetic disease evoked by a mutation in the dystrophin gene. It is associated with progressive muscle degeneration and increased inflammation. Up to this date, mainly anti-inflammatory treatment is available for patients suffering from DMD. miR-146a is known to diminish inflammation and fibrosis in different tissues by downregulating the expression of proinflammatory cytokines. However, its role in DMD has not been studied so far.In our work, we have generated mice globally lacking both dystrophin and miR-146a (miR-146a -/- mdx) and examined them together with wild-type, single miR-146a knockout and dystrophic (mdx-lacking dystrophin) mice in a variety of aspects associated with DMD pathophysiology (muscle degeneration, inflammatory reaction, muscle satellite cells, muscle regeneration, and fibrosis).We have shown that miR-146a level is increased in dystrophic muscles in comparison to wild-type mice. Its deficiency augments the expression of proinflammatory cytokines (IL-1β, CCL2, TNFα). However, muscle degeneration was not significantly worsened in mdx mice lacking miR-146a up to 24 weeks of age, although some aggravation of muscle damage and inflammation was evident in 12-week-old animals, though no effect of miR-146a deficiency was visible on quantity, proliferation, and in vitro differentiation of muscle satellite cells isolated from miR-146a -/- mdx mice vs. mdx. Similarly, muscle regeneration and collagen deposition were not changed by miR-146a deficiency. Nevertheless, the lack of miR-146a is associated with decreased Vegfa and increased Tgfb1.Overall, the lack of miR-146a did not aggravate significantly the dystrophic conditions in mdx mice, but its effect on DMD in more severe conditions warrants further investigation.

Cyclosporine A (CsA), a widely used immunosuppressive drug, exerts nephrotoxic activities, as demonstrated by increased tubulointerstitial fibrosis, inflammation and podocyte damage. Recently, a number of microRNAs expressed in the kidney have been reported to be elevated during renal damage. Our aim was to investigate the effect of CsA on selected microRNAs in the mouse kidney after CsA treatment. Moreover, as heme oxygenase-1 (HO-1, encoded by the Hmox1 gene) was shown to play a protective role during kidney disorders, we assessed whether HO-1 deficiency in vivo influences the CsA-regulated microRNAs' expression. We have observed that the pro-fibrotic miR-21 and pro-apoptotic miR-34a expression was upregulated in kidneys of HO-1 deficient mice and it was further enhanced by CsA. Concomitantly, the level of anti-fibrotic microRNAs, belonging to miR-29 and miR-200 families, was down-regulated after CsA treatment. Generally, Hmox1 knock-out (Hmox1-/-) animals were more susceptible to CsA treatment, as the mortality rate was 4 out of 9 Hmox1-/- mice, and increased fibrosis (Tgfb2, Pai1), inflammation (Il6) and apoptosis (Cdkn1a-p21) were noticed in the HO-1 deficient kidneys. In summary, our data demonstrate that CsA induces significant changes in the expression of renal microRNAs and emphasize HO-1 deficiency as an important factor contributing to the CsA-mediated renal toxicity.

Background: Sarcoidosis is characterized by exaggerated immune response to unknown agent and can affect different organs. One of the main players in the pathology of the disease are regulatory T cells (Tregs), however, up to date the mechanisms of the possible molecular alterations of this particular cell subset are not known., Methods: In the current study we looked for the global transcriptomic changes of miRNAs, using predefined array, and mRNAs (RNA seq analysis) of Tregs of patients with the most predominant form of the disease - acute pulmonary sarcoidosis (PS). For this purpose sorted CD4+/CD25+/CD127- Tregs from peripheral blood (PB) and CD4+/CD25 + Tregs from bronchoalveolar lavage (BAL) were used., Results: MiRNA analysis revealed that Tregs isolated from PB and BAL display significantly different miRNA profile, suggesting an important role of the pulmonary microenvironment in creating these changes. Among disease-related miRNAs of PB Tregs we identified miR-155 and miR-223. Moreover, looking at the global transcriptome of PB Tregs, we recognized alterations in TLR-2 signaling pathway and in the downstream of NF-κB apoptosis and proliferation signals. However, induction of TLR-2 expression was found not only in Tregs, but also in the heterogeneous population of peripheral blood mononuclear cells (PBMC) as well as two PBMC subpopulations (CD4+/CD25-and CD4-/CD25-) of patients with PS. This indicates that activation of TLR signaling pathway in sarcoidosis does not occur only in Tregs., Conclusion: Our findings offer a deeper insight into the molecular mechanisms of Tregs reduced suppression and increased apoptosis in patients with PS. Based on the current results, future studies should focus on possible therapeutic effect of TLR-2 signaling inhibition., (Copyright © 2018. Published by Elsevier Ltd.)

Therapeutic options for amyotrophic lateral sclerosis (ALS) are still limited. Great hopes, however, are placed in growth factors that show neuroprotective abilities (e.g., nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and vascular endothelial growth factor (VEGF)) and in the immune modulating features, in particular, the anti-inflammatory effects. In our study we aimed to investigate whether a bone marrow-derived lineage-negative (Lin-) cells population, after autologous application into cerebrospinal fluid (CSF), is able to produce noticeable concentrations of trophic factors and inflammatory-related proteins and thus influence the clinical course of ALS. To our knowledge, the evaluation of Lin- cells transplantation for ALS treatment has not been previously reported. Early hematopoietic Lin- cells were isolated from twelve ALS patients’ bone marrow, and later, the suspension of cells was administered into the subarachnoid space by lumbar puncture. Concentrations of selected proteins in the CSF and plasma were quantified by multiplex fluorescent bead-based immunoassays at different timepoints post-transplantation. We also chose microRNAs (miRNAs) related to muscle biology (miRNA-1, miRNA-133a, and miRNA-206) and angiogenesis and inflammation (miRNA-155 and miRNA-378) and tested, for the first time, their expression profiles in the CSF and plasma of ALS patients after Lin- cells transplantation. The injection of bone marrow cells resulted in decreased concentration of selected inflammatory proteins (C3) after Lin- cells injection, particularly in patients who had a better clinical outcome. Moreover, several analyzed miRNAs have changed expression levels in the CSF and plasma of ALS patients subsequent to Lin- cells administration. Interestingly, the expression of miR-206 increased in ALS patients, while miR-378 decreased both in the CSF and plasma one month after the cells’ injection. We propose that autologous lineage-negative early hematopoietic cells injected intrathecally may be a safe and feasible source of material for transplantations to the central nervous system (CNS) environment aimed at anti-inflammatory support provision for ALS adjuvant treatment strategies. Further research is needed to evaluate whether the observed effects could significantly influence the ALS progression.

Rhabdomyosarcoma (RMS) is an aggressive soft tissue cancer characterized by disturbed myogenic differentiation. Here we report a role for the oxidative stress response factor HO-1 in progression of RMS. We found that HO-1 was elevated and its effector target miR-206 decreased in RMS cell lines and clinical primary tumors of the more aggressive alveolar phenotype (aRMS). In embryonal RMS (eRMS), HO-1 expression was induced by Pax3/7-FoxO1, an aRMS hallmark oncogene, followed by a drop in miR-206 levels. Inhibition of HO-1 by tin protoporphyrin (SnPP) or siRNA downregulated Pax3/7-FoxO1 target genes and induced a myogenic program in RMS. These effects were not mediated by altered myoD expression; instead, cells with elevated HO-1 produced less reactive oxygen species, resulting in nuclear localization of HDAC4 and miR-206 repression. HO-1 inhibition by SnPP reduced growth and vascularization of RMS tumors in vivo accompanied by induction of miR-206. Effects of SnPP on miR-206 expression and RMS tumor growth were mimicked by pharmacologic inhibition of HDAC. Thus, HO-1 inhibition activates an miR-206-dependent myogenic program in RMS, offering a novel therapeutic strategy for treatment of this malignancy. Cancer Res; 76(19); 5707-18. ©2016 AACR., (©2016 American Association for Cancer Research.)

Renal fibrosis, irrespective of its etiology, is a final common stage of almost all chronic kidney diseases. Increased apoptosis, epithelial-to-mesenchymal transition, and inflammatory cell infiltration characterize the injured kidney. On the molecular level, transforming growth factor-β1 (TGF-β1)-Smad3 signaling pathway plays a central role in fibrotic kidney disease. Recent findings indicate the prominent role of microRNAs, small noncoding RNA molecules that inhibit gene expression through the posttranscriptional repression of their target mRNAs, in different pathologic conditions, including renal pathophysiology. miR-21 was also shown to play a dynamic role in inflammatory responses and in accelerating injury responses to promote organ failure and fibrosis. Understanding the cellular and molecular bases of miR-21 involvement in the pathogenesis of kidney diseases, including inflammatory reaction, could be crucial for their early diagnosis. Moreover, the possibility of influencing miR-21 level by specific antagomirs may be considered as an approach for treatment of renal diseases.

Sarcoidosis is a multi-organ disease in which affected tissues are invaded with non-necrotizing granulomatous structures, mostly consisted of T helper 1 (Th1) cells and multinucleate giant cells. However, the etiology and pathogenesis of sarcoidosis is not known and the diagnosis is usually based on clinical examination involving radiography and histopathological analysis of biopsies of affected organs. Although the knowledge on the molecular background of sarcoidosis is limited, it seems that the important pathways involve transforming growth factor-β (TGF-β) and JAK/STAT, which may influence the interferon-γ (IFN-γ)-mediated signaling. Additionally, recently the role of microRNAs (miRNAs), the small non-coding RNA molecules, has been emphasized in different pathological conditions including autoimmune diseases. This review summarizes the current knowledge on the molecular pathways in the pathogenesis of sarcoidosis with a special emphasis on cytokines and miRNAs controlling immune cells proliferation and differentiation. Moreover, the possible role of T regulatory cells (CD4(+) CD25(+) FoxP3(+)) in this disease has been discussed.

Sarcoidosis is a granulomatous disease of unknown etiology. The disease has an important inflammatory and immune component; however, its immunopathogenesis is not completely understood. Recently, the role of microRNAs (miRNAs), the small non-coding RNAs, has attracted attention as both being involved in pathogenesis and serving as disease markers. Accordingly, changes in the expression of some miRNAs have been also associated with different autoimmune pathologies. However, not much is known about the role of miRNAs in sarcoidosis. Therefore, the aim of this study was to compare the level of expression of selected miRNAs in healthy individuals and patients with sarcoidosis. We detected significantly increased level of miR-34a in peripheral blood mononuclear cells isolated from sarcoidosis patients. Moreover, significantly up-regulated levels of interferon (IFN)-γ, IFN-γ inducible protein (IP-10) and vascular endothelial growth factor were detected in sera of patients when compared to healthy subjects. Our results add to a known inflammatory component in sarcoidosis. Changes in the levels of miR-34a may suggest its involvement in the pathology of this disease.

Rhabdomyosarcoma is the most common type of soft tissue sarcoma in children. Two main subtypes of rhabdomyosarcoma with different molecular pattern and distinct clinical behaviour may be identified - embryonal and alveolar rhabdomyosarcoma. All types of rhabdomyosarcoma are believed to be of myogenic origin as they express high levels of myogenesis-related factors. They all, however, fail to undergo a terminal differentiation which results in tumour formation. In the aberrant regulation of myogenesis in rhabdomyosarcoma, microRNAs and epigenetic factors are particularly involved. Indeed, these mediators seem to be even more significant for the development of rhabdomyosarcoma than canonical myogenic transcription factors like MyoD, a master regulatory switch for myogenesis. Therefore, in this review we focus on the regulation of rhabdomyosarcoma progression by microRNAs, and especially on microRNAs of the myo-miRNAs family (miR-1, -133a/b and -206), other well-known myogenic regulators like miR-29, and on microRNAs recently recognized to play a role in the differentiation of rhabdomyosarcoma, such as miR-450b-5p or miR-203. We also review changes in epigenetic modifiers associated with rhabdomyosarcoma, namely histone deacetylases and methyltransferases, especially from the Polycomp Group, like Yin Yang1 and Enhancer of Zeste Homolog2. Finally, we summarize how the functioning of these molecules can be affected by oxidative stress and how antioxidative enzymes can influence the development of this tumour. This article is part of a Directed Issue entitled: Rare Cancers., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Significance: Heme oxygenase-1 (HO-1) converts heme to biliverdin, carbon monoxide, and ferrous ions, but its cellular functions are far beyond heme metabolism. HO-1 via heme removal and degradation products acts as a cytoprotective, anti-inflammatory, immunomodulatory, and proangiogenic protein, regulating also a cell cycle. Additionally, HO-1 can translocate to nucleus and regulate transcription factors, so it can also act independently of enzymatic function., Recent Advances: Recently, a body of evidence has emerged indicating a role for HO-1 in postnatal differentiation of stem and progenitor cells. Maturation of satellite cells, skeletal myoblasts, adipocytes, and osteoclasts is inhibited by HO-1, whereas neurogenic differentiation and formation of cardiomyocytes perhaps can be enhanced. Moreover, HO-1 influences a lineage commitment in pluripotent stem cells and maturation of hematopoietic cells. It may play a role in development of osteoblasts, but descriptions of its exact effects are inconsistent., Critical Issues: In this review we discuss a role of HO-1 in cell differentiation, and possible HO-1-dependent signal transduction pathways. Among the potential mediators, we focused on microRNA (miRNA). These small, noncoding RNAs are critical for cell differentiation. Recently we have found that HO-1 not only influences expression of specific miRNAs but also regulates miRNA processing enzymes., Future Directions: It seems that interplay between HO-1 and miRNAs may be important in regulating fates of stem and progenitor cells and needs further intensive studies.

Aims: Heme oxygenase-1 (HO-1, HMOX1) can prevent tumor initiation; while in various tumors, it has been demonstrated to promote growth, angiogenesis, and metastasis. Here, we investigated whether HMOX1 can modulate microRNAs (miRNAs) and regulate human non-small cell lung carcinoma (NSCLC) development., Results: Stable HMOX1 overexpression in NSCLC NCI-H292 cells up-regulated tumor-suppressive miRNAs, whereas it significantly diminished the expression of oncomirs and angiomirs. The most potently down-regulated was miR-378. HMOX1 also up-regulated p53, down-regulated angiopoietin-1 (Ang-1) and mucin-5AC (MUC5AC), reduced proliferation, migration, and diminished angiogenic potential. Carbon monoxide was a mediator of HMOX1 effects on proliferation, migration, and miR-378 expression. In contrast, stable miR-378 overexpression decreased HMOX1 and p53; while enhanced expression of MUC5AC, vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), and Ang-1, and consequently increased proliferation, migration, and stimulation of endothelial cells. Adenoviral delivery of HMOX1 reversed miR-378 effect on the proliferation and migration of cancer cells. In vivo, HMOX1 overexpressing tumors were smaller, less vascularized and oxygenated, and less metastatic. Overexpression of miR-378 exerted opposite effects. Accordingly, in patients with NSCLC, HMOX1 expression was lower in metastases to lymph nodes than in primary tumors., Innovation and Conclusion: In vitro and in vivo data indicate that the interplay between HMOX1 and miR-378 significantly modulates NSCLC progression and angiogenesis, suggesting miR-378 as a new therapeutic target. REBOUND TRACK: This work was rejected during standard peer review and rescued by Rebound Peer Review (Antioxid Redox Signal 16, 293-296, 2012) with the following serving as open reviewers: James F. George, Mahin D. Maines, Justin C. Mason, and Yasufumi Sato.

Scope: Ochratoxin A (OTA) is a mycotoxin exhibiting nephrotoxic and potential carcinogenic activity. We investigated the cross-talk between microRNAs, nuclear factor E2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) in ochratoxin A-mediated effects., Methods and Results: In porcine renal proximal tubular cells, OTA increased expression of profibrotic transforming growth factors β (TGFβ) while concomitantly decreasing expression of Nrf2, HO-1, and erythropoietin. Adenoviral overexpression of Nrf2 counteracted OTA-mediated reduction in HO-1 and erythropoietin expression and cell proliferation as well as increase in reactive oxygen species (ROS) generation and TGFβ expression. Additionally, inhibition of HO activity enhanced whereas adenoviral overexpression of HO-1 reduced expression of TGFβ. Moreover, antioxidants, N-acetyl-cysteine and desferioxamine, prevented OTA-mediated enhancement of ROS generation, and TGFβ expression. Finally, OTA modulated microRNA processing by upregulating LINeage protein 28 and DiGeorge syndrome critical region-8, increasing the total pool of cellular microRNAs and elevating the expression of miR-132 and miR-200c. Inhibition of miR-132 by specific antagomir restored the OTA-driven reduction in Nrf2 expression. Moreover, anti-miR-132 and anti-miR-200c counteracted OTA-mediated decrease in HO-1 levels as well as increase in ROS production and TGFβ expression., Conclusion: We showed that attenuation of Nrf2 and HO-1 expression through induction of miR-132 and miR-200c by OTA elevates ROS levels and profibrotic TGFβ expression., (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Reprogramming of somatic cells with defined transcription factors which leads to the acquisition of pluripotent phenotype requires many modifications in gene expression profile, metabolism and chromatin structure. MicroRNAs, a short non-coding RNA that inhibit translation of recognized mRNA sequences play an important role in this process. Because of the pleiotropism of their action microRNAs regulate subsequent steps in cellular reprogramming, among others activation of p53, mesenchymal-to-epithelial transition and development of embryonic gene expression profile. Further studies on the function of microRNA in reprogramming can increase our understandbing of generation, maintenance and differentiation of induced pluripotent stem cells.

Endothelium has an immense impact on the tissue regeneration, regulation of atherosclerosis and tumour growth. Therefore, modification of endothelial cell differentiation and function seems a promising target for many therapies. MicroRNAs are small RNA molecules, which recognize and inhibit specific mRNAs. In that way, they can regulate and orchestrate whole signalling pathways. It has been shown that microRNAs can fine-tune endothelial cell functions since they have either pro- and antiangiogenic activity, regulate expression of e.g. adhesion molecules or nitric oxide synthase. Furthermore, microRNAs modulate differentiation of embryonic stem cells to endothelial cells and their further specialization towards specific vascular bed. This review focuses mainly on the influence of microRNA on the angiogenesis and endothelial cell differentiation.

MicroRNAs (miRNAs) are small, noncoding RNA molecules with the ability to posttranscriptionally regulate gene expression via targeting the 3' untranslated region of messenger RNAs. miRNAs are critical for normal cellular functions such as the regulation of the cell cycle, differentiation, and apoptosis, and they target genes during embryonal and postnatal development, whereas their expression is unbalanced in various pathological states. Importantly, miRNAs are abundantly present in body fluids (e.g., blood), which are routinely examined in patients. These molecules circulate in free and exosome encapsulated forms, and can be efficiently detected and amplified by means of molecular biology tools such as real-time PCR. Together with relative stability, specificity, and reproducibility, they are seen as good candidates for early recognition of the onset of disease. Thus, miRNAs might be considered as biomarkers for many pathological states., (© Springer-Verlag 2011)

In the present study the effect of quercetin and its major metabolites quercetin-3-glucuronide (Q3G) and isorhamnetin on inflammatory gene expression was determined in murine RAW264.7 macrophages stimulated with lipopolysaccharide. Quercetin and isorhamnetin but not Q3G significantly decreased mRNA and protein levels of tumor necrosis factor alpha. Furthermore a significant decrease in mRNA levels of interleukin 1β, interleukin 6, macrophage inflammatory protein 1α and inducible nitric oxide synthase was evident in response to the quercetin treatment. However Q3G did not affect inflammatory gene expression. Anti-inflammatory properties of quercetin and isorhamnetin were accompanied by an increase in heme oxygenase 1 protein levels, a downstream target of the transcription factor Nrf2, known to antagonize chronic inflammation. Furthermore, proinflammatory microRNA-155 was down-regulated by quercetin and isorhamnetin but not by Q3G. Finally, anti-inflammatory properties of quercetin were confirmed in vivo in mice fed quercetin-enriched diets (0.1 mg quercetin/g diet) over 6 weeks., (Copyright © 2011 Elsevier Inc. All rights reserved.)