Characterization of Key Odorants in Lushan Yunwu Tea in Response to Intercropping with Flowering Cherry

Lushan Yunwu tea (LSYWT) is a famous green tea in China. However, the effects of intercropping tea with flowering cherry on the overall aroma of tea have not been well understood. In this study, headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used for analysis. A total of 54 volatile compounds from eight chemical classes were identified in tea samples from both the intercropping and pure-tea-plantation groups. Principal component analysis (PCA), orthogonal partial least-squares discriminant analysis (OPLS-DA), and odor activity value (OAV) methods combined with sensory evaluation identified cis-jasmone, nonanal, and linalool as the key aroma compounds in the intercropping group. Benzaldehyde, α-farnesene, and methyl benzene were identified as the main volatile compounds in the flowering cherry using headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS). These findings will enrich the research on tea aroma chemistry and offer new insights into the product development and quality improvement of LSYWT.

Comparative analysis of lipid Nanoparticle-Mediated delivery of CRISPR-Cas9 RNP versus mRNA/sgRNA for gene editing in vitro and in vivo

The discovery that the bacterial defense mechanism, CRISPR-Cas9, can be reprogrammed as a gene editing tool has revolutionized the field of gene editing. CRISPR-Cas9 can introduce a double-strand break at a specific targeted site within the genome. Subsequent intracellular repair mechanisms repair the double strand break that can either lead to gene knock-out (via the non-homologous end-joining pathway) or specific gene correction in the presence of a DNA template via homology-directed repair. With the latter, pathological mutations can be cut out and repaired. Advances are being made to utilize CRISPR-Cas9 in patients by incorporating its components into non-viral delivery vehicles that will protect them from premature degradation and deliver them to the targeted tissues. Herein, CRISPR-Cas9 can be delivered in the form of three different cargos: plasmid DNA, RNA or a ribonucleoprotein complex (RNP). We and others have recently shown that Cas9 RNP can be efficiently formulated in lipid-nanoparticles (LNP) leading to functional delivery in vitro. In this study, we compared LNP encapsulating the mRNA Cas9, sgRNA and HDR template against LNP containing Cas9-RNP and HDR template. Former showed smaller particle sizes, better protection against degrading enzymes and higher gene editing efficiencies on both reporter HEK293T cells and HEPA 1-6 cells in in vitro assays. Both formulations were additionally tested in female Ai9 mice on biodistribution and gene editing efficiency after systemic administration. LNP delivering mRNA Cas9 were retained mainly in the liver, with LNP delivering Cas9-RNPs additionally found in the spleen and lungs. Finally, gene editing in mice could only be concluded for LNP delivering mRNA Cas9 and sgRNA. These LNPs resulted in 60 % gene knock-out in hepatocytes. Delivery of mRNA Cas9 as cargo format was thereby concluded to surpass Cas9-RNP for application of CRISPR-Cas9 for gene editing in vitro and in vivo.

Exercise Inhibits Doxorubicin-Induced Cardiotoxicity via Regulating B Cells

BACKGROUND

Doxorubicin is an effective chemotherapeutic agent, but its use is limited by acute and chronic cardiotoxicity. Exercise training has been shown to protect against doxorubicin-induced cardiotoxicity, but the involvement of immune cells remains unclear. This study aimed to investigate the role of exercise-derived B cells in protecting against doxorubicin-induced cardiotoxicity and to further determine whether B cell activation and antibody secretion play a role in this protection.

METHODS

Mice that were administered with doxorubicin (5 mg/kg per week, 20 mg/kg cumulative dose) received treadmill running exercise. The adoptive transfer of exercise-derived splenic B cells to μMT-/- (B cell-deficient) mice was performed to elucidate the mechanism of B cell regulation that mediated the effect of exercise.

RESULTS

Doxorubicin-administered mice that had undergone exercise training showed improved cardiac function, and low levels of cardiac apoptosis, atrophy, and fibrosis, and had reduced cardiac antibody deposition and proinflammatory responses. Similarly, B cell pharmacological and genetic depletion alleviated doxorubicin-induced cardiotoxicity, which phenocopied the protection of exercise. In vitro performed coculture experiments confirmed that exercise-derived B cells reduced cardiomyocyte apoptosis and fibroblast activation compared with control B cells. Importantly, the protective effect of exercise on B cells was confirmed by the adoptive transfer of splenic B cells from exercised donor mice to μMT-/- recipient mice. However, blockage of Fc gamma receptor IIB function using B cell transplants from exercised Fc gamma receptor IIB-/- mice abolished the protection of exercise-derived B cells against doxorubicin-induced cardiotoxicity. Mechanistically, we found that Fc gamma receptor IIB, an important B cell inhibitory receptor, responded to exercise and increased B cell activation threshold, which participated in exercise-induced protection against doxorubicin-induced cardiotoxicity.

CONCLUSIONS

Our results demonstrate that exercise training protects against doxorubicin-induced cardiotoxicity by upregulating Fc gamma receptor IIB expression in B cells, which plays an important anti-inflammatory role and participates in the protective effect of exercise against doxorubicin-induced cardiotoxicity.

Vitamin C facilitates direct cardiac reprogramming by inhibiting reactive oxygen species

BACKGROUND

After myocardial infarction, the lost myocardium is replaced by fibrotic tissue, eventually progressively leading to myocardial dysfunction. Direct reprogramming of fibroblasts into cardiomyocytes via the forced overexpression of cardiac transcription factors Gata4, Mef2c, and Tbx5 (GMT) offers a promising strategy for cardiac repair. The limited reprogramming efficiency of this approach, however, remains a significant challenge.

METHODS

We screened seven factors capable of improving direct cardiac reprogramming of both mice and human fibroblasts by evaluating small molecules known to be involved in cardiomyocyte differentiation or promoting human-induced pluripotent stem cell reprogramming.

RESULTS

We found that vitamin C (VitC) significantly increased cardiac reprogramming efficiency when added to GMT-overexpressing fibroblasts from human and mice in 2D and 3D model. We observed a significant increase in reactive oxygen species (ROS) generation in human and mice fibroblasts upon Doxy induction, and ROS generation was subsequently reduced upon VitC treatment, associated with increased reprogramming efficiency. However, upon treatment with dehydroascorbic acid, a structural analog of VitC but lacking antioxidant properties, no difference in reprogramming efficiency was observed, suggesting that the effect of VitC in enhancing cardiac reprogramming is partly dependent of its antioxidant properties.

CONCLUSIONS

Our findings demonstrate that VitC supplementation significantly enhances the efficiency of cardiac reprogramming, partially by suppressing ROS production in the presence of GMT.

Extracellular vesicle-mediated delivery of CRISPR/Cas9 ribonucleoprotein complex targeting proprotein convertase subtilisin-kexin type 9 (Pcsk9) in primary mouse hepatocytes

The loss-of-function of the proprotein convertase subtilisin-kexin type 9 (Pcsk9) gene has been associated with significant reductions in plasma serum low-density lipoprotein cholesterol (LDL-C) levels. Both CRISPR/Cas9 and CRISPR-based editor-mediated Pcsk9 inactivation have successfully lowered plasma LDL-C and PCSK9 levels in preclinical models. Despite the promising preclinical results, these studies did not report how vehicle-mediated CRISPR delivery inactivating Pcsk9 affected low-density lipoprotein receptor recycling in vitro or ex vivo. Extracellular vesicles (EVs) have shown promise as a biocompatible delivery vehicle, and CRISPR/Cas9 ribonucleoprotein (RNP) has been demonstrated to mediate safe genome editing. Therefore, we investigated EV-mediated RNP targeting of the Pcsk9 gene ex vivo in primary mouse hepatocytes. We engineered EVs with the rapamycin-interacting heterodimer FK506-binding protein (FKBP12) to contain its binding partner, the T82L mutant FKBP12-rapamycin binding (FRB) domain, fused to the Cas9 protein. By integrating the vesicular stomatitis virus glycoprotein on the EV membrane, the engineered Cas9 EVs were used for intracellular CRISPR/Cas9 RNP delivery, achieving genome editing with an efficacy of ±28.1% in Cas9 stoplight reporter cells. Administration of Cas9 EVs in mouse hepatocytes successfully inactivated the Pcsk9 gene, leading to a reduction in Pcsk9 mRNA and increased uptake of the low-density lipoprotein receptor and LDL-C. These readouts can be used in future experiments to assess the efficacy of vehicle-mediated delivery of genome editing technologies targeting Pcsk9. The ex vivo data could be a step towards reducing animal testing and serve as a precursor to future in vivo studies for EV-mediated CRISPR/Cas9 RNP delivery targeting Pcsk9.

High temperature stress induced oxidative stress, gut inflammation and disordered metabolome and microbiome in tsinling lenok trout

Tsinling lenok trout (Brachymystax lenok tsinlingensis Li) is a species of cold-water salmon that faces serious challenges due to global warming. High temperature stress has been found to damage the gut integrity of cold-water fish, impacting their growth and immunity. However, limited research exists on the causal relationship between gut microbial disturbance and metabolic dysfunction in cold-water fish induced by high temperature stress. To address this gap, we conducted a study to investigate the effects of high temperature stress (24 °C) on the gut tissue structure, antioxidant capacity, gut microorganisms, and metabolome reactions of tsinling lenok trout. Our analysis using 16 S rDNA gene sequencing revealed significant changes in the gut microbial composition and metabolic profile. Specifically, the abundance of Firmicutes and Gemmatimonadetes decreased significantly with increasing temperature, while the abundance of Bacteroidetes increased significantly. Metabolic analysis revealed a significant decrease in the abundance of glutathione, which is synthesized from glutamate and glycine, under high temperature stress. Additionally, there was a notable reduction in the levels of adenosine, inosine, xanthine, guanosine, and deoxyguanosine, which are essential for DNA/RNA synthesis. Conversely, there was a significant increase in the abundance of D-glucose 6 P. Furthermore, high temperature stress adversely affects intestinal structure and barrier function. Our findings provide valuable insights into the mechanism of high temperature stress in cold-water fish and serve as a foundation for future research aimed at mitigating the decline in production performance caused by such stress.

Single Cell Analysis of Macrophage Heterogeneity and NK-Cell Exhaustion in Lewis Lung Cancer Xenograft Tumor

PURPOSE/OBJECTIVE(S)

Stereotactic body radiation therapy (SBRT) has attracted much attention because of its ability to stimulate anti-tumor immune response. However, the mechanism of SBRT reprogramming the tumor microenvironment remains to be elucidated.

MATERIALS/METHODS

Using Lewis lung carcinoma (LLC) xenograft mice model treated with SBRT (8Gy x 3F), multiplex assay was performed to measure serum chemokine levels, and single-cell RNA sequencing was performed to assess tumor microenvironment. The differential expression genes of each cell subcluster were identified by the "Find-All markers" function with default parameters provided by Seurat. Intercellular communication analysis was explored by using CellPhone DB package.

RESULTS

The majority of serum chemokines involved macrophage recruitment, including CCL3, CCL4, CCL8, and CCL20, were highly secreted at 7 days after SBRT. Single-cell RNA sequencing of 108,741 cells were contained from 6 mouse Lewis lung carcinoma samples (n = 3 tumors for SBRT, n = 3 tumors pooled for SHAM). Besides Lewis cancer cells, myeloid cells were 57.61% ,70.82% in Sham-irradiation (SHAM) and SBRT while NT and T cells were 20.50%, 7.81% in SHAM and SBRT, respectively. When compared with SHAM group, upregulation of Ccl3, Ccl4, Ccl8 chemokine genes were observed in cancer cells of SBRT group. Differential expression genes analysis showed high expression level of Ccl8 (Log2FC 2.54, p<0.01) in cluster of Mrc1+macrophage. The SBRT group consisted of more Ccl8+Mrc1+macrophages (proportion 36.28% for SBRT, 27.44% for SHAM) and exhausted NK cells (proportion 22.56% for SBRT, 13.70% for SHAM). More importantly, intercellular communication analysis revealed a potential communication network between Ccl8+Mrc1+macrophages and exhausted NK cells.

CONCLUSION

Our results provide a potential therapeutic strategy by disrupting Ccl8+ Mrc1+macrophages and NK-cell interaction to facilitate the stimulation of the anti-tumor immune response by SBRT.

Cellular polyploidy in organ homeostasis and regeneration

Polyploid cells, which contain more than one set of chromosome pairs, are very common in nature. Polyploidy can provide cells with several potential benefits over their diploid counterparts, including an increase in cell size, contributing to organ growth and tissue homeostasis, and improving cellular robustness via increased tolerance to genomic stress and apoptotic signals. Here, we focus on why polyploidy in the cell occurs and which stress responses and molecular signals trigger cells to become polyploid. Moreover, we discuss its crucial roles in cell growth and tissue regeneration in the heart, liver, and other tissues.

High-Flux Neutron Generator Based on Laser-Driven Collisionless Shock Acceleration

A novel compact high-flux neutron generator with a pitcher-catcher configuration based on laser-driven collisionless shock acceleration (CSA) is proposed and experimentally verified. Different from those that previously relied on target normal sheath acceleration (TNSA), CSA in nature favors not only acceleration of deuterons (instead of hydrogen contaminants) but also increasing of the number of deuterons in the high-energy range, therefore having great advantages for production of high-flux neutron source. The proof-of-principle experiment has observed a typical CSA plateau feature from 2 to 6 MeV in deuteron energy spectrum and measured a forward neutron flux with yield 6.6×10^{7}  n/sr from the LiF catcher target, an order of magnitude higher than the compared TNSA case, where the laser intensity is 10^{19}  W/cm^{2}. Self-consistent simulations have reproduced the experimental results and predicted that a high-flux forward neutron source with yield up to 5×10^{10}  n/sr can be obtained when laser intensity increases to 10^{21}  W/cm^{2} under the same laser energy.

The Preparation, Structural Design, and Application of Electroactive Poly(vinylidene fluoride)-Based Materials for Wearable Sensors and Human Energy Harvesters

Owing to their biocompatibility, chemical stability, film-forming ability, cost-effectiveness, and excellent electroactive properties, poly(vinylidene fluoride) (PVDF) and PVDF-based polymers are widely used in sensors, actuators, energy harvesters, etc. In this review, the recent research progress on the PVDF phase structures and identification of different phases is outlined. Several approaches for obtaining the electroactive phase of PVDF and preparing PVDF-based nanocomposites are described. Furthermore, the potential applications of these materials in wearable sensors and human energy harvesters are discussed. Finally, some challenges and perspectives for improving the properties and boosting the applications of these materials are presented.

HIPK1 Inhibition Protects against Pathological Cardiac Hypertrophy by Inhibiting the CREB-C/EBPβ Axis

Inhibition of pathological cardiac hypertrophy is recognized as an important therapeutic strategy for heart failure, although effective targets are still lacking in clinical practice. Homeodomain interacting protein kinase 1 (HIPK1) is a conserved serine/threonine kinase that can respond to different stress signals, however, whether and how HIPK1 regulates myocardial function is not reported. Here, it is observed that HIPK1 is increased during pathological cardiac hypertrophy. Both genetic ablation and gene therapy targeting HIPK1 are protective against pathological hypertrophy and heart failure in vivo. Hypertrophic stress-induced HIPK1 is present in the nucleus of cardiomyocytes, while HIPK1 inhibition prevents phenylephrine-induced cardiomyocyte hypertrophy through inhibiting cAMP-response element binding protein (CREB) phosphorylation at Ser271 and inactivating CCAAT/enhancer-binding protein β (C/EBPβ)-mediated transcription of pathological response genes. Inhibition of HIPK1 and CREB forms a synergistic pathway in preventing pathological cardiac hypertrophy. In conclusion, HIPK1 inhibition may serve as a promising novel therapeutic strategy to attenuate pathological cardiac hypertrophy and heart failure.

TOP-EVs: Technology of Protein delivery through Extracellular Vesicles is a versatile platform for intracellular protein delivery

Extracellular vesicles (EVs) have emerged as biocompatible drug delivery vehicles due to their native ability to deliver bioactive cargo to recipient cells. However, the application of EVs as a therapeutic delivery vehicle is hampered by effective methods for endogenously loading target proteins inside EVs and unloading proteins after delivery to recipient cells. Most EV-based engineered loading methods have a limited delivery efficiency owing to their inefficient endosomal escape or cargo release from the intraluminal attachment from the EV membrane. Here, we describe the 'Technology Of Protein delivery through Extracellular Vesicles' (TOP-EVs) as a tool for efficient intracellular delivery of target proteins mediated via EVs. The vesicular stomatitis virus glycoprotein and the rapamycin-heterodimerization of the FKBP12/T82L mutant FRB proteins were both important for the effective protein delivery through TOP-EVs. We showed that TOP-EVs could efficiently deliver Cre recombinase and CRISPR/Cas9 ribonucleoprotein complex in vitro. Moreover, our results demonstrated that the capacity of TOP-EVs to deliver intracellular proteins in recipient cells was not an artifact of plasmid contamination or direct plasmid loading into EVs. Finally, we showed that TOP-EVs could successfully mediate intracellular protein delivery in the liver in vivo. Taken together, TOP-EVs are a versatile platform for efficient intracellular protein delivery in vitro and in vivo, which can be applied to advance the development of protein-based therapeutics.

Circular RNAs in cardiovascular diseases: regulation and therapeutic applications

Cardiovascular disease is one of the leading causes of mortality worldwide. Recent studies have shown that circular RNAs (circRNAs) have emerged as important players in the prevention and treatment of cardiovascular diseases. circRNAs are a class of endogenous noncoding RNAs that are generated by back-splicing and are involved in many pathophysiological processes. In this review, we outline the current research progress on the regulatory roles of circRNAs in cardiovascular diseases. Further, new technologies and methods available for identifying, validating, synthesizing, and analyzing circRNAs, as well as their applications in therapeutics, are highlighted here. Moreover, we summarize the increasing insights into the potential use of circRNAs as circulating diagnostic and prognostic biomarkers. Finally, we discuss the prospects and challenges of circRNA therapeutic applications for cardiovascular disease therapy, with a particular focus on developing circRNA synthesis and engineering delivery systems.

Small molecule-mediated rapid maturation of human induced pluripotent stem cell-derived cardiomyocytes

BACKGROUND

Human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs) do not display all hallmarks of mature primary cardiomyocytes, especially the ability to use fatty acids (FA) as an energy source, containing high mitochondrial mass, presenting binucleation and increased DNA content per nuclei (polyploidism), and synchronized electrical conduction. This immaturity represents a bottleneck to their application in (1) disease modelling-as most cardiac (genetic) diseases have a middle-age onset-and (2) clinically relevant models, where integration and functional coupling are key. So far, several methods have been reported to enhance iPSC-CM maturation; however, these protocols are laborious, costly, and not easily scalable. Therefore, we developed a simple, low-cost, and rapid protocol to promote cardiomyocyte maturation using two small molecule activators of the peroxisome proliferator-activated receptor β/δ and gamma coactivator 1-alpha (PPAR/PGC-1α) pathway: asiatic acid (AA) and GW501516 (GW). METHODS AND RESULTS: Monolayers of iPSC-CMs were incubated with AA or GW every other day for ten days resulting in increased expression of FA metabolism-related genes and markers for mitochondrial activity. AA-treated iPSC-CMs responsiveness to the mitochondrial respiratory chain inhibitors increased and exhibited higher flexibility in substrate utilization. Additionally, structural maturity improved after treatment as demonstrated by an increase in mRNA expression of sarcomeric-related genes and higher nuclear polyploidy in AA-treated samples. Furthermore, treatment led to increased ion channel gene expression and protein levels.

CONCLUSIONS

Collectively, we developed a fast, easy, and economical method to induce iPSC-CMs maturation via PPAR/PGC-1α activation. Treatment with AA or GW led to increased metabolic, structural, functional, and electrophysiological maturation, evaluated using a multiparametric quality assessment.

Evaluation and manipulation of tissue and cellular distribution of cardiac progenitor cell-derived extracellular vesicles

Cardiac progenitor cell-derived extracellular vesicles (CPC-EVs) have been successfully applied via different delivery routes for treating post-myocardial infarction injury in several preclinical models. Hence, understanding the in vivo fate of CPC-EVs after systemic or local, i.e. myocardial, delivery is of utmost importance for the further therapeutic application of CPC-EVs in cardiac repair. Here, we studied the tissue- and cell distribution and retention of CPC-EVs after intramyocardial and intravenous injection in mice by employing different EV labeling and imaging techniques. In contrast to progenitor cells, CPC-EVs demonstrated no immediate flush-out from the heart upon intramyocardial injection and displayed limited distribution to other organs over time, as determined by near-infrared imaging in living animals. By employing CUBIC tissue clearing and light-sheet fluorescent microscopy, we observed CPC-EV migration in the interstitial space of the myocardium shortly after EV injection. Moreover, we demonstrated co-localization with cTnI and CD31-positive cells, suggesting their interaction with various cell types present in the heart. On the contrary, after intravenous injection, most EVs accumulated in the liver. To potentiate such a potential systemic cardiac delivery route, targeting the cardiac endothelium could provide openings for directed CPC-EV therapy. We therefore evaluated whether decorating EVs with targeting peptides (TPs) RGD-4C or CRPPR connected to Lamp2b could enhance EV delivery to endothelial cells. Expression of both TPs enhanced CPC-EV uptake under in vitro continuous flow, but did not affect uptake under static cell culture conditions. Together, these data demonstrate that the route of administration influences CPC-EV biodistribution pattern and suggest that specific TPs could be used to target CPC-EVs to the cardiac endothelium. These insights might lead to a better application of CPC-EV therapeutics in the heart.

Small molecule-mediated rapid maturation of human induced pluripotent stem cell derived cardiomyocytes

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Gravitation Program “Materials Driven Regeneration” by the Netherlands Organization for Scientific Research (RegmedXB #024.003.013) and the Marie Skłodowska-Curie Actions (Grant agreement RESCUE #801540). The EU-funded project BRAV3 (H2020, ID:874827)

Background

Human-induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs) do not display all hallmarks of mature human primary cardiomyocytes: the ability to use fatty acids as an energy source, high mitochondrial mass, increased nuclei polyploidism, synchronized electrical conduction, and forceful contractions. Instead, their phenotype is similar to immature cardiomyocytes in the late fetal stage. This immaturity represents a bottleneck to their application in 1) disease modeling – as most cardiac (genetic) diseases have a middle-age onset – and 2) clinical use, where integration and functional coupling are key. So far, the mainly used methods to enhance iPSC-CM maturation include prolonged time-in-culture, 3D culture, cyclic mechanical stretch, and electrical stimulation with specialized media. However, these protocols are laborious, costly, and not easily scalable.

Methods

In this study, we developed a simple, low cost, and rapid protocol using two peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A/PGC-1α) activating small molecules: Asiatic Acid (AA) and GW501516 (GW) to promote cardiomyocyte maturity by inducing a metabolic switch to fatty acid utilization and increased mitochondrial biogenesis.

Results

Monolayers of iPSC-CMs were incubated with AA and GW every other day for 10 days resulting in increased expression of fatty acid-metabolism-related genes (5 and 10-fold increase in CPT1B gene expression, respectively), mitochondria biogenesis (protein expression of ATP5A) and fusion (50 and 100-fold increase in OPA1 gene expression, respectively). In addition, AA treated iPSC-CMs responded in the seahorse mitochondria stress test more rapidly to an artificial increase in mitochondrial activity and showed a higher flexibility in substrate utilization in the seahorse stress test. A more mature electrophysiological functionality was shown by increased ion channel gene expression (KCNA4, SCN5A, GJA1, CACNA1C, and SCN1B) and enhanced synchronous contraction in treated samples. Moreover, maturation was further shown by increased sarcomeric gene expression (5 and 7-fold increase in TNNI3 in AA and GW respectively) and nuclear polyploidism (&gt;4N fold 2.16 and 1.48-fold increase in AA and GW respectively).

Conclusions

Collectively, these findings show that AA and GW trigger a metabolic switch and induce extensive maturation of iPSC-CMs, providing a rapid and cost-effective method to obtain iPSC-CMs that more closely resemble their adult counterparts.

E2F7/8 is involved in cardiomyocyte polyploidy but does not affect myocardial reperfusion injury recovery

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): CSC fellowship

Background

Polyploidy cells consist of more than two complete sets of homologous chromosomes. Although a characteristic feature of cardiomyocytes and observed in all mammalian species, its molecular mechanism and biological functions are still unknown. Cardiomyocytes polyploidy in rodents occurs mainly through incomplete cytokinesis and increases with age. Studies have demonstrated that E2F7/8 transcription factors are key regulators of polyploidy in the liver and pancreas, however, it remains unclear if E2F7/8 control the generation of polyploidy cardiomyocytes and what the functional consequence is post-myocardial infarction (MI).

Methods

By using a tamoxifen inducible Cre/LoxP approach in new-born mice, we deleted E2F7/8 transcription factors ubiquitously and evaluated the biological significance of postnatal E2F7/8 loss. Mice underwent myocardial ischemia reperfusion injury (IRI) and heart function was assessed by 4D-echocardiography. Cardiomyocyte nucleus polyploidy was measured by FACS and microscope.

Results

Deficiency of E2F7/8 significantly suppress cardiomyocyte mononucleated and multinucleated polyploidy, as well as dramatically decreased hepatocytes polyploidy. E2F7/8 defect also led to a decrease in cardiac stress related marker lever such as ANP, BNP, MMP2, β-MHC/α-MHC and an increase in CD31 expression level. Surprisingly, E2F7/8 deletion did not have impact on cardiac function and dimensions post-IRI.

Conclusion

In summary, we identified that E2F7/8 activity is involved in the cellular polyploidy in the heart but did not affect myocardial function after myocardial injury.

Myocardial tissue slices for modeling of the human PLN p.Arg14del associated cardiomyopathy

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): NWO - The Dutch Research Council

Background

Current in vivo preclinical models lack the predictability of the clinical efficacy resulting in a high dropout rate of therapeutic candidates. Advanced human-based models are required to bridge this gap and indicate the potential of novel therapeutic approaches[1].  Myocardial tissue slices are an in vitro model that recapitulates the native multicellular architecture of the heart. This allows for modeling cellular processes in a macroscopic context entailing great promise. The most common cardiomyopathy-related mutation in the Netherlands is the loss of arginine at position 14 (p.Arg14del) in the phospholamban protein (PLN). PLN is a critical regulator of calcium cycling and contractility in the heart. The p.Arg14del mutation results in a super inhibition of SERCA2a and thus aberrant calcium handling and reduced contractile force. Mice models harbouring the PLN p.Arg14del do not completely recapitulate the human manifestation mainly due to the difference between species; heart rate, Calcium-cycling and ion properties, and different myosin heavy chain isoforms, showing the unmet need for a human-based model[2,3].

Methods & Results

300 µm thick viable myocardial tissue were sectioned from a PLN p.Arg14del patient’s left ventricle. Although the myocardial tissue slices were kept alive for eight days in static culture, these conditions initiated cell death and dedifferentiation. The tissue slices show the greatest resemblance to the intact architecture of the in vivo human heart, it is the most relevant model for viral transduction in the human heart, and proof-of-principle of this is performed. Myocardial tissue slices of a PLN p.Arg14del patient retain the structural phenotype shown by the fibrofatty deposition. Similarly, functional patient characteristics, aberrant calcium handling, and reduced contractile force are preserved.

Conclusion

Myocardial tissue slices recapitulate the (patho)physiology of the heart, as shown here with the PLN p.Arg14del case. However, the static culture conditions induce remodeling of the heart and thus only allow for acute measures in the native heart. To prolong the period that the slices recapitulate the native heart, culture conditions should mimic the environment of the heart. The tissue slices allow for a currently unmet need to modulate the complex architecture of the human heart with e.g. novel delivery tools or therapeutic interventions. All in all, myocardial tissue slices are a promising model that can give novel insights into the physiology of the human heart, and therapeutic intervention on induced or genetic cardiomyopathies.

Extracellular vesicles enclosed-miR-421 suppresses air pollution (PM2.5 )-induced cardiac dysfunction via ACE2 signalling

Air pollution, via ambient PM_2.5, is a big threat to public health since it associates with increased hospitalisation, incidence rate and  mortality of cardiopulmonary injury. However, the potential mediators of pulmonary injury in PM_2.5‐induced cardiovascular disorder are not fully understood. To investigate a potential cross talk between lung and heart upon PM_2.5 exposure, intratracheal instillation in vivo, organ culture ex vivo and human bronchial epithelial cells (Beas‐2B) culture in vitro experiments were performed respectively. The exposed supernatants of Beas‐2B were collected to treat primary neonatal rat cardiomyocytes (NRCMs). Upon intratracheal instillation, subacute PM_2.5 exposure caused cardiac dysfunction, which was time‐dependent secondary to lung injury in mice, thereby demonstrating a cross‐talk between lungs and heart potentially mediated via small extracellular vesicles (sEV). We isolated sEV from PM_2.5‐exposed mice serum and Beas‐2B supernatants to analyse the change of sEV subpopulations in response to PM_2.5. Single particle interferometric reflectance imaging sensing analysis (SP‐IRIS) demonstrated that PM_2.5 increased CD63/CD81/CD9 positive particles. Our results indicated that respiratory system‐derived sEV containing miR‐421 contributed to cardiac dysfunction post‐PM_2.5 exposure. Inhibition of miR‐421 by AAV9‐miR421‐sponge could significantly reverse PM_2.5‐induced cardiac dysfunction in mice. We identified that cardiac angiotensin converting enzyme 2 (ACE2) was a downstream target of sEV‐miR421, and induced myocardial cell apoptosis and cardiac dysfunction. In addition, we observed that GW4869 (an inhibitor of sEV release) or diminazene aceturate (DIZE, an activator of ACE2) treatment could attenuate PM_2.5‐induced cardiac dysfunction in vivo. Taken together, our results suggest that PM_2.5 exposure promotes sEV‐linked miR421 release after lung injury and hereby contributes to PM_2.5‐induced cardiac dysfunction via suppressing ACE2.

Delivery of modified mRNA to damaged myocardium by systemic administration of lipid nanoparticles

Lipid Nanoparticles (LNPs) are a promising drug delivery vehicle for clinical siRNA delivery. Modified mRNA (modRNA) has recently gained great attention as a therapeutic molecule in cardiac regeneration. However, for mRNA to be functional, it must first reach the diseased myocardium, enter the target cell, escape from the endosomal compartment into the cytosol and be translated into a functional protein. However, it is unknown if LNPs can effectively deliver mRNA, which is much larger than siRNA, to the ischemic myocardium. Here, we evaluated the ability of LNPs to deliver mRNA to the myocardium upon ischemia-reperfusion injury functionally. By exploring the bio-distribution of fluorescently labeled LNPs, we observed that, upon reperfusion, LNPs accumulated in the infarct area of the heart. Subsequently, the functional delivery of modRNA was evaluated by the administration of firefly luciferase encoding modRNA. Concomitantly, a significant increase in firefly luciferase expression was observed in the heart upon myocardial reperfusion when compared to sham-operated animals. To characterize the targeted cells within the myocardium, we injected LNPs loaded with Cre modRNA into Cre-reporter mice. Upon LNP infusion, Tdtomato+ cells, derived from Cre mediated recombination, were observed in the infarct region as well as the epicardial layer upon LNP infusion. Within the infarct area, most targeted cells were cardiac fibroblasts but also some cardiomyocytes and macrophages were found. Although the expression levels were low compared to LNP-modRNA delivery into the liver, our data show the ability of LNPs to functionally deliver modRNA therapeutics to the damaged myocardium, which holds great promise for modRNA-based cardiac therapies.

MicroRNA-214-3p Ameliorates LPS-Induced Cardiomyocyte Injury by Inhibiting Cathepsin B

Myocardial injury is a common complication of sepsis. MicroRNA (miRNA) miR-214-3p is protective against myocardial injury caused by sepsis, but its mechanism in lipopolysaccharide (LPS)- induced cardiomyocyte injury is still unclear. An AC16 cell injury model was induced by LPS treatment. Cell Counting Kit-8 and flow cytometry assay showed decreased cell viability and increased apoptosis in LPS-treated AC16 cells. The levels of caspase- 3, Bax, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), myosin 6 (Myh6), myosin 7 (Myh7), reactive oxygen species (ROS), and malondialdehyde (MDA) were increased in LPS-treated AC16 cells, but the levels of Bcl-2 and superoxide dismutase (SOD) were decreased. MiR-214-3p was down-regulated and cathepsin B (CTSB) was upregulated in LPS-treated AC16 cells. At the same time, miR-214-3p could target CTSB and reduce its expression. We also found that a miR-214-3p mimic or CTSB silencing could significantly reduce LPSinduced apoptosis, decrease ROS, MDA, caspase-3, and Bax and increase SOD and Bcl-2. CTSB silencing could significantly reduce ANP, BNP, Myh6, and Myh7 in LPS-treated AC16 cells. The effects of CTSB silencing were reversed by a miR-214-3p inhibitor. In summary, miR-214-3p could inhibit LPSinduced myocardial injury by targeting CTSB, which provides a new idea for myocardial damage caused by sepsis.

Onset of inverse magnetic energy transfer in collisionless turbulent plasmas

Inverse magnetic energy transfer from small to large scales is a key physical process for the origin of large-scale strong magnetic fields in the universe. However, so far, from the magnetohydrodynamic perspective, the onset of inverse transfer is still not fully understood, especially the underlying dynamics. Here, we use both two-dimensional and three-dimensional particle-in-cell simulations to show the self-consistent dynamics of inverse transfer in collisionless decaying turbulent plasmas. Using the space filtering technique in theory and numerical analyses, we identify magnetic reconnection as the onset and fundamental drive for inverse transfer, where, specifically, the subscale electromotive force driven by magnetic reconnection do work on the large-scale magnetic field, resulting in energy transfer from small to large scales. The mechanism is also verified by the strong correlations in locations and characteristic scales between inverse transfer and magnetic reconnection.

miR-132/212 Impairs Cardiomyocytes Contractility in the Failing Heart by Suppressing SERCA2a

Compromised cardiac function is a hallmark for heart failure, mostly appearing as decreased contractile capacity due to dysregulated calcium handling. Unfortunately, the underlying mechanism causing impaired calcium handling is still not fully understood. Previously the miR-132/212 family was identified as a regulator of cardiac function in the failing mouse heart, and pharmaceutically inhibition of miR-132 is beneficial for heart failure. In this study, we further investigated the molecular mechanisms of miR-132/212 in modulating cardiomyocyte contractility in the context of the pathological progression of heart failure. We found that upregulated miR-132/212 expressions in all examined hypertrophic heart failure mice models. The overexpression of miR-132/212 prolongs calcium decay in isolated neonatal rat cardiomyocytes, whereas cardiomyocytes isolated from miR-132/212 KO mice display enhanced contractility in comparison to wild type controls. In response to chronic pressure-overload, miR-132/212 KO mice exhibited a blunted deterioration of cardiac function. Using a combination of biochemical approaches and in vitro assays, we confirmed that miR-132/212 regulates SERCA2a by targeting the 3′-end untranslated region of SERCA2a. Additionally, we also confirmed PTEN as a direct target of miR-132/212 and potentially participates in the cardiac response to miR132/212. In end-stage heart failure patients, miR-132/212 is upregulated and correlates with reduced SERCA2a expression. The up-regulation of miR-132/212 in heart failure impairs cardiac contractile function by targeting SERCA2a, suggesting that pharmaceutical inhibition of miR-132/212 might be a promising therapeutic approach to promote cardiac function in heart failure patients.

Downregulated long noncoding RNA LUCAT1 inhibited proliferation and promoted apoptosis of cardiomyocyte via miR-612/HOXA13 pathway in chronic heart failure

OBJECTIVE

Long non-coding RNAs (lncRNAs) have been reported to play important roles in numerous kinds of cardiovascular disease, including chronic heart failure (CHF). In this study, we mainly focused on investigating the potential roles of lncRNA LUCAT1 patients with CHF.

PATIENTS AND METHODS

RT-PCR was used to detect the expressions of LUCAT1 and miR-612 in serum samples of CHF patients (n=60) and healthy volunteers. Relationships between the expressions of LUCAT1 and miR-612, LUCAT1 and overall survival (OS) were analyzed using the Kaplan-Meier method. Si-LUCAT1 and miR-612 mimic were constructed and respectively transfected into AC16 cells to explore the functions of LUCAT1 and miR-612. Cell proliferation abilities were detected by CCK-8 assay AC16 cells. Cell apoptotic rates were measured by flow cytometry (FACS) analysis. Western blot (WB) was performed to detect the protein levels of HOXA13, Bcl-2, Bax, Bad and Cleaved Caspase3. In addition, luciferase gene reporter assay was used to prove the relationships between LUCAT1 and miR-612, miR-612 and HOXA13.

RESULTS

Firstly, we found that LUCAT1 was decreased for 1.7 folds in CHF patients, which was correlated with poor prognosis patients. LUCAT1 repression inhibited cell proliferation and promoted cell apoptosis in human cardiomyocyte cell line AC16 cells. Furthermore, we found that miR-612 was increased for 2.0 folds in CHF patients, which was negatively interacted with LUCAT1 expression. Luciferase gene reporter assay demonstrated that LUCAT1 could directly bind with miR-612 in AC16 cells. Moreover, miR-612 overexpression also inhibited cell proliferation and promoted cell apoptosis in AC16 cells. Luciferase reporter assay indicated that miR-612 could directly target at HOXA13 in AC16 cells, which was associated with cell proliferation and apoptosis. Finally, miR-612 inhibitor was transfected into AC16 cells with si-LUCAT1. The results showed that the inhibited cell proliferation and promoted cell apoptosis were reversed, which confirmed that LUCAT1 repression inhibited cell proliferation and promoted apoptosis via miR-612/HOXA13 axis in CHF patients.

CONCLUSIONS

According to the above results, our study revealed that LUCAT1 was decreased in CHF patients, which was correlated with poor prognosis of CHF patients. Furthermore, the downregulation of LUCAT1 inhibited cell proliferation and promoted cell apoptosis via targeting miR-612/HOXA13 axis. Our results elucidated a potential mechanism underlying cardiomyocyte apoptosis, which might be used as a promising prognostic marker and a potential target for CHF patients.

Structure and thermal properties of beeswax-based oleogels with different types of vegetable oil

Beeswax-based oleogels with different types of vegetable oil, including camellia oil (CO), soybean oil (SO), sunflower oil (SFO), or flaxseed oil (FO), were prepared and their structure and thermal properties were evaluated. The critical concentration of oleogel obtained from each of CO, SO, and SFO at 25 °C was 3% (w/w), and that from FO was 4%. Thermal measurements revealed similar thermodynamic curves for oleogels in different lipid phases. X-Ray diffraction showed orthorhombic perpendicular subcell packing and characteristic peaks of the β’ form. Furthermore, a morphology analysis of the crystals showed that they were needle shaped. Fourier transform-infrared spectra revealed that beeswax-based oleogels were formed via non-covalent bonds and may be stabilized with physical entanglements. The oleogels showed oil type-dependent oxidative abilities, but they were all stable and showed no obvious changes in peroxide value during 90 days of storage at 5 °C.

Repairing the heart: State-of the art delivery strategies for biological therapeutics

Myocardial infarction (MI) is one of the leading causes of mortality worldwide. It is caused by an acute imbalance between oxygen supply and demand in the myocardium, usually caused by an obstruction in the coronary arteries. The conventional therapy is based on the application of (a combination of) anti-thrombotics, reperfusion strategies to open the occluded artery, stents and bypass surgery. However, numerous patients cannot fully recover after these interventions. In this context, new therapeutic methods are explored. Three decades ago, the first biologicals were tested to improve cardiac regeneration. Angiogenic proteins gained popularity as potential therapeutics. This is not straightforward as proteins are delicate molecules that in order to have a reasonably long time of activity need to be stabilized and released in a controlled fashion requiring advanced delivery systems. To ensure long-term expression, DNA vectors-encoding for therapeutic proteins have been developed. Here, the nuclear membrane proved to be a formidable barrier for efficient expression. Moreover, the development of delivery systems that can ensure entry in the target cell, and also correct intracellular trafficking towards the nucleus are essential. The recent introduction of mRNA as a therapeutic entity has provided an attractive intermediate: prolonged but transient expression from a cytoplasmic site of action. However, protection of the sensitive mRNA and correct delivery within the cell remains a challenge. This review focuses on the application of synthetic delivery systems that target the myocardium to stimulate cardiac repair using proteins, DNA or RNA.

Cellular and Molecular Mechanism of Cardiac Regeneration: A Comparison of Newts, Zebrafish, and Mammals

Cardiovascular disease is the leading cause of death worldwide. Current palliative treatments can slow the progression of heart failure, but ultimately, the only curative treatment for end-stage heart failure is heart transplantation, which is only available for a minority of patients due to lack of donors' hearts. Explorative research has shown the replacement of the damaged and lost myocardium by inducing cardiac regeneration from preexisting myocardial cells. Lower vertebrates, such as the newt and zebrafish, can regenerate lost myocardium through cardiomyocyte proliferation. The preexisting adult cardiomyocytes replace the lost cells through subsequent dedifferentiation, proliferation, migration, and re-differentiation. Similarly, neonatal mice show complete cardiac regeneration post-injury; however, this regenerative capacity is remarkably diminished one week after birth. In contrast, the adult mammalian heart presents a fibrotic rather than a regenerative response and only shows signs of partial pathological cardiomyocyte dedifferentiation after injury. In this review, we explore the cellular and molecular responses to myocardial insults in different adult species to give insights for future interventional directions by which one can promote or activate cardiac regeneration in mammals.

Oscillatory surface deformation of paramagnetic rare-earth solutions driven by an inhomogeneous magnetic field

The deformation of the free surface of a paramagnetic liquid subjected to a nonuniform magnetic field is studied. A transient deformation of the surface caused by the interplay of gravity, magnetic field, and surface tension is observed when a permanent magnet is moved vertically downward to the free surface of the liquid. Different concentrations of rare-earth-metal salt (DyCl_{3}) are used and different magnet velocities are studied. The deformation of the interface is followed optically by means of a microscope and recorded with a high-speed camera. The experimental results are compared and discussed with complementary numerical simulations. Detailed results are given for the static shape of the deformed surface and the temporal evolution of the surface deformation below the center of the magnet. The frequency of the surface oscillations is found to depend on the concentration of the salt and is compared with analytical findings. Finally, a potential application of the effects observed is presented.

Improvement of gibberellin production by a newly isolated Fusarium fujikuroi mutant

AIMS

To obtain and investigate the potential mechanism for GA₃ production in Fusarium fujikuroi GA-251, a high GA₃ producer.

METHODS AND RESULTS

Fusarium fujikuroi IMI 58289 was bred with Cobalt-60 (⁶⁰ Co) radiation and lithium chloride treatment. The best mutant strain GA-251 was obtained for the subsequent optimization of fermentation conditions. The yield of GA₃ by GA-251 was 2100 mg l^-1 , while the wild-type strain was 100 mg l^-1 , which is a 21-fold increase in the yield. To elucidate the mechanism of high GA₃ yield of GA-251, the genome was sequenced and compared with wild-type strain IMI 58289. The results showed 2295 single nucleotide polymorphisms, 1242 small indels and 30 structural variants. These mutations were analysed and enriched in the MAPK signalling pathway, the mRNA surveillance pathway and endocytosis. The potential reasons for the improved GA₃ biosynthesis were investigated.

CONCLUSIONS

The potential mechanism of high GA₃ yield was attributed to endocytosis pathway and histone modification proteins family.

SIGNIFICANCE AND IMPACT OF THE STUDY

A mutant strain GA-251 in this work that could potentially be utilized in the industrial yield of GA₃ . The comparative genome analysis would shed light onto the mechanism of yield improvement and be a theoretical guide for further metabolic engineering.

Loss of miR-132/212 Has No Long-Term Beneficial Effect on Cardiac Function After Permanent Coronary Occlusion in Mice

Background: Myocardial infarction (MI) is caused by occlusion of the coronary artery and induces ischemia in the myocardium and eventually a massive loss in cardiomyocytes. Studies have shown many factors or treatments that can affect the healing and remodeling of the heart upon infarction, leading to better cardiac performance and clinical outcome. Previously, miR-132/212 has been shown to play an important role in arteriogenesis in a mouse model of hindlimb ischemia and in the regulation of cardiac contractility in hypertrophic cardiomyopathy in mice. In this study, we explored the role of miR-132/212 during ischemia in a murine MI model.

Methods and Results: miR-132/212 knockout mice show enhanced cardiac contractile function at baseline compared to wild-type controls, as assessed by echocardiography. One day after induction of MI by permanent occlusion, miR-132/212 knockout mice display similar levels of cardiac damage as wild-type controls, as demonstrated by infarction size quantification and LDH release, although a trend toward more cardiomyocyte cell death was observed in the knockout mice as shown by TUNEL staining. Four weeks after MI, miR-132/212 knockout mice show no differences in terms of cardiac function, expression of cardiac stress markers, and fibrotic remodeling, although vascularization was reduced. In line with these in vivo observation, overexpression of miR-132 or miR-212 in neonatal rat cardiomyocyte suppress hypoxia induced cardiomyocyte cell death.

Conclusion: Although we previously observed a role in collateral formation and myocardial contractility, the absence of miR-132/212 did not affect the overall myocardial performance upon a permanent occlusion of the coronary artery. This suggests an interplay of different roles of this miR-132/212 before and during MI, including an inhibitory effect on cell death and angiogenesis, and a positive effect on cardiac contractility and autophagic response. Thus, spatial or tissue specific manipulation of this microRNA family may be essential to fully understand the roles and to develop interventions to reduce infarct size.

Biofabrication of Cell-Derived Nanovesicles: A Potential Alternative to Extracellular Vesicles for Regenerative Medicine

Extracellular vesicles (EVs) are mediators of intercellular communication by transferring functional biomolecules from their originating cells to recipient cells. This intrinsic ability has gained EVs increased scientific interest in their use as a direct therapeutic in the field of regenerative medicine or as vehicles for drug delivery. EVs derived from stem cells or progenitor cells can act as paracrine mediators to promote repair and regeneration of damaged tissues. Despite substantial research efforts into EVs for various applications, their use remains limited by the lack of highly efficient and scalable production methods. Here, we present the biofabrication of cell-derived nanovesicles (NVs) as a scalable, efficient, and cost-effective production alternative to EVs. We demonstrate that NVs have a comparable size and morphology as EVs, but lack standard EV (surface) markers. Additionally, in vitro uptake experiments show that human fetal cardiac fibroblast, endothelial cells, and cardiomyocyte progenitor cells internalize NVs. We observed that cardiac progenitor cell-derived NVs and EVs are capable of activating mitogen-activated protein kinase 1/2 (MAPK1/2)-extracellular signal-regulated kinase, and that both NVs and EVs derived from A431 and HEK293 cells can functionally deliver Cre-recombinase mRNA or protein to other cells. These observations indicate that NVs may have similar functional properties as EVs. Therefore, NVs have the potential to be applied for therapeutic delivery and regenerative medicine purposes.

Injectable Supramolecular Ureidopyrimidinone Hydrogels Provide Sustained Release of Extracellular Vesicle Therapeutics

Extracellular vesicles (EVs) are small vesicles secreted by cells and have gained increasing interest as both drug delivery vehicles or as cell-free therapeutics for regenerative medicine. To achieve optimal therapeutic effects, strategies are being developed to prolong EV exposure to target organs. One promising approach to achieve this is through EV-loaded injectable hydrogels. In this study, the use of a hydrogel based on ureido-pyrimidinone (UPy) units coupled to poly(ethylene glycol) chains (UPy-hydrogel) is examined as potential delivery platform for EVs. The UPy-hydrogel undergoes a solution-to-gel transition upon switching from a high to neutral pH, allowing immediate gelation upon administration into physiological systems. Here, sustained EV release from the UPy-hydrogel measured over a period of 4 d is shown. Importantly, EVs retain their functional capacity after release. Upon local administration of fluorescently labeled EVs incorporated in a UPy-hydrogel in vivo, EVs are still detected in the UPy-hydrogel after 3 d, whereas in the absence of a hydrogel, EVs are internalized by fat and skin tissue near the injection site. Together, these data demonstrate that UPy-hydrogels provide sustained EV release over time and enhance local EV retention in vivo, which could contribute to improved therapeutic efficacy upon local delivery and translation toward new applications.

Rosehip Oil Promotes Excisional Wound Healing by Accelerating the Phenotypic Transition of Macrophages

Poor wound healing is a major and global threat to public health. Efforts have been made to better understand the underlying mechanisms and develop effective remedies, though the advancements that have been made are still limited. As there are no effective and generally applicable therapies available for skin injuries and fibrosis, it is urgent to develop new drugs and therapies that facilitate wound healing and effectively improve scars. In this study, GC-MS analysis was performed to identify the chemical composition of rosehip oil. The excisional wound healing model and the carrageenan-induced paw edema method were respectively applied to evaluate the wound healing activity and anti-inflammatory activity of rosehip oil. Hematoxylin and eosin staining was used to assess the pathological changes of sections, and Sirius-red staining was performed to analyze the ratio of collagen I/III in wound tissues. Immunohistological staining for CD68, CCR7 (CD197), CD163, TGF-β1, and α-SMA was applied to determine the macrophage phenotypes transition (M1-to-M2) and demonstrate the scar-improving efficacy of rosehip oil on wound healing. Results showed that rosehip oil significantly promoted wound healing and effectively improved scars. This efficacy might be exerted by accelerating the macrophage phenotypes transition and inhibiting the process of epithelial-mesenchymal transition.

Engineering CRISPR/Cpf1 with tRNA promotes genome editing capability in mammalian systems

CRISPR/Cpf1 features a number of properties that are distinct from CRISPR/Cas9 and provides an excellent alternative to Cas9 for genome editing. To date, genome engineering by CRISPR/Cpf1 has been reported only in human cells and mouse embryos of mammalian systems and its efficiency is ultimately lower than that of Cas9 proteins from Streptococcus pyogenes. The application of CRISPR/Cpf1 for targeted mutagenesis in other animal models has not been successfully verified. In this study, we designed and optimized a guide RNA (gRNA) transcription system by inserting a transfer RNA precursor (pre-tRNA) sequence downstream of the gRNA for Cpf1, protecting gRNA from immediate digestion by 3'-to-5' exonucleases. Using this new gRNAtRNA system, genome editing, including indels, large fragment deletion and precise point mutation, was induced in mammalian systems, showing significantly higher efficiency than the original Cpf1-gRNA system. With this system, gene-modified rabbits and pigs were generated by embryo injection or somatic cell nuclear transfer (SCNT) with an efficiency comparable to that of the Cas9 gRNA system. These results demonstrated that this refined gRNAtRNA system can boost the targeting capability of CRISPR/Cpf1 toolkits.

MMISH: Multicolor microRNA in situ hybridization for paraffin embedded samples

•

A robust, sensitive and flexible multicolor miRNA in situ hybridization (MMISH) technique for paraffin embedded sections can be combined with both immunohistochemical and immunofluorescent staining.

•

Usage of urea in our buffers which enhances the target-probe affinity by preventing intermolecular interaction within miRNAs or individual probes, and by reversing the EDC fixation induced epitope loss by denaturing the antigens, less toxic compared to toxic formamide.

•

Second, it can be combined with immunofluorescent stainings, which allows one to analyze the expression and precise (sub)cellular location of the miRNA of interest.

To understand and assess the roles of miRNAs, visualization of the expression patterns of specific miRNAs is needed at the cellular level in a wide variety of different tissue types. Although miRNA in situ hybridization techniques have been greatly improved in recent years, they remain difficult to routinely perform due to the complexity of the procedure. In addition, as it is crucial to define which tissues or cells are expressing a particular miRNA in order to elucidate the biological function of the miRNA, incorporation of additional stainings for different cellular markers is necessary. Here, we describe a robust and flexible multicolor miRNA in situ hybridization (MMISH) technique for paraffin embedded sections. We show that the miRNA in situ protocol is sensitive and highly specific and can successfully be combined with both immunohistochemical and immunofluorescent stainings.