RESUMO
Human induced pluripotent stem cells (hiPSCs) offer opportunities to study human biology where primary cell types are limited. CRISPR technology allows forward genetic screens using engineered Cas9-expressing cells. Here, we sought to generate a CRISPR activation (CRISPRa) hiPSC line to activate endogenous genes during pluripotency and differentiation. We first targeted catalytically inactive Cas9 fused to VP64, p65 and Rta activators (dCas9-VPR) regulated by the constitutive CAG promoter to the AAVS1 safe harbor site. These CRISPRa hiPSC lines effectively activate target genes in pluripotency, however the dCas9-VPR transgene expression is silenced after differentiation into cardiomyocytes and endothelial cells. To understand this silencing, we systematically tested different safe harbor sites and different promoters. Targeting to safe harbor sites hROSA26 and CLYBL loci also yielded hiPSCs that expressed dCas9-VPR in pluripotency but silenced during differentiation. Muscle-specific regulatory cassettes, derived from cardiac troponin T or muscle creatine kinase promoters, were also silent after differentiation when dCas9-VPR was introduced. In contrast, in cell lines where the dCas9-VPR sequence was replaced with cDNAs encoding fluorescent proteins, expression persisted during differentiation in all loci and with all promoters. Promoter DNA was hypermethylated in CRISPRa-engineered lines, and demethylation with 5-azacytidine enhanced dCas9-VPR gene expression. In summary, the dCas9-VPR cDNA is readily expressed from multiple loci during pluripotency but induces silencing in a locus- and promoter-independent manner during differentiation to mesoderm derivatives. Researchers intending to use this CRISPRa strategy during stem cell differentiation should pilot their system to ensure it remains active in their population of interest.
Assuntos
Células-Tronco Pluripotentes Induzidas , Células-Tronco Pluripotentes , Humanos , Miócitos Cardíacos , Células Endoteliais , Diferenciação Celular/genética , EndotélioRESUMO
After myocardial infarction (MI), a significant portion of heart muscle is replaced with scar tissue, progressively leading to heart failure. Human pluripotent stem cell-derived cardiomyocytes (hPSC-CM) offer a promising option for improving cardiac function after MI. However, hPSC-CM transplantation can lead to engraftment arrhythmia (EA). EA is a transient phenomenon arising shortly after transplantation then spontaneously resolving after a few weeks. The underlying mechanism of EA is unknown. We hypothesize that EA may be explained partially by time-varying, spatially heterogeneous, graft-host electrical coupling. Here, we created computational slice models derived from histological images that reflect different configuration of grafts in the infarcted ventricle. We ran simulations with varying degrees of connection imposed upon the graft-host perimeter to assess how heterogeneous electrical coupling affected EA with non-conductive scar, slow-conducting scar and scar replaced by host myocardium. We also quantified the effect of variation in intrinsic graft conductivity. Susceptibility to EA initially increased and subsequently decreased with increasing graft-host coupling, suggesting the waxing and waning of EA is regulated by progressive increases in graft-host coupling. Different spatial distributions of graft, host and scar yielded markedly different susceptibility curves. Computationally replacing non-conductive scar with host myocardium or slow-conducting scar, and increasing intrinsic graft conductivity both demonstrated potential means to blunt EA vulnerability. These data show how graft location, especially relative to scar, along with its dynamic electrical coupling to host, can influence EA burden; moreover, they offer a rational base for further studies aimed to define the optimal delivery of hPSC-CM injection. KEY POINTS: Human pluripotent stem cell-derived cardiomyocytes (hPSC-CM) hold great cardiac regenerative potential but can also cause engraftment arrhythmias (EA). Spatiotemporal evolution in the pattern of electrical coupling between injected hPSC-CMs and surrounding host myocardium may explain the dynamics of EA observed in large animal models. We conducted simulations in histology-derived 2D slice computational models to assess the effects of heterogeneous graft-host electrical coupling on EA propensity, with or without scar tissue. Our findings suggest spatiotemporally heterogeneous graft-host coupling can create an electrophysiological milieu that favours graft-initiated host excitation, a surrogate metric of EA susceptibility. Removing scar from our models reduced but did not abolish the propensity for this phenomenon. Conversely, reduced intra-graft electrical connectedness increased the incidence of graft-initiated host excitation. The computational framework created for this study can be used to generate new hypotheses, targeted delivery of hPSC-CMs.
Assuntos
Cicatriz , Infarto do Miocárdio , Animais , Humanos , Cicatriz/patologia , Miocárdio/patologia , Miócitos Cardíacos/patologia , Infarto do Miocárdio/patologia , Arritmias Cardíacas , Diferenciação CelularRESUMO
RESEARCH QUESTION: Does cholesterol metabolism differ in patients with diminished ovarian reserve (DOR) compared to patients with normal ovarian reserve (NOR)? DESIGN: The current research included 72 women with NOR and 86 women with DOR. Data on the cholesterol metabolism in granulosa cells of these women were analysed. RESULTS: On the day of human chorionic gonadotrophin injection, serum oestradiol and progesterone in the DOR group were significantly lower than in the control group (P < 0.001). There were no significant differences in serum concentrations of total cholesterol, triglyceride, high-density lipoprotein and low-density lipoprotein between the NOR and DOR groups. The cholesterol-regulated gene SCAP in granulosa cells from women with DOR was down-regulated (Pâ¯=â¯0.024). Cholesterol synthesis and transport genes (e.g. IDI1, FDFT1, CYP51A1, SRB1 and STARD1) were also significantly decreased (Pâ¯=â¯0.026, Pâ¯=â¯0.044, Pâ¯=â¯0.049, Pâ¯=â¯0.004 and P < 0.001, respectively). In granulosa cells of patients with DOR, cholesterol-related substances such as coprostanone, 11A-acetoxyprogesterone and 17α-hydroxyprogesterone were significantly reduced (Pâ¯=â¯0.0008, Pâ¯=â¯0.0269, Pâ¯=â¯0.0337, respectively). CYP19A1, a key steroidogenesis gene, was significantly reduced (Pâ¯=â¯0.009). 17α-hydroxyprogesterone and oestradiol decreased (Pâ¯=â¯0.004 and Pâ¯=â¯0.039, respectively). CONCLUSION: Decreased cholesterol metabolism affecting steroid hormone synthesis in granulosa cells might be a possible mechanism for DOR.
Assuntos
Infertilidade Feminina , Doenças Ovarianas , Reserva Ovariana , Estradiol/metabolismo , Feminino , Células da Granulosa/metabolismo , Humanos , Infertilidade Feminina/metabolismo , Masculino , Doenças Ovarianas/metabolismo , Reserva Ovariana/genéticaRESUMO
Oleuropein is an ester of elenolic acid and hydroxytyrosol (3, 4-dihydroxyphenylethanol). It is a phenolic compound and the most luxuriant in olives. The detailed information related to the anticancer effects of oleuropein was collected from the internet database PubMed/Medline, ResearchGate, Web of Science, Wiley Online Library, and Cnki using appropriate keywords until the end of October 2021. Oleuropein has been shown to have antioxidant, anticancer, antiinflammatory, cardioprotective, neuroprotective, and hepatoprotective effects. Previous studies also revealed that oleuropein could effectively inhibit the malignant progression of esophageal cancer, gastric cancer, breast cancer, lung cancer, liver cancer, pancreatic cancer, ovarian cancer, prostate cancer, and cervical cancer. Recently, the role of oleuropein in inhibiting tumor cell proliferation, invasion, and migration and inducing tumor cell apoptosis has gained extensive attention. In this review, we have summarized the latest research progress related to the antioncogenic mechanisms and the potential role of oleuropein in targeting different human malignancies. Based on these findings, it can be concluded that oleuropein can function as a promising chemopreventive and chemotherapeutic agent against cancer, but its more detailed anticancer effects and underlying mechanisms need to be further validated in future preclinical as well as clinical studies.
Assuntos
Antineoplásicos , Neoplasias Pancreáticas , Humanos , Glucosídeos Iridoides , Iridoides/farmacologia , MasculinoRESUMO
Compared to beta-cyclodextrins (beta-CD), hydroxypropyl-beta-cyclodextrins (HP-beta-CD) are a more popular material used to prepare inclusion complexes due to their superior solubility and intestinal absorption. In this study, oleuropein (OL) inclusion complexes with beta-CD (beta-CD:OL) and HP-beta-CD (HP-beta-CD:OL) were prepared and the formation of inclusion complexes was validated by IR, PXRD, and DSC. A phase solubility test showed that the lgK (25 °C) and binding energy of beta-CD:OL and HP-beta-CD:OL was 2.32 versus 1.98, and −6.1 versus −24.66 KJ/mol, respectively. Beta-CD:OL exhibited a more powerful effect than HP-beta-CD:OL in protecting OL from degradation upon exposure to light, high temperature and high humidity. Molecular docking, peak intensity of carbonyls in IR, and ferric reducing power revealed that beta-CD:OL formed more hydrogen bonds with the unstable groups of OL. Both inclusion complexes significantly enhanced the solubility, intestinal permeation and antioxidant activity of OL (p < 0.05). Though HP-beta-CD:OL had higher solubility and intestinal absorption over beta-CD:OL, the difference was not significant (p > 0.05). The study implies that lower binding energy is not always associated with the higher stability of a complex. Beta-CD can protect a multiple-hydroxyl compound more efficiently than HP-beta-CD with the intestinal permeation comparable to HP-beta-CD complex.
Assuntos
Antioxidantes , beta-Ciclodextrinas , 2-Hidroxipropil-beta-Ciclodextrina/química , Antioxidantes/farmacologia , Glucosídeos Iridoides , Simulação de Acoplamento Molecular , beta-Ciclodextrinas/químicaRESUMO
The chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing family (CMTM) is a gene family that has been implicated in male reproduction. CMTM4 is an evolutionarily conserved member that is highly expressed in the testis. However, its function in male fertility remains unknown. Here, we demonstrate that CMTM4 is associated with spermatogenesis and sperm quality. Using Western blotting and immunohistochemical analyses, we found CMTM4 expression to be decreased in poor-quality human spermatozoa, old human testes, and testicular biopsies with nonobstructive azoospermia. Using CRISPR-Cas9 technology, we knocked out the Cmtm4 gene in mice. These Cmtm4 knockout (KO) mice showed reduced testicular daily sperm production, lower epididymal sperm motility and increased proportion of abnormally backward-curved sperm heads and bent sperm midpieces. These mice also had an evident sub-fertile phenotype, characterized by low pregnancy rates on prolonged breeding with wild type female mice, reduced in vitro fertilization efficiency and a reduced percentage of acrosome reactions. We then performed quantitative proteomic analysis of the testes, where we identified 139 proteins to be downregulated in Cmtm4-KO mice, 100 (71.9%) of which were related to sperm motility and acrosome reaction. The same proteomic analysis was performed on sperm, where we identified 3588 proteins with 409 being differentially regulated in Cmtm4-KO mice. Our enrichment analysis showed that upregulated proteins were enriched with nucleosomal DNA binding functions and the downregulated proteins were enriched with actin binding functions. These findings elucidate the roles of CMTM4 in male fertility and demonstrates its potential as a promising molecular candidate for sperm quality assessment and the diagnosis or treatment of male infertility.
Assuntos
Fertilidade , Proteínas com Domínio MARVEL/genética , Proteoma/metabolismo , Adulto , Animais , Sequência de Bases , Proteína 9 Associada à CRISPR/administração & dosagem , Feminino , Humanos , Marcação por Isótopo , Proteínas com Domínio MARVEL/metabolismo , Masculino , Camundongos Knockout , Microinjeções , Fenótipo , Proteômica , Espermatogênese , Espermatozoides , Testículo/metabolismoRESUMO
BACKGROUND: The giant sarcomere protein titin is important in both heart health and disease. Mutations in the gene encoding for titin (TTN) are the leading known cause of familial dilated cardiomyopathy. The uneven distribution of these mutations within TTN motivated us to seek a more complete understanding of this gene and the isoforms it encodes in cardiomyocyte (CM) sarcomere formation and function. METHODS: To investigate the function of titin in human CMs, we used CRISPR/Cas9 to generate homozygous truncations in the Z disk (TTN-Z-/-) and A-band (TTN-A-/-) regions of the TTN gene in human induced pluripotent stem cells. The resulting CMs were characterized with immunostaining, engineered heart tissue mechanical measurements, and single-cell force and calcium measurements. RESULTS: After differentiation, we were surprised to find that despite the more upstream mutation, TTN-Z-/--CMs had sarcomeres and visibly contracted, whereas TTN-A-/--CMs did not. We hypothesized that sarcomere formation was caused by the expression of a recently discovered isoform of titin, Cronos, which initiates downstream of the truncation in TTN-Z-/--CMs. Using a custom Cronos antibody, we demonstrate that this isoform is expressed and integrated into myofibrils in human CMs. TTN-Z-/--CMs exclusively express Cronos titin, but these cells produce lower contractile force and have perturbed myofibril bundling compared with controls expressing both full-length and Cronos titin. Cronos titin is highly expressed in human fetal cardiac tissue, and when knocked out in human induced pluripotent stem cell derived CMs, these cells exhibit reduced contractile force and myofibrillar disarray despite the presence of full-length titin. CONCLUSIONS: We demonstrate that Cronos titin is expressed in developing human CMs and is able to support partial sarcomere formation in the absence of full-length titin. Furthermore, Cronos titin is necessary for proper sarcomere function in human induced pluripotent stem cell derived CMs. Additional investigation is necessary to understand the molecular mechanisms of this novel isoform and how it contributes to human cardiac disease.
Assuntos
Conectina/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Sarcômeros/metabolismo , Sistemas CRISPR-Cas , Sinalização do Cálcio , Células Cultivadas , Conectina/genética , Coração Fetal/metabolismo , Edição de Genes , Genótipo , Humanos , Mutação , Contração Miocárdica/genética , FenótipoRESUMO
Pluripotent stem cells provide a potential solution to current epidemic rates of heart failure by providing human cardiomyocytes to support heart regeneration. Studies of human embryonic-stem-cell-derived cardiomyocytes (hESC-CMs) in small-animal models have shown favourable effects of this treatment. However, it remains unknown whether clinical-scale hESC-CM transplantation is feasible, safe or can provide sufficient myocardial regeneration. Here we show that hESC-CMs can be produced at a clinical scale (more than one billion cells per batch) and cryopreserved with good viability. Using a non-human primate model of myocardial ischaemia followed by reperfusion, we show that cryopreservation and intra-myocardial delivery of one billion hESC-CMs generates extensive remuscularization of the infarcted heart. The hESC-CMs showed progressive but incomplete maturation over a 3-month period. Grafts were perfused by host vasculature, and electromechanical junctions between graft and host myocytes were present within 2 weeks of engraftment. Importantly, grafts showed regular calcium transients that were synchronized to the host electrocardiogram, indicating electromechanical coupling. In contrast to small-animal models, non-fatal ventricular arrhythmias were observed in hESC-CM-engrafted primates. Thus, hESC-CMs can remuscularize substantial amounts of the infarcted monkey heart. Comparable remuscularization of a human heart should be possible, but potential arrhythmic complications need to be overcome.
Assuntos
Células-Tronco Embrionárias/citologia , Coração , Infarto do Miocárdio/patologia , Infarto do Miocárdio/terapia , Miócitos Cardíacos/citologia , Regeneração , Animais , Arritmias Cardíacas/fisiopatologia , Cálcio/metabolismo , Sobrevivência Celular , Vasos Coronários/fisiologia , Criopreservação , Modelos Animais de Doenças , Eletrocardiografia , Humanos , Macaca nemestrina , Masculino , Camundongos , Medicina Regenerativa/métodosRESUMO
In metazoans, transition from fetal to adult heart is accompanied by a switch in energy metabolism-glycolysis to fatty acid oxidation. The molecular factors regulating this metabolic switch remain largely unexplored. We first demonstrate that the molecular signatures in 1-year (y) matured human embryonic stem cell-derived cardiomyocytes (hESC-CMs) are similar to those seen in in vivo-derived mature cardiac tissues, thus making them an excellent model to study human cardiac maturation. We further show that let-7 is the most highly up-regulated microRNA (miRNA) family during in vitro human cardiac maturation. Gain- and loss-of-function analyses of let-7g in hESC-CMs demonstrate it is both required and sufficient for maturation, but not for early differentiation of CMs. Overexpression of let-7 family members in hESC-CMs enhances cell size, sarcomere length, force of contraction, and respiratory capacity. Interestingly, large-scale expression data, target analysis, and metabolic flux assays suggest this let-7-driven CM maturation could be a result of down-regulation of the phosphoinositide 3 kinase (PI3K)/AKT protein kinase/insulin pathway and an up-regulation of fatty acid metabolism. These results indicate let-7 is an important mediator in augmenting metabolic energetics in maturing CMs. Promoting maturation of hESC-CMs with let-7 overexpression will be highly significant for basic and applied research.
Assuntos
MicroRNAs/genética , MicroRNAs/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Adulto , Diferenciação Celular/genética , Linhagem Celular , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Metabolismo Energético , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Modelos Cardiovasculares , Contração Miocárdica , Miócitos Cardíacos/fisiologia , Transdução de Sinais , Engenharia Tecidual , Regulação para CimaRESUMO
The discovery of human pluripotent stem cells (hPSCs), including both human embryonic stem cells and human-induced pluripotent stem cells, has opened up novel paths for a wide range of scientific studies. The capability to direct the differentiation of hPSCs into functional cardiomyocytes has provided a platform for regenerative medicine, development, tissue engineering, disease modeling, and drug toxicity testing. Despite exciting progress, achieving the optimal benefits has been hampered by the immature nature of these cardiomyocytes. Cardiac maturation has long been studied in vivo using animal models; however, finding ways to mature hPSC cardiomyocytes is only in its initial stages. In this review, we discuss progress in promoting the maturation of the hPSC cardiomyocytes, in the context of our current knowledge of developmental cardiac maturation and in relation to in vitro model systems such as rodent ventricular myocytes. Promising approaches that have begun to be examined in hPSC cardiomyocytes include long-term culturing, 3-dimensional tissue engineering, mechanical loading, electric stimulation, modulation of substrate stiffness, and treatment with neurohormonal factors. Future studies will benefit from the combinatorial use of different approaches that more closely mimic nature's diverse cues, which may result in broader changes in structure, function, and therapeutic applicability.
Assuntos
Diferenciação Celular/fisiologia , Engenharia Celular/métodos , Células-Tronco Pluripotentes Induzidas/fisiologia , Miócitos Cardíacos/fisiologia , Animais , Células Cultivadas , Engenharia Genética , Humanos , Células-Tronco Pluripotentes Induzidas/transplante , Modelos Animais , Miócitos Cardíacos/transplante , Células-Tronco Pluripotentes/fisiologia , Células-Tronco Pluripotentes/transplante , Fatores de TempoRESUMO
1. In China, Fructus Gardeniae was used as a traditional Chinese medicine (TCM) with a wide array of biological activities. The bioactive components identified in Fructus Gardeniae mainly included iridoids, flavonids, pigments, and so on. Among them, iridoids were regarded as important compounds in Fructus Gardeniae. Though analyses of the constituents in biological samples after oral administration of Fructus Gardeniae effective fraction or its active compounds have been reported, few efforts have been made to investigate the metabolic profile of Fructus Gardeniae in humans. In this study, the constituents and metabolites of Fructus Gardeniae in human blood and urine after oral administration of Fructus Gardeniae were investigated using ultra high-performance liquid chromatography (UHPLC) coupled with high-resolution LTQ-Orbitrap mass spectrometery. 2. Totally, 14 constituents (two parent compounds and 12 metabolites) of Fructus Gardeniae were identified in human plasma and urine either by comparing the retention time and mass spectrometry data with that of reference compounds or by the accurate high-resolution MS/MS data of the chemicals. The compounds identified were mainly iridoid glycosides such as geniposide and the derivatives of genipin-O-glucuronide. Among them, 11 metabolites were detected in human plasma and urine while the other three metabolites including geniposidic acid (M1), demethylation derivative of genipin-O-glucuronide (M2), and dehydration product of mono-hydroxylated genipin-O-glucuronide (M9) were only discovered in human urine. Further, the possible metabolic pathways of Fructus Gardeniae in vivo were proposed and the peak area-time curve of the most abundant metabolite genipin-O-glucuronide (M13) in human plasma after oral administration of Fructus Gardeniae was depicted. The results suggested that a metabolic difference existed between rats and humans. 3. The results obtained in the present research would provide basic information to understand the metabolic profile of Fructus Gardeniae in humans and explore the chemicals responsible for the hepatotoxicity of Fructus Gardeniae in vivo. Moreover, it would be beneficial for us to further study the pharmacokinetic behavior of Fructus Gardeniae in humans systematically.
Assuntos
Medicamentos de Ervas Chinesas/metabolismo , Gardenia , Animais , Cromatografia Líquida de Alta Pressão , Humanos , Ratos , Espectrometria de Massas em TandemRESUMO
BACKGROUND: Cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CMs) have great potential as a cell source for therapeutic applications such as regenerative medicine, disease modeling, drug screening, and toxicity testing. This potential is limited, however, by the immature state of the cardiomyocytes acquired using current protocols. Tri-iodo-l-thyronine (T3) is a growth hormone that is essential for optimal heart growth. In this study, we investigated the effect of T3 on hiPSC-CM maturation. METHODS AND RESULTS: A one-week treatment with T3 increased cardiomyocyte size, anisotropy, and sarcomere length. T3 treatment was associated with reduced cell cycle activity, manifest as reduced DNA synthesis and increased expression of the cyclin-dependent kinase inhibitor p21. Contractile force analyses were performed on individual cardiomyocytes using arrays of microposts, revealing an almost two-fold higher force per-beat after T3 treatment and also an enhancement in contractile kinetics. This improvement in force generation was accompanied by an increase in rates of calcium release and reuptake, along with a significant increase in sarcoendoplasmic reticulum ATPase expression. Finally, although mitochondrial genomes were not numerically increased, extracellular flux analysis showed a significant increase in maximal mitochondrial respiratory capacity and respiratory reserve capability after T3 treatment. CONCLUSIONS: Using a broad spectrum of morphological, molecular, and functional parameters, we conclude that T3 is a driver for hiPSC-CM maturation. T3 treatment may enhance the utility of hiPSC-CMs for therapy, disease modeling, or drug/toxicity screens.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Sarcômeros/efeitos dos fármacos , Tri-Iodotironina/farmacologia , Animais , Cálcio/metabolismo , Ciclo Celular/efeitos dos fármacos , Células Cultivadas , Meios de Cultivo Condicionados/farmacologia , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Expressão Gênica , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Pulmão/citologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Sarcômeros/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismoRESUMO
Surgery is one of the most important paradigms for tumor therapy, while fluorescence imaging (FI) offers real-time intraoperative guidance, greatly boosting treatment prognosis. The imaging fidelity heavily relies on not only imaging facilities but also probes for imaging-guided surgery (IGS). So far, a great number of IGS probes with emission in visible (400-700 nm) and near-infrared (NIR 700-1700 nm) windows have been developed for pinpointing disease margins intraoperatively. Herein, the state-of-the-art fluorescent probes for IGS are timely updated, with a special focus on the fluorescent probes under clinical examination. For a better demonstration of the superiority of NIR FI over visible FI, both imaging modalities are critically compared regarding signal-to-background ratio, penetration depth, resolution, tissue autofluorescence, photostability, and biocompatibility. Various types of fluorescence IGS have been summarized to demonstrate its importance in the medical field. Furthermore, the most recent progress of fluorescent probes in NIR-I and NIR-II windows is summarized. Finally, an outlook on multimodal imaging, FI beyond NIR-II, efficient tumor targeting, automated IGS, the use of AI and machine learning for designing fluorescent probes, and the fluorescence-guided da Vinci surgical system is given. We hope this review will stimulate interest among researchers in different areas and expedite the translation of fluorescent probes from bench to bedside.
Assuntos
Corantes Fluorescentes , Neoplasias , Imagem Óptica , Cirurgia Assistida por Computador , Humanos , Cirurgia Assistida por Computador/métodos , Corantes Fluorescentes/química , Neoplasias/diagnóstico por imagem , Neoplasias/cirurgia , AnimaisRESUMO
Objective: This study aimed to develop and validate a machine learning-based risk prediction model for catheter-related bloodstream infection (CRBSI) following implantation of totally implantable venous access ports (TIVAPs) in patients. Methods: A retrospective cohort study design was employed, utilizing the R software package mlr3. Various algorithms including logistic regression, naive Bayes, K nearest neighbor, classification tree, and random forest were applied. Addressing class imbalance, benchmarks were used, and model performance was assessed using the area under the curve (AUC). The final model, chosen for its superior performance, was interpreted using variable importance scores. Additionally, a nomogram was developed to calculate individualized risk probabilities, enhancing clinical utility. Results: The study involved 755 patients across both development and validation cohorts, with a TIVAP-CRBSI rate of 14.17%. The random forest model demonstrated the highest discrimination ability, achieving a validated AUC of 0.94, which was consistent in the validation cohort. Conclusions: This study successfully developed a robust predictive model for TIVAP-CRBSI risk post-implantation. Implementation of this model may aid healthcare providers in making informed decisions, thereby potentially improving patient outcomes.
RESUMO
Cellular therapies with cardiomyocytes produced from induced pluripotent stem cells (iPSC-CMs) offer a potential route to cardiac regeneration as a treatment for chronic ischemic heart disease. Here, we report successful long-term engraftment and in vivo maturation of autologous iPSC-CMs in two rhesus macaques with small, subclinical chronic myocardial infarctions, all without immunosuppression. Longitudinal positron emission tomography imaging using the sodium/iodide symporter (NIS) reporter gene revealed stable grafts for over 6 and 12 months, with no teratoma formation. Histological analyses suggested capability of the transplanted iPSC-CMs to mature and integrate with endogenous myocardium, with no sign of immune cell infiltration or rejection. By contrast, allogeneic iPSC-CMs were rejected within 8 weeks of transplantation. This study provides the longest-term safety and maturation data to date in any large animal model, addresses concerns regarding neoantigen immunoreactivity of autologous iPSC therapies, and suggests that autologous iPSC-CMs would similarly engraft and mature in human hearts.
Assuntos
Células-Tronco Pluripotentes Induzidas , Macaca mulatta , Miócitos Cardíacos , Animais , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/citologia , Diferenciação Celular , Humanos , Transplante Autólogo , Tomografia por Emissão de Pósitrons , Fatores de Tempo , Infarto do Miocárdio/terapia , Infarto do Miocárdio/patologiaRESUMO
BACKGROUND: Recent studies in rabbits have demonstrated that platelet P2Y12 receptor antagonists are cardioprotective, and that the mechanism is surprisingly not related to blockade of platelet aggregation but rather to triggering of the same signal transduction pathway seen in pre- and postconditioning. We wanted to determine whether this same cardioprotection could be documented in a primate model and whether the protection was limited to P2Y12 receptor antagonists or was a class effect. METHODS: Thirty-one macaque monkeys underwent 90-min LAD occlusion/4-h reperfusion. RESULTS: The platelet P2Y12 receptor blocker cangrelor started just prior to reperfusion significantly decreased infarction by an amount equivalent to that seen with ischemic postconditioning (p < 0.001). For any size of risk zone, infarct size in treated hearts was significantly smaller than that in control hearts. OM2, an investigational murine antibody against the primate collagen receptor glycoprotein (GP) VI, produced similar protection (p < 0.01) suggesting a class effect. Both cangrelor and OM2 were quite effective at blocking platelet aggregation (94 % and 97 %, respectively). CONCLUSIONS: Thus in a primate model in which infarct size could be determined directly platelet anti-aggregatory agents are cardioprotective. The important implication of these investigations is that patients with acute myocardial infarction who are treated with platelet anti-aggregatory agents prior to revascularization may already be in a postconditioned state. This hypothesis may explain why in recent clinical trials postconditioning-mimetic interventions which were so protective in animal models had at best only a modest effect.
Assuntos
Monofosfato de Adenosina/análogos & derivados , Anticorpos/administração & dosagem , Infarto do Miocárdio/tratamento farmacológico , Inibidores da Agregação Plaquetária/administração & dosagem , Glicoproteínas da Membrana de Plaquetas/imunologia , Antagonistas do Receptor Purinérgico P2Y/administração & dosagem , Monofosfato de Adenosina/administração & dosagem , Animais , Pressão Sanguínea/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Macaca fascicularis , Masculino , Infarto do Miocárdio/fisiopatologia , Agregação Plaquetária/efeitos dos fármacosRESUMO
BACKGROUND: To determine the predictive value of serum abnormal prothrombin (PIVKA-II) and alpha-fetoprotein (AFP) for the non-objective response of HBV-associated hepatocellular carcinoma (HCC) after transarterial chemoembolization (TACE). METHODS: This prospective study included HBV-associated HCC patients who underwent TACE at the Fourth People's Hospital of Qinghai Province between December 2021 and July 2022. According to contrast-enhanced ultrasound and upper abdomen contrast-enhanced MRI, the patients were divided into the objective response group and the non-objective response group 3 months after TACE. RESULTS: There were 54 patients, of whom 31 experienced non-objective responses. The PIVKA-II levels in the objective response group were significantly lower than in the non-objective response group at 1 month [352.00 (142.16-722.54) vs. 528.58(241.32-1681.23) mAU/ml, Pâ =â 0.005] and 3 months [28.96 (20.01-42.49) vs. 2082.55 (52.63-10 057.30) mAU/ml, Pâ =â 0.016] after TACE. The Spearman rank correlation analysis showed no significant correlation between PIVKA-II and AFP (râ =â 0.315, Pâ >â 0.05). The areas under the curve (AUCs) of AFP and PIVKA-II before TACE were 0.632 and 0.529. One month after TACE, the AUC of PIVKA-II combined with AFP (AUCâ =â 0.787) was higher than for PIVKA-II (AUCâ =â 0.658) and AFP (AUCâ =â 0.749). CONCLUSION: PIVKA-II does not outperform AFP in predicting non-objective response after TACE in HCC patients. The combination of PIVKA-II and AFP might improve the diagnosis of HCC non-objective response after TACE.
Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , alfa-Fetoproteínas/análise , Protrombina , Vírus da Hepatite B , Estudos Prospectivos , Neoplasias Hepáticas/diagnóstico , Curva ROC , Quimioembolização Terapêutica/efeitos adversos , Biomarcadores , Biomarcadores TumoraisRESUMO
In recent times, magnetic resonance imaging (MRI) has emerged as a highly promising modality for diagnosing severe diseases. Its exceptional spatiotemporal resolution and ease of use have established it as an indispensable clinical diagnostic tool. Nevertheless, there are instances where MRI encounters challenges related to low contrast, necessitating the use of contrast agents (CAs). Significant efforts have been made by scientists to enhance the precision of observing diseased body parts by leveraging the synergistic potential of MRI in conjunction with other imaging techniques and thereby modifying the CAs. In this work, our focus is on elucidating the rational designing approach of CAs and optimizing their compatibility for multimodal imaging and other intelligent applications. Additionally, we emphasize the importance of incorporating various artificial intelligence tools, such as machine learning and deep learning, to explore the future prospects of disease diagnosis using MRI. We also address the limitations associated with these techniques and propose reasonable remedies, with the aim of advancing MRI as a cutting-edge diagnostic tool for the future.
RESUMO
Vascular endothelial cells are a mesoderm-derived lineage with many essential functions, including angiogenesis and coagulation. The gene-regulatory mechanisms underpinning endothelial specialization are largely unknown, as are the roles of chromatin organization in regulating endothelial cell transcription. To investigate the relationships between chromatin organization and gene expression, we induced endothelial cell differentiation from human pluripotent stem cells and performed Hi-C and RNA-sequencing assays at specific time points. Long-range intrachromosomal contacts increase over the course of differentiation, accompanied by widespread heteroeuchromatic compartment transitions that are tightly associated with transcription. Dynamic topologically associating domain boundaries strengthen and converge on an endothelial cell state, and function to regulate gene expression. Chromatin pairwise point interactions (DNA loops) increase in frequency during differentiation and are linked to the expression of genes essential to vascular biology. Chromatin dynamics guide transcription in endothelial cell development and promote the divergence of endothelial cells from cardiomyocytes.