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Fibroblasts can be reprogrammed into cardiovascular progenitor cells (CPCs) using transgenic approaches, although the underlying mechanism remains unclear. We determined whether activation of endogenous genes such as Gata4, Nkx2.5, and Tbx5 can rapidly establish autoregulatory loops and initiate CPC generation in adult extracardiac fibroblasts using a CRISPR activation system. The induced fibroblasts (>80%) showed phenotypic changes as indicated by an Nkx2.5 cardiac enhancer reporter. The progenitor characteristics were confirmed by colony formation and expression of cardiovascular genes. Cardiac sphere induction segregated the early and late reprogrammed cells that can generate functional cardiomyocytes and vascular cells in vitro. Therefore, they were termed CRISPR-induced CPCs (ciCPCs). Transcriptomic analysis showed that cell cycle and heart development pathways were important to accelerate CPC formation during the early reprogramming stage. The CRISPR system opened the silenced chromatin locus, thereby allowing transcriptional factors to access their own promoters and eventually forming a positive feedback loop. The regenerative potential of ciCPCs was assessed after implantation in mouse myocardial infarction models. The engrafted ciCPCs differentiated into cardiovascular cells in vivo but also significantly improved contractile function and scar formation. In conclusion, multiplex gene activation was sufficient to drive CPC reprogramming, providing a new cell source for regenerative therapeutics.

In this work, the different selectivity of SO

The efficiency and mechanism of heterogeneous catalytic O

A series of investigations have been carried out to study the decomposition of methylene blue (MB) by the VUV/UVC based AOPs. However, MB degradation by VUV/UVC direct photolysis has not been reported previously. For the first time, the degradation kinetics and mechanisms of methylene blue by a chemical-free technology VUV/UVC (185 nm/254 nm) irradiation were systematically investigated in bench scale. Firstly, we investigated the impact of reaction conditions (i.e., VUV power, temperature, initial pH, and initial MB concentration on the VUV/UVC irradiation process. We found that MB degradation by VUV/UVC irradiation is an endothermic reaction, and the apparent activation energy was calculated to be 14.72 kJ·mol-1, which is similar UVC/TiO2 and electrical discharge plasma system, while higher VUV power and lower initial MB concentration have enhancement effects. The degradation rate constant was a convex function of the solution pH and reached the optimal value at pH 9.19. Compared with VUV/UVC irradiation and UVC/H2O2 processes, hydroxyl radical (·OH) plays the dominated role in VUV/UVC irradiation system, while both ·OH and HO2· contribute to conventional UVC/H2O2 process. The degradation pathways were proposed including demethylation and chromophores oxidation, and the possible pathway was confirmed by combining the experimental observations with the density functional theory (DFT) calculation. In summary, this study provides the results that VUV/UVC is an effective and chemical-free technology for MB removal from water.

The DNA-dependent protein kinase (DNA-PK), which comprises the KU heterodimer and a catalytic subunit (DNA-PKcs), is a classical non-homologous end-joining (cNHEJ) factor1. KU binds to DNA ends, initiates cNHEJ, and recruits and activates DNA-PKcs. KU also binds to RNA, but the relevance of this interaction in mammals is unclear. Here we use mouse models to show that DNA-PK has an unexpected role in the biogenesis of ribosomal RNA (rRNA) and in haematopoiesis. The expression of kinase-dead DNA-PKcs abrogates cNHEJ2. However, most mice that both expressed kinase-dead DNA-PKcs and lacked the tumour suppressor TP53 developed myeloid disease, whereas all other previously characterized mice deficient in both cNHEJ and TP53 expression succumbed to pro-B cell lymphoma3. DNA-PK autophosphorylates DNA-PKcs, which is its best characterized substrate. Blocking the phosphorylation of DNA-PKcs at the T2609 cluster, but not the S2056 cluster, led to KU-dependent defects in 18S rRNA processing, compromised global protein synthesis in haematopoietic cells and caused bone marrow failure in mice. KU drives the assembly of DNA-PKcs on a wide range of cellular RNAs, including the U3 small nucleolar RNA, which is essential for processing of 18S rRNA4. U3 activates purified DNA-PK and triggers phosphorylation of DNA-PKcs at T2609. DNA-PK, but not other cNHEJ factors, resides in nucleoli in an rRNA-dependent manner and is co-purified with the small subunit processome. Together our data show that DNA-PK has RNA-dependent, cNHEJ-independent functions during ribosome biogenesis that require the kinase activity of DNA-PKcs and its phosphorylation at the T2609 cluster.

CeO2-AgI, synthesized via depositing AgI nanoparticles onto CeO2 nanorods, was utilized for bacterial disinfection and organic contaminant degradation. Escherichia coli (E. coli) and Bisphenol A (BPA) were used as the model bacteria and emerging organic contaminant to test the photocatalytic activity of CeO2-AgI, respectively. Results showed that CeO2-AgI with the optimal AgI content exhibited superior photocatalytic activity over pure CeO2 or AgI for both inactivation of E. coli cells and BPA removal. However, the photocatalytic mechanisms for E. coli inactivation and BPA degradation were different. Specifically, the photo-generated holes (h+), photo-generated electrons (e−) and superoxide radicals ( O2−) were the dominated active species for E. coli inactivation, whereas, BPA degradation relied on the generation of O2− and e−. Cell membrane disruption was found to be the main disinfection mechanism. The decomposition of BPA was clarified by detecting the degradation intermediates by LC–MS and DFT calculation. The facile synthesized CeO2-AgI exhibited good photocatalytic stability in four reused cycles and thus could be potentially applied to purify water.

Heart transplantation continues to be the gold standard clinical intervention to treat patients with end-stage heart failure. However, there are major complications associated with this surgical procedure that reduce the survival prognosis of heart transplant patients, including allograft rejection, malignancies, infections, and other complications that arise from the use of broad-spectrum immunosuppression drugs. Recent studies have demonstrated the use of mesenchymal stem cells (MSCs) against allotransplantation rejection in both in vitro and in vivo settings due to their immunomodulatory properties. Therefore, utilization of MSCs provides new and exciting strategies to improve heart transplantation and potentially reduce the use of broad-spectrum immunosuppression drugs while alleviating allograft rejection. In this review, we will discuss the current research on the mechanisms of cardiac allograft rejection, the physiological and immunological characteristics of MSCs, the effects of MSCs on the immune system, and immunomodulation of heart transplantation by MSCs.

Reactive oxygen species (ROS) have been implicated in mechanisms of heart development and regenerative therapies such as the use of pluripotent stem cells. The roles of ROS mediating cell fate are dependent on the intensity of stimuli, cellular context, and metabolic status. ROS mainly act through several targets (such as kinases and transcription factors) and have diverse roles in different stages of cardiac differentiation, proliferation, and maturation. Therefore, further detailed investigation and characterization of redox signaling will help the understanding of the molecular mechanisms of ROS during different cellular processes and enable the design of targeted strategies to foster cardiac regeneration and functional recovery. In this review, we focus on the roles of ROS in cardiac differentiation as well as transdifferentiation (direct reprogramming). The potential mechanisms are discussed in regard to ROS generation pathways and regulation of downstream targets. Further methodological optimization is required for translational research in order to robustly enhance the generation efficiency of cardiac myocytes through metabolic modulations. Additionally, we highlight the deleterious effect of the host’s ROS on graft (donor) cells in a paracrine manner during stem cell-based implantation. This knowledge is important for the development of antioxidant strategies to enhance cell survival and engraftment of tissue engineering-based technologies. Thus, proper timing and level of ROS generation after a myocardial injury need to be tailored to ensure the maximal efficacy of regenerative therapies and avoid undesired damage.

Background and Objective: CRISPR tools that allow for precise manipulation of individual loci have not been used in generation of i nduced c ardiac p rogenitor c ells ( iCPC s). This study was designed to determine the feasibility and effectiveness of reprogramming fibroblasts into iCPC using CRISPR activation (CRISPRa) system. Methods: Tail-tip fibroblasts (TTFs) were isolated from Nkx2-5 cardiac enhancer GFP reporter mice. A gRNA pool targeting 17 progenitor genes was synthesized and transduced with dCas9-VP64 lentivirus into TTFs ( Fig.1A ). The phenotype of iCPCs was then characterized by immunostaining and FACS of progenitor markers. Finally, the cardiac-lineage differentiation potential of iCPCs was determined by immunostaining and electrophysiological assay under defined induction mediums. Results: iCPCs with GFP expression were formed in TTFs after transduction of CRISPRa targeting Isl1, Gata4, Baf60c, Tbx5 and Nkx2-5 (Fig.1B), while GFP was not activated by control virus. Cardiac progenitor markers were activated in iCPCs as shown by immunostaining (Fig.1C). The generation efficiency of Flk1-postive iCPCs induced by CRISPRa was ~60% as showed by FACS. iCPCs can be differentiated into cardiomyocytes as identified by immunostaining of cardiac-specific markers (Fig.1D). The iCPC-derived cardiomyocytes displayed spontaneous beating and showed cardiac action potentials (Fig.1E). Conclusion: The CRISPRa system is an efficient and specific way to generate iCPCs, which could provide a novel source of cells for cardiac regenerative medicine. Conversion of fibroblasts into cardiac progenitors poses a novel therapeutic option for repair of myocardial infarction.

BiOI microspheres doped with different amounts of Ti were fabricated and used to remove diclofenac (DCF) from water under visible light irradiation. The fabricated photocatalysts were well characterized. Ti doped BiOI microspheres were found to exhibit higher photocatalytic activity towards DCF under visible light compared with BiOI. Ti doping broadened the band gap of BiOI, which leads to a more negative conduction band edge and a higher reducing activity of photo-generated electrons, thus facilitates ·O2− production during photocatalysis. Among all the fabricated Ti doped BiOI microspheres, TB450 exhibited the highest DCF photocatalytic removal efficiency. Specifically, 99.2% of DCF (C0 = 10 mg L−1) was removed by TB450 (250 mg L−1) at pH 5 within 90 min under visible light irradiation. Scavenger experiments indicated that active species including h+, ·O2− and H2O2 played important roles in the photocatalytic process. The degradation pathway of DCF was elucidated by theoretical density functional theory (DFT) and by-products identification through liquid chromatograph mass spectrometer (LC-MS) analysis. DCF degradation pathway mainly included hydroxylation and the cleavage of C N bond. DFT calculation can well interpret the degradation mechanism and the sites of DCF molecule with high radical-attack Fukui index (f0) exhibit high reactivity. Acidic condition was found to facilitate the DCF photocatalytic removal. Due to strong photo-stability, Ti doped BiOI microspheres contained good visible-light-driven (VLD) photocatalytic removal efficiency for DCF in the fourth consecutive reused cycle. Ti doped BiOI microspheres can be employed as a cost-effective and high-efficient material to efficiently degrade emerging contaminants (e.g., pharmaceutical) from wastewaters under visible light conditions.

Rural development, as one of the biggest challenges facing human beings recently, has attracted widely attention in the world, among which rural environment protection is essential for sustainable development. In response to the call to build “green livable villages”, the environmental monitoring and remediation in rural project (EMR-rural project) is launched. EMR-rural (2019 to 2022) is funded by the Ministry of Science and Technology of the People’s Republic of China (MOST). The project aims to develop key techniques and devices for contamination classification, risk assessment, pollution sources tracing and environmental remediation with regard to soil, underground and surface water quality in rural area. To this end, a new generation of physical, chemical and biological tools is integrated with intelligent management platform. The project follows a problem-oriented approach by in situ investigation, lab/pilot-scale mechanism exploration and field determination. EMR-rural takes advantage of the access to the applicable techniques and devices to investigate and to restore soil and water pollution in river network areas, mountainous areas as well as cold areas of China.

Oligodendrocytes (OLs) are the myelin-forming cells of the central nervous system. They are derived from differentiation of oligodendrocyte progenitors through a process requiring cell cycle exit and histone modifications. Here we identify the histone arginine methyl-transferase PRMT5, a molecule catalyzing symmetric methylation of histone H4R3, as critical for developmental myelination. PRMT5 pharmacological inhibition, CRISPR/cas9 targeting, or genetic ablation decrease p53-dependent survival and impair differentiation without affecting proliferation. Conditional ablation of Prmt5 in progenitors results in hypomyelination, reduced survival and differentiation. Decreased histone H4R3 symmetric methylation is followed by increased nuclear acetylation of H4K5, and is rescued by pharmacological inhibition of histone acetyltransferases. Data obtained using purified histones further validate the results obtained in mice and in cultured oligodendrocyte progenitors. Together, these results identify PRMT5 as critical for oligodendrocyte differentiation and developmental myelination by modulating the cross-talk between histone arginine methylation and lysine acetylation., Myelin-forming cells derive from oligodendrocyte progenitors. Here the authors identify histone arginine methyl-transferase PRMT5 as critical for developmental myelination by modulating the cross-talk between histone arginine methylation and lysine acetylation, to favor differentiation.

BiOBr-AgBr hybrid photocatalysts were synthesized via a facile precipitation and in-situ ion exchange method at room temperature. The as-synthesized photocatalysts were well characterized with different techniques. The disinfection activities of BiOBr-AgBr towards model bacterial strain Gram-negative Escherichia coli (E. coli) were tested under both dark and visible light irradiation conditions. 1 × 107 CFU/mL of E. coli cells could be completely inactivated by BiOBr-AgBr with the optimal silver amount (BiOBr-0.5AgBr) in 24 min under visible light irradiation, while 1.5 log CFU/mL decrease of viable cell density was achieved at the same experiment duration under dark condition. Obviously, with the visible light irradiation, the bactericidal efficiency BiOBr-0.5AgBr was significantly enhanced. The subsequent disinfection mechanism analysis showed that Ag+ released from BiOBr-0.5AgBr did not contribute to E. coli inactivation, while reactive oxygen species including h+, surfaced bounded OH, O2−, and H2O2 were found to play important roles in the disinfection process. The presence of dissolved O2 and the direct contact of cells with photocatalysts was found to be essential for the disinfection process. The reactive species induced the destruction of cell membrane, thus led to the death of bacteria. In addition, BiOBr-0.5AgBr exhibited good bactericidal activity within a wide pH range (5–9) and contained effective antibacterial activity even in fifth consecutive reuse cycles.

Many craniofacial disorders are caused by heterozygous mutations in general regulators of housekeeping cellular functions such as transcription or ribosome biogenesis1,2. Although it is understood that many of these malformations are a consequence of defects in cranial neural crest cells, a cell type that gives rise to most of the facial structures during embryogenesis3,4, the mechanism underlying cell-type selectivity of these defects remains largely unknown. By exploring molecular functions of DDX21, a DEAD-box RNA helicase involved in control of both RNA polymerase (Pol) I- and II-dependent transcriptional arms of ribosome biogenesis5, we uncovered a previously unappreciated mechanism linking nucleolar dysfunction, ribosomal DNA (rDNA) damage, and craniofacial malformations. Here we demonstrate that genetic perturbations associated with Treacher Collins syndrome, a craniofacial disorder caused by heterozygous mutations in components of the Pol I transcriptional machinery or its cofactor TCOF1 (ref. 1), lead to relocalization of DDX21 from the nucleolus to the nucleoplasm, its loss from the chromatin targets, as well as inhibition of rRNA processing and downregulation of ribosomal protein gene transcription. These effects are cell-type-selective, cell-autonomous, and involve activation of p53 tumour-suppressor protein. We further show that cranial neural crest cells are sensitized to p53-mediated apoptosis, but blocking DDX21 loss from the nucleolus and chromatin rescues both the susceptibility to apoptosis and the craniofacial phenotypes associated with Treacher Collins syndrome. This mechanism is not restricted to cranial neural crest cells, as blood formation is also hypersensitive to loss of DDX21 functions. Accordingly, ribosomal gene perturbations associated with Diamond-Blackfan anaemia disrupt DDX21 localization. At the molecular level, we demonstrate that impaired rRNA synthesis elicits a DNA damage response, and that rDNA damage results in tissue-selective and dosage-dependent effects on craniofacial development. Taken together, our findings illustrate how disruption in general regulators that compromise nucleolar homeostasis can result in tissue-selective malformations.

Bi2MoO6-AgBr hybrid photocatalyst was synthesized via a mixed solvothermal-precipitation method. The as-synthesized photocatalysts were well characterized by Powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopic (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX), high resolution transmission electron microscope (HRTEM), UV-vis diffuse reflectance spectra (DRS), as well as photoluminescence spectra (PL). The visible light driven (VLD) disinfection activity of Bi2MoO6-AgBr was tested using Escherichia coli as the model bacteria. Complete disinfection of 3×106 CFU mL-1 viable cell density was observed in 90min under visible light irradiation for Bi2MoO6-AgBr with the optimal AgBr amount. Ag+ released from the photocatalysts did not affect the inactivation process due to the low concentration. Whereas, photo-generated holes, H2O2 and O2- were the main active species involved in the photocatalytic disinfection reaction. The presence of O2 and direct contact between photocatalysts and bacterial cells were found to be indispensable for the cell inactivation. In addition, neutral and slight alkaline conditions was beneficial for the disinfection process.

Vacuum UV (VUV) has become a powerful tool for light-assisted advanced oxidation processes because it efficiently dissociates water to produce reactive oxygen species in situ. Heretofore, the performance and synergistic mechanism for emerging contaminants (ECs) removal by VUV/Fe2+/PS have not been reported. Compared with its sub-processes, integrated VUV/Fe2+/PS process can significantly accelerate the degradation and mineralization of three ECs. The synergistic factors of degradation of norfloxacin (NOR), sulfadiazine and tetracycline in VUV/Fe2+/PS process were 1.52, 1.62 and 2.70, respectively. The influence mechanisms of process parameters (PS and Fe2+ dose, initial pH) on the performance of VUV/Fe2+/PS were elaborated, and VUV/Fe2+/PS process can effectively remove NOR at wide pH range (3–10). Combining radical quenching experiments and characteristic substance capture experiments, hydroxyl radical (HO•), sulfate radical (SO4•-), singlet oxygen (1O2), and Fe(IV) were identified as main radical and non-radical species in VUV/Fe2+/PS process. The radical species dominated by HO• and SO4•- contributed more to the degradation of three ECs by VUV/Fe2+/PS (over 60%), and the non-radical species dominated by Fe(IV) and 1O2 also played an important role in ECs removal. Degradation by-products and pathways of NOR by VUV/Fe2+/PS were also investigated. Moreover, synergistic reaction pathways in VUV/Fe2+/PS process were proposed. Effects of water matrices on the performance of VUV/Fe2+/PS were also studied. The secondary wastewater was considered an ideal application scenario for VUV/Fe2+/PS process. All results clearly indicate that VUV/Fe2+/PS is a promising process for ECs removal.

g-C 3 N 4 -AgBr was synthesized by depositing AgBr nanoparticles onto g-C 3 N 4 . Scanning electron microscopy (SEM), Transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (DRS) and Photoluminescence (PL) spectra were employed to characterize the as-synthesized photocatalysts. The disinfection activities towards representative Gram-negative strain E. coli and Gram-positive strain S. aureus were examined under visible light irradiation. Complete inactivation of 3 × 10 6 CFU/mL viable cell density was reached in 60 min for E. coli and 150 min for S. aureus , respectively. Ag + released from the photocatalysts did not contribute to the photocatalytic disinfection process. Direct contact of g-C 3 N 4 -AgBr composites and bacterial cells, as well as the presence of O 2 was indispensable for the cell inactivation. Photo-generated holes, surface bounded OH, and indirect generation of intracellular active species played important roles in disinfection process of g-C 3 N 4 -AgBr under visible light irradiation. The disruption of outside structure of cells as well as inner cell injury led to the inactivation. High pH condition led to increasing the cell disinfection due to the generation of surface bounded OH.

The interplay of transcription and epigenetic marks is essential for oligodendrocyte progenitor cell (OPC) proliferation and differentiation during development. Here, we review the recent advances in this field and highlight mechanisms of transcriptional repression and activation involved in OPC proliferation, differentiation and plasticity. We also describe how dysregulation of these epigenetic events may affect demyelinating disorders, and consider potential ways to manipulate NG2 cell behavior through modulation of the epigenome. This article is part of a Special Issue entitled SI:NG2-glia(Invited only).

Herein, through supramolecular gel assisted pre-configuration, a novel bamboo-like porous graphitic carbon nitride (g-C3N4) deposited with single-atom Fe was successfully prepared and used for sulfite (S(IV)) activation. Unexpectedly, owing to the presence of single-atom Fe, hybrid material with only 2.5‰ of Fe exhibited 16 times higher S(IV) activation efficiency for diclofenac removal than pure g-C3N4 under visible light irradiation. Moreover, a synergetic effect of Fe and g-C3N4 was found to play the dominate role, and the synergetic factor was calculated to be 0.84. The synergetic mechanism mainly related to the generation of surface Fe-S(IV) complex, which could be affected by S(IV) species or the presence of H2PO4−. DCF removal was significantly enhanced at alkaline condition, but the enhancement was mainly attributed to photocatalysis but not synergetic effect. Decarboxylation, hydroxylation, chlorine abstraction and cleavages at bridging N atom were the main degradation pathways of DCF, which agreed well with Fukui index prediction. The toxicity of DCF was alleviated during the degradation process through successful mineralization of chlorine atoms.

Limited adult cardiac cell proliferation after cardiovascular disease, such as heart failure, hampers regeneration, resulting in a major loss of cardiomyocytes (CMs) at the site of injury. Recent studies in cellular reprogramming approaches have provided the opportunity to improve upon previous techniques used to regenerate damaged heart. Using these approaches, new CMs can be regenerated from differentiation of iPSCs (similar to embryonic stem cells), the direct reprogramming of fibroblasts [induced cardiomyocytes (iCMs)], or induced cardiac progenitors. Although these CMs have been shown to functionally repair infarcted heart, advancements in technology are still in the early stages of development in research laboratories. In this review, reprogramming-based approaches for generating CMs are briefly introduced and reviewed, and the challenges (including low efficiency, functional maturity, and safety issues) that hinder further translation of these approaches into a clinical setting are discussed. The creative and combined optimal methods to address these challenges are also summarized, with optimism that further investigation into tissue engineering, cardiac development signaling, and epigenetic mechanisms will help to establish methods that improve cell-reprogramming approaches for heart regeneration.

The DNA-dependent protein kinase (DNA-PK), which comprises the KU heterodimer and a catalytic subunit (DNA-PKcs), is a classical non-homologous end-joining (cNHEJ) factor

Pluripotent stem cells (PSCs) are an attractive, reliable source for generating functional cardiomyocytes for regeneration of infarcted heart. However, inefficient cell engraftment into host tissue remains a notable challenge to therapeutic success due to mechanical damage or relatively inhospitable microenvironment. Evidence has shown that excessively formed scar tissues around cell delivery sites present as mechanical and biological barriers that inhibit migration and engraftment of implanted cells. In this review, we focus on the functional responses of stem cells and cardiomyocytes during the process of cardiac fibrosis and scar formation. Survival, migration, contraction, and coupling function of implanted cells may be affected by matrix remodeling, inflammatory factors, altered tissue stiffness, and presence of electroactive myofibroblasts in the fibrotic microenvironment. Although paracrine factors from implanted cells can improve cardiac fibrosis, the transient effect is insufficient for complete repair of an infarcted heart. Furthermore, investigation of interactions between implanted cells and fibroblasts including myofibroblasts helps the identification of new targets to optimize the host substrate environment for facilitating cell engraftment and functional integration. Several antifibrotic approaches, including the use of pharmacological agents, gene therapies, microRNAs, and modified biomaterials, can prevent progression of heart failure and have been developed as adjunct therapies for stem cell-based regeneration. Investigation and optimization of new biomaterials is also required to enhance cell engraftment of engineered cardiac tissue and move PSCs from a laboratory setting into translational medicine.

Background and Objective: CRISPR tools that allow for precise manipulation of individual loci have not been used in generation of i nduced c ardiac p rogenitor c ells ( iCPC s). This study was designed to determine the feasibility and effectiveness of reprogramming fibroblasts into iCPC using CRISPR activation (CRISPRa) system. Methods: Tail-tip fibroblasts (TTFs) were isolated from Nkx2-5 cardiac enhancer GFP reporter mice. A gRNA pool targeting 17 progenitor genes was synthesized and transduced with dCas9-VP64 lentivirus into TTFs ( Fig.1A ). The phenotype of iCPCs was then characterized by immunostaining and FACS of progenitor markers. Finally, the cardiac-lineage differentiation potential of iCPCs was determined by immunostaining and electrophysiological assay under defined induction mediums. Results: iCPCs with GFP expression were formed in TTFs after transduction of CRISPRa targeting Isl1 , Gata4 , Baf60c , Tbx5 and Nkx2-5 (Fig.1B), while GFP was not activated by control virus. Cardiac progenitor markers were activated in iCPCs as shown by immunostaining (Fig.1C). The generation efficiency of Flk1-postive iCPCs induced by CRISPRa was ~60% as showed by FACS. iCPCs can be differentiated into cardiomyocytes as identified by immunostaining of cardiac-specific markers (Fig.1D). The iCPC-derived cardiomyocytes displayed spontaneous beating and showed cardiac action potentials (Fig.1E). Conclusion: The CRISPRa system is an efficient and specific way to generate iCPCs, which could provide a novel source of cells for cardiac regenerative medicine.

Citrullination, the deimination of arginine residues into citrulline, has been implicated in the aetiology of several diseases. In multiple sclerosis (MS), citrullination is thought to be a major driver of pathology, through hypercitrullination and destabilization of myelin. As such, inhibition of citrullination has been suggested as a therapeutic strategy for MS. Here, in contrast, we show citrullination by peptidylarginine deiminase 2 (PADI2) is required for normal oligodendrocyte differentiation, myelination and motor function. We identify several targets for PADI2, including myelin-related proteins and chromatin-associated proteins, implicating PADI2 in epigenetic regulation. Accordingly, we observe that PADI2 inhibition and its knockdown affect chromatin accessibility and prevent the upregulation of oligodendrocyte differentiation genes. Moreover, mice lacking PADI2, display motor dysfunction and decreased number of myelinated axons in the corpus callosum. We conclude that citrullination is required for oligodendrocyte lineage progression and myelination and suggest its targeted activation in the oligodendrocyte lineage might be beneficial in the context of remyelination.

The AgI/AgBr/BiOBr0.75I0.25 nanocomposites were synthesized by a solvothermal process, followed by an in-situ ion exchange reaction. The disinfection activities of the as-synthesized photocatalyst to model cell type, Gram-negative Escherichia coli (E. coli), were investigated under visible light irradiation condition (λ≥400 nm). Results showed that 80 mg/L AgI/AgBr/BiOBr0.75I0.25 could completely inactivate 3×10(7) CFU mL(-1)E. coli cells within 30 min under visible light irradiation. Moreover, the bactericidal mechanisms involved in the photocatalytic disinfection process were systematically investigated. Ag(+) ions released from the nanocomposites negligibly contributed to the bactericidal activity, while active species including h(+), e(-) and ·O2(-) played important roles in the disinfection system. Direct contact of bacterial cells and nanoparticles was found to be the prerequisite for both the generation of ·O2(-) and the disinfection processes. The disruption of cell membrane and emission of cytoplasm directly inactivated E. coli cells. In addition, AgI/AgBr/BiOBr0.75I0.25 exhibited strong antibacterial activity toward E. coli even in four consecutive reused cycles.

Functionalized magnetic nanoparticles have shown great application potentials in water treatment processes especially for bacterial removal. Antibacterial agent, cetyltrimethylammonium bromide (CTAB), was employed to modify Fe3O4 nanoparticles to fabricate bactericidal paramagnetic nanoparticles (Fe3O4@CTAB). The as-prepared Fe3O4@CTAB could effectively capture both Gram-negative Escherichia coli and Gram-positive Bacillus subtilis from water. For both cell types, more than 99% of bacteria with initial concentration of 1.5 × 10(7)CFU/mL could be inactivated by Fe3O4@CTAB (0.5 g/L) within 60 min. Fe3O4@CTAB could remove more than 99% of cells over a wide pH (from 3 to 10) and solution ionic strength range (from 0 to 1000 mM). The copresence of sulfate and nitrate did not affect the bacterial capture efficiencies, whereas, phosphate and silicate slightly decreased the bacterial removal rates. However, more than 91% and 81% of cells could be captured at 10mM of phosphate and silicate, respectively. Over 80% of cells could be removed even in the presence of 10mg/L of humic acid. Moreover, Fe3O4@CTAB exhibited good reusability, and greater than 83% of cells could be captured even in the fifth regeneration cycle. Fe3O4@CTAB prepared in this study have great application potentials for water disinfection.

The BiOI–AgI nanocomposites were synthesized by a solvothermal process, followed by an in-situ ion exchange reaction. The disinfection activities of BiOI–AgI on model cell type, Gram-negative Escherichia coli ( E. coli ), were examined under visible light irradiation conditions. BiOI–AgI could completely inactivate 5 × 10 7 CFU mL −1 E. coli cells in 18 min under visible light irradiation ( λ ⩾ 400 nm). The bactericidal mechanisms involved in this photocatalytic disinfection process were systematically investigated. Ag + ions released from the nanocomposites did not contribute to the bactericidal activity of BiOI–AgI. Active species including h + , O 2 − , e − , and H 2 O 2 generated by BiOI–AgI played important roles in the inactivation of bacteria. Direct contact of bacterial cells and nanoparticles was found to be essential for the disinfection processes. The destruction of cell membrane and emission of cytoplasm directly inactivated the cells. The influence of solution chemistry (pH and ionic strength) on disinfection process was also estimated. Low pH condition was found to be favorable for the inactivation process. High disinfection efficiencies were achieved at a wide range of solution ionic strength (0–1000 mM). The reusability of BiOI–AgI were also determined. BiOI–AgI exhibited strong antibacterial activity toward E. coli even in five consecutively reused cycles. This study indicated that the fabricated BiOI–AgI could be potentially utilized to disinfect bacteria in water (even with high salinity).

Au@TNBs nanocomposites were synthesized by depositing Au nanoparticles onto the surfaces of TiO2 nanobelts (TNBs). The disinfection activities of Au@TNBs on model cell type, Gram-negative Escherichia coli (E. coli), were examined under visible light irradiation conditions. Au@TNBs exhibited stronger bactericidal properties toward E. coli than those of TNBs and Au NPs under visible light irradiation. The bactericidal mechanisms of Au@TNBs under light conditions were explored, specifically, the specific active species controlling the inactivation of bacteria were determined. Active species (H2O2, diffusing ∙OH, ∙O2-, 1O2, and e-) generated by Au@TNBs were found to play important roles on the inactivation of bacteria. Moreover, the concentrations of H2O2, ·OH, ·O2-, and 1O2 generated in the antimicrobial system were estimated. Without the presence of active species, the direct contact of Au@TNBs with bacterial cells was found to have no bactericidal effect. The reusability of Au@TNBs were also determined. Au@TNBs exhibited strong antibacterial activity toward E. coli even in five consecutively reused cycles. This study indicated that the fabricated Au@TNBs could be potentially utilized to inactivate bacteria in water.

The goal of replenishing the cardiomyocyte (CM) population using regenerative therapies following myocardial infarction (MI) is hampered by the limited regeneration capacity of adult CMs, partially due to their withdrawal from the cell cycle. Here, we show that microRNA-128 (miR-128) is upregulated in CMs during the postnatal switch from proliferation to terminal differentiation. In neonatal mice, cardiac-specific overexpression of miR-128 impairs CM proliferation and cardiac function, while miR-128 deletion extends proliferation of postnatal CMs by enhancing expression of the chromatin modifier SUZ12, which suppresses p27 (cyclin-dependent kinase inhibitor) expression and activates the positive cell cycle regulators Cyclin E and CDK2. Furthermore, deletion of miR-128 promotes cell cycle re-entry of adult CMs, thereby reducing the levels of fibrosis, and attenuating cardiac dysfunction in response to MI. These results suggest that miR-128 serves as a critical regulator of endogenous CM proliferation, and might be a novel therapeutic target for heart repair., During early postnatal development in mammals, cardiomyocytes exit the cell cycle, losing their regenerative capacity. Here the authors show that, following myocardial infarction, loss of microRNA-128 promotes cardiomyocyte proliferation and cardiac regeneration in adult mice partly via enhancing the expression of the chromatin modifier SUZ12.

The chemokine (C-X-C motif) receptor 4 (CXCR4) is expressed on native cardiomyocytes and can modulate isolated cardiomyocyte contractility. This study examines the role of CXCR4 in cardiomyocyte response to ischaemia-reperfusion (I/R) injury. Isolated adult rat ventricular cardiomyocytes were subjected to hypoxia/reoxygenation (H/R) to simulate I/R injury. In response to H/R injury, the decrease in CXCR4 expression was associated with dysfunctional energy metabolism indicated by an increased adenosine diphosphate/adenosine triphosphate (ADP/ATP) ratio. CXCR4-overexpressing cardiomyocytes were used to determine whether such overexpression (OE) can prevent bio-energetic disruption-associated cell death. CXCR4 OE was performed with adenoviral infection with CXCR4 encoding-gene or non-translated nucleotide sequence (Control). The increased CXCR4 expression was observed in cardiomyocytes post CXCR4-adenovirus transduction and this OE significantly reduced the cardiomyocyte contractility under basal conditions. Although the same extent of H/R-provoked cytosolic calcium overload was measured, the hydrogen peroxide-induced decay of mitochondrial membrane potential was suppressed in CXCR4 OE group compared with control group, and the mitochondrial swelling was significantly attenuated in CXCR4 group, implicating that CXCR4 OE prevents permeability transition pore opening exposure to overload calcium. Interestingly, this CXCR4-induced mitochondrial protective effect is associated with the enhanced signal transducer and activator of transcription 3 (expression in mitochondria. Consequently, in the presence of H/R, mitochondrial dysfunction was mitigated and cardiomyocyte death was decreased to 65% in the CXCR4 OE group as compared with the control group. I/R injury leads to the reduction in CXCR4 in cardiomyocytes associated with the dysfunctional energy metabolism, and CXCR4 OE can alleviate mitochondrial dysfunction to improve cardiomyocyte survival.

Although resident cardiac stem cells have been reported, regeneration of functional cardiomyocytes (CMs) remains a challenge. The present study identifies an alternative progenitor source for CM regeneration without the need for genetic manipulation or invasive heart biopsy procedures. Unlike limb skeletal muscles, masseter muscles (MM) in the mouse head are developed from Nkx2-5 mesodermal progenitors. Adult masseter muscle satellite cells (MMSCs) display heterogeneity in developmental origin and cell phenotypes. The heterogeneous MMSCs that can be characterized by cell sorting based on stem cell antigen-1 (Sca1) show different lineage potential. While cardiogenic potential is preserved in Sca1(+) MMSCs as shown by expression of cardiac progenitor genes (including Nkx2-5), skeletal myogenic capacity is maintained in Sca1(−) MMSCs with Pax7 expression. Sca1(+) MMSC-derived beating cells express cardiac genes and exhibit CM-like morphology. Electrophysiological properties of MMSC-derived CMs are demonstrated by calcium transients and action potentials. These findings show that MMSCs could serve as a novel cell source for cardiomyocyte replacement.