Hepatic macrophages, encompassing embryonic Kupffer cells (emKCs) and monocyte-derived macrophages (MoMFs), are recognized as important regulators of hepatic homeostasis and key players in the pathogenesis of liver diseases such as metabolic dysfunction-associated steatotic liver disease (MASLD). Emerging research focuses on the critical role of hepatic macrophages in mediating liver repair and regeneration following injury, where they closely interact with hepatocytes as well as hepatic stellate cells (HSCs) to regulate inflammation, fibrosis, tissue remodeling and regeneration. The latest single-cell and spatial omics technologies have profoundly deepened our understanding of the hepatic immune response, revealing the remarkable phenotypic and spatial heterogeneity of macrophages, including distinct subsets such as lipid-associated macrophages (LAMs) within steatotic and fibrotic regions. Macrophage subsets sense systemic (e.g. gut-liver axis, adipose tissue) and local stress signals and orchestrate disease-defining cellular responses in hepatocytes, HSC and other immune cells. Dynamic tools such as intravital microscopy have further unveiled functional properties in the spatial context hitherto unknown. Herein, we review the multifaceted roles of hepatic macrophages in liver injury and repair, with an emphasis on their role in steatosis, inflammation, fibrosis, and regeneration. We also discuss how these insights may inform the development of novel macrophage-targeted therapeutic interventions.

The sustained production of blood and immune cells is driven by a pool of hematopoietic stem cells (HSCs) and their offspring. Due to the intrinsic heterogeneity of HSCs, the composition of emergent clones changes over time, leading to a reduced clonality in aging mice and humans. Theoretical analyses suggest that clonal conversion rates and clonal complexity depend not only on HSC heterogeneity, but also on additional stress conditions. These insights are particularly relevant in the context of stem cell transplantations, which still remain the only curative option for many hematologic diseases, increasingly considered viable for elderly individuals. However, age-related clonal changes post-transplantation are not well understood.

The precise timing of stem cell specification and niche formation during murine incisor development is poorly understood, and it is unclear whether these processes occur simultaneously or in a sequential manner. Functional dental epithelial stem cells are marked by the expression of Sox2, a transcription factor that is broadly expressed in the dental epithelium at the dentition onset and restricted to stem cells in fully developed incisor. Using genetic lineage tracing in Sox2CreERT2/+; R26RmT/mGand Sox2CreERT2/+; R26RtdT/+embryos along with a single-cell RNA sequencing at different stages of incisor development, we investigated the timing of the stem cell specification and its temporal relationship with niche formation. Our results reveal the presence of a Sox2-expressing stem cell-like population prior to formation of the functional niche. These cells localize to the leading edge of the advancing incisor epithelium where they are maintained in an undifferentiated state. Our data demonstrate presence of actomyosin network and a generation of a contractile tension which helps confine Sox2+ stem cells to the leading edge. This mechanical confinement likely plays an important role in maintaining their stemness until the niche is functionally and structurally established. Partial or complete disruption of the actomyosin network disables the clustering of Sox2-expressing cells, potentially triggering their premature differentiation, and ultimately leads to impaired formation of the functional stem cell niche and abnormal growth of the incisor.

Mesenchymal stromal/stem cell (MSC) transplantation has emerged as a promising therapeutic strategy for managing cutaneous scarring, an issue associated with significant aesthetic and functional morbidity. This systematic review evaluates the potential of MSCs to modulate scarring, highlighting their efficacy and distinct mechanisms from traditional scar treatments.

The fate of hematopoietic stem cells (HSCs) is determined by a complex regulatory network supporting self-renewal and quiescence within a niche. Umbilical cord mesenchymal stromal cells (UC-MSCs) are classified as an alternative niche for the expansion of hematopoietic stem and progenitor cells (HSPCs). The molecular mechanisms by which UC-MSCs regulate hematopoiesis are still not fully understood. In this study, the cocultures of UC-MSCs and umbilical cord blood CD34+ (UCB-CD34+) cells were established. Immunophenotype, cell proliferation, and hematopoietic function of UCB-CD34+ cells were evaluated on days 0 to 7. UC-MSCs promoted UCB-CD34+ cell proliferation but were less effective at preserving their stemness. Notably, UC-MSCs promoted the myeloid lineage commitment, significantly observed on day 3. Integrative transcriptomic analysis highlighted the molecular signature and regulatory networks of UC-MSCs. The long non-coding RNA (lncRNA)-RNA binding protein (RBP) interaction network and lncRNA cis- and trans-regulatory networks were evident. The significant 3-gene modules and a set of 10-hub genes were identified in the protein-protein interaction (PPI) network, including RPS16, CD74, RPL35, COX7C, RPL38, RPS28, RPS27, RPS10, TARDBP, and TOMM7. These findings exemplify the niche activity of UC-MSCs in regulating cell differentiation, genomic stability maintenance, and modulation of the hematopoietic supportive niche. The transcriptional landscape, together with the identified regulatory networks, gene modules, and key hub genes provide new insights into the molecular mechanisms of UC-MSCs and establish a basis for refining ex vivo culture systems for therapeutic HSC expansion.

Hematopoietic stem cell (HSC) transplantation is a lifesaving therapy for hematologic diseases, but its broader application remains constrained by challenges in sourcing, manipulating, and reliably expanding functional HSCs. In this review, we discuss strategies to expand and engineer HSCs by recreating essential aspects of the bone marrow niche. These include defined cytokine cocktails, small molecule modulators, stromal co-culture systems, and biomaterials that promote self-renewal while limiting differentiation. We highlight advances in three-dimensional organoid models and microfluidic platforms that better support long-term repopulating cells and reflect native microenvironments. In parallel, progress in gene delivery platforms, including both viral and nonviral approaches, is enabling more efficient and targeted modification of HSCs for therapeutic use in genetic disorders such as sickle cell disease and β-thalassemia. While these tools have advanced significantly, significant hurdles remain in scaling, preserving stem cell identity, and reducing culture-induced stress. Continued refinement of biomimetic systems and genome engineering technologies will be central to expanding the clinical utility of HSC-based therapies.

Breast cancer is a highly heterogeneous disease with diverse phenotypes. At present, increasing evidence supports the role of ribosomal biogenesis in human diseases and tumorigenesis. PNO1, as a ribosome assembly factor, plays a key role in the biological synthesis of ribosomes and ribosomal protein mutations associated with human diseases and tumor development. This study explored PNO1's role as a prognostic biomarker for breast cancer.

The adult heart consists of a fixed number of cardiomyocytes (CMs) determined at birth. CMs once lost due to injury in the adult heart are never replaced, initiating a viscous cycle of adverse events leading to heart failure. Therapeutic interventions that drive cardiac repair by proliferation of the endogenous CMs or adoptive transfer of stem cells such as cardiac tissue derived stem/progenitor cells (CPCs) are promising albeit limited in their ability to repair the heart. Numerous studies have identified an inherent regenerative power of the heart during embryonic and postnatal development. The developmental cardiac tissue can initiate a robust regenerative response leading to complete resolution of injury. Unique cellular and molecular mechanisms in the developmental heart are at the core of this regenerative ability. Upon cardiac maturation, cellular differentiation and changes in molecular signaling hubs active developmentally are 'switched off' in the adult heart. Recent work has shown convincing results for promoting cardiac repair in the adult heart by reactivation of developmental signaling. CPCs engineering with developmental factors or their CMs specific delivery of can reactivate regenerative signaling to augment cardiac structure and function in the adult heart. This review aims to summarize efforts regarding reactivation of developmental signaling factors in the heart using CPCs and CMs. A special emphasis is on embryonic/developmental microRNAs governed signaling pathways for cardiac repair. We provide an in-depth analysis of the current state of the field including discussion of some of the limitations that will be beneficial for future studies. Significance statement: Reactivation of developmental signaling in the heart is promising approach to increase cardiac regeneration after myocardial injury. This article summarizes current state of the field regarding signaling factors that regulated developmental signaling in the context of cardiac progenitor cells and cardiomyocytes to promote cell proliferation and increase their overall repair ability.

Bovine embryonic stem cells (bESCs) can greatly enhance the understanding of bovine embryonic development and applications for disease-resistance, biomedical and zoonotic pre-clinical models. However, formative bESCs with distinct morphology and complete differentiation capacity are still unreported. We document here the generation of formative bESCs (bFSCs) which are pluripotent both in vitro and in vivo, and efficiently converted into neural progenitor cells (NPCs) and primordial germ cell-like cells (PGCLCs) by direct differentiation. Transcriptomic analysis reveal these cells exhibited distinct metabolic features from human and mouse ESCs and early embryos. bFSCs contributed to a wide range of cell types within embryonic and extraembryonic tissues after aggregating with mouse and bovine embryos, as confirmed by chimeric experiment and single cell RNA-seq (scRNA-seq). The establishment of bFSCs with dual developmental plasticity represents a milestone for agricultural biotechnology and decoding the underlying mechanism of bona fide bovine pluripotency.

A reduction in circulating endothelial progenitor cells (EPCs) comprise an important part of vascular aging. However, the underlying mechanisms that mediate this EPC decline remain unclear. Here, we demonstrate a novel molecular mechanism where aging increases inhibitory T cell subsets and impairs SDF1-mediated increase of circulating EPCs. SomaScan proteomics and western blot analysis revealed FABP4 as the top upregulated protein in plasma and was also increased in the bone marrow in aging. Importantly, treatment with FABP4 in bone marrow cells increased inhibitory T cells while decreased SDF-1 receptor, CXCR4 in EPCs, whereas blocking FABP4 signaling by BMS309403 or depleting these T cells restored surface expression of CXCR4 in EPCs. Notably, FABP4-mediated decrease of circulating EPC in aging were restored by therapeutic administration of mitochondria, wherein plasma FABP4 was decreased along with reducing inhibitory T cell induction in bone marrow and increasing circulating EPCs in older mice. Collectively, these findings provide new insight into the involvement of age-associated T cell immunity in EPC dysregulation, and FABP4 may be a therapeutic target to detain vascular aging.

Determining the potency of MSCs is a critical component of their application as cellular therapies. The function of MSCs does not rely on a single mechanism but rather on overlapping and cumulative effector pathways, which necessitates the assay matrix strategy in potency analysis. Artificial intelligence (AI) tools can significantly enhance the assay matrix strategy by generating novel potency scores that capture unified critical quality attributes that may not be readily discernible through human analysis. AI can provide precise potency metrics for investigational MSC products by comparing them to appropriate controls. The next generation of MSC potency analysis will increasingly rely on AI tools, as they can match patients with MSC products exhibiting the most appropriate potency profiles for personalized and targeted therapies. A significant challenge in deploying AI tools is the need for robust predictors of efficacy that relates to the potency of Investigational MSC products. Nevertheless, AI has the potential to stratify patients who are most likely to respond to MSC therapy by leveraging clinical data in combination with detailed potency analyses. We discuss these opportunities and challenges in this perspective article.

The development of committed erythroid progenitors and their continued maturation into erythrocytes requires the cytokine erythropoietin (Epo). Here, we describe the immunophenotypic identification of a CD34- colony-forming unit-erythroid (CFU-E) progenitor subtype, termed late CFU-E (lateC), that arises in an Epo-dependent manner during human early erythropoiesis (EE). LateC cells lack CD235a (glycophorin A) but have high levels of CD71 and CD105, characterized as Lin-CD123-CD235a-CD49d+CD117+CD34-CD71hiCD105hi. Analysis of ex vivo cultures of bone marrow (BM) CD34+ cells showed that acquisition of the CD71hiCD105hi phenotype in lateC occurs through the formation of four other EE subtypes. Of these, two are CD34+ burst-forming unit-erythroid (BFU-E) cells, distinguishable as CD71loCD105lo early BFU-E (earlyB) and CD71hiCD105lo late BFU-E (lateB), and two are CD34- CFU-E, also distinguishable as CD71loCD105lo early CFU-E (earlyC) and CD71hiCD105lo mid CFU-E (midC). The EE transitions are accompanied by a rise in CD36 expression, such that all lateC cells are immunophenotypically CD36+. Patterns of CD34, CD36, and CD71 indicate two differentiation routes-in one earlyB lose CD34 to form earlyC, and in another, earlyB gain CD36 and CD71hi expression prior to losing CD34 to form midC, bypassing the earlyC stage. Regardless of the route, the transition from midC to lateC requires Epo. All five EE subtypes could be prospectively detected in human BM cells and, upon isolation and reculture, exhibited the potential to continue differentiating along the erythroid trajectory. Finally, we find that all five EE populations can also be detected in cultures of cord blood-derived CD34+ cells at levels similar to those observed in BM CD34+ cell cultures.

The study by Ye et al., published in Stem Cells, represents a significant advancement in the field of cellular reprogramming and pluripotency. The authors meticulously investigate the essential roles of the miR-290 and miR-302 microRNA clusters in the reprogramming of fibroblasts to induced pluripotent stem cells (iPSCs). This work is distinguished by its comprehensive experimental design and rigorous methodology, providing novel insights into the molecular mechanisms underlying iPSC formation.

Adipose-derived stem cells exosome (ADSC-exo) has been reported to be effective in alleviating organ dysfunction in sepsis, including acute liver injury (ALI). Whether ADSC-exo protects the liver via suppression of vascular endothelial cell (VEC) ferroptosis is unclear.

One of the most important properties of human embryonic stem cells (hESCs) is their ability to exist in primed and naive pluripotent states. Our previous meta-analysis indicated the existence of heterogeneous pluripotent states derived from diverse naive protocols. In this study, we characterized a commercial, RSeT-based pluripotent state under various growth conditions. Notably, RSeT hESCs can circumvent the hypoxic growth conditions required by naive hESCs, although some RSeT cells (eg, H1 cells) exhibit much lower single-cell plating efficiency and display altered or significantly retarded cell growth under both normoxia and hypoxia. Importantly, RSeT hPSCs lack many transcriptomic hallmarks of naive and formative pluripotency (the phase between naive and primed states). Integrative transcriptome analysis suggests that our primed and RSeT hESCs are similar to the early stage of post-implantation embryos, in line with previously reported primary hESCs and early hESC cultures. Moreover, RSeT hESCs do not express naive surface markers such as SUSD2 and CD75 at significant levels. At the biochemical level, RSeT hESCs show differential dependence on FGF2 and co-independency on both Janus kinase (JAK) and TGFβ signaling in a cell line-specific manner. Thus, RSeT hESCs represent a previously unrecognized pluripotent state downstream of naive pluripotency. Our data suggest that human naive pluripotent potentials may be restricted in RSeT medium, which sustains FGF2 activity. Hence, this study provides new insights into pluripotent state transitions in vitro.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and malignant cancer of the pancreas characterized by various genetic mutations and metabolic dysregulations. Stem cells play a critical role in the initiation, progression, and resistance of PDAC due to their plasticity, self-renewal capabilities, and ability to drive tumorigenesis. The gut microbiome, a diverse ecosystem of microorganisms, has a profound influence on systemic health, including the development of cancer. Recent studies have highlighted that the microbiome composition within the tumor can modulate stem cell behavior by shaping the tumor microenvironment (TME), enhancing cellular plasticity, and promoting the stemness properties of PDAC. In this review, we explore the potential crosstalk between the gut microbiome and PDAC stem cells, focusing on how microbiome-derived signals impact stem cell maintenance, inflammation, metastasis, TME modulation, and metabolic reprogramming.

A systems-level understanding of immunomodulatory, regenerative, and pro-/antifibrosis functions of mesenchymal stromal cells (MSCs) is critical to advance MSCs as a viable therapeutic option. Given the complexity of MSCs and their interactions with microenvironmental cells, a systems biology approach may enable such understanding to achieve practical objectives such as target identification, combination therapeutics, clinical strategies, and avoidance of adverse effects. In this study, a molecular systems architecture of MSCs microenvironment is developed to organize the complexity of biomolecular interactions between MSCs and other microenvironmental cells. This architecture provides a visual mapping of MSC interactions, identifies the complex crosstalk between MSCs and cells in the microenvironment, reveals potential targets, and offers a framework for creating future predictive, quantitative computational (in silico) models of the MSC microenvironment. The development of combination therapeutics, clinical strategies to improve therapeutic efficacy, and avoidance of adverse effects can be facilitated by such in silico models. However, it must all begin with a molecular systems architecture of MSCs-the objective and result of this study.