Conserved transcription factors promote cell fate stability and restrict reprogramming potential in differentiated cells

Advances in transcription factor delivery: Target selection, engineering strategies, and delivery platforms

Recent advances in delivery systems for transcription factors (TFs) have opened new therapeutic opportunities in regenerative medicine, cancer therapy, and genetic disorders. However, effective TF delivery still faces substantial obstacles, including limited cellular uptake, inefficient nuclear translocation, low cargo stability, and insufficient target specificity. Furthermore, artificial TFs have enabled targeted modulation of gene expression, further expanding their therapeutic potential. This review comprehensively discusses current progress in TF delivery methodologies, including direct TF protein delivery using cell-penetrating peptides, and extracellular vesicles, as well as TF gene delivery approaches utilizing both lipid-based nanoparticles and viral strategies. Notably, engineered nanoparticles have emerged as promising platforms due to their precise control over TF delivery, improved specificity, and minimized off-target effects. Despite these significant advancements, major hurdles in delivery efficiency, cargo stability, and overall safety persist. Overcoming these obstacles will be essential to accelerate the clinical translation of TF-based therapeutics for a broad spectrum of diseases.

Deep Neural Networks Based on Sp7 Protein Sequence Prediction in Peri-Implant Bone Formation

Objective: Peri-implant bone regeneration is crucial for dental implant success, particularly in managing peri-implantitis, which causes inflammation and bone loss. SP7 (Osterix) is vital for osteoblast differentiation and bone matrix formation. Advances in deep neural networks (DNNs) offer new ways to analyze protein sequences, potentially improving our understanding of SP7's role in bone formation. This study aims to develop and utilize DNNs to predict the SP7 protein sequence and understand its role in peri-implant bone formation. Materials: and Methods: Sequences were retrieved from UniProt IDs Q8TDD2 and Q9V3Z2 using the UniProt dataset. The sequences were Sp7 fasta sequences. These sequences were located, and their quality was assessed. We built an architecture that can handle a wide range of input sequences using a DNN technique, with computing needs based on the length of the input sequences. Results: Protein sequences were analyzed using a DNN architecture with ADAM optimizer over 50 epochs, achieving a sensitivity of 0.89 and a specificity of 0.82. The receiver operating characteristic (ROC) curve demonstrated high true-positive rates and low false-positive rates, indicating robust model performance. Precision-recall analysis underscored the model's effectiveness in handling imbalanced data, with significant area under the curve (AUC-PR). Epoch plots highlighted consistent model accuracy throughout training, confirming its reliability for protein sequence analysis. Conclusion: The DNN employed with ADAM optimizer demonstrated robust performance in analyzing protein sequences, achieving an accuracy of 0.85 and high sensitivity and specificity. The ROC curve highlighted the model's effectiveness in distinguishing true positives from false positives, which is essential for reliable protein classification. These findings suggest that the developed model is promising for enhancing predictive capabilities in computational biology and biomedical research, particularly in protein function prediction and therapeutic development applications.

Pan-cancer bioinformatics indicates zinc finger protein 207 is a promising prognostic biomarker and immunotherapeutic target

In the era of personalized cancer treatment, understanding the complexities of tumor biology and immune modulation is paramount. This comprehensive analysis delves into the multifaceted role of zinc finger protein 207 (ZNF207) in pan-cancer, shedding light on its involvement in tumorigenesis, immune evasion, and therapeutic implications. Through integrated genomic and clinical data analysis, we reveal consistent upregulation of ZNF207 across diverse cancer types, highlighting its potential as a prognostic marker and therapeutic target, particularly for liver cancers. Notably, ZNF207 demonstrates intricate associations with clinical-pathological features, immune subtypes, and molecular pathways, indicating its pervasive influence in cancer biology. Furthermore, our study uncovers ZNF207's involvement in immune escape mechanisms, suggesting its potential as a modulator of immune responses within the tumor microenvironment. These findings underscore the significance of ZNF207 in shaping cancer progression and immune landscape, presenting promising avenues for targeted therapy and immunomodulation. Recognizing ZNF207's multifaceted contributions to cancer progression and immune evasion suggests its central role in understanding tumor immunology, beyond mere therapeutic targeting. Nevertheless, further mechanistic studies are imperative to elucidate ZNF207's precise molecular mechanisms and therapeutic implications in cancer treatment. This study primarily utilized various bioinformatics tools such as TIMER 2.0, cProSite, UALCAN, SangerBox, GEPIA2, TISIDB, and TIDE to analyze the expression of ZNF207 in multiple cancer samples from the TCGA database.

The combination of decitabine with multi-omics confirms the regulatory pattern of the correlation between DNA methylation of the CACNA1C gene and atrial fibrillation

Background

Studies have shown that DNA methylation of the CACNA1C gene is involved in the pathogenesis of various diseases and the mechanism of drug action. However, its relationship with atrial fibrillation (AF) remains largely unexplored.

Objective

To investigate the association between DNA methylation of the CACNA1C gene and AF by combining decitabine (5-Aza-2'-deoxycytidine, AZA) treatment with multi-omics analysis.

Methods

HepG2 cells were treated with AZA to observe the expression of the CACNA1C gene, which was further validated using gene expression microarrays. Pyrosequencing was employed to validate differentially methylated sites of the CACNA1C gene observed in DNA methylation microarrays. A custom DNA methylation dataset based on the MSigDB database was combined with ChIP-sequencing and RNA-sequencing data to explore the regulatory patterns of DNA methylation of the CACNA1C gene.

Results

Treatment of HepG2 cells with three different concentrations of AZA (2.5 µM, 5.0 µM, and 10.0 µM) resulted in 1.6, 2.5, and 2.9-fold increases in the mRNA expression of the CACNA1C gene, respectively, compared to the DMSO group, with statistical significance at the highest concentration group (p < 0.05). Similarly, AZA treatment of T47D cells showed upregulated mRNA expression of the CACNA1C gene in the gene expression microarray results (adj P < 0.05). DNA methylation microarray analysis revealed that methylation of a CpG site in intron 30 of the CACNA1C gene may be associated with AF (adj P < 0.05). Pyrosequencing of this site and its adjacent two CpG sites demonstrated significant differences in DNA methylation levels between AF and sinus rhythm groups (p < 0.05). Subsequent multivariate logistic regression models confirmed that the DNA methylation degree of these three sites and their average was associated with AF (p < 0.05). Additionally, the UCSC browser combined with ChIP-sequencing revealed that the aforementioned region was enriched in enhancer markers H3K27ac and H3K4me1. Differential expression and pathway analysis of RNA-sequencing data ultimately identified ATF7IP and KAT2B genes as potential regulators of the CACNA1C gene.

Conclusion

The DNA methylation levels at three CpG sites in intron 30 of the CACNA1C gene are associated with AF status, and potentially regulated by ATF7IP and KAT2B.

Genome-wide identification of alternative splicing related with transcription factors and splicing regulators in breast cancer stem cells responding to fasting-mimicking diet

Fasting-mimicking diet (FMD) can effectively inhibit the viability of breast cancer stem cells (CSCs). However, the molecular mechanisms underlying the inhibitory function of FMD on breast CSCs remain largely unknown. Elucidating the mechanisms by which FMD suppresses breast CSCs is beneficial to targeting breast CSCs. Herein, we systematically analyze alternative splicing and RNA binding protein (RBP) expression in breast CSCs during FMD. The analysis results show that a large number of regulated alternative splicing (RAS) and differentially expressed genes (DEGs) appear responding to FMD. Further studies show that there are potential regulatory relationships between transcription factors (TFs) with RAS (RAS-TFs) and their differentially expressed target genes (RAS-TF-DEGs). Moreover, differentially expressed RNA binding proteins (DERBPs) exhibit potential regulatory functions on RAS-TFs. In short, DERBPs potentially control the alternative splicing of TFs (RAS-TFs), regulating their target gene (RAS-TF-DEG) expression, which leads to the regulation of biological processes in breast CSCs during FMD. In addition, the alternative splicing and DEGs are compared between breast CSCs and differentiated cancer cells during FMD, providing new interpretations for the different responses of the two types of cells. Our studies will shed light on the understanding of the molecular mechanisms underlying breast CSC inhibition induced by FMD.

Single-cell multi-modal integrative analyses highlight functional dynamic gene regulatory networks directing human cardiac development

Illuminating the precise stepwise genetic programs directing cardiac development provides insights into the mechanisms of congenital heart disease and strategies for cardiac regenerative therapies. Here, we integrate in vitro and in vivo human single-cell multi-omic studies with high-throughput functional genomic screening to reveal dynamic, cardiac-specific gene regulatory networks (GRNs) and transcriptional regulators during human cardiomyocyte development. Interrogating developmental trajectories reconstructed from single-cell data unexpectedly reveal divergent cardiomyocyte lineages with distinct gene programs based on developmental signaling pathways. High-throughput functional genomic screens identify key transcription factors from inferred GRNs that are functionally relevant for cardiomyocyte lineages derived from each pathway. Notably, we discover a critical heat shock transcription factor 1 (HSF1)-mediated cardiometabolic GRN controlling cardiac mitochondrial/metabolic function and cell survival, also observed in fetal human cardiomyocytes. Overall, these multi-modal genomic studies enable the systematic discovery and validation of coordinated GRNs and transcriptional regulators controlling the development of distinct human cardiomyocyte populations.

Cell-fate conversion of intestinal cells in adult Drosophila midgut by depleting a single transcription factor

The manipulation of cell identity by reprograming holds immense potential in regenerative medicine, but is often limited by the inefficient acquisition of fully functional cells. This problem can potentially be resolved by better understanding the reprogramming process using in vivo genetic models, which are currently scarce. Here we report that both enterocytes (ECs) and enteroendocrine cells (EEs) in adult Drosophila midgut show a surprising degree of cell plasticity. Depleting the transcription factor Tramtrack in the differentiated ECs can initiate Prospero-mediated cell transdifferentiation, leading to EE-like cells. On the other hand, depletion of Prospero in the differentiated EEs can lead to the loss of EE-specific transcription programs and the gain of intestinal progenitor cell identity, allowing cell cycle re-entry or differentiation into ECs. We find that intestinal progenitor cells, ECs, and EEs have a similar chromatin accessibility profile, supporting the concept that cell plasticity is enabled by pre-existing chromatin accessibility with switchable transcription programs. Further genetic analysis with this system reveals that the NuRD chromatin remodeling complex, cell lineage confliction, and age act as barriers to EC-to-EE transdifferentiation. The establishment of this genetically tractable in vivo model should facilitate mechanistic investigation of cell plasticity at the molecular and genetic level.

Transcription Factors in Brain Regeneration: A Potential Novel Therapeutic Target

Transcription factors play a crucial role in providing identity to each cell population. To maintain cell identity, it is essential to balance the expression of activator and inhibitor transcription factors. Cell plasticity and reprogramming offer great potential for future therapeutic applications, as they can regenerate damaged tissue. Specific niche factors can modify gene expression and differentiate or transdifferentiate the target cell to the required fate. Ongoing research is being carried out on the possibilities of transcription factors in regenerating neurons, with neural stem cells (NSCs) being considered the preferred cells for generating new neurons due to their epigenomic and transcriptome memory. NEUROD1/ASCL1, BRN2, MYTL1, and other transcription factors can induce direct reprogramming of somatic cells, such as fibroblasts, into neurons. However, the molecular biology of transcription factors in reprogramming and differentiation still needs to be fully understood.

Programming human cell fate: overcoming challenges and unlocking potential through technological breakthroughs

In recent years, there have been notable advancements in the ability to programme human cell identity, enabling us to design and manipulate cell function in a Petri dish. However, current protocols for generating target cell types often lack efficiency and precision, resulting in engineered cells that do not fully replicate the desired identity or functional output. This applies to different methods of cell programming, which face similar challenges that hinder progress and delay the achievement of a more favourable outcome. However, recent technological and analytical breakthroughs have provided us with unprecedented opportunities to advance the way we programme cell fate. The Company of Biologists' 2023 workshop on 'Novel Technologies for Programming Human Cell Fate' brought together experts in human cell fate engineering and experts in single-cell genomics, manipulation and characterisation of cells on a single (sub)cellular level. Here, we summarise the main points that emerged during the workshop's themed discussions. Furthermore, we provide specific examples highlighting the current state of the field as well as its trajectory, offering insights into the potential outcomes resulting from the application of these breakthrough technologies in precisely engineering the identity and function of clinically valuable human cells.

Can we stop one heart from breaking: triumphs and challenges in cardiac reprogramming

Ischemic cardiac injury causes irreversible muscle loss and scarring, but recent years have seen dramatic advances in cardiac reprogramming, the field focused on regenerating cardiac muscle. With SARS-CoV2 increasing the age-adjusted cardiovascular disease mortality rate, it is worth evaluating the state of this field. Here, we summarize novel innovations in reprogramming strategies, insights into their mechanisms, and technologies for factor delivery. We also propose a broad model of reprogramming to suggest directions for future research. Poet Emily Dickinson wrote, "If I can stop one heart from breaking, I shall not live in vain." Today, researchers studying cardiac reprogramming view this line as a call to action to translate this revolutionary approach into life-saving treatments for patients with cardiovascular diseases.

Improving Efficiency of Direct Pro-Neural Reprogramming: Much-Needed Aid for Neuroregeneration in Spinal Cord Injury

Spinal cord injury (SCI) is a medical condition affecting ~2.5-4 million people worldwide. The conventional therapy for SCI fails to restore the lost spinal cord functions; thus, novel therapies are needed. Recent breakthroughs in stem cell biology and cell reprogramming revolutionized the field. Of them, the use of neural progenitor cells (NPCs) directly reprogrammed from non-neuronal somatic cells without transitioning through a pluripotent state is a particularly attractive strategy. This allows to "scale up" NPCs in vitro and, via their transplantation to the lesion area, partially compensate for the limited regenerative plasticity of the adult spinal cord in humans. As recently demonstrated in non-human primates, implanted NPCs contribute to the functional improvement of the spinal cord after injury, and works in other animal models of SCI also confirm their therapeutic value. However, direct reprogramming still remains a challenge in many aspects; one of them is low efficiency, which prevents it from finding its place in clinics yet. In this review, we describe new insights that recent works brought to the field, such as novel targets (mitochondria, nucleoli, G-quadruplexes, and others), tools, and approaches (mechanotransduction and electrical stimulation) for direct pro-neural reprogramming, including potential ones yet to be tested.

Amending the injured heart by in vivo reprogramming

Ischemic heart injury causes death of cardiomyocyte (CM), formation of a fibrotic scar, and often adverse cardiac remodeling, resulting in chronic heart failure. Therapeutic interventions have lowered myocardial damage and improved heart function, but pharmacological treatment of heart failure has only shown limited progress in recent years. Over the past two decades, different approaches have been pursued to regenerate the heart, by transplantation of newly generated CMs derived from pluripotent stem cells, generation of new CMs by reprogramming of cardiac fibroblasts, or by activating proliferation of preexisting CMs. Here, we summarize recent progress in the development of strategies for in situ generation of new CMs, review recent advances in understanding the underlying mechanisms, and discuss the challenges and future directions of the field.