Sustained cardiac hypertrophy is often accompanied by maladaptive cardiac remodeling leading to decreased compliance and increased risk for heart failure. Maladaptive hypertrophy is considered to be ...a therapeutic target for heart failure. MicroRNAs (miRNAs) and long noncoding RNAs (lncRNAs) have various biological functions and have been extensively investigated in past years.
We identified miR-489 and lncRNAs (cardiac hypertrophy related factor, CHRF) from hypertrophic cardiomyocytes. Here, we tested the hypothesis that miR-489 and CHRF can participate in the regulation of cardiac hypertrophy in vivo and in vitro.
A microarray was performed to analyze miRNAs in response to angiotensin II treatment, and we found miR-489 was substantially reduced. Enforced expression of miR-489 in cardiomyocytes and transgenic overexpression of miR-489 both exhibited reduced hypertrophic response on angiotensin II treatment. We identified myeloid differentiation primary response gene 88 (Myd88) as a miR-489 target to mediate the function of miR-489 in cardiac hypertrophy. Knockdown of Myd88 in cardiomyocytes and Myd88-knockout mice both showed attenuated hypertrophic responses. Furthermore, we explored the molecular mechanism by which miR-489 expression is regulated and found that an lncRNA that we named CHRF acts as an endogenous sponge of miR-489, which downregulates miR-489 expression levels. CHRF is able to directly bind to miR-489 and regulate Myd88 expression and hypertrophy.
Our present study reveals a novel cardiac hypertrophy regulating model that is composed of CHRF, miR-489, and Myd88. The modulation of their levels may provide a new approach for tackling cardiac hypertrophy.
Abnormal mitochondrial fission participates in the pathogenesis of many diseases. Long non-coding RNAs (lncRNAs) are emerging as new players in gene regulation, but how lncRNAs operate in the ...regulation of mitochondrial network is unclear. Here we report that a lncRNA, named cardiac apoptosis-related lncRNA (CARL), can suppress mitochondrial fission and apoptosis by targeting miR-539 and PHB2. The results show that PHB2 is able to inhibit mitochondrial fission and apoptosis. miR-539 is responsible for the dysfunction of PHB2 and regulates mitochondrial fission and apoptosis by targeting PHB2. Further, we show that CARL can act as an endogenous miR-539 sponge that regulates PHB2 expression, mitochondrial fission and apoptosis. Our present study reveals a model of mitochondrial fission regulation that is composed of CARL, miR-539 and PHB2. Modulation of their levels may provide a new approach for tackling apoptosis and myocardial infarction.
Background
MicroRNAs (miRNAs) have become increasingly prevalent as a result of the association of their deregulation with neurodegenerative disorders, especially Alzheimer's disease (AD). However, ...the association between miRNAs and AD remains unclear.
Methods
In the present study, Nine representative miRNA datasets were selected for the identification of the critical miRNAs by analyzing the overlapping relationships among them. TargetScan software (http://www.targetscan.org) was used to predict the target genes of these miRNAs. In addition, the Database for Annotation Visualization and Integrated Discovery (DAVID; http://david.abcc.ncifcrf.gov) and TfactS (http://www.tfacts.org) datasets were used for combined analysis of functional enrichment and transcription factor (TF) analysis.
Results
Thirteen key miRNAs were identified, of which four were significantly up‐regulated (hsa‐miR‐101,hsa‐miR‐155, has‐miR‐34a, has‐miR‐9) and eight were found to be significantly down‐regulated (hsa‐let‐7d‐5p, hsa‐let‐7 g‐5p, hsa‐miR‐15b, has‐miR‐191‐5p, hsa‐miR‐125b, has‐miR‐26b‐5p, hsa‐miR‐29b, hsa‐miR‐342‐3p). The functional enrichment analysis indicated that up‐regulated signature miRNA targets were associated with transcription from the RNA polymerase II promoter process and the chemical synaptic transmission process. Down‐regulated signature miRNA targets were mostly enriched with respect to positive regulation of transcription from the RNA polymerase II promoter process, p53 signaling, and microRNAs in cancer pathways. TF analysis showed that 87 TFs were influenced by the up‐regulated miRNAs, and 134 TFs were influenced by the down‐regulated miRNAs. In total, 70 (45.5%) TFs were affected by both up‐regulated and down‐regulated miRNAs.
Conclusions
In summary, 13 key miRNAs were found to have a vital function in the pathological progress of AD, as well as the target genes and TFs of these miRNAs. The potential functions of these miRNAs as diagnostic and therapeutic targets of the AD are revealed by the present study.
Abstract Painful peripheral neuropathy is a dose-limiting side effect of paclitaxel therapy, which hampers the optimal clinical management of chemotherapy in cancer patients. Currently the underlying ...mechanisms remain largely unknown. Here we showed that the clinically relevant dose of paclitaxel (3 × 8 mg/kg, cumulative dose 24 mg/kg) induced significant upregulation of the chemokine CX3CL1 in the A-fiber primary sensory neurons in vivo and in vitro and infiltration of macrophages into the dorsal root ganglion (DRG) in rats. Paclitaxel treatment also increased cleaved caspase-3 expression, induced the loss of primary afferent terminal fibers and decreased sciatic-evoked A-fiber responses in the spinal dorsal horn, indicating DRG neuronal apoptosis induced by paclitaxel. In addition, the paclitaxel-induced DRG neuronal apoptosis occurred exclusively in the presence of macrophage in vitro study. Intrathecal or systemic injection of CX3CL1 neutralizing antibody blocked paclitaxel-induced macrophage recruitment and neuronal apoptosis in the DRG, and also attenuated paclitaxel-induced allodynia. Furthermore, depletion of macrophage by systemic administration of clodronate inhibited paclitaxel-induced allodynia. Blocking CX3CL1 decreased activation of p38 MAPK in the macrophage, and inhibition of p38 MAPK activity blocked the neuronal apoptosis and development of mechanical allodynia induced by paclitaxel. These findings provide novel evidence that CX3CL1-recruited macrophage contributed to paclitaxel-induced DRG neuronal apoptosis and painful peripheral neuropathy.
Background:
Although paclitaxel is a frontline antineoplastic agent for treatment of solid tumors, the paclitaxel-evoked pain syndrome is a serious problem for patients. There is currently no valid ...drug to prevent or treat the paclitaxel-induced allodynia, partly due to lack of understanding regarding the cellular mechanism. Studies have shown that minocycline, an inhibitor of microglia/macrophage, prevented neuropathic pain and promoted neuronal survival in animal models of neurodegenerative disease. Recently, Cata et al also reported that minocycline inhibited allodynia induced by low-dose paclitaxel (2 mg/kg) in rats, but the mechanism is still unclear.
Results:
Here, we investigate by immunohistochemistry the change of intraepidermal nerve fiber (IENF) in the hind paw glabrous skin, expression of macrophage and activating transcription factor 3 (ATF3) in DRG at different time points after moderate-dose paclitaxel treatment (cumulative dose 24 mg/kg; 3 × 8 mg/kg) in rats. Moreover, we observe the effect of minocycline on the IENF, macrophages and ATF3. The results showed that moderate-dose paclitaxel induced a persisted, gradual mechanical allodynia, which was accompanied by the loss of IENF in the hind paw glabrous skin and up-regulation of macrophages and ATF3 in DRG in rats. The expressions of ATF3 mainly focus on the NF200-positive cells. More importantly, we observed that pretreatment of minocycline at dose of 30 mg/kg or 50 mg/kg, but not 5 mg/kg, prevented paclitaxel-evoked allodynia. The evidence from immunohistochemistry showed that 30 mg/kg minocycline rescued the degeneration of IENF, attenuated infiltration of macrophages and up-regulation of ATF3 induced by paclitaxel treatment in rats.
Conclusions:
Minocycline prevents paclitaxel-evoked allodynia, likely due to its inhibition on loss of IENF, infiltration of macrophages and up-regulation of ATF3 in rats. The finding might provide potential target for preventing paclitaxel-induced neuropathic pain.
Objective
Although several individual nutrients/foods are associated with uric acid status, the association of overall diet quality with hyperuricemia remains unclear. The current study was ...undertaken to examine the association between adherence to the Dietary Approaches to Stop Hypertension (DASH) diet and the odds of having hyperuricemia in a Chinese adult population.
Methods
Included were 71,893 Chinese participants in the Kailuan I study and the Kailuan II study (mean age 51.4 years) who were free of gout prior to or in 2014. Dietary intakes were assessed using a validated food frequency questionnaire, and the DASH diet score was calculated based on consumptions of vegetables, fruit, dairy, beans, whole grains, meat, fat, sodium, and sugar‐sweetened beverages. Fasting blood samples were collected in 2014, and hyperuricemia was defined as serum uric acid concentrations of ≥7 mg/dl for men, and of ≥6 mg/dl for women. The association between DASH diet score and hyperuricemia was assessed using multiple logistic regression models, adjusting for age, sex, total energy, obesity, physical activity, education, smoking, alcohol drinking, blood pressure, fasting glucose, lipid profiles, renal function, and presence of cardiovascular disease.
Results
A High DASH diet score was associated with low odds of having hyperuricemia (adjusted odds ratio for quartile 4 versus quartile 1 0.70 95% confidence interval 0.66, 0.75, P for trend < 0.001) after adjusting for potential confounders. The association between the DASH diet and hyperuricemia was more pronounced among older individuals (age ≥50 years), women, and physically inactive participants compared with their counterparts (P for interaction < 0.01 for all).
Conclusion
The DASH diet was associated with a low likelihood of having hyperuricemia in Chinese adults.
Herbal blends containing synthetic cannabinoids have become popular alternatives to marijuana. The number of synthetic cannabinoids and speed of their emergence enable this group of compounds ...particularly challenging in terms of detection, monitoring, and responding. In this work, both gas chromatography‐mass spectrometry (GC‐MS) and nuclear magnetic resonance spectroscopy (NMR) methods were developed for the identification and quantification of synthetic cannabinoids in herbal blends. Ten types of indole/indazole carboxamide synthetic cannabinoids, which showed different types of substitutions connected to nitrogen of the indole/indazole carboxamide, were detected in 36 herbal blends. The GC‐MS fragmentation routes of indole/indazole carboxamide synthetic cannabinoids were discussed in detail for structure identification purpose. The concentration range of synthetic cannabinoid in 36 herbal blends was 1.9–50.6 mg/g using GC‐MS method, while 1.5–49.0 mg/g by NMR method. Nicotine in herbal blends was quantified by NMR method without using reference material, and showed a variation of 5.3–44.7 mg/g. For quantitative analysis, NMR method showed great advantage in the absence of reference material, while GC‐MS method showed great merit for multiple‐compound analysis when reference material was available. Therefore, for the quantitative analysis of new emerged synthetic cannabinoid in herbal blends, different methods could be chosen by considering whether reference material is available, as well as the number and types of synthetic cannabinoids detected in a single sample.
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.
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.
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.
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.
Bee venom and its main constituent melittin (MEL) have been extensively studied in the treatment of tumors. However, the non-specific cytotoxicity and hemolytic activity have hampered the clinical ...application. Currently, a number of research groups have reported a series of optimization strategies, including gene therapy, recombinant immunotoxin incorporating MEL or MEL nanoparticles, targeting tumor cells to attenuate the cytotoxicity and improve its antitumor efficiency and therapeutic capabilities, which have shown very promising in overcoming some of these obstacles. In this review, we summarize the current knowledge regarding anticancer effects of bee venom and its main compound MEL on different kinds of tumor cells as well as elucidate their possible anticancer mechanisms. It could be concluded that MEL exerts multiple effects on cellular functions of cancerous cells such as proliferation, apoptosis, metastasis, angiogenesis as well as cell cycle, and the anticancer processes involve diverse signal molecules and regulatory pathways. We also highlight the recent research progress for efficient delivery of MEL peptide, thus providing new ideas and hopeful strategies for the in vivo application of MEL.
The major innate immune cell types involved in tuberculosis (TB) infection are macrophages, dendritic cells (DCs), neutrophils and natural killer (NK) cells. These immune cells recognize the ...TB-causing pathogen Mycobacterium tuberculosis (Mtb) through various pattern recognition receptors (PRRs), including but not limited to Toll-like receptors (TLRs), Nod-like receptors (NLRs) and C-type lectin receptors (CLRs). Upon infection by Mtb, the host orchestrates multiple signaling cascades via the PRRs to launch a variety of innate immune defense functions such as phagocytosis, autophagy, apoptosis and inflammasome activation. In contrast, Mtb utilizes numerous exquisite strategies to evade or circumvent host innate immunity. Here we discuss recent research on major host innate immune cells, PRR signaling, and the cellular functions involved in Mtb infection, with a specific focus on the host's innate immune defense and Mtb immune evasion. A better understanding of the molecular mechanisms underlying host-pathogen interactions could provide a rational basis for the development of effective anti-TB therapeutics.
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