Specific Signaling Pathways Research Articles

Biological and therapeutic impact of tumor mutational burden in microsatellite instability/mismatch repair-deficient (MSI/dMMR) metastatic colorectal cancer (mCRC) treated with immune checkpoint inhibitors (ICI).

272 Background: Microsatellite instability (MSI) is linked to hypermutability and response to ICI(s), especially in colorectal cancer. The predictive impact of tumor mutational burden (TMB) in ICI-treated MSI/dMMR metastatic colorectal cancer remains controversial, with some studies suggesting low TMB as a potential biomarker of resistance to ICI(s). We aimed to investigate the biological relevance of TMB in MSI/dMMR mCRC and its impact on survival outcomes in ICI(s)-treated patients (pts). Methods: MSI/dMMR mCRC pts treated with ICI(s) from the NIPICOL trial (NCT03350126) and the immunoMSI prospective monocentric cohort with available data from whole exome sequencing (WES) and RNA-sequencing (RNA-seq) were included. All cases were centrally assessed for MSI and dMMR status. TMB was calculated as described (Dupain et al., BMC, 2024). The search for a cutpoint able to optimize the difference in survival between 2 groups of patients with low and high-TMB was applied. The main endpoint was progression free survival (PFS) by iRECIST criteria. The cohort (NIPICOL, immunoMSI) was included as a covariate in the analysis of differential gene expression and pathway enrichment, with various tumor mutational burden (TMB) thresholds evaluated, specifically 10 and 30 mutations per megabase (mut/Mb). Results: A total of 99 pts were analyzed, with 4 (4%) excluded after central MSI/dMMR status review. Of these, 52 received anti-PD1 plus anti-CTLA4 therapy, while 43 received anti-PD1 alone. Median follow-up was 25 months. Median TMB was 51.8 mut/Mb (IQR: 35.9-74.9). TMB was not predictive of patient PFS, whatever the TMB threshold applied, including cutpoints already reported in the literature, the 2-year PFS rates being 80% versus 80% for TMB ≤ 10 and > 10 mut/Mb, and 79% versus 82% for TMB ≤ 30 and > 30 mut/Mb, respectively. Multivariate analysis including treatment type confirmed no association between TMB and PFS (HR 1.00, 95% CI [0.97–1.04]). TMB levels were not linked with specific signalling pathways related to immune checkpoints or antigen presentation as evaluated by RNA-seq with Gene Set Enrichment Analysis (GSEA) at a TMB threshold of 10 or 30 mut/Mb. However pathways involved in cell proliferation (e.g., “cell cycle”, “DNA replication”) were increased in TMB high (adjusted p-value <0.05). RNA-seq signature quantification and deconvolution analysis revealed similar cell populations (e.g., fibroblasts, B cells, T cells) between high and low TMB groups at a TMB threshold of 10 and 30 mut/Mb. Conclusions: TMB has no survival impact for patients with ICI(s)-treated dMMR/MSI mCRC and does not discriminate two biologically distinct subpopulations. Other biomarkers should be developed for personalized medicine amongst these patients.

Alterations in gut microbiome in age- and diet-induced colorectal cancer (CRC) progression in a preclinical model.

223 Background: CRC is the third leading cause of cancer related deaths worldwide with age and diet among the strongest risk factors. Emerging evidence suggests gut microbiome plays important role in CRC and is highly impacted by the exposome primarily the food intake. Since diet and age plays an important role in gut microbiome diversity, the present study aimed to investigate the alterations in the gut microbiome in young versus old mice harboring CRC allografts and fed with different diets. Methods: Two cohorts of C57BL/6 including young (n = 9, age = 6 weeks) and old (n = 9, age = 20-24 months) mice were implanted with 1x10 6 MSI (microsatellite instable) CRC MC38 tumor cells. Mice in both cohorts were randomized into three different diet groups: normal diet (ND; standard chow), high-fat (HF) and calorie-restricted (CR: 30% reduction in total calories). Mice were housed individually under standard laboratory conditions. Mice fecal samples were collected and subjected to DNA isolation (ZymoBIOMICS-96 MagBead DNA Kit), followed by metagenomic shotgun and whole genome sequencing (ZymoBIOMICSe and Illumina NovaSeq, respectively). P ≤ 0.05 were considered as statistically significant. Results: Fecal microbiome analysis showed that old microbiome has higher alpha diversity compared to the young mice. No statistically significant differences in were found in microbiome diversities between the diet groups. Pairwise permanova results showed statistically significant differences between microbiomes of old vs. young groups ( P : 0.001), CR vs. HF groups ( P : 0.012) and HF vs. ND groups ( P : 0.021). ANCOM-BC analysis determined the differentiating features and microbial functional pathways in the young mice compared to the old mice group and in different diet groups with relative abundance differences of larger than log 10 2. Bacteroides thetaiotaomicron ( P : 1.43E-39) and Parabacteroides goldsteinii ( P : 2.20E-23) were enriched in young and old groups, respectively. Akkermansia muciniphila ( P : 0.008) was significantly enriched in ND compared to CR group. Lactococcus lactis ( P : 9.94E-160) and Lachnospiraceae bacterium A4 ( P : 4.95E-10) were significantly enriched in HF compared to ND diet groups and vice-versa, respectively. Among the functional pathways, CMP-legionaminate biosynthesis I ( P : 2.38E-13) and L-arginine biosynthesis IV (archaebacteria) ( P : 4.77E-11) were the most significantly enriched in young and old groups, respectively. Conclusions: Our findings highlight the differential diversity and microbial features of gut microbiome in age- and diet-induced CRC progression. Collectively, alteration in diet and age of the host lead to changes in gut microbiota which has a direct impact on activation of specific signaling pathways, metabolism and local and systemic immune responses, which may in turn affect chemosensitivity and outcome in CRC

The role of circular RNAs in autoimmune diseases: Potential diagnostic biomarkers and therapeutic targets.

With the emergence of high-quality sequencing technologies, further research on transcriptomes has become possible. Circular RNA (circRNA), a novel type of endogenous RNA molecule with a covalently closed circular structure through "back-splicing," is reported to be widely present in eukaryotic cells and participates mainly in regulating gene and protein expression in various ways. It is becoming a research hotspot in the non-coding RNA field. CircRNA shows close relation to several varieties of autoimmune diseases (AIDs) in both the physiological and pathological level and could potentially be used clinically in terms of diagnosis and treatment. Here, we focus on reviewing the importance of circRNA in various AIDs, with the aim of establishing new biomarkers and providing novel insights into understanding the role and functions of circRNA in AIDs. Specific signaling pathways of how circular RNAs are regulated in AIDs will also be illustrated in this review.

Dietary Restrictions and Cancer Prevention: State of the Art

Worldwide, almost 10 million cancer deaths occurred in 2022, a number that is expected to rise to 16.3 million by 2040. Primary prevention has long been acknowledged as a crucial approach to reducing cancer incidence. In fact, between 30 and 50 percent of all tumors are known to be preventable by eating a healthy diet, staying active, avoiding alcohol, smoking, and being overweight. Accordingly, many international organizations have created tumor prevention guidelines, which underlie the importance of following a diet that emphasizes eating plant-based foods while minimizing the consumption of red/processed meat, sugars, processed foods, and alcohol. However, further research is needed to define the relationship between the effect of specific diets or nutritional components on cancer prevention. Interestingly, reductions in food intake and dietetic restrictions can extend the lifespan of yeast, nematodes, flies, and rodents. Despite controversial results in humans, those approaches have the potential to ameliorate health via direct and indirect effects on specific signaling pathways involved in cancer onset. Here, we describe the latest knowledge on the cancer-preventive potential of dietary restrictions and the biochemical processes involved. Molecular, preclinical, and clinical studies evaluating the effects of different fasting strategies will also be reviewed.

A Coordination Nanosystem Enables Endogenous Ferric Ion-Initiated Multi-Catalysis for Synergistic Tumor-Specific Ferroptosis and Gene Therapy.

Emerging evidence demonstrates that inducing ferroptosis, a nonapoptotic programmed cell death mode, holds significant potential for tumor treatment. However, current ferroptosis strategies utilizing exogenous Fenton-type heavy metal species or introducing glutathione (GSH)/glutathione peroxidase 4 (GPX4) suppressants are hampered by latent adverse effects toward organisms, while utilizing endogenous iron may cause undesirable tumor angiogenesis through specific signaling pathways. Here, aferric ion (Fe3+)-responsive and DNAzyme-delivered coordination nanosystem (ZDD) is developed to achieve a novel scheme of synergistic tumor-specific ferroptosis and gene therapy, which modulates and harnesses the endogenous iron in tumors for inducing ferroptosis while intercepting tumor angiogenesis to enhance therapeutic efficacy. Profiting from the characteristic coordination structure and components, ZDD can not only specifically capture tumor endogenous Fe3+ into the tumor cells to promote the catalytic generation of hydroxyl radicals (·OH) and superoxide anions (O2·-) under acidic environment and the catalytic GSH oxidation, arousing potent ferroptotic cell death, but also effectively deliver specific DNAzyme and release abundant zinc ion (Zn2+) as a powerful cofactor to activate the biocatalytic cleavage of vascular endothelial growth factor receptor 2 (VEGFR2) gene for angiogenesis suppression. Ultimately, the ZDD-enabled synergistic therapy prominently inhibited tumor growth and prevented metastasis, representing a promising nanotherapeutic formula for safe and efficient tumor therapy.

From actinic keratosis to cutaneous squamous cell carcinoma: the key pathogenesis and treatments

Cutaneous squamous cell carcinoma (cSCC) is the second most common non-melanoma skin cancer, among which 82% arise from actinic keratosis (AK) characterized by lesions of epidermal keratinocyte dysplasia. It is of great significance to uncover the progression mechanisms from AK to cSCC, which will facilitate the early therapeutic intervention of AK before malignant transformation. Thus, more and more studies are trying to ascertain the potential transformation mechanisms through multi-omics, including genetics, transcriptomics, and epigenetics. In this review, we gave an overview of the specific biomarkers and signaling pathways that may be involved in the pathogenesis from AK to cSCC, pointing out future possible molecular therapies for the early intervention of AK and cSCC. We also discussed current interventions on AK and cSCC, together with future perspectives.

Cancer Stem Cell Regulation as a Target of Therapeutic Intervention: Insights into Breast, Cervical and Lung Cancer.

Cancer Stem Cells (CSCs) play an important role in the development, resistance, and recurrence of many malignancies. These subpopulations of tumor cells have the potential to self-renew, differentiate, and resist conventional therapy, highlighting their importance in cancer etiology. This review explores the regulatory mechanisms of CSCs in breast, cervical, and lung cancers, highlighting their plasticity, self-renewal, and differentiation capabilities. CD44+/CD24- cells are a known marker for breast CSCs. Markers like as CD133 and ALDH have been discovered in cervical cancer CSCs. Similarly, in lung cancer, CSCs identified by CD44, CD133, and ALDH are linked to aggressive tumor behavior and poor therapy results. The commonalities between these tumors highlight the general necessity of targeting CSCs in treatment efforts. However, the intricacies of CSC activity, such as their interaction with the tumor microenvironment and particular signaling pathways differ between cancer types, demanding specialized methods. Wnt/β-catenin, Notch, and Hedgehog pathways are one of the essential signaling pathways, targeting them, may show ameliorative effects on breast, lung and cervical carcinomas and their respective CSCs. Pre-clinical data suggests targeting specific signaling pathways can eliminate CSCs, but ongoing clinical trials are on utilizing signaling pathway inhibitors in patients. In recent studies it has been reported that CAR T based targeting of specific markers may be used as combination therapy. Ongoing research related to nanobiotechnology can also play a significant role in diagnosis and treatment purpose targeting CSCs, as nanomaterials can be used for precise targeting and identification of CSCs. Further research into the targeting of signaling pathways and its precursors could prove to be right step into directing therapies towards CSCs for cancer therapy.

Attributes novel drug candidate: Constitutive GPCR signal bias mediated by purinergic receptors.

G protein-coupled receptors (GPCRs) can transmit signals via G protein-dependent or independent pathways due to the conformational changes of receptors and ligands, which is called biased signaling. This concept posits that ligands can selectively activate a specific signaling pathway after receptor activation, facilitating downstream signaling along a preferred pathway. Biased agonism enables the development of ligands that prioritize therapeutic signaling pathways while mitigating on-target undesired effects. As a class of GPCRs located on the surface of cell membranes, the discovery and clinical implementation of adenosine and P2Y receptors purinergic signaling modulators have progressed dramatically. However, many preclinical drug candidates targeting purinergic receptors have failed in clinical trials due to limited efficacy and/or severe on-target undesired effects. To overcome the key barriers typically encountered when transitioning ligands into the clinic, the renewed impetus has focused on the modulation of purinergic receptor function by exogenous agonists/antagonists and allosteric modulators to exploit biased agonism. This article provides a brief overview of the research progress on the mechanism of purinergic biased signal transduction from the conformational changes of purinergic GPCRs and biased ligands primarily, and highlights therapeutically relevant biased agonism at purinergic receptors.

Regulatory Mechanisms of Signaling Pathways in Liver Cancer Treatment with Traditional Chinese Medicine.

Traditional Chinese Medicine (TCM), as a longstanding therapeutic approach, offers unique advantages and potential in the treatment of liver cancer. Recent studies have highlighted its role in preventing liver cancer progression by modulating key signaling pathways. TCM's multi-component, multi-target, and multi-pathway mechanisms of action have garnered significant attention in the medical community for their ability to address complex diseases like liver cancer. This review examines the current status and challenges in the application of TCM to regulate specific signaling pathways, including PI3K/Akt, NF-κB, TGF-β, Wnt/β-Catenin, and Notch, in liver cancer treatment. The goal is to further elucidate the critical roles of these pathways in liver cancer progression and provide new insights into the modern scientific interpretation of TCM. Literature was retrieved from PubMed and Web of Science databases using keywords such as "traditional Chinese medicine," "Chinese medicine," and "signaling pathway." The articles reviewed span from 2004 to 2024. TCM demonstrates significant therapeutic and preventive effects in liver cancer by modulating signaling pathways involved in tumorigenesis. These pathways influence processes such as cell growth, invasion, proliferation, and inflammatory responses, contributing to the anti-cancer effects of TCM. By modulating key signaling pathways such as PI3K/Akt, NF-κB, TGF-β, Wnt/β-Catenin, and Notch, TCM plays an important role in both the treatment and prevention of liver cancer, offering a promising therapeutic approach grounded in traditional practices and modern scientific understanding.

LGR4 is a key regulator of hepatic gluconeogenesis.

Emerging evidence underscored the significance of leucine-rich repeat-containing G protein-coupled receptor (LGR) 4 in endocrine and metabolic disorders. Despite this, its role in LGR4 in hepatic glucose metabolism remains poorly understood. In this study we set out to test whether LGR4 regulates glucose production in liver through a specific signaling pathway. Hepatic glucose production and gluconeogenic gene expressions were detected after silence of LGR4 in three obese mice models. Then, whole-body LGR4-deficient (LGR4 KO) mice, liver-specific LGR4 knockout (LGR4LKO) mice, and liver-specific LGR4 overexpression (LGR4LOV) mice were generated, in which we analyzed the effects of LGR4 on hepatic glucose metabolism upon HFD feeding, among which live imaging and quantitative analysis of hepatic phosphoenolpyruvate carboxykinase (PEPCK)-luciferase activity were conducted. LGR4 expression was significantly upregulated in the liver of three obese mouse models, and presented dynamic expression patterns in response to nutritional fluxes. We utilized global and liver-specific LGR4 knockouts (LGR4LKO), along with adenoviral-mediated LGR4 knockdown in mice, to show improved glucose tolerance and decreased hepatic gluconeogenesis. Specifically, the expression of rate-limiting gluconeogenic enzymes, PEPCK was significantly downregulated. Conversely, mouse model with adenovirus-mediated LGR4 overexpression (LGR4LOV) exhibited elevated gluconeogenesis and PEPCK expression and reversed the suppression observed in LGR4 knockout models. Notably, neither RANKL nor PKA signaling pathways, which were reported to take part in LGR4's function, were involved in the process of LGR4 regulating PEPCK. Instead, TopFlash reporter system and inhibitors application suggested that LGR4's influence on hepatic gluconeogenesis operates through the canonical Wnt/β-catenin/TCF7L2 signaling pathway. Overall, these findings underscore a novel mechanism by which LGR4 regulates hepatic gluconeogenesis, presenting a potential therapeutic target for diabetes management.

Comprehensive review of plant small signaling peptides: From stress adaptation mechanisms to practical solutions for crop resilience.

Small signaling peptides (SSPs), short proteins of fewer than 100 amino acids, serve as pivotal signaling molecules with diverse structural features, post-translational modifications, and functional roles. They regulate various aspects of plant growth and development by modulating specific cellular signaling pathways. Research has shown that many SSPs are essential for mediating responses to environmental stresses. This review presents the structure, characteristics, and classification of plant SSPs and elucidates their roles in resistance signaling pathways through interactions with their specific receptors. We then summarize recent findings on the biological functions and regulatory mechanisms of SSPs in response to both biotic and abiotic stresses. Finally, we discuss the potential applications and future prospects of these peptides in plant protection. This review offers valuable insights for enhancing plant resilience to environmental stress and advancing sustainable agricultural practices, while also providing key references and perspectives to accelerate research on SSPs in plants.

Applications and prospects of graphene and its derivatives in bone repair

To summarize the latest research progress of graphene and its derivatives (GDs) in bone repair. The relevant research literature at home and abroad in recent years was extensively accessed. The properties of GDs in bone repair materials, including mechanical properties, electrical conductivity, and antibacterial properties, were systematically summarized, and the unique advantages of GDs in material preparation, functionalization, and application, as well as the contributions and challenges to bone tissue engineering, were discussed. The application of GDs in bone repair materials has broad prospects, and the functionalization and modification technology effectively improve the osteogenic activity and material properties of GDs. GDs can induce osteogenic differentiation of stem cells through specific signaling pathways and promote osteogenic activity through immunomodulatory mechanisms. In addition, the parameters of GDs have significant effects on the cytotoxicity and degradation behavior. GDs has great potential in the field of bone repair because of its excellent physical and chemical properties and biological properties. However, the cytotoxicity, biodegradability, and functionalization strategies of GDs still need to be further studied in order to achieve a wider application in the field of bone tissue engineering.

Ezetimibe Anticancer Activity via the p53/Mdm2 Pathway.

Ezetimibe is used to treat cardiovascular disease as it blocks the sterol transporter Niemann-Pick C1-Like 1 (NPC1CL1) protein. However, recent evidence indicates that Ezetimibe inhibits several cancers indirectly by reducing circulating cholesterol or via specific signalling pathways. Our in silico studies indicate that Ezetimibe binds to the Tp53 binding domain in Mdm2, forming a more thermodynamically stable complex than nutlin3a. Furthermore, a docking study of the newly developed inhibitors-RG7388 and RG7112-was conducted. This further showed lower binding energies of -6.337 kcal/mol and -6.222 kcal/mol, respectively, when compared to the -7.919 kcal/mol exhibited by Ezetimibe. We show that Ezetimibe inhibits the growth of several cancer cell lines at concentrations that are not toxic to a normal cell line. Thus, Ezetimibe is probably active against cancers that overexpress Mdm2. Moreover, inhibitors of RBBP6 may be combined with Ezetimibe for effective anticancer activity. Due to poor oral bioavailability, Ezetimibe must be administered parenterally for cancer treatment.

Role of exosomal miRNAs and macrophage polarization in gastric cancer: A novel therapeutic strategy.

Gastric cancer (GC) is one of the most common gastrointestinal cancers worldwide, with consistently high morbidity and mortality rates and poor prognosis. Most patients are diagnosed at an advanced stage due to the lack of specific presentation in the early stages. Exosomes are a class of extracellular vesicles (EVs) widely found in body fluids and can release genetic material or multiple proteins to facilitate intercellular communication. In recent years, exosomal miRNAs have gained attention for their role in various cancers. These exosomal miRNAs can impact GC development and progression by targeting specific genes or influencing signaling pathways and cytokines involved in Angiogenesis, epithelial-mesenchymal transition (EMT), drug resistance, and immune regulation. They show great potential in terms of diagnosis, prognosis, and treatment of GC. Notably, the gastrointestinal tract has the largest number of macrophages, which play a significant role in GC progression. Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment (TME) and can influence macrophage programming through various mediators, including macrophage polarization. Macrophage polarization is involved in inflammatory responses and significantly impacts the GC process.

Integrated approach with UHPLC-Q-Exactive-tandem mass spectrometry, network analysis, and molecular docking to determine potential active compounds and mechanisms of Rhizoma Musae decoction in osteoarthritis treatment.

This study aimed to identify the potential active compounds in Rhizoma Musae decoction and understand their mechanisms of action in osteoarthritis treatment. UHPLC-Q-Exactive-MS/MS technology was used for an in-depth analysis of the chemical compounds present in Rhizoma Musae decoction. A network analysis approach was used to construct a comprehensive network of compounds, targets, and pathways, which provided insights into the molecular mechanisms of Rhizoma Musae decoction in osteoarthritis treatment. The integrated analysis revealed the presence of 534 chemical compounds in Rhizoma Musae decoction, with 7beta-hydroxyrutaecarpine, 7,8-dihydroxycoumarin, pinocembrin diacetate, and scopoletin being identified as potential active compounds. Potential targets such as GAPDH, AKT1, TNF, IL6, and SRC were implicated in key pathways including MAPK signaling pathway, lipid and atherosclerosis, PI3K-Akt signaling pathway, and IL-17 signaling pathway. Molecular docking studies showed significant binding affinity between the core targets and key components. In vitro cell experiments have demonstrated that RM decoction can enhance cell proliferation and upregulates the expression of TNFα, IL-6, and SRC, while down-regulating the expression of GAPDH and AKT1. The potential active compounds present in Rhizoma Musae decoction influence specific targets and signaling pathways involved in osteoarthritis pathogenesis, providing new insights for the functional development and utilization of RM.

Modulation of post‐surgery fibrosis in glaucoma filtration surgery by targeting retinoic acid signaling

Aims/Purpose: Glaucoma filtration surgery (GFS) aims to alleviate intraocular pressure by improving fluid drainage from the eye. However, post‐surgery scarring, particularly around the surgical site, can impede fluid flow and compromise surgical outcomes. Dysregulated inflammatory responses and abnormal extracellular matrix (ECM) remodeling contribute to excessive scarring. Retinoic acid signaling is known to modulate immune responses, ECM remodeling, and fibrosis in various organs. This study seeks to investigate the influence of key retinoic acid signaling components on post‐surgery scarring in the eye.Methods: Expression levels and patterns of selected retinoic acid signaling pathway components were assessed in conjunctival tissues of C57BL/6 mice undergoing GFS using RT‐PCR and Western blot analysis. Mice with global deletion of specific retinoic acid signaling pathway components underwent GFS to evaluate their role in subconjunctival fibrosis. Inflammatory responses were evaluated by immunofluorescence staining for the pan‐myeloid marker CD11b, and fibrotic tissue was visualized using Masson's trichrome stain. Subconjunctival tissues from knockout and wild‐type littermate controls were analyzed for inflammatory cytokines, chemokines, and fibrotic markers via Western blot analysis.Results: GFS induced the expression of different components of the retinoic acid signaling pathway in mice. Deletion of specific retinoic acid signaling pathway components resulted in alterations in GFS‐induced recruitment of myeloid cells and ECM remodeling.Conclusions: Modulating retinoic acid signaling presents a promising approach for controlling post‐surgery fibrosis in the eye, offering an alternative avenue to enhance the outcomes of glaucoma filtration surgery.

A Guide to Breast Cancer Research: An Introduction.

"A Guide to Breast Cancer Research: From Cells and Molecular Mechanisms to Therapy" is designed as a comprehensive reference for early career investigators and postgraduate students. This book aims to provide a broad overview of contemporary breast cancer research. It covers key areas including development and cancer, metastasis and immunology, subtypes, signalling, therapy, and resistance. This book is organised into seven sections addressing mammary gland development, model systems, cellular origins and heterogeneity, cellular and molecular bases, signalling pathways, metastasis and immunity, and treatment and resistance mechanisms. A few topics such as specific signalling pathways, some emerging therapies, imaging technologies, and AI applications are only briefly mentioned or omitted, reflecting the ever-evolving nature of breast cancer research. This book emphasises the importance of collaboration in advancing cancer research. Initiatives like the Cancer Moonshot and Cancer Grand Challenges advocate for "radical collaboration" of researchers with shared visions and resources. We also note the significance of global efforts in breast cancer research, the need for addressing disparities in care across different regions and for equity in healthcare. Overall, this book showcases milestones and advances in breast cancer research over the past three decades, reflecting significant progress in understanding and treating the disease, which has led to improved patient outcomes.

Dual-stimuli-responsive nanoparticles for the co-delivery of small molecules to promote neural differentiation of human iPSCs.

The differentiation of human induced pluripotent stem cells (hiPSCs) into neural progenitor cells (NPCs) is a promising approach for the treatment of neurodegenerative diseases and regenerative medicine. Dual-SMAD inhibition using small molecules has been identified as a key strategy for directing the differentiation of hiPSCs into NPCs by regulating specific cell signaling pathways. However, conventional culture methods are time-consuming and exhibit low differentiation efficiency in neural differentiation. Nanocarriers can address these obstacles as an efficient platform for the controlled release and accurate delivery of small molecules. In this paper, we developed calcium phosphate-coated mesoporous silica nanoparticles capable of delivering multiple small molecules, including LDN193189 as a bone morphogenetic protein (BMP) inhibitor and SB431542 as a transforming growth factor (TGF)-beta inhibitor, for direct differentiation of hiPSC-mediated NPCs. Our results demonstrated that this nanocarrier-mediated small molecule release system not only enhanced the in vitro formation of neural rosettes but also modulated the expression levels of key markers. In particular, it downregulated OCT4, a marker of pluripotency, while upregulating PAX6, a critical marker for the neuroectoderm. These findings suggest that this controlled small molecule release system holds significant potential for therapeutic applications in neural development and neurodegenerative diseases.

Recording Lineage History with Cellular Barcodes in the Mammary Epithelium and in Breast Cancer.

Lineage tracing methods have extensively advanced our understanding of physiological cell behaviour in vivo and in situ and have vastly contributed to decipher the phylogeny and cellular hierarchies during normal and tumour development. In recent years, increasingly complex systems have been developed to track thousands of cells within a given tissue or even entire organisms. Cellular barcoding comprises all techniques designed to genetically label single cells with unique DNA sequences or with a combination of fluorescent proteins, in order to trace their history and lineage production in space and time. We distinguish these two types of cellular barcoding as genetic or optical barcodes. Furthermore, transcribed cellular barcodes can integrate the lineage information with single-cell profiling of each barcoded cell. This enables the potential identification of specific markers or signalling pathways defining distinct stem cell states during development, but also signals promoting tumour growth and metastasis or conferring therapy resistance.In this chapter, we describe recent advances in cellular barcoding technologies and outline experimental and computational challenges. We discuss the biological questions that can be addressed using single-cell dynamic lineage tracing, with a focus on the study of cellular hierarchies in the mammary epithelium and in breast cancer.

Reactive oxygen species: Orchestrating the delicate dance of platelet life and death.

Platelets, which are vital for blood clotting and immunity, need to maintain a delicately balanced relationship between generation and destruction. Recent studies have highlighted that reactive oxygen species (ROS), which act as second messengers in crucial signaling pathways, are crucial players in this dance. This review explores the intricate connection between ROS and platelets, highlighting their dual nature. Moderate ROS levels act as potent activators, promoting megakaryocyte (MK) differentiation, platelet production, and function. They enhance platelet binding to collagen, increase coagulation, and directly trigger cascades for thrombus formation. However, this intricate role harbors a double-edged sword. Excessive ROS unleash its destructive potential, triggering apoptosis and reducing the lifespan of platelets. High levels can damage stem cells and disrupt vital redox-dependent signaling, whereas uncontrolled activation promotes inappropriate clotting, leading to thrombosis. Maintaining a precise balance of ROS within the hematopoietic microenvironment is paramount for optimal platelet homeostasis. While significant progress has been made, unanswered questions remain concerning specific ROS signaling pathways and their impact on platelet disorders. Addressing these questions holds the key to unlocking the full potential of ROS-based therapies for treating platelet-related diseases such as thrombocytopenia and thrombosis. This review aims to contribute to this ongoing dialog and inspire further exploration of this exciting field, paving the way for novel therapeutic strategies that harness the benefits of ROS while mitigating their dangers.