The J bs-5YP peptide can alleviate dementia in senile mice by restoring the transcription of Slc40a1 to secrete the excessive iron from brain.

INTRODUCTION: With age and ATP decrease in the body, the transcription factors hypophosphorylation weakens the transcription of Slc40a1 and hinders the expression of the iron discharger ferroportin. This may lead to iron accumulation in the brain and the catalysis of free radicals that damage cerebral neurons and eventually lead to Alzheimer's disease (AD). OBJECTIVES: To prevent AD caused by brain iron excretion disorders and reveal the mechanism of J bs-5YP peptide restoring ferroportin. METHODS: We prepared J bs-YP peptide and administered it to the senile mice with dementia. Then, the intelligence of the mice was tested using a Morris Water Maze. The ATP content in the body was detected using the ATP hydrophysis and Phosphate precipitation method. The activation of Slc40a1 transcription was assayed with ATAC seq and the ferroportin, as well as the phosphorylation levels of Ets1 in brain were detected by Western Blot. RESULTS: The phosphorylation level of Ets1in brain was enhanced, and subsequently, the transcription of Slc40a1 was activated and ferroportin was increased in the brain, the levels of iron and free radicals were reduced, with the neurons protection, and the dementia was ultimately alleviated in the senile mice. CONCLUSION: J bs-5YP can recover the expression of ferroportin to excrete excessive iron in the brain of senile mice with dementia by enhancing the transcription of Slc40a1 via phosphorylating Ets1, revealing the potential of J bs-5YP as a drug to alleviate senile dementia.

Pichia kurtzmaniana f.a. sp. nov., with the transfer of eight Candida species to Pichia.

Three yeast strains belonging to the ascomycetous yeast genus Pichia were isolated from two soil samples from Yunnan and Guizhou provinces and a marine water sample from Liaoning province, PR China. Phylogenetic analyses based on the sequences of the D1/D2 domains of the large subunit(LSU) rRNA gene and the internal transcribed spacer (ITS) region indicate that these three strains, together with 12 additional strains isolated from various substrates collected in different regions or countries of the world, represent a novel species of the genus Pichia, for which the name Pichia kurtzmaniana sp. nov. (holotype: strain CGMCC 2.7213) is proposed. The novel species differs from its close relatives Candida californica by eight (1.5 %) and 26 (11.1 %) mismatches in the D1/D2 domains and the ITS region, respectively; and from Pichia chibodasensis by 11 (2.1 %) and 20 (8.7 %) mismatches in the D1/D2 domains and the ITS region, respectively. In addition, eight Candida species which belong to the Pichia clade are transferred to the genus Pichia, resulting in the proposal of the following new combinations: Pichia cabralensis comb. nov., Pichia californica comb. nov., Pichia ethanolica comb. nov., Pichia inconspicua comb. nov., Pichia phayaonensis comb. nov., Pichia pseudolambica comb. nov., Pichia rugopelliculosa comb. nov., and Pichia thaimueangensis comb. nov.

Immediate and delayed effects of environmental temperature on schizophrenia admissions in Liuzhou, China, 2013-2020: a time series analysis.

This study aimed to investigate the associations between environmental temperature and schizophrenia admissions in Liuzhou, China. A Poisson generalized linear model combined with a distributed lag nonlinear model was used to analyze the effects of daily mean temperature on schizophrenia admissions from 2013 to 2020 in Liuzhou. Additionally, subgroup analyses were conducted to investigate possible modifications stratified by gender, marital status, and age. In this study, 10,420 schizophrenia admissions were included. The relative risks of schizophrenia admissions increased as the temperature rose, and the lag effects of high temperature on schizophrenia admissions were observed when the daily mean temperature reached 21.65°C. The largest single effect was observed at lag0, while the largest cumulative effect was observed at lag6. The single effects of high temperatures on schizophrenia admissions were statistically significant in both males and females, but the cumulative effects were statistically significant only in males, with the greatest effect at lag0-7. The single effect of high temperatures on admissions for unmarried schizophrenics was greatest at lag5, while the maximum cumulative effect for unmarried schizophrenia was observed at lag0-7. The single effects of high temperatures on schizophrenia admissions were observed in those aged 0-20, 21-40, and 41-60. The cumulative effects for schizophrenics aged 21-40 were observed from lag0-3 to lag0-7, with the maximum effect at lag0-7. In conclusion, the risk of schizophrenia admissions increased as the environmental temperature increased. The schizophrenics who were unmarried appeared to be more vulnerable to the single and cumulative effects of high temperature.

Saturnispora sinensis sp. nov., a new ascomycetous yeast species from soil and rotten wood.

A yeast strain (CGMCC 2.6937T) belonging to the ascomycetous yeast genus Saturnispora was recently isolated from soil collected in Xinghuacun, Shanxi Province, PR China. The strain produces one or two ellipsoid or spherical ascospores in asci formed by the conjugation between a cell and its bud. Phylogenetic analyses of the internal transcribed spacer (ITS) region and the D1/D2 domain of the large subunit rRNA gene suggest that this strain is conspecific with strains NYNU 14639 isolated from rotten wood collected in Funiu Mountain, Henan province and ES13S05 from soil collected in Nantou County, Taiwan. The CGMCC 2.6937T group is most closely related to Saturnispora dispora and Saturnispora zaruensis. However, strain CGMCC 2.6937T differs from S. dispora by 17 (3.2 %, 13 substitutions and four gaps) and 77 (18.8 %, 52 substitutions and 25 gaps) mismatches, and from S. zaruensis by 15 (2.9 %, 12 substitutions and three gaps) and 64 (15.6 %, 44 substitutions and 20 gaps) mismatches, in the D1/D2 domain and ITS region, respectively. The results suggest that the CGMCC 2.6937T group represents an undescribed species in the genus Saturnispora, for which the name Saturnispora sinensis sp. nov. is proposed. The holotype strain is CGMCC 2.6937T.

Vishniacozyma pseudocarnescens sp. nov., a new anamorphic tremellomycetous yeast species.

Three strains belonging to the basidiomycetous yeast genus Vishniacozyma were isolated from marine water samples collected from intertidal zones in Liaoning province, northeast China. Phylogenetic analyses based on the sequences of the small subunit (SSU) ribosomal DNA (rDNA), the D1/D2 domain of the large subunit (LSU) ribosomal DNA (rDNA), the internal transcribed spacer region (ITS), the two subunits of DNA polymerase II (RPB1 and RPB2), the translation elongation factor 1-α (TEF1), and the mitochondrial gene cytochrome b (CYTB) showed that these strains together with 20 strains from various geographic and ecological origins from other regions of the world represent a novel species in the genus Vishniacozyma. We propose the name Vishniacozyma pseudocarnescens sp. nov. (holotype CGMCC 2.6457) for the new species, which differs phenotypically from its close relatives V. carnescens, V. tephrensis, and V. victoriae by its ability to grow at 30 °C and on 50 % (w/v) glucose-yeast extract agar.

Microbial communities and their correlation with flavor compound formation during the mechanized production of light-flavor Baijiu.

Light-flavor Baijiu fermentation is a typical spontaneous solid-state fermentation process fueled by a variety of microorganisms. Mechanized processes have been increasingly employed in Baijiu production to replace traditional manual operation processes, however, the microbiological and physicochemical dynamics in mechanized processes remain largely unknown. Here, we investigated the microbial community succession and flavor compound formation during a whole mechanized fermentation process of light-flavor Baijiu using the conventional dilution plating method, PacBio single-molecule real-time (SMRT) sequencing and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. The results showed that largely different fungal and bacterial communities were involved in the soaking and fermentation processes. A clear succession from Pantoea agglomerans to Bacillus (B.) smithii and B. coagulans in dominant bacterial species and from Cladosporium exasperatum to Saccharomyces cerevisiae and Lichtheimia ramosa in dominant fungal species occurred in the soaking processes. In the fermentation process, the most dominant bacterial species was shifted from Pantoea agglomerans to Lactobacillus (La.) acetotolerans and the most dominant fungal species were shifted from Lichtheimia ramose and Rhizopus arrhizus to Saccharomyces cerevisiae. The bacterial and fungal species positively associated with acidity and the formation of ethanol and different flavor compounds were specified. The microbial species exhibited strong co-occurrence or co-exclusion relationships were also identified. The results are helpful for the improvement of mechanized fermentation process of light-flavor Baijiu production.

CCND2 Modified mRNA Activates Cell Cycle of Cardiomyocytes in Hearts With Myocardial Infarction in Mice and Pigs.

BACKGROUND: Experiments in mammalian models of cardiac injury suggest that the cardiomyocyte-specific overexpression of CCND2 (cyclin D2, in humans) improves recovery from myocardial infarction (MI). The primary objective of this investigation was to demonstrate that our specific modified mRNA translation system (SMRTs) can induce CCND2 expression in cardiomyocytes and replicate the benefits observed in other studies of cardiomyocyte-specific CCND2 overexpression for myocardial repair. METHODS: The CCND2-cardiomyocyte-specific modified mRNA translation system (cardiomyocyte SMRTs) consists of 2 modRNA constructs: one codes for CCND2 and contains a binding site for L7Ae, and the other codes for L7Ae and contains recognition elements for the cardiomyocyte-specific microRNAs miR-1 and miR-208. Thus, L7Ae suppresses CCND2 translation in noncardiomyocytes but is itself suppressed by endogenous miR-1 and -208 in cardiomyocytes, thereby facilitating cardiomyocyte-specific CCND2 expression. Experiments were conducted in both mouse and pig models of MI, and control assessments were performed in animals treated with an SMRTs coding for the cardiomyocyte-specific expression of luciferase or green fluorescent protein (GFP), in animals treated with L7Ae modRNA alone or with the delivery vehicle, and in Sham-operated animals. RESULTS: CCND2 was abundantly expressed in cultured, postmitotic cardiomyocytes 2 days after transfection with the CCND2-cardiomyocyte SMRTs, and the increase was accompanied by the upregulation of markers for cell-cycle activation and proliferation (eg, Ki67 and Aurora B kinase). When the GFP-cardiomyocyte SMRTs were intramyocardially injected into infarcted mouse hearts, the GFP signal was observed in cardiomyocytes but no other cell type. In both MI models, cardiomyocyte proliferation (on day 7 and day 3 after treatment administration in mice and pigs, respectively) was significantly greater, left-ventricular ejection fractions (days 7 and 28 in mice, days 10 and 28 in pigs) were significantly higher, and infarcts (day 28 in both species) were significantly smaller in animals treated with the CCND2-cardiomyocyte SMRTs than in any other group that underwent MI induction. CONCLUSIONS: Intramyocardial injections of the CCND2-cardiomyocyte SMRTs promoted cardiomyocyte proliferation, reduced infarct size, and improved cardiac performance in small and large mammalian hearts with MI.

Microbial Community Affects Daqu Quality and the Production of Ethanol and Flavor Compounds in Baijiu Fermentation.

Daqu is a traditional starter for Baijiu fermentation and is produced by spontaneous fermentation of ground and moistened barley or wheat. The quality of Daqu is traditionally evaluated based on physicochemical and subjective sensory parameters without microbiological analysis. Here, we compared the physicochemical characteristics of qualified (QD) and inferior (ID) Daqu, their microbial communities based on plate counting and PacBio SMRT sequencing of rRNA gene libraries, and their impacts on Baijiu fermentation. The results showed that the glucoamylase and α-amylase activities of QD were significantly higher than those of ID. The counts of yeasts and relative abundances of functional microbes, especially the amylolytic bacterium Bacillus licheniformis and fungi Saccharomycopsis fibuligera and Lichtheimia ramosa, were significantly higher in QD than in ID. The laboratory-scale Baijiu fermentation tests showed that the relative abundances of the amylolytic microbes were higher in the QD than the ID fermentation set, resulting in more efficient fermentation, as indicated by more weight loss and higher moisture content in the former. Consequently, more glycerol, acetic acid, ethanol, and other volatile compounds were produced in the QD than in the ID fermentation set. The results suggest that Daqu quality is determined by, and can be evaluated based on, its microbial community.

Ascorbic acid induces MLC2v protein expression and promotes ventricular-like cardiomyocyte subtype in human induced pluripotent stem cells derived cardiomyocytes.

Introduction: The potentially unlimited number of cardiomyocyte (CMs) derived from human induced pluripotent stem cells (hiPSCs) in vitro facilitates high throughput applications like cell transplantation for myocardial repair, disease modelling, and cardiotoxicity testing during drug development. Despite promising progress in these areas, a major disadvantage that limits the use of hiPSC derived CMs (hiPSC-CMs) is their immaturity. Methods: Three hiPSC lines (PCBC-hiPSC, DP3-hiPSCs, and MLC2v-mEGFP hiPSC) were differentiated into CMs (PCBC-CMs, DP3-CMs, and MLC2v-CMs, respectively) with or without retinoic acid (RA). hiPSC-CMs were either maintained up to day 30 of contraction (D30C), or D60C, or purified using lactate acid and used for experiments. Purified hiPSC-CMs were cultured in basal maturation medium (BMM) or BMM supplemented with ascorbic acid (AA) for 14 days. The AA treated and non-treated hiPSC-CMs were characterized for sarcomeric proteins (MLC2v, TNNI3, and MYH7), ion channel proteins (Kir2.1, Nav1.5, Cav1.2, SERCA2a, and RyR), mitochondrial membrane potential, metabolomics, and action potential. Bobcat339, a selective and potent inhibitor of DNA demethylation, was used to determine whether AA promoted hiPSC-CM maturation through modulating DNA demethylation. Results: AA significantly increased MLC2v expression in PCBC-CMs, DP3-CMs, MLC2v-CMs, and RA induced atrial-like PCBC-CMs. AA treatment significantly increased mitochondrial mass, membrane potential, and amino acid and fatty acid metabolism in PCBC-CMs. Patch clamp studies showed that AA treatment induced PCBC-CMs and DP3-CMs adaptation to a ventricular-like phenotype. Bobcat339 inhibited MLC2v protein expression in AA treated PCBC-CMs and DP3-CMs. DNA demethylation inhibition was also associated with reduced TET1 and TET2 protein expressions and reduced accumulation of the oxidative product, 5 hmC, in both PCBC-CMs and DP3-CMs, in the presence of AA. Conclusions: Ascorbic acid induced MLC2v protein expression and promoted ventricular-like CM subtype in hiPSC-CMs. The effect of AA on hiPSC-CM was attenuated with inhibition of TET1/TET2 mediated DNA demethylation.

Analysis of cardiac single-cell RNA-sequencing data can be improved by the use of artificial-intelligence-based tools.

Single-cell RNA sequencing (scRNAseq) enables researchers to identify and characterize populations and subpopulations of different cell types in hearts recovering from myocardial infarction (MI) by characterizing the transcriptomes in thousands of individual cells. However, the effectiveness of the currently available tools for processing and interpreting these immense datasets is limited. We incorporated three Artificial Intelligence (AI) techniques into a toolkit for evaluating scRNAseq data: AI Autoencoding separates data from different cell types and subpopulations of cell types (cluster analysis); AI Sparse Modeling identifies genes and signaling mechanisms that are differentially activated between subpopulations (pathway/gene set enrichment analysis), and AI Semisupervised Learning tracks the transformation of cells from one subpopulation into another (trajectory analysis). Autoencoding was often used in data denoising; yet, in our pipeline, Autoencoding was exclusively used for cell embedding and clustering. The performance of our AI scRNAseq toolkit and other highly cited non-AI tools was evaluated with three scRNAseq datasets obtained from the Gene Expression Omnibus database. Autoencoder was the only tool to identify differences between the cardiomyocyte subpopulations found in mice that underwent MI or sham-MI surgery on postnatal day (P) 1. Statistically significant differences between cardiomyocytes from P1-MI mice and mice that underwent MI on P8 were identified for six cell-cycle phases and five signaling pathways when the data were analyzed via Sparse Modeling, compared to just one cell-cycle phase and one pathway when the data were analyzed with non-AI techniques. Only Semisupervised Learning detected trajectories between the predominant cardiomyocyte clusters in hearts collected on P28 from pigs that underwent apical resection (AR) on P1, and on P30 from pigs that underwent AR on P1 and MI on P28. In another dataset, the pig scRNAseq data were collected after the injection of CCND2-overexpression Human-induced Pluripotent Stem Cell-derived cardiomyocytes (CCND2hiPSC) into injured P28 pig heart; only the AI-based technique could demonstrate that the host cardiomyocytes increase proliferating by through the HIPPO/YAP and MAPK signaling pathways. For the cluster, pathway/gene set enrichment, and trajectory analysis of scRNAseq datasets generated from studies of myocardial regeneration in mice and pigs, our AI-based toolkit identified results that non-AI techniques did not discover. These different results were validated and were important in explaining myocardial regeneration.

Single-cell RNA sequencing analysis identifies one subpopulation of endothelial cells that proliferates and another that undergoes the endothelial-mesenchymal transition in regenerating pig hearts.

Background: In our previous work, we demonstrated that when newborn pigs undergo apical resection (AR) on postnatal day 1 (P1), the animals' hearts were completely recover from a myocardial infarction (MI) that occurs on postnatal day 28 (P28); single-nucleus RNA sequencing (snRNAseq) data suggested that this recovery was achieved by regeneration of pig cardiomyocyte subpopulations in response to MI. However, coronary vasculature also has a key role in promoting cardiac repair. Method: Thus, in this report, we used autoencoder algorithms to analyze snRNAseq data from endothelial cells (ECs) in the hearts of the same animals. Main results: Our results identified five EC clusters, three composed of vascular ECs (VEC1-3) and two containing lymphatic ECs (LEC1-2). Cells from VEC1 expressed elevated levels of each of five cell-cyclespecific markers (Aurora Kinase B [AURKB], Marker of Proliferation Ki-67 [MKI67], Inner Centromere Protein [INCENP], Survivin [BIRC5], and Borealin [CDCA8]), as well as a number of transcription factors that promote EC proliferation, while (VEC3 was enriched for genes that regulate intercellular junctions, participate in transforming growth factor ß (TGFß), bone morphogenic protein (BMP) signaling, and promote the endothelial mesenchymal transition (EndMT). The remaining VEC2 did not appear to participate directly in the angiogenic response to MI, but trajectory analyses indicated that it may serve as a reservoir for the generation of VEC1 and VEC3 ECs in response to MI. Notably, only the VEC3 cluster was more populous in regenerating (i.e., ARP1MIP28) than non-regenerating (i.e., MIP28) hearts during the 1-week period after MI induction, which suggests that further investigation of the VEC3 cluster could identify new targets for improving myocardial recovery after MI. Histological analysis of KI67 and EndMT marker PDGFRA demonstrated that while the expression of proliferation of endothelial cells was not significantly different, expression of EndMT markers was significantly higher among endothelial cells of ARP1MIP28 hearts compared to MIP28 hearts, which were consistent with snRNAseq analysis of clusters VEC1 and VEC3. Furthermore, upregulated secrete genes by VEC3 may promote cardiomyocyte proliferation via the Pi3k-Akt and ERBB signaling pathways, which directly contribute to cardiac muscle regeneration. Conclusion: In regenerative heart, endothelial cells may express EndMT markers, and this process could contribute to regeneration via a endothelial-cardiomyocyte crosstalk that supports cardiomyocyte proliferation.

Role of micronutrients in Alzheimer's disease: Review of available evidence.

Alzheimer's disease (AD) is one of the most common age-related neurodegenerative disorders that have been studied for more than 100 years. Although an increased level of amyloid precursor protein is considered a key contributor to the development of AD, the exact pathogenic mechanism remains known. Multiple factors are related to AD, such as genetic factors, aging, lifestyle, and nutrients. Both epidemiological and clinical evidence has shown that the levels of micronutrients, such as copper, zinc, and iron, are closely related to the development of AD. In this review, we summarize the roles of eight micronutrients, including copper, zinc, iron, selenium, silicon, manganese, arsenic, and vitamin D in AD based on recently published studies.

The bs-YHEDA peptide protects the brains of senile mice and thus recovers intelligence by reducing iron and free radicals.

Iron accumulates in the brain with age and catalyzes free radical damage to neurons, thus playing a pathogenic role in Alzheimer's disease (AD). To decrease the incidence of AD, we synthesized the iron-affinitive peptide 5YHEDA to scavenge the excess iron in the senile brain. However, the blood-brain barrier (BBB) blocks the entrance of macromolecules into the brain, thus decreasing the therapeutic effects. To facilitate the entrance of the 5YHEDA peptide, we linked the low-density lipoprotein receptor (LDLR)-binding segment of ApoB-100 to 5YHEDA (named "bs-YHEDA"). The results of intravenous injections of bs-5YHEDA into senescent mice demonstrated that bs-YHEDA entered the brain, increased ferriportin levels, reduced iron and free radical levels, decreased the consequences of neuronal necrosis and ameliorated cognitive disfunction without kidney or liver damage. bs-5YHEDA is a safe iron and free radical remover that potentially alleviates aging and Alzheimer's disease.

A three-dimensional culture system for generating cardiac spheroids composed of cardiomyocytes, endothelial cells, smooth-muscle cells, and cardiac fibroblasts derived from human induced-pluripotent stem cells.

Cardiomyocytes (CMs), endothelial cells (ECs), smooth-muscle cells (SMCs), and cardiac fibroblasts (CFs) differentiated from human induced-pluripotent stem cells (hiPSCs) are the fundamental components of cell-based regenerative myocardial therapy and can be used as in-vitro models for mechanistic studies and drug testing. However, newly differentiated hiPSC-CMs tend to more closely resemble fetal CMs than the mature CMs of adult hearts, and current techniques for improving CM maturation can be both complex and labor-intensive. Thus, the production of CMs for commercial and industrial applications will require more elementary methods for promoting CM maturity. CMs tend to develop a more mature phenotype when cultured as spheroids in a three-dimensional (3D) environment, rather than as two-dimensional monolayers, and the activity of ECs, SMCs, and CFs promote both CM maturation and electrical activity. Here, we introduce a simple and reproducible 3D-culture-based process for generating spheroids containing all four cardiac-cell types (i.e., cardiac spheroids) that is compatible with a wide range of applications and research equipment. Subsequent experiments demonstrated that the inclusion of vascular cells and CFs was associated with an increase in spheroid size, a decline in apoptosis, an improvement in sarcomere maturation and a change in CM bioenergetics.

Cardiomyocyte Cell-Cycle Regulation in Neonatal Large Mammals: Single Nucleus RNA-Sequencing Data Analysis via an Artificial-Intelligence-Based Pipeline.

Adult mammalian cardiomyocytes have very limited capacity to proliferate and repair the myocardial infarction. However, when apical resection (AR) was performed in pig hearts on postnatal day (P) 1 (ARP1) and acute myocardial infarction (MI) was induced on P28 (MIP28), the animals recovered with no evidence of myocardial scarring or decline in contractile performance. Furthermore, the repair process appeared to be driven by cardiomyocyte proliferation, but the regulatory molecules that govern the ARP1-induced enhancement of myocardial recovery remain unclear. Single-nucleus RNA sequencing (snRNA-seq) data collected from fetal pig hearts and the hearts of pigs that underwent ARP1, MIP28, both ARP1 and MI, or neither myocardial injury were evaluated via autoencoder, cluster analysis, sparse learning, and semisupervised learning. Ten clusters of cardiomyocytes (CM1-CM10) were identified across all experimental groups and time points. CM1 was only observed in ARP1 hearts on P28 and was enriched for the expression of T-box transcription factors 5 and 20 (TBX5 and TBX20, respectively), Erb-B2 receptor tyrosine kinase 4 (ERBB4), and G Protein-Coupled Receptor Kinase 5 (GRK5), as well as genes associated with the proliferation and growth of cardiac muscle. CM1 cardiomyocytes also highly expressed genes for glycolysis while lowly expressed genes for adrenergic signaling, which suggested that CM1 were immature cardiomyocytes. Thus, we have identified a cluster of cardiomyocytes, CM1, in neonatal pig hearts that appeared to be generated in response to AR injury on P1 and may have been primed for activation of CM cell-cycle activation and proliferation by the upregulation of TBX5, TBX20, ERBB4, and GRK5.

The role of non-coding RNAs in ferroptosis regulation.

Ferroptosis is a newly recognized form of cell death that is distinct from apoptosis, necrosis, autophagy in morphology, biochemistry, and heredity. The basic process of ferroptosis involves disordered permeability of plasma membrane, which is caused by abnormal accumulation of lipids and reactive oxygen species (ROS). The regulatory mechanism of ferroptosis is important due to its involvement in tumor progression, neurotoxicity, neurodegenerative diseases, acute renal failure, and ischemia-reperfusion injury. Recent studies have shown that in ferroptosis metabolism, non-coding RNAs (ncRNAs) can interfere with multiple signaling pathways at both the pre-transcriptional and post-transcriptional levels. Despite great progress, current research on the mechanism of ncRNAs and ferroptosis remains insufficient. This review provides an overview of the main mechanisms and targets of ferroptosis and focuses on the mechanisms of non-coding RNA regulation. Analyzing the deficiencies in current research may provide ideas for future studies to investigate.

Cyclin D2 Overexpression Enhances the Efficacy of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes for Myocardial Repair in a Swine Model of Myocardial Infarction.

BACKGROUND: Human induced pluripotent stem cells with normal (wild-type) or upregulated (overexpressed) levels of CCND2 (cyclin D2) expression were differentiated into cardiomyocytes (CCND2WTCMs or CCND2OECMs, respectively) and injected into infarcted pig hearts. METHODS: Acute myocardial infarction was induced by a 60-minute occlusion of the left anterior descending coronary artery. Immediately after reperfusion, CCND2WTCMs or CCND2OECMs (3×107 cells each) or an equivalent volume of the delivery vehicle was injected around the infarct border zone area. RESULTS: The number of the engrafted CCND2OECMs exceeded that of the engrafted CCND2WTCMs from 6- to 8-fold, rising from 1 week to 4 weeks after implantation. In contrast to the treatment with the CCND2WTCMs or the delivery vehicle, the administration of CCND2OECM was associated with significantly improved left ventricular function, as revealed by magnetic resonance imaging. This correlated with reduction of infarct size, fibrosis, ventricular hypertrophy, and cardiomyocyte apoptosis, and increase of vascular density and arterial density, as per histologic analysis of the treated hearts. Expression of cell proliferation markers (eg, Ki67, phosphorylated histone 3, and Aurora B kinase) was also significantly upregulated in the recipient cardiomyocytes from the CCND2OECM-treated than from the CCND2WTCM-treated pigs. The cell proliferation rate and the hypoxia tolerance measured in cultured human induced pluripotent stem cell cardiomyocytes were significantly greater after treatment with exosomes isolated from the CCND2OECMs (CCND2OEExos) than from the CCND2WTCMs (CCND2WTExos). As demonstrated by our study, CCND2OEExos can also promote the proliferation activity of postnatal rat and adult mouse cardiomyocytes. A bulk miRNA sequencing analysis of CCND2OEExos versus CCND2WTExos identified 206 and 91 miRNAs that were significantly upregulated and downregulated, respectively. Gene ontology enrichment analysis identified significant differences in the expression profiles of miRNAs from various functional categories and pathways, including miRNAs implicated in cell-cycle checkpoints (G2/M and G1/S transitions), or the mechanism of cytokinesis. CONCLUSIONS: We demonstrated that enhanced potency of CCND2OECMs promoted myocyte proliferation in both grafts and recipient tissue in a large mammal acute myocardial infarction model. These results suggest that CCND2OECMs transplantation may be a potential therapeutic strategy for the repair of infarcted hearts.

Visualization and Identification of Bioorthogonally Labeled Exosome Proteins Following Systemic Administration in Mice.

Exosomes transport biologically active cargo (e.g., proteins and microRNA) between cells, including many of the paracrine factors that mediate the beneficial effects associated with stem-cell therapy. Stem cell derived exosomes, in particular mesenchymal stem cells (MSCs), have been shown previously to largely replicate the therapeutic activity associated with the cells themselves, which suggests that exosomes may be a useful cell-free alternative for the treatment of cardiovascular disorders. However, the mechanisms that govern how exosomes home to damaged cells and tissues or the uptake and distribution of exosomal cargo are poorly characterized, because techniques for distinguishing between exosomal proteins and proteins in the targeted tissues are lacking. Here, we report the development of an in vivo model that enabled the visualization, tracking, and quantification of proteins from systemically administered MSC exosomes. The model uses bioorthogonal chemistry and cell-selective metabolic labeling to incorporate the non-canonical amino acid azidonorleucine (ANL) into the MSC proteome. ANL incorporation is facilitated via expression of a mutant (L274G) methionyl-tRNA-synthetase (MetRS∗) and subsequent incubation with ANL-supplemented media; after which ANL can be covalently linked to alkyne-conjugated reagents (e.g., dyes and resins) via click chemistry. Our results demonstrate that when the exosomes produced by ANL-treated, MetRS∗-expressing MSCs were systemically administered to mice, the ANL-labeled exosomal proteins could be accurately and reliably identified, isolated, and quantified from a variety of mouse organs, and that myocardial infarction (MI) both increased the abundance of exosomal proteins and redistributed a number of them from the membrane fraction of intact hearts to the cytosol of cells in infarcted hearts. Additionally, we found that Desmoglein-1c is enriched in MSC exosomes and taken up by ischemic myocardium. Collectively, our results indicate that this newly developed bioorthogonal system can provide crucial insights into exosome homing, as well as the uptake and biodistribution of exosomal proteins.

Human Mesenchymal Stem Cell-Derived Exosomal microRNA-143 Promotes Apoptosis and Suppresses Cell Growth in Pancreatic Cancer via Target Gene Regulation.

BACKGROUND: This study aimed to explore the regulatory mechanism of hsa-miR-143-3p and lncRNA RP11-363N22.3-functioning upstream of KRAS-in exosomes derived from human mesenchymal stem cells (hMSCs) in pancreatic cancer. METHODS: Western blotting and quantitative PCR were used to determine gene expression. In vitro, cell proliferation, apoptosis, and cell cycle and invasion were evaluated using CCK-8 assay, flow cytometry, and transwell assays, respectively. In vivo, the effect of hsa-miR143-3p was investigated using a tumorigenesis test in nude mice. The association between hsa-miR-143-3p and lncRNA RP11-363N22.3 was investigated using the dual-luciferase assay. RESULTS: hsa-miR-143-3p expression significantly increased in hMSC exosomes than in those in human pancreatic cancer cell line (CFPAC-1) exosomes. In vitro, compared to the MOCK (CFPAC-1 only) group, cell proliferation and invasion were inhibited and apoptosis was induced in the inhibitor NC (CFPAC-1 + MSC-hsa-miR-3p inhibitor NC) group, while these changes were reversed in the inhibitor (CFPAC-1 + MSC-hsa-miR-3p inhibitor) group. The expression of lncRNA RP11-363N22.3 and genes related to miR-143 significantly decreased in the inhibitor NC group compared to the MOCK group, and increased in the inhibitor group compared to inhibitor NC group. A targeted combinatorial effect was observed between lncRNA RP11-363N22.3 and hsa-miR-143-3p. In vivo, the tumor volume of the mimics (CFPAC-1 + MSC-hsa-miR-143-3p mimics) group was smaller than that of the mimics NC (CFPAC-1 + MSC-hsa-miR-143-3p mimics NC) and MOCK groups. H&E staining showed that there were no obvious pathological changes in MOCK and mimic NC groups, while cell necrosis was seen in some regions in mimic groups. CONCLUSION: hsa-miR-143-3p may promote apoptosis and suppress cell growth and invasion in pancreatic cancer.