搜索结果：NPJ Regenerative medicine

Regeneration can rely on multiple cellular sources, including stem cells, self-duplicating cells, and transdifferentiating cells. A central question in regenerative biology is how these distinct lineages contribute to repair and interact within a functionally regenerated tissue. We previously developed the CellCousin system to study cellular plasticity using inducible recombination and nitroreductase-mediated ablation in zebrafish. Here, we present CellCousin2, which introduces two key improvements for the long-term tracking of spared and regenerating cells. First, to reduce background recombination, we developed a Dihydrofolate Reductase (DHFR)-CreER system with dual control: DHFR-mediated degradation in the absence of trimethoprim, and tamoxifen-dependent activation. This combination minimizes leakiness while maintaining high recombination efficiency. Second, we replaced the original nitroreductase with NTR2.0, enabling effective ablation with a tenfold lower metronidazole concentration, reducing off-target effects on the liver. Together, these enhancements make CellCousin2 a robust platform for dissecting the dynamics and interactions of regenerative lineages.

In this perspective, we explore the developmental mechanisms of muscle stem cells in multiple non-mammalian vertebrate species, and we compare these phenomena to those in mammals. Particularly, we discuss two recently described populations of noncanonical muscle progenitors in regenerative vertebrates: one in zebrafish and one in axolotl. We discuss the capabilities of these two populations during muscle development and regeneration, including the implications for muscle repair in mammals.

Organic anion transporting polypeptides (OATPs) are hepatic membrane transporters responsible for the uptake of numerous endogenous compounds and drugs. Among these, OATP1B1 and OATP1B3 in humans, and their orthologs in other species, mediate the cellular uptake of clinically approved hepatospecific MRI contrast agents, rendering them suitable candidates for use as MRI reporter proteins. This review examines the structural biology, evolutionary divergence, and transport mechanisms of hepatic OATPs, with a focus on their capacity to serve as genetically encoded imaging reporters. We survey the uptake and imaging characteristics of clinically available and experimental contrast agents in species-specific contexts and detail how hepatic OATPs have been leveraged in preclinical models for tracking engineered cells in oncology, regenerative medicine, and immunotherapy. Special attention is given to the pioneering studies that established OATP1A1 and OATP1B3 as MRI reporter proteins, the challenges related to contrast dose and imaging timing, and the emerging solutions such as dual-reporter systems and dynamic imaging protocols. Compared to traditional labeling strategies like iron oxide nanoparticles, OATP-based reporters enable positive contrast on T1-weighted MRI, avoid signal ambiguity, and permit multimodal imaging using clinically approved probes. The integration of hepatic OATPs as MRI reporter proteins offers a translationally feasible platform for non-invasive, longitudinal imaging of therapeutic cells in clinical trials and medicine. This technology has the potential to improve safety, efficacy, and mechanistic understanding across a wide array of biomedical applications.

Axolotl digits offer an experimentally versatile model for studying complex tissue regeneration. Here, we provide a comprehensive morphological and molecular characterization of digit regeneration, revealing both conserved features and notable divergences from classical limb regeneration. Digit blastemas progress through similar morphological stages, are nerve-dependent, contain key regenerative cell populations, and express many canonical morphogens and mitogens. However, they exhibit minimal expression of the A-P patterning genes Shh, Fgf8, and Grem1; suggesting distal outgrowth and patterning occur independently of these signals. Joint regenerative fidelity varies significantly across digits and cannot be explained by differences in nerve supply, cell proliferation, or differential expression of any patterning genes assessed in this study. Furthermore, functional experiments reveal Hedgehog signaling is essential for interphalangeal joint regeneration, but activation alone is insufficient to improve fidelity in less robust digits. This system combines experimental accessibility with intrinsic variation in regenerative outcomes, making it an ideal platform to identify critical determinants of successful tissue regeneration and refine models of appendage patterning.

Kidney organoids derived from human pluripotent stem cells have emerged as promising models for studying kidney disease and therapeutic development. However, the lack of a scalable production system has limited their industrial applications in regenerative medicine. Here, we have developed a cost-effective mass-production method for manufacturing vascularized kidney organoids, which has improved production efficiency by more than 50 times compared to conventional culture systems. The incorporation of a dynamic culture environment in delta-wing stirred bioreactors has significantly enhanced the glomerular vascularization of kidney organoids via mechanosensory integrin α2β1. Single-cell RNA sequencing and functional analyses demonstrated the enhanced maturation in STR nephron epithelia. The large quantities of vascularized kidney organoids enabled the fabrication of a nephron sheet with nephron numbers equivalent to those found in two rat kidneys. Intravital imaging of a nephron sheet implanted in a dorsal skinfold chamber of mice revealed filtration function with size selectability in the organoid glomeruli vascularized with human endothelia. This work may represent a significant step towards bridging the gap between basic research and commercial products, paving the way towards developing bioengineered kidneys for kidney replacement therapy.

Direct cellular reprogramming, converting one differentiated cell type directly into another, holds immense promise for regenerative medicine, developmental biology, and disease modeling. Identifying optimal transcription factor (TF) combinations to control this process remains complex and labor-intensive. Over the last decade, various computational tools emerged to infer TF sets for reprogramming. However, current methodologies possess critical limitations, and the absence of robust benchmarking standards makes it impossible to precisely validate and compare their performance. To address these challenges, we present a comprehensive analysis of existing computational methods for direct reprogramming and introduce a web application designed to support researchers in identifying and validating optimal TF sets. Our platform integrates predictions from established tools, incorporates a state-of-the-art Retrieval-Augmented Generation (RAG) system for efficient literature querying, and offers tools to further validate predictions. By providing a unified and interactive resource, our web application enhances the accessibility and efficiency of TF discovery for direct reprogramming. Furthermore, we discuss critical limitations shared by current methodologies and highlight the need for computational tools that can account for the complex regulatory dynamics of direct reprogramming. This work not only advances the toolkit available to researchers but also lays the groundwork for future innovations aimed at realizing the full potential of direct reprogramming.

Engineering functional tissues for transplantation requires insight into epigenetic mechanisms that regulate stem cell fate. We have developed the Wnt-induced osteogenic tissue model (WIOTM), a platform that recapitulates human osteogenesis, and identified acetylation of histone H3 at lysine 14 (H3K14ac) as a critical epigenetic regulator in human skeletal stem cells (hSSCs). In WIOTM, localized Wnt signals drive asymmetric cell division (ACD), yielding a proximal hSSC with high H3K14ac and a distal daughter with reduced H3K14ac that migrates into the 3D collagen matrix and initiates osteogenic differentiation. Disrupting H3K14ac in hSSCs abrogates ACD and WIOTM formation. To test whether hSSCs maintain H3K14ac in vivo, we formed the WIOTM on Wnt-functionalized polymer bandages and transplanted them into calvarial defects. The WIOTM contributed to bone repair, and human cells adjacent to the bandages retained high H3K14ac despite the injury environment. These findings establish WIOTM as both a mechanistic and translational platform for regenerative medicine.

Children with congenital heart defects increasingly survive to adulthood, but the non-physiological Fontan circulation imposed by current surgical palliation leads to significant sequelae and reduced lifespan. Restoring subpulmonic pumping function remains a long-standing goal, and there have been several attempts using regenerative medicine approaches. These efforts have lacked biomechanical rigor, however, and have not achieved the requisite functionality. Here, we introduce an analytically based framework that grounds pulsatile conduit design in biomechanical principles, coupling the architecture and properties of a passive matrix with embedded myofibers to optimize performance within pediatric anatomical constraints. Parametric exploration of matrix properties and myofiber orientations yields biomechanically feasible designs. Sensitivity analyses demonstrate design robustness and highlight parameters critical for reproducible biomanufacturing and surgical implementation. To illustrate clinical potential, a patient-specific lumped-parameter hemodynamic model shows that an optimized pulsatile conduit can generate physiologically meaningful pressures and flows and outperform passive grafts.

Directed differentiation of human induced pluripotent stem cells (iPSCs) into anterior foregut endoderm (AFE) and lung progenitors (LPs) has wide-ranging implications for lung developmental biology, disease modeling, and regenerative medicine. We expand on a previously developed mathematical modeling framework and apply it to the directed differentiation of AFE into LPs. A model-based approach guides experimental design, followed by a multistage model inference process: maximum likelihood estimation based on in vitro data and identifiability analyses to eliminate unidentifiable candidates, thereby guiding model selection. To the authors' knowledge, this is the first mathematical model of the population dynamics of directed differentiation of AFE into LPs. The model suggests that the overall dynamics are primarily driven by AFE proliferation and differentiation into LPs. In silico experiments predict that daily media change nearly doubles LP yields compared to cultures without media replenishment. Moreover, the model suggests that higher split ratios on day 10 enhance yield per input cell, a measure of differentiation efficiency, by 26%. This work provides a blueprint for refining iPSC-based lung lineage differentiation protocols by combining empirical data and mathematical modeling.

Peripheral artery disease (PAD) causes progressive arterial narrowing in the lower limbs and can advance to critical limb ischemia (CLI). Limited revascularization options highlight the need for safer, more effective therapies. Vascular multipotent stem cells (VMSCs) and adipose-derived stem cells (ADSCs) were isolated from adipose tissue, characterized phenotypically, and tested for angiogenic activity in vitro. Their therapeutic efficacy was then examined in a murine critical limb ischemia model through intramuscular transplantation, assessing limb preservation, neovascularization, and cell integration. VMSCs shared mesenchymal stem cell-like features with ADSCs and exhibited robust proliferative capacity, enabling rapid expansion to clinically relevant numbers. VMSCs also demonstrated endothelial-like properties, including CD31, VE-cadherin, and CD141 expression, and formed capillary-like structures in vitro. In contrast, ADSCs displayed perivascular characteristics with α-SMA and Transgelin expression. Co-culture of VMSCs and ADSCs promoted the development of mature tubular networks in vitro. Combined cell transplantation markedly decreased limb loss and promoted both angiogenesis and arteriogenesis in ischemic tissue, with transplanted cells partially integrating into the host vasculature to form hybrid vascular structures. VMSCs and ADSCs show complementary regenerative functions, sustained engraftment, and support for large-vessel formation, underscoring their potential for stem cell-based vascular therapies.

Chronic diabetic wounds represent a major clinical challenge, compounded by persistent inflammation, microbial invasion, and deficient angiogenesis. To address these intertwined pathophysiological features, we developed a copper-ion coordinated andrographolide-loaded hydrogel (ASFH), significantly enhancing andrographolide solubility and promoting wound healing dynamics. In vitro assessments demonstrated superior antimicrobial activity, optimal mechanical strength, self-healing ability, and cytocompatibility. In diabetic mice, ASFH notably accelerated wound closure, stimulated collagen maturation and re-epithelialization, dynamically shifted macrophages toward an anti-inflammatory phenotype, and markedly enhanced angiogenesis. Mechanistic studies integrating network pharmacology, molecular docking, dynamics simulations, and SPR validation pinpointed the Rac1/JNK1/Jun/Fos signaling cascade as a primary mediator of these regenerative effects. This work presents ASFH as a translationally relevant dressing system, simultaneously addressing critical limitations in diabetic wound management through targeted molecular therapeutic intervention.

The restricted regenerative potential of adult hearts poses a significant barrier to effective repair following injury. In contrast to numerous vertebrates, mammalian hearts exhibit only transient neonatal renewal capacity during the initial days of life. Beyond cardiomyocytes, understanding the diverse compositions of non-cardiomyocytes (non-CMs) is imperative for maintaining heart microenvironment homeostasis during neonatal heart regeneration. Here, we conduct single-cell ATAC sequencing on neonatal hearts at varying time points post-apical resection to profile the epigenetic landscape. Intriguingly, fibroblasts and endothelial cells, as the most abundant populations in the heart, exhibit the most dynamic chromatin remodeling upon injury. Furthermore, we reveal CEBPD and AP-1 family transcriptional factors as pivotal trans-regulators orchestrating these alterations, governing beneficial fibroblast activation and endothelial cell angiogenesis crucial for cardiac regeneration, respectively. Collectively, our study delineates the cellular identity of non-CMs at the epigenome level using single-cell approaches, offering insights into cell type-targeted interventions for heart regeneration.

Mammals have evolutionarily sacrificed their cardiac regenerative capacity in order to maintain high-output contractile function. This developmental trade-off involves integrated metabolic and epigenetic regulation, as well as microenvironmental maturation, all of which contribute to the withdrawal of cardiomyocytes from the cell-cycle. Reactivating juvenile regulatory networks-through the induction of transcription factors, metabolic reprogramming, and modulation of the cellular niche-may offer a strategy to restore proliferative potential in adult cardiomyocytes. Notably, cardiac aging appears to recapitulate the disruption of these regulatory mechanisms. Therefore, we propose that reprogramming strategies capable of reversing the developmental barriers to regeneration may represent a promising approach to counteract cardiac senescence.

Neurogenic bladder (NB) is a disabling condition lacking effective therapies. This study investigated whether CD73-expressing adipose-derived stem cells (ADSCs) promote bladder repair in a rat model of NB and explored the underlying mechanisms. ADSCs were sorted into CD73⁺ and CD73⁻ populations, and CD73⁺ cells were further modified to generate CD73⁺/ev ADSCs and CD73-overexpressing CD73⁺/⁺ADSCs, while CD73 inhibition was achieved using APCP. Conditioned media were applied to rat bladder smooth muscle cells in vitro, and ADSCs were injected into the bladder wall of rats subjected to bilateral pelvic nerve crush. Four weeks after treatment, bladder function, histology, and molecular markers were evaluated. CD73 overexpression enhanced VEGF and SDF-1 expression, promoted cell proliferation, and reduced inflammatory cytokines, whereas APCP suppressed VEGF. In vivo, CD73⁺/⁺ADSCs improved cystometric parameters, regenerated bladder tissue, reduced pyroptosis, and activated the PI3K/AKT/mTOR pathway, while suppressing NF-κB/NLRP3/caspase-1 signaling. CD73 expression and VEGF progressively declined in untreated NB rats but were restored by CD73⁺/⁺ADSCs. These findings indicate that CD73 enhances ADSC-mediated bladder repair through dual pro-regenerative and anti-inflammatory actions, suggesting a promising therapeutic strategy for NB.

Guidelines for managing scientific data have been established under the FAIR principles, requiring that data be Findable, Accessible, Interoperable, and Reusable. In many scientific disciplines, especially computational biology, both data and models are key to progress. For this reason, and recognizing that such models are a very special type of "data", we argue that computational models, especially mechanistic models prevalent in medicine, physiology and systems biology, deserve a complementary set of guidelines. We propose the CURE principles, emphasizing that models should be Credible, Understandable, Reproducible, and Extensible. We delve into each principle, discussing verification, validation, and uncertainty quantification for model credibility; the clarity of model descriptions and annotations for understandability; adherence to standards and open science practices for reproducibility; and the use of open standards and modular code for extensibility and reuse. We outline recommended and baseline requirements for each aspect of CURE, aiming to enhance the impact and trustworthiness of computational models, particularly in biomedical applications where credibility is paramount. Our perspective underscores the need for a more disciplined approach to modeling, aligning with emerging trends such as Digital Twins and emphasizing the importance of data and modeling standards for interoperability and reuse. Finally, we emphasize that given the non-trivial effort required to implement the guidelines, the community should strive to automate as many of the guidelines as possible.

Repairing osteochondral tissue is challenging due to its hierarchical structure, mechanical heterogeneity, and the need for spatial control over stem cell differentiation. Advances in tissue engineering have facilitated the development of biphasic cartilage-bone integrated scaffolds for osteochondral repair. The cartilage layer, composed of an IGF-1-loaded polydopamine-ZIF8/HAMA hydrogel, mimicked native tissue and enabled controlled cytokine release. This layer promoted M2 macrophage polarization, enhanced BMSC migration and chondrogenesis, and improved cartilage anabolism. The subchondral bone layer was a nanoclay (XLS)-functionalized 3D bioglass scaffold, which provided superior mechanical strength and supported osteogenic differentiation. These layers were integrated via partial interpenetration of the HAMA hydrogel. Importantly, in vivo studies confirmed that our biphasic scaffold effectively promoted osteochondral defects regeneration in a rat lower femoral osteochondral defect model. Collectively, this biphasic scaffold system presents a promising therapeutic strategy for osteochondral tissue regeneration.

Cardiac spheroids (CSs) offer valuable insights into the fundamental aspects of cardiac biology as they model molecular, cellular, and extracellular features typical of the myocardium. This review introduces current engineering methods for CS generation and their applications. Commonly referred to as "mini hearts", their applications include disease modelling, drug and toxicity screening, and personalised therapeutics in cardiac regenerative medicine.

Osteoarthritis (OA) is a progressive joint disease characterized by cartilage degeneration. Although the current use of mesenchymal stromal cells (MSCs) treatment provides a novel therapeutic option, stem cell therapy is limited to the risk of immune rejection, and stem cell-derived extracellular vesicles (Exos) are emerging as a more potential choice. Antler is a truly regenerative organ with unprecedented regenerative capacity and chondrogenic potential, and its derived antler stem cells (ASCs) provide a unique and sustainable biological resource for obtaining bioactive ASC-Exos. In this study, we found that intra-articular injection of ASC-Exos can effectively promote cartilage repair. Further analysis indicated that the key functional component of these exosomes is mir-140, which functions by regulating its target, matrix metalloproteinase 13 (MMP13). Finally, we found that miR-140-engineered ASC-Exo promotes chondrocyte activity, reduces apoptosis both in vitro and in vivo, and alleviates inflammation while inhibiting cartilage matrix degradation. Therefore, this study provides a new regenerative medical strategy for the treatment of osteoarthritis.

Chronic and acute skin wounds affect more than six million people in the United States each year. Many heal with basic care, but others do not and become infected, scarred, or chronic. These wounds reduce quality of life and increase healthcare costs. Bioelectronic integrated wound dressings and smart bandages can improve healing by delivering treatments locally and on demand, including electric field therapy and the release of pharmacological compounds. Localized bioelectronic delivery improves healing outcomes and reduces off-target effects. Here, we demonstrate a flexible bioelectronic wound dressing that combines electric field therapy and drug delivery, employing integrated microfluidics to switch between therapeutic modalities. Treatment with the bioelectronic dressing in a pilot porcine wound study showed promising results, including increased wound closure rates, improved tissue maturity, and reduced inflammatory response, compared with standard of care.