miR-145 attenuates cardiac fibrosis through the AKT/GSK-3β/β-catenin signaling pathway by directly targeting SOX9 in fibroblasts

MicroRNA miR-145-5p Inhibits Cutaneous Wound Healing by Targeting PDGFD in Diabetic Foot Ulcer

Diabetic foot ulcer (DFU) is one major, common and serious chronic complication of diabetes mellitus, which is characterized by high incidence, high risk, high burden, and high treatment difficulty and is a leading cause of disability and death in patients with diabetes. Long-term hyperglycemia can result in cellular dysfunction of fibroblasts, which play pivotal roles in wound healing. MicroRNAs (miRNAs) were reported to mediate the pathological processes of multiple diseases, including diabetic wound healing. This research aimed to investigate the functional role of miR-145-5p in high-glucose (HG)-exposed fibroblasts and in DFU mouse models. Human foreskin fibroblast cells (HFF-1) were stimulated by HG to induce cell injury. MiR-145-5p level in HG-stimulated HFF-1 cells was detected via RT-qPCR. The binding between miR-145-5p and PDGFD was validated by Luciferase reporter assay. The effects of the miR-145-5p/PDGFD axis on the viability, migration, and apoptosis of HG-exposed HFF-1 cells were determined by CCK-8, wound healing, and flow cytometry assays. DFU mouse models were subcutaneously injected at the wound edges with miR-145-5p inhibitor/mimics. Images of the wounds were captured on day 0 and 8 post-injection, and wound samples were collected after mice were sacrificed for histological analysis by H&E staining. HG decreased cell viability and increased miR-145-5p expression in HFF-1 cells in a dose- and time-dependent manner. MiR-145-5p downregulation promoted cell viability and migration and inhibited cell apoptosis of HG-stimulated HFF-1 cells, while miR-145-5p overexpression exerted an opposite effect on cell viability, migration, and apoptosis. PDGFD was a direct target gene of miR-145-5p, whose silencing reversed the influence of miR-145-5p downregulation on HG-induced cellular dysfunction of HFF-1 cells. Additionally, downregulating miR-145-5p facilitated while overexpressing miR-145-5p inhibited wound healing in DFU mouse models. MiR-145-5p level was negatively associated with PDGFD level in wound tissue samples of DFU mouse models. MiR-145-5p inhibition improves wound healing in DFU through upregulating PDGFD expression.

Current Concepts in the Epigenetic Regulation of Cardiac Fibrosis

Cardiac fibrosis is a significant driver of congestive heart failure, a syndrome that continues to affect a growing patient population globally. Cardiac fibrosis results from a constellation of complex processes at the transcription, receptor, and signaling axes levels. Various mediators and signaling cascades, such as the transformation growth factor-beta pathway, have been implicated in the pathophysiology of cardiac tissue fibrosis. Our understanding of these markers and pathways has improved in recent years as more advanced technologies and assays have been developed, allowing for better delineation of the crosstalk between specific factors. There is mounting evidence suggesting that epigenetic modulation plays a pivotal role in the progression of cardiac fibrosis. Transcriptional regulation of key pro- and anti-fibrotic pathways can accentuate or blunt the rate and extent of fibrosis at the tissue level. Exosomes, micro-RNAs, and long non-coding RNAs all belong to factors that can impact the epigenetic signature in cardiac fibrosis. Herein, we comprehensively review the latest literature about exosomes, their contents, and cardiac fibrosis. In doing so, we highlight the specific transcriptional factors with pro- or anti-fibrotic properties. We also assimilate the data supporting these mediators' potential utility as diagnostic or prognostic biomarkers. Finally, we offer insight into where further work can be done to fill existing gaps to translate pre-clinical findings better and improve clinical outcomes.

Ischemia-reperfusion injury: molecular mechanisms and therapeutic targets

Ischemia-reperfusion (I/R) injury paradoxically occurs during reperfusion following ischemia, exacerbating the initial tissue damage. The limited understanding of the intricate mechanisms underlying I/R injury hinders the development of effective therapeutic interventions. The Wnt signaling pathway exhibits extensive crosstalk with various other pathways, forming a network system of signaling pathways involved in I/R injury. This review article elucidates the underlying mechanisms involved in Wnt signaling, as well as the complex interplay between Wnt and other pathways, including Notch, phosphatidylinositol 3-kinase/protein kinase B, transforming growth factor-β, nuclear factor kappa, bone morphogenetic protein, N-methyl-D-aspartic acid receptor-Ca2+-Activin A, Hippo-Yes-associated protein, toll-like receptor 4/toll-interleukine-1 receptor domain-containing adapter-inducing interferon-β, and hepatocyte growth factor/mesenchymal-epithelial transition factor. In particular, we delve into their respective contributions to key pathological processes, including apoptosis, the inflammatory response, oxidative stress, extracellular matrix remodeling, angiogenesis, cell hypertrophy, fibrosis, ferroptosis, neurogenesis, and blood-brain barrier damage during I/R injury. Our comprehensive analysis of the mechanisms involved in Wnt signaling during I/R reveals that activation of the canonical Wnt pathway promotes organ recovery, while activation of the non-canonical Wnt pathways exacerbates injury. Moreover, we explore novel therapeutic approaches based on these mechanistic findings, incorporating evidence from animal experiments, current standards, and clinical trials. The objective of this review is to provide deeper insights into the roles of Wnt and its crosstalk signaling pathways in I/R-mediated processes and organ dysfunction, to facilitate the development of innovative therapeutic agents for I/R injury.

Bidirectional negative feedback actions of DNMT3A and miR-145 in regulating autophagy in cardiac fibroblasts and affecting myocardial fibrosis

Epigenetic regulation has crucial implications for myocardial fibrosis. It has been reported that autophagy, regulated by miR-145, is implicated in the proliferation and fibrosis of cardiac fibroblasts (CFs). However, how it works during the process remains unclear. This study explored the exact effects of epigenetic regulation of miR-145 expression on autophagy, proliferation, and fibrosis of CFs. To examine the expression levels of myocardial fibrosis markers (α-SMA and collagen I), autophagy-related proteins (LC3I, LC3II, p62), DNMT3A, and miR-145, qRT-PCR and western blot were employed. And the proliferation of CFs was detected by CCK-8 and ErdU. As for the determination of the binding relationship between DNMT3A and miR-145, dual-luciferase assay was conducted. Next, the detection of the methylation level of the pre-miR-145 promoter region was completed by MSP. And the verification of the effect of the DNMT3A/miR-145 axis on myocardial fibrosis was accomplished by constructing mouse myocardial infarction (MI) models based on the ligation of the left anterior descending method. In TGF-β1-activated CFs, remarkable up-regulation of DNMT3 and considerable down-regulation of miR-145 were observed. And further experiments indicated that DNMT3A was able to down-regulate miR-145 expression by maintaining the hypermethylation level of the pre-miR-145 promoter region. In addition, DNMT3A expression could be directly targeted and negatively modulated by miR-145. Moreover, in vitro cell experiments and mouse MI models demonstrated that DNMT3A overexpression could inhibit autophagy, and promote cell proliferation and fibrosis of CFs. However, this kind of effect could be reversed by miR-145 overexpression. In summary, myocardial fibroblast autophagy can be regulated by bidirectional negative feedback actions of DNMT3A and miR-145, thus affecting myocardial fibrosis. This finding will provide a potential target for the clinical treatment of myocardial fibrosis.

MicroRNA delivery based on nanoparticles of cardiovascular diseases

Cardiovascular disease, especially myocardial infarction, is a serious threat to human health. Many drugs currently used cannot achieve the desired therapeutic effect due to the lack of selectivity. With the in-depth understanding of the role of microRNA (miRNA) in cardiovascular disease and the wide application of nanotechnology, loading drugs into nanoparticles with the help of nano-delivery system may have a better effect in the treatment of cardiomyopathy. In this review, we highlight the latest research on miRNAs in the treatment of cardiovascular disease in recent years and discuss the possibilities and challenges of using miRNA to treat cardiomyopathy. Secondly, we discuss the delivery of miRNA through different nano-carriers, especially inorganic, polymer and liposome nano-carriers. The preparation of miRNA nano-drugs by encapsulating miRNA in these nano-materials will provide a new treatment option. In addition, the research status of miRNA in the treatment of cardiomyopathy based on nano-carriers is summarized. The use of this delivery tool cannot only realize therapeutic potential, but also greatly improve drug targeting and reduce side effects.

MircroRNA-145 Attenuates Cardiac Fibrosis Via Regulating Mitogen-Activated Protein Kinase Kinase Kinase 3

PURPOSE

This study aimed to explore the effect of microRNA (miR)-145 on cardiac fibrosis in heart failure mice and its target.

METHODS

Experiments were carried out in mice receiving left coronary artery ligation, transverse aortic constriction (TAC), or angiotensin (Ang) II to trigger heart failure, and in cardiac fibroblasts (CFs) with Ang II-induced fibrosis.

RESULTS

The miR-145 levels were decreased in the mice hearts of heart failure induced by myocardial infarction (MI), TAC or Ang II infusion, and in the Ang II-treated CFs. The impaired cardiac function was ameliorated by miR-145 agomiR in MI mice. The increased fibrosis and the levels of collagen I, collagen III, and transforming growth factor-beta (TGF-β) in MI mice were inhibited by miR-145 agomiR or miR-145 transgene (TG). The agomiR of miR-145 also attenuated the increases of collagen I, collagen III, and TGF-β in Ang II-treated CFs. Bioinformatics analysis and luciferase reporter assays indicated that mitogen-activated protein kinase kinase kinase 3 (MAP3K3) was a direct target gene of miR-145. MAP3K3 expression was suppressed by MiR-145 in CFs, while the MAP3K3 over-expression reversed the inhibiting effects of miR-145 agomiR on the Ang II-induced increases of collagen I, collagen III, and TGF-β in CFs.

CONCLUSION

These results indicated that miR-145 upregulation could improve cardiac dysfunction and cardiac fibrosis by inhibiting MAP3K3 in heart failure. Thus, upregulating miR-145 or blocking MAP3K3 can be used to treat heart failure and cardiac fibrosis.

Fucoxanthin alleviated atherosclerosis by regulating PI3K/AKT and TLR4/NFκB mediated pyroptosis in endothelial cells

Fucoxanthin, a type of natural xanthophyll carotenoid, is mainly present in seaweeds and various microalgae. This compound has been proved to possess multiple functions including antioxidation, anti-inflammation and anti-tumor. Atherosclerosis is widely deemed as a chronic inflammation disease, and as the basis of vascular obstructive disease. However, there is rare research about fucoxanthin's effects on atherosclerosis. In this study, we demonstrated that the plaque area of mice treated with fucoxanthin was significantly reduced compared to the group that did not receive fucoxanthin. In addition, Bioinformatics analysis showed that PI3K/AKT signaling might be involved in the protective effect of fucoxanthin, and this hypothesis was then verified in vitro endothelial cell experiments. Besides, our further results showed that endothelial cell mortality measured by TUNEL and flow cytometry was significantly increased in the oxidized low-density lipoprotein (ox-LDL) treatment group while significantly decreased in the fucoxanthin treatment group. In addition, the pyroptosis protein expression level in the fucoxanthin group was significantly lower than that in the ox-LDL group, which indicated that fucoxanthin improved the pyroptosis level of endothelial cells. Furthermore, it was revealed that TLR4/NFκB signaling were also participated in the protection of fucoxanthin on endothelial pyroptosis. Moreover, the protection of fucoxanthin on endothelial cell pyroptosis was abrogated when PI3K/AKT was inhibited or TLR4 was overexpressed, which further suggested the anti-pyroptosis effect of fucoxanthin was mediated through regulations of PI3K/AKT and TLR4/NFκB signaling.

Network model integrated with multi-omic data predicts MBNL1 signals that drive myofibroblast activation

RNA-binding protein muscleblind-like1 (MBNL1) was recently identified as a central regulator of cardiac wound healing and myofibroblast activation. To identify putative MBNL1 targets, we integrated multiple genome-wide screens with a fibroblast network model. We expanded the model to include putative MBNL1-target interactions and recapitulated published experimental results to validate new signaling modules. We prioritized 14 MBNL1 targets and developed novel fibroblast signaling modules for p38 MAPK, Hippo, Runx1, and Sox9 pathways. We experimentally validated MBNL1 regulation of p38 expression in mouse cardiac fibroblasts. Using the expanded fibroblast model, we predicted a hierarchy of MBNL1 regulated pathways with strong influence on αSMA expression. This study lays a foundation to explore the network mechanisms of MBNL1 signaling central to fibrosis.

Post-myocardial infarction fibrosis: Pathophysiology, examination, and intervention

Cardiac fibrosis plays an indispensable role in cardiac tissue homeostasis and repair after myocardial infarction (MI). The cardiac fibroblast-to-myofibroblast differentiation and extracellular matrix collagen deposition are the hallmarks of cardiac fibrosis, which are modulated by multiple signaling pathways and various types of cells in time-dependent manners. Our understanding of the development of cardiac fibrosis after MI has evolved in basic and clinical researches, and the regulation of fibrotic remodeling may facilitate novel diagnostic and therapeutic strategies, and finally improve outcomes. Here, we aim to elaborate pathophysiology, examination and intervention of cardiac fibrosis after MI.

The Role of ncRNAs in Cardiac Infarction and Regeneration

Myocardial infarction is the most prevalent cardiovascular disease worldwide, and it is defined as cardiomyocyte cell death due to a lack of oxygen supply. Such a temporary absence of oxygen supply, or ischemia, leads to extensive cardiomyocyte cell death in the affected myocardium. Notably, reactive oxygen species are generated during the reperfusion process, driving a novel wave of cell death. Consequently, the inflammatory process starts, followed by fibrotic scar formation. Limiting inflammation and resolving the fibrotic scar are essential biological processes with respect to providing a favorable environment for cardiac regeneration that is only achieved in a limited number of species. Distinct inductive signals and transcriptional regulatory factors are key components that modulate cardiac injury and regeneration. Over the last decade, the impact of non-coding RNAs has begun to be addressed in many cellular and pathological processes including myocardial infarction and regeneration. Herein, we provide a state-of-the-art review of the current functional role of diverse non-coding RNAs, particularly microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in different biological processes involved in cardiac injury as well as in distinct experimental models of cardiac regeneration.

Umbilical cord mesenchymal stem cell-derived exosomes reverse endometrial fibrosis by the miR-145-5p/ZEB2 axis in intrauterine adhesions

RESEARCH QUESTION

What is the specific mechanism of umbilical cord mesenchymal stem cell-derived exosomes (UCMSC-exos) in regulating endometrial repair and regeneration?

DESIGN

In this study, UCMSC-exos were harvested by differential ultracentrifugation from umbilical cord mesenchymal stem cell culture supernatant and identified with western blotting, transmission electron microscopy and nanoparticle tracking analysis. Transforming growth factor-β1 (TGFβ1) at different concentrations was used to construct the intrauterine adhesions cell model. The fibrotic markers were assessed by quantitative reverse transcription-polymerase chain reaction and western blotting. The effects of miR-145-5p over-expression on endometrial fibrosis were assessed. Dual luciferase assay was performed to verify the relationship between miR-145-5p and zinc finger E-box binding homeobox 2 (ZEB2).

RESULTS

The isolated UCMSC-exos had a typical cup-shaped morphology, expressed the specific exosomal markers Alix, CD63 and TSG101, and were approximately 50-150 nm in diameter. TGFβ1 at 10 ng/ml significantly promoted endometrial fibrosis, which was reversed by 20 µg/ml UCMSC-exos. Exosomal miR-145-5p ameliorated TGFβ1-induced endometrial fibrosis. ZEB2 was inversely regulated by exosomal miR-145-5p as a direct target.

CONCLUSIONS

UCMSC-exos might reverse endometrial stromal cell fibrosis by regulating the miR-145-5p/ZEB2 axis, representing a potential novel strategy to promote endometrial repair.

The role of β-catenin in cardiac diseases

The Wnt/β-catenin signaling pathway is a classical Wnt pathway that regulates the stability and nuclear localization of β-catenin and plays an important role in adult heart development and cardiac tissue homeostasis. In recent years, an increasing number of researchers have implicated the dysregulation of this signaling pathway in a variety of cardiac diseases, such as myocardial infarction, arrhythmias, arrhythmogenic cardiomyopathy, diabetic cardiomyopathies, and myocardial hypertrophy. The morbidity and mortality of cardiac diseases are increasing, which brings great challenges to clinical treatment and seriously affects patient health. Thus, understanding the biological roles of the Wnt/β-catenin pathway in these diseases may be essential for cardiac disease treatment and diagnosis to improve patient quality of life. In this review, we summarize current research on the roles of β-catenin in human cardiac diseases and potential inhibitors of Wnt/β-catenin, which may provide new strategies for cardiac disease therapies.

miR-145 from Bone Marrow Mesenchymal Stem Cells (BMSC) Improves Cardiac Function After Myocardial Infarction in Rat with Diabetes

This study assesses the role of miR-145 from BMSC in the cardiac function after MI in rat with diabetes. Rat with T1DM model was established and then were treated with PBS, DM-BMSC with overexpression of miR-145, BMSC with the knockdown of miR-145 respectively after twenty-four hours followed by analysis of the remodeling of vessels and protein, mRNA expressions. miR-145 in DM-BMSC was significantly reduced compared with control group and DM-BMSC prolonged the survival rate of rats. The formation of blood capillary and axon growth in DM-BMSC was increased and decreased in BMSC with knockdown of miR-145. The therapeutic action of DM-BMSC could be improved notably and remodeling of vessels and protein was increased. Smad1 was a target gene of miR-145. In conclusion, cardiac function and neurological recovery in MI is improved by miR-145 through targeting Smad1 expression, indicating that miR-145 might be a novel target for the treatment of MI.

mir-145-5p is a suppressor of colorectal cancer at early stage, while promotes colorectal cancer metastasis at late stage through regulating AKT signaling evoked EMT-mediated anoikis

Background:

miR-145-5P is generally considered as a tumor suppressor at early stage of colorectal cancer, but up-regulation occurs in the progressive and later stages which is associated with metastasis, indicating miR-145-5p may play dual role in colorectal cancer (CRC). To explore the detailed mechanism of miR-145-5p in carcinogenic is of importance.

Methods:

The expression pattern of miR-145-5p in CRC patients was downloaded from TCGA database, and the probable mechanism involved in the carcinogenic effect of miR-145-5p was predicted by bioinformatics analysis. Then, interference of miR-145-5p on SW480 and SW620 cells was conducted, and the influences on tumor cell viability, invasion ability, epithelial-mesenchymal transition (EMT), anoikis, and relative protein expression were examined respectively.

Results:

A total of 522 CRC patients’ data indicated that miR-145-5p expression was significantly higher in metastatic CRC than that in non-metastatic CRC, and higher expression of miR-145-5p was correlate with worse prognosis. Overexpression of miR-145-5P-5p enhanced the proliferation and invasion ability of SW620, but inhibited them in SW480. EMT was induced in SW620 after miR-145-5p overexpression and mesenchymal–epithelial transition (MET) was induced in SW480, resulted in the decreased apoptotic rate in SW620 and elevated apoptotic rate in SW480 respectively. Western blot results showed that AKT signaling pathway was involved in the miR-145-5p evoked EMT-mediated anoikis process in SW620 and SW480 cells.

Conclusion:

miR-145-5p is a tumor suppressor at early stage of CRC, and an oncogene at advanced stage of CRC. AKT signaling evoked EMT-mediated anoikis might be the pathway by which miR-145-5P regulates CRC cell invasion and metastasis.

FGF5 alleviated acute lung injury via AKT signal pathway in endothelial cells

Acute lung injury (ALI), with high morbidity and mortality, is mainly resulted by infectious or non-infectious inflammatory stimulators, and it will further evolve into acute respiratory distress syndrome if not controlled. Fibroblast growth factors (FGFs) consist of more than 23 kinds of members, which are involved in various pathophysiological processes of body. However, the effect of FGF5, one member of FGFs, is still not certain in lipopolysaccharide (LPS)-induced ALI. In this study, we explored the possible impacts of FGF5 in LPS-induced ALI and primarily focused on endothelial cell, which was one of the most vulnerable cells in septic ALI. In the mouse group of FGF5 overexpression, LPS-induced lung injuries were mitigated, as well as the pyroptosis levels of pulmonary vascular endothelial cells. Additionally, in vitro human umbilical vein endothelial cells (HUVECs), our results showed that the level of cell pyroptosis was ameliorated with FGF5 overexpression, and AKT signal was activated with the overexpression of FGF5, whereas after administration of MK2206, an inhibitor of AKT signal, the protection of FGF5 was inhibited. Therefore, these results suggested that FGF5 exerted protective effects in endothelial cells exposed to LPS, and this protection of FGF5 could be attributed to activated AKT signal.

Novel Therapies for the Treatment of Cardiac Fibrosis Following Myocardial Infarction

Cardiac fibrosis is a common pathological consequence of most myocardial diseases. It is associated with the excessive accumulation of extracellular matrix proteins as well as fibroblast differentiation into myofibroblasts in the cardiac interstitium. This structural remodeling often results in myocardial dysfunctions such as arrhythmias and impaired systolic function in patients with heart conditions, ultimately leading to heart failure and death. An understanding of the precise mechanisms of cardiac fibrosis is still limited due to the numerous signaling pathways, cells, and mediators involved in the process. This review article will focus on the pathophysiological processes associated with the development of cardiac fibrosis. In addition, it will summarize the novel strategies for anti-fibrotic therapies such as epigenetic modifications, miRNAs, and CRISPR technologies as well as various medications in cellular and animal models.

Selenium alleviates heart remodeling through Sirt1/AKT/GSK-3β pathway

Selenium, reported as an important medium for maintaining the body's homeostasis, acts to have multiple bioeffects including anti-inflammatory, anti-oxidant and anti-apoptosis effects. However, its role in heart failure still remains unclear. In this study, we explored the effects of selenium on heart failure and its possible mechanism. The heart failure models were induced by aortic banding and isoproterenol. H&E, TUNEL and PSR staining were performed to detect the degree of cardiomyocyte hypertrophy, apoptosis rates and heart fibrosis, respectively. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to detect different mRNA levels, and western blot was applied to assess the expressions of relative proteins. Immunofluorescence staining was used to evaluate α-SMA density. We first found that treatment of selenium alleviated heart fibrosis and the development of heart failure but not cardiomyocyte cross sectional areas. Besides, selenium improved heart levels of superoxide dismutase2 (SOD2), glutathione peroxidase (Gpx) and glutathione (GSH) and the activity of SOD, accompanied by decreased apoptosis rate. In addition, our in vitro study has shown that selenium reduced mRNA levels of collagen Ⅰ and collagen III, expressions of a-SMA, p-AKT/AKT and p-GSK-3β/ GSK-3β, apoptosis rates and reactive oxygen species (ROS) levels in H9C2 cardio-myoblasts treated with TGF-β1. Moreover, the level of Sirt1 was found to be up-regulated by selenium which effects were weakened after the administration of small interfering RNA (siRNA)-Sirt1 or EX527 (inhibitor of Sirt1). Our current results have demonstrated that the protective effects of selenium on heart hypertrophy is through the regulation of Sirt1 and AKT/GSK-3β pathway.

Bellidifolin Inhibits SRY-Related High Mobility Group-Box Gene 9 to Block TGF-β Signalling Activation to Ameliorate Myocardial Fibrosis

Myocardial fibrosis is the main morphological change of ventricular remodelling caused by cardiovascular diseases, mainly manifested due to the excessive production of collagen proteins. SRY-related high mobility group-box gene 9 (SOX9) is a new target regulating myocardial fibrosis. Bellidifolin (BEL), the active component of G. acuta, can prevent heart damage. However, it is unclear whether BEL can regulate SOX9 to alleviate myocardial fibrosis. The mice were subjected to isoproterenol (ISO) to establish myocardial fibrosis, and human myocardial fibroblasts (HCFs) were activated by TGF-β1 in the present study. The pathological changes of cardiac tissue were observed by HE staining. Masson staining was applied to reveal the collagen deposition in the heart. The measurement for expression of fibrosis-related proteins, SOX9, and TGF-β1 signalling molecules adopted Western blot and immunohistochemistry. The effects of BEL on HCFs, activity were detected by CCK-8. The result showed that BEL did not affect cell viability. And, the data indicated that BEL inhibited the elevations in α-SMA, Collagen I, and Collagen III by decreasing SOX9 expression. Additionally, SOX9 suppression by siRNA downregulated the TGF-β1 expression and prevented Smad3 phosphorylation, as supported by reducing the expression of α-SMA, Collagen I, and Collagen III. In vivo study verified that BEL ameliorated myocardial fibrosis by inhibiting SOX9. Therefore, BEL inhibited SOX9 to block TGF-β1 signalling activation to ameliorate myocardial fibrosis.

Insight into the Role of the PI3K/Akt Pathway in Ischemic Injury and Post-Infarct Left Ventricular Remodeling in Normal and Diabetic Heart

Despite the significant decline in mortality, cardiovascular diseases are still the leading cause of death worldwide. Among them, myocardial infarction (MI) seems to be the most important. A further decline in the death rate may be achieved by the introduction of molecularly targeted drugs. It seems that the components of the PI3K/Akt signaling pathway are good candidates for this. The PI3K/Akt pathway plays a key role in the regulation of the growth and survival of cells, such as cardiomyocytes. In addition, it has been shown that the activation of the PI3K/Akt pathway results in the alleviation of the negative post-infarct changes in the myocardium and is impaired in the state of diabetes. In this article, the role of this pathway was described in each step of ischemia and subsequent left ventricular remodeling. In addition, we point out the most promising substances which need more investigation before introduction into clinical practice. Moreover, we present the impact of diabetes and widely used cardiac and antidiabetic drugs on the PI3K/Akt pathway and discuss the molecular mechanism of its effects on myocardial ischemia and left ventricular remodeling.

Signaling pathways and targeted therapy for myocardial infarction

Although the treatment of myocardial infarction (MI) has improved considerably, it is still a worldwide disease with high morbidity and high mortality. Whilst there is still a long way to go for discovering ideal treatments, therapeutic strategies committed to cardioprotection and cardiac repair following cardiac ischemia are emerging. Evidence of pathological characteristics in MI illustrates cell signaling pathways that participate in the survival, proliferation, apoptosis, autophagy of cardiomyocytes, endothelial cells, fibroblasts, monocytes, and stem cells. These signaling pathways include the key players in inflammation response, e.g., NLRP3/caspase-1 and TLR4/MyD88/NF-κB; the crucial mediators in oxidative stress and apoptosis, for instance, Notch, Hippo/YAP, RhoA/ROCK, Nrf2/HO-1, and Sonic hedgehog; the controller of myocardial fibrosis such as TGF-β/SMADs and Wnt/β-catenin; and the main regulator of angiogenesis, PI3K/Akt, MAPK, JAK/STAT, Sonic hedgehog, etc. Since signaling pathways play an important role in administering the process of MI, aiming at targeting these aberrant signaling pathways and improving the pathological manifestations in MI is indispensable and promising. Hence, drug therapy, gene therapy, protein therapy, cell therapy, and exosome therapy have been emerging and are known as novel therapies. In this review, we summarize the therapeutic strategies for MI by regulating these associated pathways, which contribute to inhibiting cardiomyocytes death, attenuating inflammation, enhancing angiogenesis, etc. so as to repair and re-functionalize damaged hearts.

Post-Transcriptional Regulation of Molecular Determinants during Cardiogenesis

Cardiovascular development is initiated soon after gastrulation as bilateral precardiac mesoderm is progressively symmetrically determined at both sides of the developing embryo. The precardiac mesoderm subsequently fused at the embryonic midline constituting an embryonic linear heart tube. As development progress, the embryonic heart displays the first sign of left-right asymmetric morphology by the invariably rightward looping of the initial heart tube and prospective embryonic ventricular and atrial chambers emerged. As cardiac development progresses, the atrial and ventricular chambers enlarged and distinct left and right compartments emerge as consequence of the formation of the interatrial and interventricular septa, respectively. The last steps of cardiac morphogenesis are represented by the completion of atrial and ventricular septation, resulting in the configuration of a double circuitry with distinct systemic and pulmonary chambers, each of them with distinct inlets and outlets connections. Over the last decade, our understanding of the contribution of multiple growth factor signaling cascades such as Tgf-beta, Bmp and Wnt signaling as well as of transcriptional regulators to cardiac morphogenesis have greatly enlarged. Recently, a novel layer of complexity has emerged with the discovery of non-coding RNAs, particularly microRNAs and lncRNAs. Herein, we provide a state-of-the-art review of the contribution of non-coding RNAs during cardiac development. microRNAs and lncRNAs have been reported to functional modulate all stages of cardiac morphogenesis, spanning from lateral plate mesoderm formation to outflow tract septation, by modulating major growth factor signaling pathways as well as those transcriptional regulators involved in cardiac development.

Sox9 Promotes Cardiomyocyte Apoptosis After Acute Myocardial Infarction by Promoting miR-223-3p and Inhibiting MEF2C

Acute myocardial infarction (AMI) is a severe and even fatal cardiovascular disease. The effect of transcription factors on AMI is intensively explored. Our experiment attempts to probe the role of Sox9 in cardiomyocyte apoptosis after AMI. AMI cell model was established in AC16 cells by hypoxia treatment. Cell viability and apoptosis were assessed. Then, the levels of BAX, Bcl-2, Sox9, miR-223-3p, and MEF2C were detected. The binding relation between Sox9 and miR-223-3p and between miR-223-3p and MEF2C was verified. The expression of miR-223-3p was upregulated using the miR-223-3p mimic, and collaborative experiments were conducted as si-Sox9 or si-MEF2C was transfected into cells to inhibit the expression of Sox9 or MEF2C. Sox9 was highly expressed in cardiomyocyte apoptosis after hypoxia, while Sox9 silencing protected hypoxia-treated cardiomyocytes from apoptosis by enhancing cell viability, quenching apoptosis, and reducing activity of caspase-3 and caspase-9. Essentially, Sox9 bound to the miR-223-3p promoter region to upregulate its expression. miR-223-3p targeted MEF2C transcription. miR-223-3p overexpression and MEF2C silencing could counteract the suppressive role of Sox9 silencing in hypoxia-treated cardiomyocyte apoptosis. Sox9 exacerbated hypoxia-induced cardiomyocyte apoptosis by promoting miR-223-3p expression and inhibiting MEF2C transcription.

Non-Coding RNAs: lncRNAs, miRNAs, and piRNAs in Sexual Development

Non-coding RNAs (ncRNAs) are a group of RNAs that do not encode functional proteins, including long non-coding RNAs (lncRNAs), microRNAs (miRNAs), PIWI-interacting RNAs (piRNAs), and short interfering RNAs (siRNAs). In the last 2 decades an effort has been made to uncover the role of ncRNAs during development and disease, and nowadays it is clear that these molecules have a regulatory function in many of the developmental and physiological processes where they have been studied. In this review, we provide an overview of the role of ncRNAs during gonad determination and development, focusing mainly on mammals, although we also provide information from other species, in particular when there is not much information on the function of particular types of ncRNAs during mammalian sexual development.

miR-139-5p sponged by LncRNA NEAT1 regulates liver fibrosis via targeting β-catenin/SOX9/TGF-β1 pathway

Liver fibrosis is a patho-physiological process which can develop into cirrhosis, and hepatic carcinoma without intervention. Our study extensively investigated the mechanisms of lncRNA NEAT1 and miR-139-5p in regulating liver fibrosis progression. Our results demonstrated that the expression of lncRNA NEAT1 was increased and the expression of miR-139-5p was decreased in fibrotic liver tissues. LncRNA NEAT1 could sponge miR-139-5p and promoted hepatic stellate cells (HSCs) activation by directly inhibiting the expression of miR-139-5p. The co-localization of lncRNA NEAT1 with miR-139-5p was shown in the cytosols of activated HSCs. miR-139-5p upregulation could suppress the expression of β-catenin. The overexpression of β-catenin promoted HSCs activation. Moreover, we found that β-catenin could interact with SOX9 promoted HSCs activation. Our further studies demonstrated that SOX9 could bind with the TGF-β1 promoter and promoted the transcription activity of TGF-β1. The upregulation of TGF-β1 further promoted HSCs activation. In vivo study also suggested that lncRNA NEAT1 knockdown and miR-139-5p overexpression alleviated murine liver fibrosis. LncRNA NEAT1 exacerbated liver fibrosis by suppressing the expression of miR-139-5p. Collectively, our study suggested that miR-139-5p sponged by lncRNA NEAT1 regulated liver fibrosis via targeting β-catenin/SOX9/TGF-β1 Pathway.

MSCs-Derived Extracellular Vesicles Carrying miR-212-5p Alleviate Myocardial Infarction-Induced Cardiac Fibrosis via NLRC5/VEGF/TGF-β1/SMAD Axis

The purpose of the present study was to define the role of mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) in the progression of myocardial infarction (MI)-induced cardiac fibrosis. An in vitro cell model of hypoxia-induced cardiac fibrosis was constructed in cardiac fibroblasts (CFs). miR-212-5p was poorly expressed in clinical pathological samples and animal models of cardiac fibrosis caused by MI, while miR-212-5p expression was enriched in EVs released from MSCs. EVs from MSCs were isolated, evaluated, and co-cultured with CFs. Dual-luciferase reporter gene assay revealed that miR-212-5p negatively targeted NLRC5 progression of cardiac fibrosis. Following loss- and gain-function assay, EVs expressing miR-212-5p protected against cardiac fibrosis evidenced by reduced levels of α-SMA, Collagen I, TGF-β1, and IL-1β. In vivo experiments further confirmed the above research results. Collectively, EVs from MSCs expressing miR-212-5p may attenuate MI by suppressing the NLRC5/VEGF/TGF-β1/SMAD axis.

Pinocembrin ameliorates post-infarct heart failure through activation of Nrf2/HO-1 signaling pathway

Background

Oxidative stress is an important factor involved in the progress of heart failure. The current study was performed to investigate whether pinocembrin was able to ameliorate post-infarct heart failure (PIHF) and the underlying mechanisms.

Methods

Rats were carried out left anterior descending artery ligation to induce myocardial infarction and subsequently raised for 6 weeks to produce chronic heart failure. Then pinocembrin was administrated every other day for 2 weeks. The effects were evaluated by echocardiography, western blot, Masson’s staining, biochemical examinations, immunohistochemistry, and fluorescence. In vitro we also cultured H9c2 cardiomyocytes and cardiac myofibroblasts to further testify the mechanisms.

Results

We found that PIHF-induced deteriorations of cardiac functions were significantly ameliorated by administrating pinocembrin. In addition, the pinocembrin treatment also attenuated collagen deposition and augmented vascular endothelial growth factor receptor 2 in infarct border zone along with an attenuated apoptosis, which were related to an amelioration of oxidative stress evidenced by reduction of reactive oxygen species (ROS) in heart tissue and malondialdehyde (MDA) in serum, and increase of superoxide dismutase (SOD). This were accompanied by upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2)/ heme oxygenase-1 (HO-1) pathway. In vitro experiments we found that specific Nrf2 inhibitor significantly reversed the effects resulted from pinocembrin including antioxidant, anti-apoptosis, anti-fibrosis and neovascularization, which further indicated the amelioration of PIHF by pinocembrin was in a Nrf2/HO-1 pathway-dependent manner.

Conclusion

Pinocembrin ameliorated cardiac functions and remodeling resulted from PIHF by ROS scavenging and Nrf2/HO-1 pathway activation which further attenuated collagen fibers deposition and apoptosis, and facilitated angiogenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00363-7.

MicroRNAs in organ fibrosis: From molecular mechanisms to potential therapeutic targets

Fibrosis is caused by chronic tissue injury and characterized by the excessive deposition of extracellular matrix (ECM) that ultimately results in organ failure and death. Owing to lacking of effective treatment against tissue fibrosis, it causes a high morbidity and mortality worldwide. Thus, it is of great importance to find an effective therapy strategy for the treatment of fibrosis. MicroRNAs (miRNAs) play vital roles in many biological processes by targeting downstream genes. Numerous studies demonstrated that miRNAs served as biomarkers of various diseases, suggesting the potential therapeutic targets for diseases. It was recently reported that miRNAs played an important role in the development of organ fibrosis, which showed a promising prospect against fibrosis by targeting intervention. Here, we summarize the roles of miRNAs in the process of organ fibrosis, including liver, lung, heart and kidney, and highlight miRNAs being novel therapeutic targets for organ fibrosis.

Conservation of Zebrafish MicroRNA-145 and Its Role during Neural Crest Cell Development

The neural crest is a multipotent cell population that develops from the dorsal neural fold of vertebrate embryos in order to migrate extensively and differentiate into a variety of tissues. A number of gene regulatory networks coordinating neural crest cell specification and differentiation have been extensively studied to date. Although several publications suggest a common role for microRNA-145 (miR-145) in molecular reprogramming for cell cycle regulation and/or cellular differentiation, little is known about its role during in vivo cranial neural crest development. By modifying miR-145 levels in zebrafish embryos, abnormal craniofacial development and aberrant pigmentation phenotypes were detected. By whole-mount in situ hybridization, changes in expression patterns of col2a1a and Sry-related HMG box (Sox) transcription factors sox9a and sox9b were observed in overexpressed miR-145 embryos. In agreement, zebrafish sox9b expression was downregulated by miR-145 overexpression. In silico and in vivo analysis of the sox9b 3′UTR revealed a conserved potential miR-145 binding site likely involved in its post-transcriptional regulation. Based on these findings, we speculate that miR-145 participates in the gene regulatory network governing zebrafish chondrocyte differentiation by controlling sox9b expression.