Long Noncoding RNA CPR (Cardiomyocyte Proliferation Regulator) Regulates Cardiomyocyte Proliferation and Cardiac Repair.

BACKGROUND: The adult mammalian cardiomyocytes lose their proliferative capacity, which is responsible for cardiac dysfunction and heart failure following injury. The molecular mechanisms underlying the attenuation of adult cardiomyocyte proliferation remain largely unknown. Because long noncoding RNAs (lncRNAs) have a critical role in the development of cardiovascular problems, we investigated whether lncRNAs have any role in the regulation of cardiomyocyte proliferation and cardiac repair. METHODS: Using bioinformatics and initial analysis, we identified an lncRNA, named CPR (cardiomyocyte proliferation regulator), that has a potential regulatory role in cardiomyocyte proliferation. For in vivo experiments, we generated CPR knockout and cardiac-specific CPR-overexpressing mice. In isolated cardiomyocytes, we used adenovirus for silencing (CPR-small interfering RNA) or overexpressing CPR. To investigate the mechanisms of CPR function in cardiomyocyte proliferation, we performed various analyses including quantitative reverse transcription-polymerase chain reaction, Western blot, histology, cardiac function (by echocardiography), transcriptome analyses (microarray assay), RNA pull-down assay, and chromatin immunoprecipitation assay. RESULTS: CPR level is comparatively higher in the adult heart than in the fetal stage. The silencing of CPR significantly increased cardiomyocyte proliferation in postnatal and adult hearts. Moreover, CPR deletion restored the heart function after myocardial injury, which was evident from increased cardiomyocyte proliferation, improvement of myocardial function, and reduced scar formation. In contrast, the neonatal cardiomyocyte proliferation and cardiac regeneration were remarkably suppressed in CPR-overexpressing mice or adeno-associated virus serotype 9-CPR-overexpressing heart. These results indicate that CPR acts as a negative regulator of cardiomyocyte proliferation and regeneration. Next, we found that CPR targets minichromosome maintenance 3, an initiator of DNA replication and cell cycle progression, to suppress cardiomyocyte proliferation. CPR silenced minichromosome maintenance 3 expression through directly interacting and recruiting DNMT3A to its promoter cysteine-phosphate-guanine sites, as evident from decreased minichromosome maintenance 3 promoter methylation and increased minichromosome maintenance 3 expression in CPR knocked-down cardiomyocytes and CPR knockout mouse heart. These results were confirmed in CPR-overexpressing cardiomyocytes and CPR-overexpressing mouse heart. CONCLUSIONS: Together, our findings identified that CPR is a suppressor of cardiomyocyte proliferation and indicated that lncRNAs take part in the regulation of cardiomyocyte proliferation and cardiac repair. Our study provides an lncRNA-based therapeutic strategy for effective cardiac repair and regeneration.

A circular RNA protects the heart from pathological hypertrophy and heart failure by targeting miR-223.

AIMS: Sustained cardiac hypertrophy accompanied by maladaptive cardiac remodelling represents an early event in the clinical course leading to heart failure. Maladaptive hypertrophy is considered to be a therapeutic target for heart failure. However, the molecular mechanisms that regulate cardiac hypertrophy are largely unknown. METHODS AND RESULTS: Here we show that a circular RNA (circRNA), which we term heart-related circRNA (HRCR), acts as an endogenous miR-223 sponge to inhibit cardiac hypertrophy and heart failure. miR-223 transgenic mice developed cardiac hypertrophy and heart failure, whereas miR-223-deficient mice were protected from hypertrophic stimuli, indicating that miR-223 acts as a positive regulator of cardiac hypertrophy. We identified ARC as a miR-223 downstream target to mediate the function of miR-223 in cardiac hypertrophy. Apoptosis repressor with CARD domain transgenic mice showed reduced hypertrophic responses. Further, we found that a circRNA HRCR functions as an endogenous miR-223 sponge to sequester and inhibit miR-223 activity, which resulted in the increase of ARC expression. Heart-related circRNA directly bound to miR-223 in cytoplasm and enforced expression of HRCR in cardiomyocytes and in mice both exhibited attenuated hypertrophic responses. CONCLUSIONS: These findings disclose a novel regulatory pathway that is composed of HRCR, miR-223, and ARC. Modulation of their levels provides an attractive therapeutic target for the treatment of cardiac hypertrophy and heart failure.

The Role of MicroRNAs in Myocardial Infarction: From Molecular Mechanism to Clinical Application.

MicroRNAs (miRNAs) are a class of small single-stranded and highly conserved non-coding RNAs, which are closely linked to cardiac disorders such as myocardial infarction (MI), cardiomyocyte hypertrophy, and heart failure. A growing number of studies have demonstrated that miRNAs determine the fate of the heart by regulating cardiac cell death and regeneration after MI. A deep understanding of the pathophysiology of miRNA dependent regulatory pathways in these processes is required. The role of miRNAs as diagnostic, prognostic, and therapeutic targets also needs to be explored in order to utilize them in clinical settings. This review summarizes the role of miRNAs in myocardial infarction and focuses mainly on their influence on cardiomyocyte regeneration and cell death including apoptosis, necrosis, and autophagy. In addition, the targets of pro- and anti-MI miRNAs are comparatively described. In particular, the possibilities of miRNA-based diagnostic and therapeutic strategies for myocardial infarction are discussed in this review.

[Platelet rich plasma intra-articular and extra-articular injection for the treatment of knee osteoarthritis].

OBJECTIVE: To observe clinical effects of platelet-rich plasma (PRP) intra-articular and extra-articular injection for patients with knee osteoarthritis (KOA), and analyze its safety and clinical efficacy. METHODS: From January to December 2017, 48 patients with KOA were randomly divided into observation group and control group, 24 cases in each group. The observation group was treated with intra-articular injection of PRP (2 ml) and extra-articular injection of PRP (2 ml), once a week, for three times, including 8 males and 16 females with an average of (58.04±7.87) years old ranging from 43 to 68 years old, the courses of disease ranged from 1 to 8 years with an average of (4.69±1.96) years, the body mass index (BMI) was (24.53±5.26) kg/m 2 . The control group was treated with intra-articular injection of sodium hyaluronate (20 mg), extra-articular injection of analgesic drug (2 ml for one point), once a week, for three times, including 7 males and 17 females with an average of (60.54±8.93) years old ranging from 47 to 72 years old, the courses of disease ranged from 1.5 to 9 years with an average of (5.27±1.68) years, BMI was (23.47±4.62) kg/m 2 . VAS score and Lysholm score before operation and the 1st, 6th month after treatment were compared between two groups. RESULTS: All patients were followed up at least 6 months without occurrence serious adverse reactions or complications. VAS score in observation group and control group before treatment and 1st, 6th month after treatment were 7.35±1.47, 4.15±1.52, 2.26±1.02 and 7.51±1.39, 3.84±1.76, 3.66±1.18, respectively; VAS score in obsevation group was lower than that of control group at 6 months after treatment. Lysholm score in observation group and control group before treatment and 1st, 6th month after treatment were 55.21±5.78, 79.16±7.25, 85.45±6.87 and 54.65± 6.40, 77.58±6.94, 82.34±7.12. There were significant differences in Lysholm score before and after injection between two groups (P<0.05) . There was no significant difference in Lysholm score between two groups at 1 month after treatment (P>0.05), while Lysholm score in observation group was better than that of control group at 6 months after treatment (P<0.05) . CONCLUSION: Intra-articular and extra-articular injection of PRP could relieve pain symptoms and improve function of knee joint with higher safety, although the short-term effect is not significantly different from traditional treatment, its medium-long-term effect is stable. It is a safe and effective method for the treatment of knee osteoarthritis.

The piRNA CHAPIR regulates cardiac hypertrophy by controlling METTL3-dependent N6-methyladenosine methylation of Parp10 mRNA.

PIWI-interacting RNAs (piRNAs) are abundantly expressed during cardiac hypertrophy. However, their functions and molecular mechanisms remain unknown. Here, we identified a cardiac-hypertrophy-associated piRNA (CHAPIR) that promotes pathological hypertrophy and cardiac remodelling by targeting METTL3-mediated N6-methyladenosine (m6A) methylation of Parp10 mRNA transcripts. CHAPIR deletion markedly attenuates cardiac hypertrophy and restores heart function, while administration of a CHAPIR mimic enhances the pathological hypertrophic response in pressure-overloaded mice. Mechanistically, CHAPIR-PIWIL4 complexes directly interact with METTL3 and block the m6A methylation of Parp10 mRNA transcripts, which upregulates PARP10 expression. The CHAPIR-dependent increase in PARP10 promotes the mono-ADP-ribosylation of GSK3ß and inhibits its kinase activity, which results in the accumulation of nuclear NFATC4 and the progression of pathological hypertrophy. Hence, our findings reveal that a piRNA-mediated RNA epigenetic mechanism is involved in the regulation of cardiac hypertrophy and that the CHAPIR-METTL3-PARP10-NFATC4 signalling axis could be therapeutically targeted for treating pathological hypertrophy and maladaptive cardiac remodelling.

[Percutaneously full endoscopic decompressive laminectomy with precise localization for the treatment of lumbar spinal stenosis].

OBJECTIVE: To explore the feasibility of full endoscopic fenestration (FE-FE) via interlaminar approach for the treatment of lumbar spinal stenosis (LSS), and meanwhile, to analyze the related practicability and clinical outcome. METHODS: Referring to the traditional laminectomy and decompression, the lumbar spinal canal decompression was performed by using the water-medium spinal endoscopy (named FE-FE technique). Thirty-seven patients with LSS treated by FE-FE technique were retrospectively analyzed. There were 19 males and 18 females, aged from 55 to 83 years old with an average of (67.1±18.9) years. Visual analogue scale(VAS), Japanese Orthopaedic Association Scores(JOA), Oswestry Disability Index (ODI) and 36-Item Short-Form Health Survey (SF-36) were recorded. The patient's conscious pain and recovery of neurological function were observed, and the clinical efficacy was evaluated according to the improvement rate of JOA score. RESULTS: All 37 patients were followed up for 8 to 24 months with an average of (13.7±6.1) months. The postoperative follow-up and clinical evaluation for conscious pain and neurological function recovery showed that VAS, JOA, ODI and SF-36 scores were significantly improved compared with those before surgery(P<0.05). According to the improvement rate of JOA score to evaluate the clinical effects, at 6 months after opertion, the results were excellent in 17 cases, good in 13 cases, fair in 5 cases, and poor in 2 cases;and the last follow-up, the results were excellent in 19 cases, good in 13 cases, fair in 4 cases, and poor in 1 case. Postoperative imaging showed significant expansion of spine canal volume, and the followed-up clinical symptoms were improved satisfactorily, with the relief of lumbago and leg pain, improvement of daily life quality, and increased adaptability to social activities and no serious complications. CONCLUSIONS: Precise localization is the key to complete the canal decompression under full endoscopic surgery. FE-FE technique can effectively enlarge the narrow lumbar canal with less trauma, positive efficacy, safety and reliability. FE-FE has a broad application prospect though large cases and multi-center studies need to be further carried out.

The circular RNA ACR attenuates myocardial ischemia/reperfusion injury by suppressing autophagy via modulation of the Pink1/ FAM65B pathway.

Dysregulated autophagy is associated with many pathological disorders such as cardiovascular diseases. Emerging evidence has suggested that circular RNAs (circRNAs) have important roles in some biological processes. However, it remains unclear whether circRNAs participate in the regulation of autophagy. Here we report that a circRNA, termed autophagy-related circular RNA (ACR), represses autophagy and myocardial infarction by targeting Pink1-mediated phosphorylation of FAM65B. ACR attenuates autophagy and cell death in cardiomyocytes. Moreover, ACR protects the heart from ischemia/reperfusion (I/R) injury and reduces myocardial infarct sizes. We identify Pink1 as an ACR target to mediate the function of ACR in cardiomyocyte autophagy. ACR activates Pink1 expression through directly binding to Dnmt3B and blocking Dnmt3B-mediated DNA methylation of Pink1 promoter. Pink1 suppresses autophagy and Pink1 transgenic mice show reduced myocardial infarction sizes. Further, we find that FAM65B is a downstream target of Pink1 and Pink1 phosphorylates FAM65B at serine 46. Phosphorylated FAM65B inhibits autophagy and cell death in the heart. Our findings reveal a novel role for the circRNA in regulating autophagy and ACR-Pink1-FAM65B axis as a regulator of autophagy in the heart will be potential therapeutic targets in treatment of cardiovascular diseases.

LncRNA CAIF inhibits autophagy and attenuates myocardial infarction by blocking p53-mediated myocardin transcription.

Increasing evidence suggests that long noncoding RNAs (lncRNAs) play crucial roles in various biological processes. However, little is known about the effects of lncRNAs on autophagy. Here we report that a lncRNA, termed cardiac autophagy inhibitory factor (CAIF), suppresses cardiac autophagy and attenuates myocardial infarction by targeting p53-mediated myocardin transcription. Myocardin expression is upregulated upon H2O2 and ischemia/reperfusion, and knockdown of myocardin inhibits autophagy and attenuates myocardial infarction. p53 regulates cardiomyocytes autophagy and myocardial ischemia/reperfusion injury by regulating myocardin expression. CAIF directly binds to p53 protein and blocks p53-mediated myocardin transcription, which results in the decrease of myocardin expression. Collectively, our data reveal a novel CAIF-p53-myocardin axis as a critical regulator in cardiomyocyte autophagy, which will be potential therapeutic targets in treatment of defective autophagy-associated cardiovascular diseases.

MicroRNA-2861 regulates programmed necrosis in cardiomyocyte by impairing adenine nucleotide translocase 1 expression.

Necrosis is programmed and is one of the main forms of cell death in the pathological process in cardiac diseases. MicroRNAs (miRNAs) have emerged as key gene regulators in many diseases. However, how miRNAs contribute to programmed necrosis is poorly defined. Here we report that miR-2861 and adenine nucleotide translocase 1 (ANT1) constitute an axis that regulates necrotic cell death in the heart. Our results show that ANT1 inhibits H2O2-induced cardiomyocytes necrosis. ANT1 also antagonizes myocardial necrosis in a mouse ischemia/reperfusion (I/R) model. We further demonstrate that miR-2861 directly binds to the coding sequence of ANT1 and suppresses the expression of ANT1 mRNA and protein. MiR-2861 induces necrotic cell death. In contrast, knockdown of miR-2861 attenuates H2O2-induced necrosis in cardiomyocytes. Also, miR-2861 knockdown protects heart from I/R injury and necrotic cell death in vivo. MiR-2861 regulates necrosis and myocardial infarction through targeting ANT1. Collectively, these data identify miR-2861 and ANT1 as two novel regulators of cardiomyocyte necrosis and myocardial infarction, and suggest potential therapeutic targets in treatment of cardiac diseases.

E2F1-dependent miR-421 regulates mitochondrial fragmentation and myocardial infarction by targeting Pink1.

Mitochondrial fragmentation plays an important role in the progression of cardiac diseases, such as myocardial infarction and heart failure. Mitochondrial network is controlled by many factors in different cell types. Here we show that the interplay between E2F1, miR-421 and Pink1 regulates mitochondrial morphology and cardiomyocyte cell death. Pink1 reduces mitochondrial fragmentation and protects cardiomyocyte from apoptosis. On the other hand, miR-421 promotes cardiomyocyte mitochondrial fragmentation, apoptosis and myocardial infarction by suppressing Pink1 translation. Finally, we show that transcription factor E2F1 activates miR-421 expression. Knocking down E2F1 suppresses mitochondrial fragmentation, apoptosis and myocardial infarction by affecting miR-421 levels. Collectively, these data identify the E2F1/miR-421/Pink axis as a regulator of mitochondrial fragmentation and cardiomyocyte apoptosis, and suggest potential therapeutic targets in treatment of cardiac diseases.