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A key goal of evolutionary genomics is to harness molecular data to draw inferences about selective forces that have acted on genomes. The field progresses in large part through the development of advanced molecular-evolution analysis methods. Here we explored the intersection between classical sequence-based tests for selection and an empirical expression-based approach, using stem cells from Mus musculus subspecies as a model. Using a test of directional, cis-regulatory evolution across genes in pathways, we discovered a unique program of induction of translation genes in stem cells of the Southeast Asian mouse M. m. castaneus relative to its sister taxa. We then mined population-genomic sequences to pursue underlying regulatory mechanisms for this expression divergence, finding robust evidence for alleles unique to M. m. castaneus at the upstream regions of the translation genes. We interpret our data under a model of changes in lineage-specific pressures across Mus musculus in stem cells with high translational capacity. Our findings underscore the rigor of integrating expression and sequence-based methods to generate hypotheses about evolutionary events from long ago.

Tumors can induce systemic disturbances in distant organs, leading to physiological changes that enhance host morbidity. In Drosophila cancer models, tumors have been known for decades to cause hypervolemic "bloating" of the abdominal cavity. Here we use allograft and transgenic tumors to show that hosts display fluid retention associated with autonomously defective secretory capacity of fly renal tubules, which function analogous to those of the human kidney. Excretion from these organs is blocked by abnormal cells that originate from inappropriate activation of normally quiescent renal stem cells (RSCs). Blockage is initiated by IL-6-like oncokines that perturb renal water-transporting cells and trigger a damage response in RSCs that proceeds pathologically. Thus, a chronic inflammatory state produced by the tumor causes paraneoplastic fluid dysregulation by altering cellular homeostasis of host renal units.

Wildlife biodiversity is essential for healthy, resilient and sustainable ecosystems. For biologists, this diversity also represents a treasure trove of genetic, molecular and developmental mechanisms that deepen our understanding of the origins and rules of life. However, the rapid decline in biodiversity reported recently foreshadows a potentially catastrophic collapse of many important ecosystems and the associated irreversible loss of many forms of life on our planet. Immediate action by conservationists of all stripes is required to avert this disaster. In this Spotlight, we draw together insights and proposals discussed at a recent workshop hosted by Revive & Restore, which gathered experts to discuss how stem cell technologies can support traditional conservation techniques and help protect animal biodiversity. We discuss reprogramming, in vitro gametogenesis, disease modelling and embryo modelling, and we highlight the prospects for leveraging stem cell technologies beyond mammalian species.

We previously showed that inhibition of glycolysis in cutaneous squamous cell carcinoma (SCC)-initiating cells had no effect on tumorigenesis, despite the perceived requirement of the Warburg effect, which was thought to drive carcinogenesis. Instead, these SCCs were metabolically flexible and sustained growth through glutaminolysis, another metabolic process frequently implicated to fuel tumorigenesis in various cancers. Here, we focused on glutaminolysis and genetically blocked this process through glutaminase (GLS) deletion in SCC cells of origin. Genetic deletion of GLS had little effect on tumorigenesis due to the up-regulated lactate consumption and utilization for the TCA cycle, providing further evidence of metabolic flexibility. We went on to show that posttranscriptional regulation of nutrient transporters appears to mediate metabolic flexibility in this SCC model. To define the limits of this flexibility, we genetically blocked both glycolysis and glutaminolysis simultaneously and found the abrogation of both of these carbon utilization pathways was enough to prevent both papilloma and frank carcinoma.

The role of mitochondria in neurodegenerative diseases is crucial, and recent developments have highlighted its significance in cell therapy. Mitochondrial dysfunction has been implicated in various neurodegenerative disorders, including Alzheimers, Parkinsons, amyotrophic lateral sclerosis, and Huntingtons diseases. Understanding the impact of mitochondrial biology on these conditions can provide valuable insights for developing targeted cell therapies. This mini-review refocuses on mitochondria and emphasizes the potential of therapies leveraging mesenchymal stem cells, embryonic stem cells, induced pluripotent stem cells, stem cell-derived secretions, and extracellular vesicles. Mesenchymal stem cell-mediated mitochondria transfer is highlighted for restoring mitochondrial health in cells with dysfunctional mitochondria. Additionally, attention is paid to gene-editing techniques such as mito-CRISPR, mitoTALENs, mito-ZNFs, and DdCBEs to ensure the safety and efficacy of stem cell treatments. Challenges and future directions are also discussed, including the possible tumorigenic effects of stem cells, off-target effects, disease targeting, immune rejection, and ethical issues.

Our understanding of the transitions of human embryonic stem cells (hESCs) between distinct stages of pluripotency relies predominantly on regulation by transcriptional and epigenetic programs with limited insight on the role of established morphological changes. We report remodeling of the actin cytoskeleton of hESCs as they transition from primed to naïve pluripotency which includes assembly of a ring of contractile actin filaments encapsulating colonies of naïve hESCs. Activity of the Arp2/3 complex is required for formation of the actin ring, to establish uniform cell mechanics within naïve colonies, to promote nuclear translocation of the Hippo pathway effectors YAP and TAZ, and for effective transition to naïve pluripotency. RNA-sequencing analysis confirms that Arp2/3 complex activity regulates Hippo signaling in hESCs, and impaired naïve pluripotency with inhibited Arp2/3 complex activity is rescued by expressing a constitutively active, nuclear-localized YAP-S127A. Moreover, expression of YAP-S127A partially restores the actin filament fence with Arp2/3 complex inhibition, suggesting that actin filament remodeling is both upstream and downstream of YAP activity. These new findings on the cell biology of hESCs reveal a mechanism for cytoskeletal dynamics coordinating cell mechanics to regulate gene expression and facilitate transitions between pluripotency states.

In lactating mothers, the high calcium (Ca2+) demand for milk production triggers significant bone loss1. Although oestrogen normally counteracts excessive bone resorption by promoting bone formation, this sex steroid drops precipitously during this postpartum period. Here we report that brain-derived cellular communication network factor 3 (CCN3) secreted from KISS1 neurons of the arcuate nucleus (ARCKISS1) fills this void and functions as a potent osteoanabolic factor to build bone in lactating females. We began by showing that our previously reported female-specific, dense bone phenotype2 originates from a humoral factor that promotes bone mass and acts on skeletal stem cells to increase their frequency and osteochondrogenic potential. This circulatory factor was then identified as CCN3, a brain-derived hormone from ARCKISS1 neurons that is able to stimulate mouse and human skeletal stem cell activity, increase bone remodelling and accelerate fracture repair in young and old mice of both sexes. The role of CCN3 in normal female physiology was revealed after detecting a burst of CCN3 expression in ARCKISS1 neurons coincident with lactation. After reducing CCN3 in ARCKISS1 neurons, lactating mothers lost bone and failed to sustain their progeny when challenged with a low-calcium diet. Our findings establish CCN3 as a potentially new therapeutic osteoanabolic hormone for both sexes and define a new maternal brain hormone for ensuring species survival in mammals.

Although microglia are macrophages of the central nervous system, their involvement is not limited to immune functions. The roles of microglia during development in humans remain poorly understood due to limited access to fetal tissue. To understand how microglia can impact human neurodevelopment, the methyl-CpG binding protein 2 (MECP2) gene was knocked out in human microglia-like cells (MGLs). Disruption of the MECP2 in MGLs led to transcriptional and functional perturbations, including impaired phagocytosis. The co-culture of healthy MGLs with MECP2-knockout (KO) neurons rescued synaptogenesis defects, suggesting a microglial role in synapse formation. A targeted drug screening identified ADH-503, a CD11b agonist, restored phagocytosis and synapse formation in spheroid-MGL co-cultures, significantly improved disease progression, and increased survival in MeCP2-null mice. These results unveil a MECP2-specific regulation of human microglial phagocytosis and identify a novel therapeutic treatment for MECP2-related conditions.

Photoreceptor degeneration is a major cause of untreatable blindness worldwide and has recently been targeted by emerging technologies, including cell- and gene-based therapies. Cell types of neural lineage have shown promise for replacing either photoreceptors or retinal pigment epithelial cells following delivery to the subretinal space, while cells of bone marrow lineage have been tested for retinal trophic effects following delivery to the vitreous cavity. Here we explore an alternate approach in which cells from the immature neural retinal are delivered to the vitreous cavity with the goal of providing trophic support for degenerating photoreceptors. Rat and human retinal progenitor cells were transplanted to the vitreous of rats with a well-studied photoreceptor dystrophy, resulting in substantial anatomical preservation and functional rescue of vision. This work provides scientific proof-of-principle for a novel therapeutic approach to photoreceptor degeneration that is currently being evaluated in clinical trials.

Fibroblasts are present throughout the body and function to maintain tissue homeostasis. Recent studies have identified diverse fibroblast subsets in healthy and injured tissues1,2, but the origins and functional roles of injury-induced fibroblast lineages remain unclear. Here we show that lung-specialized alveolar fibroblasts take on multiple molecular states with distinct roles in facilitating responses to fibrotic lung injury. We generate a genetic tool that uniquely targets alveolar fibroblasts to demonstrate their role in providing niches for alveolar stem cells in homeostasis and show that loss of this niche leads to exaggerated responses to acute lung injury. Lineage tracing identifies alveolar fibroblasts as the dominant origin for multiple emergent fibroblast subsets sequentially driven by inflammatory and pro-fibrotic signals after injury. We identify similar, but not completely identical, fibroblast lineages in human pulmonary fibrosis. TGFβ negatively regulates an inflammatory fibroblast subset that emerges early after injury and stimulates the differentiation into fibrotic fibroblasts to elicit intra-alveolar fibrosis. Blocking the induction of fibrotic fibroblasts in the alveolar fibroblast lineage abrogates fibrosis but exacerbates lung inflammation. These results demonstrate the multifaceted roles of the alveolar fibroblast lineage in maintaining normal alveolar homeostasis and orchestrating sequential responses to lung injury.

In vitro gametogenesis (IVG), the reconstitution of germ cell development in vitro, is an emerging stem cell-based technology with profound implications for reproductive science. Despite researchers' long-term goals for future clinical applications, little is currently known about the views of IVG held by the stakeholders potentially most affected by its introduction in humans. We conducted focus groups and interviews with 80 individuals with lived experience of infertility and/or LGBTQ+ family formation in the US, two intersecting groups of potential IVG users. Respondents expressed hope that IVG would lead to higher reproductive success than current assisted reproductive technology (ART), alleviate suffering associated with ART use, and promote greater social inclusion, while expressing concerns predominantly framed in terms of equity and safety. These findings underscore the importance of sustained engagement with stakeholders with relevant experience to anticipate the implications of IVG for research and clinical translation.

Tissue regeneration after damage is generally thought to involve the mobilization of adult stem cells that divide and differentiate into progressively specialized progeny. However, recent studies indicate that tissue regeneration can be accompanied by reversion to a fetal-like state. During this process, cells at the injury site reactivate programs that operate during fetal development but are typically absent in adult homeostasis. Here, we summarize our current understanding of the molecular signals and epigenetic mediators that orchestrate "fetal-like reversion" during intestinal regeneration. We also explore evidence for this phenomenon in other organs and species and highlight open questions that merit future examination.

Aging coincides with the progressive loss of muscle mass and strength, increased adiposity, and diminished physical function. Accordingly, interventions aimed at improving muscle, metabolic, and/or physical health are of interest to mitigate the adverse effects of aging. In this study, we tested a stem cell secretome product, which contains extracellular vesicles and growth, cytoskeletal remodeling, and immunomodulatory factors. We examined the effects of 4 weeks of 2×/week unilateral intramuscular secretome injections (quadriceps) in ambulatory aged male C57BL/6 mice (22-24 months) compared to saline-injected aged-matched controls. Secretome delivery substantially increased whole-body lean mass and decreased fat mass, corresponding to higher myofiber cross-sectional area and smaller adipocyte size, respectively. Secretome-treated mice also had greater whole-body physical function (grip strength and rotarod performance) and had higher energy expenditure and physical activity levels compared to control mice. Furthermore, secretome-treated mice had greater skeletal muscle Pax7+ cell abundance, capillary density, collagen IV turnover, reduced intramuscular lipids, and greater Akt and hormone sensitive lipase phosphorylation in adipose tissue. Finally, secretome treatment in vitro directly enhanced muscle cell growth and IL-6 production, and in adipocytes, it reduced lipid content and improved insulin sensitivity. Moreover, indirect treatment with secretome-treated myotube culture media also enhanced muscle cell growth and adipocyte size reduction. Together, these data suggest that intramuscular treatment with a stem cell secretome improves whole-body metabolism, physical function, and remodels skeletal muscle and adipose tissue in aged mice.

Dorsal interneurons (dIs) in the spinal cord encode the perception of touch, pain, heat, itchiness and proprioception. Previous studies using genetic strategies in animal models have revealed important insights into dI development, but the molecular details of how dIs arise as distinct populations of neurons remain incomplete. We have developed a resource to investigate dI fate specification by combining a single-cell RNA-Seq atlas of mouse embryonic stem cell-derived dIs with pseudotime analyses. To validate this in silico resource as a useful tool, we used it to first identify genes that are candidates for directing the transition states that lead to distinct dI lineage trajectories, and then validated them using in situ hybridization analyses in the developing mouse spinal cord in vivo. We have also identified an endpoint of the dI5 lineage trajectory and found that dIs become more transcriptionally homogeneous during terminal differentiation. This study introduces a valuable tool for further discovery about the timing of gene expression during dI differentiation and demonstrates its utility in clarifying dI lineage relationships.

Neural stem cells (NSCs) are multipotent and correct fate determination is crucial to guarantee brain formation and homeostasis. How NSCs are instructed to generate neuronal or glial progeny is not well understood. Here, we addressed how murine adult hippocampal NSC fate is regulated and described how scaffold attachment factor B (SAFB) blocks oligodendrocyte production to enable neuron generation. We found that SAFB prevents NSC expression of the transcription factor nuclear factor I/B (NFIB) by binding to sequences in the Nfib mRNA and enhancing Drosha-dependent cleavage of the transcripts. We show that increasing SAFB expression prevents oligodendrocyte production by multipotent adult NSCs, and conditional deletion of Safb increases NFIB expression and oligodendrocyte formation in the adult hippocampus. Our results provide novel insights into a mechanism that controls Drosha functions for selective regulation of NSC fate by modulating the post-transcriptional destabilization of Nfib mRNA in a lineage-specific manner.

Working in a stem cell laboratory necessitates a thorough understanding of complex cell culture protocols, the operation of sensitive scientific equipment, adherence to safety standards, and general laboratory etiquette. For novice student researchers, acquiring the necessary specialized knowledge before their initial laboratory experience can be a formidable task. Similarly, for experienced laboratory personnel, efficiently and uniformly training new trainees to a rigorous standard presents a significant challenge. In response to these issues, we have developed an educational and interactive virtual cell culture environment. This interactive virtual lab aims to equip students with foundational knowledge in maintaining cortical brain organoids and to instill an understanding of pertinent safety procedures and laboratory etiquette. The gamification of this training process seeks to provide laboratory supervisors in highly specialized fields with an effective tool to integrate students into their work environments more rapidly and safely.

Trophoblast stem cells (TSCs) are a proliferative multipotent population derived from the trophectoderm of the blastocyst, which will give rise to all the functional cell types of the trophoblast compartment of the placenta. The isolation and culture of TSCs in vitro represent a robust model to study mechanisms of trophoblast differentiation into mature cells both in successful and diseased pregnancy. Despite the highly conserved functions of the placenta, there is extreme variability in placental morphology, fetal-maternal interface, and development among eutherian mammals. This review aims to summarize the establishment and maintenance of TSCs in mammals such as primates, including human, rodents, and nontraditional animal models with a primary emphasis on epigenetic regulation of their origin while defining gaps in the current literature and areas of further development. FGF signaling is critical for mouse TSCs but dispensable for derivation of TSCs in other species. Human, simian, and bovine TSCs have much more complicated requirements of signaling pathways including activation of WNT and inhibition of TGFβ cascades. Epigenetic features such as DNA and histone methylation as well as histone acetylation are dynamic during development and are expressed in cell- and gestational age-specific pattern in placental trophoblasts. While TSCs from different species seem to recapitulate some select epigenomic features, there is a limitation in the comprehensive understanding of TSCs and how well TSCs retain placental epigenetic marks. Therefore, future studies should be directed at investigating epigenomic features of global and placental-specific gene expression in primary trophoblasts and TSCs.

Spermatogonial stem cells functionality reside in the slow-cycling and heterogeneous undifferentiated spermatogonia cell population. This pool of cells supports lifelong fertility in adult males by balancing self-renewal and differentiation to produce haploid gametes. However, the molecular mechanisms underpinning long-term stemness of undifferentiated spermatogonia during adulthood remain unclear. Here, we discover that an epigenetic regulator, Polycomb repressive complex 1 (PRC1), shields adult undifferentiated spermatogonia from differentiation, maintains slow cycling, and directs commitment to differentiation during steady-state spermatogenesis in adults. We show that PRC2-mediated H3K27me3 is an epigenetic hallmark of adult undifferentiated spermatogonia. Indeed, spermatogonial differentiation is accompanied by a global loss of H3K27me3. Disruption of PRC1 impairs global H3K27me3 deposition, leading to precocious spermatogonial differentiation. Therefore, PRC1 directs PRC2-H3K27me3 deposition to maintain the self-renewing state of undifferentiated spermatogonia. Importantly, in contrast to its role in other tissue stem cells, PRC1 negatively regulates the cell cycle to maintain slow cycling of undifferentiated spermatogonia. Our findings have implications for how epigenetic regulators can be tuned to regulate the stem cell potential, cell cycle and differentiation to ensure lifelong fertility in adult males.

Peripheral artery disease is an atherosclerotic disease associated with limb ischemia that necessitates limb amputation in severe cases. Cell therapies comprised of adult mononuclear or stromal cells have been clinically tested and show moderate benefits. Bioengineering strategies can be applied to modify cell behavior and function in a controllable fashion. Using mechanically tunable or spatially controllable biomaterials, we highlight examples in which biomaterials can increase the survival and function of the transplanted cells to improve their revascularization efficacy in preclinical models. Biomaterials can be used in conjunction with soluble factors or genetic approaches to further modulate the behavior of transplanted cells and the locally implanted tissue environment in vivo. We critically assess the advances in bioengineering strategies such as 3-dimensional bioprinting and immunomodulatory biomaterials that can be applied to the treatment of peripheral artery disease and then discuss the current challenges and future directions in the implementation of bioengineering strategies.

Individuals with Williams syndrome (WS), a neurodevelopmental disorder caused by hemizygous loss of 26-28 genes at 7q11.23, characteristically portray a hypersocial phenotype. Copy-number variations and mutations in one of these genes, GTF2I, are associated with altered sociality and are proposed to underlie hypersociality in WS. However, the contribution of GTF2I to human neurodevelopment remains poorly understood. Here, human cellular models of neurodevelopment, including neural progenitors, neurons, and three-dimensional cortical organoids, are differentiated from CRISPR-Cas9-edited GTF2I-knockout (GTF2I-KO) pluripotent stem cells to investigate the role of GTF2I in human neurodevelopment. GTF2I-KO progenitors exhibit increased proliferation and cell-cycle alterations. Cortical organoids and neurons demonstrate increased cell death and synaptic dysregulation, including synaptic structural dysfunction and decreased electrophysiological activity on a multielectrode array. Our findings suggest that changes in synaptic circuit integrity may be a prominent mediator of the link between alterations in GTF2I and variation in the phenotypic expression of human sociality.

Human pluripotent stem cell-derived neural progenitor cells (NPCs) are an essential tool for the study of brain development and developmental disorders such as autism. Here, we present a protocol to generate NPCs rapidly and reproducibly from human stem cells using dual-SMAD inhibition coupled with a brief pulse of mouse neurogenin-2 (Ngn2) overexpression. We detail the 48-h induction scheme deployed to produce these cells-termed stem cell-derived Ngn2-accelerated progenitor cells-followed by steps for expansion, purification, banking, and quality assessment. For complete details on the use and execution of this protocol, please refer to Wells et al.1.

The fetal brain of the mouse is thought to be dependent upon the placenta as a source of serotonin (5-hydroxytryptamine; 5-HT) and other factors. How factors reach the developing brain remains uncertain but are postulated here to be part of the cargo carried by placental extracellular vesicles (EV). We have analyzed the protein, catecholamine, and small RNA content of EV from mouse trophoblast stem cells (TSC) and TSC differentiated into parietal trophoblast giant cells (pTGC), potential primary purveyors of 5-HT. Current studies examined how exposure of mouse neural progenitor cells (NPC) to EV from either TSC or pTGC affect their transcriptome profiles. The EV from trophoblast cells contained relatively high amounts of 5-HT, as well as dopamine and norepinephrine, but there were no significant differences between EV derived from pTGC and from TSC. Content of miRNA and small nucleolar (sno)RNA, however, did differ according to EV source, and snoRNA were upregulated in EV from pTGC. The primary inferred targets of the microRNA (miRNA) from both pTGC and TSC were mRNA enriched in the fetal brain. NPC readily internalized EV, leading to changes in their transcriptome profiles. Transcripts regulated were mainly ones enriched in neural tissues. The transcripts in EV-treated NPC that demonstrated a likely complementarity with miRNA in EV were mainly up- rather than downregulated, with functions linked to neuronal processes. Our results are consistent with placenta-derived EV providing direct support for fetal brain development and being an integral part of the placenta-brain axis.

In single-cell RNA sequencing (scRNA-Seq), gene expression is assessed individually for each cell, allowing the investigation of developmental processes, such as embryogenesis and cellular differentiation and regeneration, at unprecedented resolution. In such dynamic biological systems, cellular states form a continuum, e.g., for the differentiation of stem cells into mature cell types. This process is often represented via a trajectory in a reduced-dimensional representation of the scRNA-Seq dataset. While many methods have been suggested for trajectory inference, it is often unclear how to handle multiple biological groups or conditions, e.g., inferring and comparing the differentiation trajectories of wild-type and knock-out stem cell populations. In this manuscript, we present condiments, a method for the inference and downstream interpretation of cell trajectories across multiple conditions. Our framework allows the interpretation of differences between conditions at the trajectory, cell population, and gene expression levels. We start by integrating datasets from multiple conditions into a single trajectory. By comparing the cells conditions along the trajectorys path, we can detect large-scale changes, indicative of differential progression or fate selection. We also demonstrate how to detect subtler changes by finding genes that exhibit different behaviors between these conditions along a differentiation path.

The Murphy Roths Large (MRL) mouse strain has super-healing properties that enhance recovery from injury. In mice, the DBA/2J strain intensifies many aspects of muscular dystrophy, so we evaluated the ability of the MRL strain to suppress muscular dystrophy in the Sgcg-null mouse model of limb girdle muscular dystrophy. A comparative analysis of Sgcg-null mice in the DBA/2J versus MRL strains showed greater myofiber regeneration, with reduced structural degradation of muscle in the MRL strain. Transcriptomic profiling of dystrophic muscle indicated strain-dependent expression of extracellular matrix (ECM) and TGF-β signaling genes. To investigate the MRL ECM, cellular components were removed from dystrophic muscle sections to generate decellularized myoscaffolds. Decellularized myoscaffolds from dystrophic mice in the protective MRL strain had significantly less deposition of collagen and matrix-bound TGF-β1 and TGF-β3 throughout the matrix. Dystrophic myoscaffolds from the MRL background, but not the DBA/2J background, were enriched in myokines like IGF-1 and IL-6. C2C12 myoblasts seeded onto decellularized matrices from Sgcg-/- MRL and Sgcg-/- DBA/2J muscles showed the MRL background induced greater myoblast differentiation compared with dystrophic DBA/2J myoscaffolds. Thus, the MRL background imparts its effect through a highly regenerative ECM, which is active even in muscular dystrophy.

Vascular cells self-organize into unique structures guided by cell proliferation, migration, and/or differentiation from neighboring cells, mechanical factors, and/or soluble signals. However, the relative contribution of each of these factors remains unclear. Our objective was to develop a computational model to explore the different factors affecting the emerging micropatterns in 2D. This was accomplished by developing a stochastic on-lattice population-based model starting with vascular progenitor cells with the potential to proliferate, migrate, and/or differentiate into either endothelial cells or smooth muscle cells. The simulation results yielded patterns that were qualitatively and quantitatively consistent with experimental observations. Our results suggested that post-differentiation cell migration and proliferation when balanced could generate between 30-70% of each cell type enabling the formation of vascular patterns. Moreover, the cell-to-cell sensing could enhance the robustness of this patterning. These findings computationally supported that 2D patterning is mechanistically similar to current microfluidic platforms that take advantage of the migration-directed self-assembly of mature endothelial and mural cells to generate perfusable 3D vasculature in permissible hydrogel environments and suggest that stem or progenitor cells may not be fully necessary components in many tissue formations like those formed by vasculogenesis.

LMNA-related dilated cardiomyopathy (DCM) is an autosomal-dominant genetic condition with cardiomyocyte and conduction system dysfunction often resulting in heart failure or sudden death. The condition is caused by mutation in the Lamin A/C (LMNA) gene encoding Type-A nuclear lamin proteins involved in nuclear integrity, epigenetic regulation of gene expression, and differentiation. The molecular mechanisms of the disease are not completely understood, and there are no definitive treatments to reverse progression or prevent mortality. We investigated possible mechanisms of LMNA-related DCM using induced pluripotent stem cells derived from a family with a heterozygous LMNA c.357-2A>G splice-site mutation. We differentiated one LMNA-mutant iPSC line derived from an affected female (Patient) and two non-mutant iPSC lines derived from her unaffected sister (Control) and conducted single-cell RNA sequencing for 12 samples (four from Patients and eight from Controls) across seven time points: Day 0, 2, 4, 9, 16, 19, and 30. Our bioinformatics workflow identified 125,554 cells in raw data and 110,521 (88%) high-quality cells in sequentially processed data. Unsupervised clustering, cell annotation, and trajectory inference found complex heterogeneity: ten main cell types; many possible subtypes; and lineage bifurcation for cardiac progenitors to cardiomyocytes (CMs) and epicardium-derived cells (EPDCs). Data integration and comparative analyses of Patient and Control cells found cell type and lineage-specific differentially expressed genes (DEGs) with enrichment, supporting pathway dysregulation. Top DEGs and enriched pathways included 10 ZNF genes and RNA polymerase II transcription in pluripotent cells (PP); BMP4 and TGF Beta/BMP signaling, sarcomere gene subsets and cardiogenesis, CDH2 and EMT in CMs; LMNA and epigenetic regulation, as well as DDIT4 and mTORC1 signaling in EPDCs. Top DEGs also included XIST and other X-linked genes, six imprinted genes (SNRPN, PWAR6, NDN, PEG10, MEG3, MEG8), and enriched gene sets related to metabolism, proliferation, and homeostasis. We confirmed Lamin A/C haploinsufficiency by allelic expression and Western blot. Our complex Patient-derived iPSC model for Lamin A/C haploinsufficiency in PP, CM, and EPDC provided support for dysregulation of genes and pathways, many previously associated with Lamin A/C defects, such as epigenetic gene expression, signaling, and differentiation. Our findings support disruption of epigenomic developmental programs, as proposed in other LMNA disease models. We recognized other factors influencing epigenetics and differentiation; thus, our approach needs improvement to further investigate this mechanism in an iPSC-derived model.

Retinitis pigmentosa (RP), a heterogenous group of inherited retinal disorder, causes slow progressive vision loss with no effective treatments available. Mutations in the rhodopsin gene (RHO) account for ~25% cases of autosomal dominant RP (adRP). In this study, we describe the disease characteristics of the first-ever reported mono-allelic copy number variation (CNV) in RHO as a novel cause of adRP. We (a) show advanced retinal degeneration in a male patient (68 years of age) harboring four transcriptionally active intact copies of rhodopsin, (b) recapitulated the clinical phenotypes using retinal organoids, and (c) assessed the utilization of a small molecule, Photoregulin3 (PR3), as a clinically viable strategy to target and modify disease progression in RP patients associated with RHO-CNV. Patient retinal organoids showed photoreceptors dysgenesis, with rod photoreceptors displaying stunted outer segments with occasional elongated cilia-like projections (microscopy); increased RHO mRNA expression (quantitative real-time PCR [qRT-PCR] and bulk RNA sequencing); and elevated levels and mislocalization of rhodopsin protein (RHO) within the cell body of rod photoreceptors (western blotting and immunohistochemistry) over the extended (300 days) culture time period when compared against control organoids. Lastly, we utilized PR3 to target NR2E3, an upstream regulator of RHO, to alter RHO expression and observed a partial rescue of RHO protein localization from the cell body to the inner/outer segments of rod photoreceptors in patient organoids. These results provide a proof-of-principle for personalized medicine and suggest that RHO expression requires precise control. Taken together, this study supports the clinical data indicating that RHO-CNV associated adRPdevelops as a result of protein overexpression, thereby overloading the photoreceptor post-translational modification machinery.

Metabolism participates in the control of stem cell function and subsequent maintenance of tissue homeostasis. How this is achieved in the context of adult stem cell niches in coordination with other local and intrinsic signaling cues is not completely understood. The Target of Rapamycin (TOR) pathway is a master regulator of metabolism and plays essential roles in stem cell maintenance and differentiation. In the Drosophila male germline, mTORC1 is active in germline stem cells (GSCs) and early germ cells. Targeted RNAi-mediated downregulation of mTor in early germ cells causes a block and/or a delay in differentiation, resulting in an accumulation of germ cells with GSC-like features. These early germ cells also contain unusually large and dysfunctional autolysosomes. In addition, downregulation of mTor in adult male GSCs and early germ cells causes non-autonomous activation of mTORC1 in neighboring cyst cells, which correlates with a disruption in the coordination of germline and somatic differentiation. Our study identifies a previously uncharacterized role of the TOR pathway in regulating male germline differentiation.

Over the past two decades Biomedical Engineering has emerged as a major discipline that bridges societal needs of human health care with the development of novel technologies. Every medical institution is now equipped at varying degrees of sophistication with the ability to monitor human health in both non-invasive and invasive modes. The multiple scales at which human physiology can be interrogated provide a profound perspective on health and disease. We are at the nexus of creating avatars (herein defined as an extension of digital twins) of human patho/physiology to serve as paradigms for interrogation and potential intervention. Motivated by the emergence of these new capabilities, the IEEE Engineering in Medicine and Biology Society, the Departments of Biomedical Engineering at Johns Hopkins University and Bioengineering at University of California at San Diego sponsored an interdisciplinary workshop to define the grand challenges that face biomedical engineering and the mechanisms to address these challenges. The Workshop identified five grand challenges with cross-cutting themes and provided a roadmap for new technologies, identified new training needs, and defined the types of interdisciplinary teams needed for addressing these challenges. The themes presented in this paper include: 1) accumedicine through creation of avatars of cells, tissues, organs and whole human; 2) development of smart and responsive devices for human function augmentation; 3) exocortical technologies to understand brain function and treat neuropathologies; 4) the development of approaches to harness the human immune system for health and wellness; and 5) new strategies to engineer genomes and cells.

Greenblatt and his team have unveiled vertebral skeletal stem cells (vSSCs) as a critical player in the landscape of bone metastasis. This commentary delves into the transformative discoveries surrounding vSSCs, emphasizing their distinct role in bone metastasis compared to other stem cell lineages. We illuminate the unique properties and functions of vSSCs, which may account for the elevated susceptibility of vertebral bones to metastatic invasion. Furthermore, we explore the exciting therapeutic horizons opened by this newfound understanding. These include potential interventions targeting vSSCs, modulation of associated signaling pathways, and broader implications for the treatment and management of bone metastasis. By shedding light on these game-changing insights, we hope to pave the way for novel strategies that could revolutionize the prognosis and treatment landscape for cancer patients with metastatic bone disease.

Introduction and purpose Diabetes is a disease resulting from impaired action or secretion of insulin. The number of patients currently amounts to approximately 422 million, and approximately 1.5 million deaths per year are directly attributed to this disease. Diabetes significantly reduces the quality of life and, if poorly controlled, can lead to serious complications. Mesenchymal stem cells are multipotent cells capable of differentiation. They have the ability to self-renew and have a modulating function. There are reports that they can be used in the treatment of this disease. The aim of the review was to present a new method of therapy and their possible effects. Material and methods The review was based on articles obtained from PubMed scientific database in the years 2015-2023, using the following keywords: diabetes mellitus, stem cells, diabetes complications. Results Implanted stem cells are able to transform into cells that produce and secrete insulin, and also enable better glycemic control. They can alleviate chronic inflammation and reduce fibrosis. Taking into account the complications that occur during long-term diabetes, the use of stem cells may be associated with improving the function of specific organs and tissues such as the kidneys, heart, eyes and nerves. Studies also report a positive effect of these cells on the healing process of wounds and ulcers. Conclusions Stem cells are a promising object of analysis. They can control glycemia and have a positive effect on the functioning of the kidneys, heart, eyes and nerves, and accelerate wound healing, but further, extensive research is needed to assess the effectiveness and safety of this therapy. [ABSTRACT FROM AUTHOR]

Microglia identity is determined by intersecting developmental and environmental transcriptional networks and can be induced by forced expression of key lineage transcription factors (TFs) in human pluripotent stem cells. Forward programming has emerged as a powerful tool for efficient bulk generation of microglia. Key determinants of forward programming are the choice of TFs, their mode of gene delivery, and environmental cues. Forward programming, classical directed differentiation, and blood monocyte reprogramming are diverse and complementary tools for the study of human microglia in vitro. Standardisation of human microglia cultures is key for the interpretation of future downstream analysis. Microglia play vital roles in embryonic and post-natal development, homeostasis, and pathogen defence in the central nervous system. Human induced pluripotent stem cell (hiPSC)-based methods have emerged as an important source for the study of human microglia in vitro. Classical approaches to differentiate hiPSCs into microglia suffer from limitations including extended culture periods, consistency, and efficiency. More recently, forward programming has arisen as a promising alternative for the manufacture of bulk quantities of human microglia. This review provides a comprehensive assessment of published forward programming protocols that are based on forced expression of key lineage transcription factors (TFs). We focus on the choice of reprogramming factors, transgene delivery methods, and medium composition, which impact induction kinetics and the resulting microglia phenotype. [ABSTRACT FROM AUTHOR]

The discovery of mouse embryonic stem cells in 1981 transformed research in mammalian developmental biology and functional genomics. The subsequent generation of human pluripotent stem cells (PSCs) and the development of molecular reprogramming have opened unheralded avenues for drug discovery and cell replacement therapy. Here, I review the history of PSCs from the perspective that long‐term self‐renewal is a product of the in vitro signaling environment, rather than an intrinsic feature of embryos. I discuss the relationship between pluripotent states captured in vitro to stages of epiblast in the embryo and suggest key considerations for evaluation of PSCs. A remaining fundamental challenge is to determine whether naïve pluripotency can be propagated from the broad range of mammals by exploiting common principles in gene regulatory architecture. [ABSTRACT FROM AUTHOR]

Organoids are quickly becoming an accepted model for understanding human biology and disease. Pluripotent stem cells (PSC) provide a starting point for many organs and enable modeling of the embryonic development and maturation of such organs. The foundation of PSC‐derived organoids can be found in elegant developmental studies demonstrating the remarkable ability of immature cells to undergo histogenesis even when taken out of the embryo context. PSC‐organoids are an evolution of earlier methods such as embryoid bodies, taken to a new level with finer control and in some cases going beyond tissue histogenesis to organ‐like morphogenesis. But many of the discoveries that led to organoids were not necessarily planned, but rather the result of inquisitive minds with freedom to explore. Protecting such curiosity‐led research through flexible funding will be important going forward if we are to see further ground‐breaking discoveries. [ABSTRACT FROM AUTHOR]

• The Life cell derived from amniotic membrane promote endometrial cell growth. • The Life cell derived from amniotic membrane enhance the expression of genes associated with endometrial receptivity. • The LifeCell is a potential option for patients with treatment-resistant thin endometrium in cases of infertility. Successful assisted reproductive technology (ART) requires a receptive endometrium with appropriate thickness and the presence of specific cytokines, chemokines, and growth factors. Despite advancements in ART, the success rates remain suboptimal, particularly in individuals with thin endometrium resistant to treatment. In this study, we evaluated the potential effects of LifeCell, a product of BioNano Technology, on the growth, development, and acceptance of endometrial cells. We cultured endometrial cells in a defined medium with different concentrations of LifeCell and examined cell growth, development, and the expression of genes involved in endometrial receptivity. Co-culture of primary human endometrial cells with 5 % Life cell solution significantly stimulated the endometrial cell growth, development and receptivity genes expression. The expression levels of FGF2 and CSF in the 72 h co-cultured were significantly increased compared with other groups (P < 0.01). HOXA10 and LIF significantly increased in the 72 h co-cultured compared with 24 h co-cultured and control groups but had no significant level compared with 48 h cocultured. HOXA10 significantly increased in the 48 h cocultured compared with control group. IL-6 and Hb-EGF increased in the 48 h co-cultured compared to other groups but had no significant level. VEGF increased in the treated groups compared to control but had no significant level. The expression of OPN, unlike the other genes, decreased in the treated group compared to the control, which was not significant. These findings suggest that LifeCell may be a potential option for patients with treatment-resistant thin endometrium in cases of infertility. [ABSTRACT FROM AUTHOR]

Hypertranscription occurs when cells upregulate gene expression across the majority of the transcriptome, including at housekeeping and other ubiquitously expressed genes. Although masked by standard normalization procedures, hypertranscription can be detected using modifications to sample preparation and normalization of sequencing data. Originally characterized in embryonic stem cells, recent advances have identified hypertranscription to be pervasive in stem cells across development, reprogramming, organ homeostasis, and tissue regeneration. These contexts share unified mechanistic features of hypertranscription, many of which are redeployed in hypertranscribing cancer cells. As a counterpart to the hypertranscriptive state, emerging evidence suggests that global downregulation of transcriptional output to enter hypotranscription is a key component of embryonic diapause and stem cell quiescence, possibly also being co-opted by dormant cancer cells to survive chemotherapy. Stem cells are the fundamental drivers of growth during development and adult organ homeostasis. The properties that define stem cells – self-renewal and differentiation – are highly biosynthetically demanding. In order to fuel this demand, stem and progenitor cells engage in hypertranscription, a global amplification of the transcriptome. While standard normalization methods in transcriptomics typically mask hypertranscription, new approaches are beginning to reveal a remarkable range in global transcriptional output in stem and progenitor cells. We discuss technological advancements to probe global transcriptional shifts, review recent findings that contribute to defining hallmarks of stem cell hypertranscription, and propose future directions in this field. [ABSTRACT FROM AUTHOR]

Introduction: The complex nature of xerostomia prevents the establishment of a definite cure. Recently, research has pivoted towards stem cell transplantation for glandular reconstruction. The aim of this study is to provide an updated review of the existing research, to highlight the encountered challenges and research pathways, potentially enhancing the therapeutic applications of stem cell transplantation. Methods: This is a systematic review according to PRISMA guidelines, using the following databases: PubMed (PMC), PMC Europe, Scopus, Medline, Research Gate, Elsevier. The main question was whether stem cell therapies can contribute to the treatment of xerostomia. Results: 19 of 226 publications met the criteria for this review, including 'in vivo', 'in vitro' studies and clinical trials. All 19 studies described thoroughly the stem cell source and the transplantation method, and documented results based on analytical and statistical methods of confirmation. Data show that the various sources of stem cells play a significant role, with bone marrow or adipose tissue-derived pluripotent blasts being the most utilized. Human transplants in mice have also been accepted and reversed hyposalivation. The effects have been beneficial especially in models undergone radiotherapy (IR) or exhibit Sjogren Syndrome-like symptoms (SS), suggesting that with appropriate treatment and enrichment techniques, stem cell transplantation seems effective regardless of the cause of the disorder. Extracts and co-cultures of gland and stem cells also seem to improve gland function. Conclusion: Although in its initial stages, the use of stem cells seems to be a promising therapy to alleviate xerostomia regardless of its cause. [ABSTRACT FROM AUTHOR]

This collection of articles describes how cryopreservation enables particular imaginaries about 'suspending time' thereby creating what Lemke terms "a principle of whenever." These imaginaries come to shape both intimate personal choices relating to fertility, organizational and commercial investments, research and regulatory investments in equipment and risk assessments, as well as major societal prioritizations of ecological conservation. Taken together, these articles thus unfold how mundane freezing technologies interact with profound societal changes and impact everyday lives. The politics of suspension almost seems to circumvent the political or substitute the political with 'cooling,' and yet these articles illustrate how these dynamics do not erase politics, but call for new analytical awareness to identify the political stakes. Taken collectively, the articles also illustrate inspiring approaches to three productive tensions running through much scholarship in Science and Technology Studies (STS)—tensions between technological and social determinism; technology optimism and pessimism; and between a focus on micro- and macro-practices. In doing so, the articles can be said in various ways to do the important work of a gestalt switch: shifting our attention from the well-known politics in the foreground to the tacit politics in the background. With this commentary, I suggest that the dynamics they explore can be productively viewed as instances of the 'infrastructuring' of the futures available. [ABSTRACT FROM AUTHOR]

Objectives: Dental pulp stem cells (DPSCs) have been extensively used for tissue regeneration owing to their notable capabilities. Insulin‐like growth factor‐binding protein 5 (IGFBP5) regulates osteogenic differentiation of mesenchymal stem cells (MSCs); however, the underlying regulatory mechanisms require further investigation. Materials and Methods: Carboxyfluorescein succinimidyl ester, an alkaline phosphatase (ALP) activity assay and Alizarin Red staining were used to reveal the role of IGFBP5 in DPSCs. Protein expression levels were determined using western blotting. Immunofluorescence was used to observe cell sub‐localisation. Subcutaneous transplantation in nude mice was used to observe the osteogenesis of DPSCs in vivo. Results: IGFBP5 enhanced the proliferation and osteogenic differentiation of DPSCs. Deletion of the nuclear localisation sequence (NLS) of IGFBP5 prevented its nuclear import and abolished all its promoting effects on DPSCs; ivermectin stimulation attenuated the enhancement of ALP activity by IGBFP5. Bone‐like tissue formation promoted by IGFBP5 in vivo vanishes when the NLS is deleted. Inhibition of IGFBP5 nuclear import attenuated the IGFBP5‐induced phosphorylation of JNK (p‐JNK) and phosphorylated ERK (p‐ERK) in DPSCs. Conclusion: Our findings suggest that cell proliferation and osteogenic differentiation effects exerted by IGFBP5 on DPSCs are closely associated with their entry into the nucleus, thereby providing a novel potential target for tissue regeneration. [ABSTRACT FROM AUTHOR]

Pax‐6 emerges as a critical transcription factor that guides the fate of stem cells towards neural lineages. Its expression influences the differentiation of neural progenitors into diverse neuronal subtypes, glial cells, and other neural cell types. Pax‐6 operates with other regulatory factors to ensure the precise patterning and organization of the developing nervous system. The intricate interplay between Pax‐6 and other signaling pathways, transcription factors, and epigenetic modifiers underpins the complicated balance between stem cell maintenance, proliferation, and differentiation in neuroectodermal and ocular contexts. Dysfunction of Pax‐6 can lead to a spectrum of developmental anomalies, underscoring its importance in these processes. This review highlights the essential role of Pax‐6 expression in neuroectodermal and ocular stem cells, shedding light on its significance in orchestrating the intricate journey from stem cell fate determination to the emergence of diverse neural and ocular cell types. The comprehensive understanding of Pax‐6 function gained from a developmental biology perspective offers valuable insights into normal development and potential therapeutic avenues for neuroectodermal and ocular disorders. [ABSTRACT FROM AUTHOR]

Human allogeneic liver-derived progenitor cells (HALPCs) display advanced ability to differentiate into hepatocyte-like cells and exhibit potent immunomodulatory, anti-inflammatory, and anti-fibrotic properties. HALPCs have been successfully manufactured under good manufacturing practice (GMP) and are currently in clinical development. A previous phase 2a trial demonstrated the safety of peripheral intravenous infusions of HALPCs and preliminary evidence of the cells' properties to restore liver function in patients with acute-on-chronic liver failure (ACLF), thus potentially improving their survival. A phase 2b trial is currently ongoing across multiple centers (NCT04229901) to obtain proof-of-concept on efficacy and additional safety. HALPCs are currently manufactured using fetal bovine serum (FBS), which can reveal qualitative and quantitative variations between batches. The use of serum-free medium (SFM) represents an alternative means to overcome this variability while also complying fully with regulations. The aim of this study was to compare current FBS-containing culture conditions with two industry-available GMP-compliant SFMs: StemMACS (Miltenyi Biotec, Bergisch Gladbach, Germany) and PRIME-XV (FUJIFILM Irvine Scientific, Santa Ana, California, USA). The proliferation of HALPCs was significantly stimulated by both SFMs, which shortened both their emergence period and population doubling time. This effect was correlated with a significant improvement in their genetic stability as analyzed by conventional karyotyping. The expression profile (identity and purity) and functionality of HALPCs cultured in SFM were maintained, as demonstrated by flow cytometry and enzyme-linked immunoassay (ELISA), respectively. Their potency, evaluated via prostaglandin E2 (PGE2) secretion, showed a similar effect on CD4+ T-cell proliferation in FBS and SFM conditions. Furthermore, a greater proportion of HALPCs cultured in SFM showed enhanced expression of tissue factor (CD142) compared with the FBS condition. Altogether, SFM conditions enabled consistent HALPC quality to be achieved without altering their expression and functional profiles. [ABSTRACT FROM AUTHOR]

Aim: Angiogenesis is a key event in the successful healing of pulp injuries, and hypoxia is the main stimulator of pulpal angiogenesis. In this study, we investigated the effect of hypoxia on the proangiogenic potential of human dental pulp stem cells (hDPSCs) and the role of miR‐143‐5p in the process. Methodology: Human dental pulp stem cells were isolated, cultured and characterized in vitro. Cobalt chloride (CoCl2) was used to induce hypoxia in hDPSCs. CCK‐8 and Transwell assays were used to determine the effect of hypoxia on hDPSCs proliferation and migration. Quantitative real‐time polymerase chain reaction (qRT‐PCR), Western blotting (WB) and ELISA were performed to assess the mRNA and protein levels of HIF‐1α and angiogenic cytokines in hDPSCs. The effect of hypoxia on hDPSCs proangiogenic potential was measured in vitro using Matrigel tube formation and chick chorioallantoic membrane (CAM) assays. Recombinant lentiviral vectors were constructed to stably overexpress or inhibit miR‐143‐5p in hDPSCs, and the proangiogenic effects were assessed using qRT‐PCR, WB, and tube formation assays. miR‐143‐5p target genes were identified and verified using bioinformatics prediction tools, dual‐luciferase reporter assays and RNA pull‐down experiments. Finally, a subcutaneous transplantation model in nude mice was used to determine the effects of hypoxia treatment and miR‐143‐5p overexpression/inhibition in hDPSCs in dental pulp regeneration. Results: Hypoxia promotes hDPSCs proliferation, migration and proangiogenic potential. The in vivo experiments showed that hypoxia treatment (50 and 100 μM CoCl2) promoted pulp angiogenesis and dentine formation. In contrast to the levels of proangiogenic factors, miR‐143‐5p levels decreased with increasing CoCl2 concentration. miR‐143‐5p inhibition significantly promoted proangiogenic potential of hDPSCs, whereas miR‐143‐5p overexpression inhibited angiogenesis in vitro. Dual‐luciferase reporter assay identified retinoic acid receptor‐related orphan receptor alpha (RORA) as an miR‐143‐5p target gene in hDPSCs. RNA pull‐down experiments demonstrated that HIF‐1α and RORA were pulled down by biotin‐labelled miR‐143‐5p, and the levels of HIF‐1α and RORA bound to miR‐143‐5p in the hypoxia group were lower than those in the normoxia group. Inhibition of miR‐143‐5p expression in hDPSCs promoted ectopic dental pulp tissue regeneration. Conclusions: CoCl2‐induced hypoxia promotes hDPSCs‐driven paracrine angiogenesis and pulp regeneration. The inhibition of miR‐143‐5p upregulates the proangiogenic potential of hDPSCs under hypoxic conditions by directly targeting HIF‐1α and RORA. [ABSTRACT FROM AUTHOR]

Key message: The SBP-box transcription factor PlSPL2 silencing in herbaceous peony enhanced stem strength by regulating xylem development, whereas its overexpression in tobacco resulted in weaker stem strength and undeveloped xylem. The strength of plant stems is a critical determinant of lodging resistance of plants, which significantly affects crop yield and cut-flower quality. Squamosa promoter binding (SBP) protein-like (SPL) transcription factors (TFs), participate in multiple regulatory processes, particularly in stem development. In this study, PlSPL2, an orthologous gene of Arabidopsis AtSPL2 in herbaceous peony, was isolated and found to contain a conserved SBP domain featuring two typical Zn-binding sites, as well as a nuclear localization sequence (NLS). Subsequently, transient infection of tobacco leaf epidermal cells using Agrobacterium confirmed the nuclear localization of PISPL2 protein. Additionally, gene expression analyses revealed that PlSPL2 was preferentially expressed in stems, and demonstrated a download trend in expression levels within vascular bundles during stem cell wall development. Furthermore, silencing of PlSPL2 in herbaceous peony enhanced stem strength. The silenced plants exhibited more developed xylems with wider radii and higher numbers of cell layers. Overexpression of PlSPL2 in tobacco, however, resulted in weaker stem strength, accompanied by a narrower radius of the xylem. These findings suggested that PlSPL2 was a negative regulator of herbaceous peony stem development, and its discovery and research could significantly contribute to a deeper understanding of stem growth and development mechanisms. [ABSTRACT FROM AUTHOR]

Summary: Single‐cell proteomics (SCP) is an emerging approach to resolve cellular heterogeneity within complex tissues of multi‐cellular organisms.Here, we demonstrate the feasibility of SCP on plant samples using the model plant Arabidopsis thaliana. Specifically, we focused on examining isolated single cells from the cortex and endodermis, which are two adjacent root cell types derived from a common stem cell lineage.From 756 root cells, we identified 3763 proteins and 1118 proteins/cell. Ultimately, we focus on 3217 proteins quantified following stringent filtering. Of these, we identified 596 proteins whose expression is enriched in either the cortex or endodermis and are able to differentiate these closely related plant cell types.Collectivity, this study demonstrates that SCP can resolve neighboring cell types with distinct functions, thereby facilitating the identification of biomarkers and candidate proteins to enable functional genomics. See also the Commentary on this article by van Schie & Weijers, 244: 1678–1680. [ABSTRACT FROM AUTHOR]

PIEZO1 is a eukaryotic membrane protein that assembles as trimers to form calcium‐permeable, non‐selective cation channels with exquisite capabilities for mechanical force sensing and transduction of force into effect in diverse cell types that include blood cells, endothelial cells, epithelial cells, fibroblasts and stem cells and diverse systems that include bone, lymphatics and muscle. The channel has wide‐ranging roles and is considered as a target for novel therapeutics in ailments spanning cancers and cardiovascular, dental, gastrointestinal, hepatobiliary, infectious, musculoskeletal, nervous system, ocular, pregnancy, renal, respiratory and urological disorders. The identification of PIEZO1 modulators is in its infancy but useful experimental tools emerged for activating, and to a lesser extent inhibiting, the channels. Elementary structure–activity relationships are known for the Yoda series of small molecule agonists, which show the potential for diverse physicochemical and pharmacological properties. Intriguing effects of Yoda1 include the stimulated removal of excess cerebrospinal fluid. Despite PIEZO1's broad expression, opportunities are suggested for selective positive or negative modulation without intolerable adverse effects. Here we provide a focused, non‐systematic, narrative review of progress with this pharmacology and discuss potential future directions for research in the area. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to identify the N6-methyladenosine (m6A)- circHECA molecule in secondary hair follicles (SHFs) of cashmere goats, and generate its potential regulatory network, as well as explore the potential relationship between transcriptional pattern of m6A-circHECA and promoter methylation of its host gene (HECA). Methods: The validation of circHECA m6A sites was performed using methylation immunoprecipitation (Me-RIP) along with reverse transcription-quantitative polymerase chain reaction (RT-qPCR) technique. The nucleus and cytoplasm localizations of m6A- circHECA were performed using SHF stem cells of cashmere goats with RT-qPCR analysis. Based on in-silico analysis, the regulatory networks of m6A-circHECA were generated with related signal pathway enrichment. The methylation level of promoter region of m6A-circHECA host gene (HECA) was assessed by the bisulfite sequencing PCR (BSPPCR) technique. Results: The m6A-circHECA was confirmed to contain four m6A modification sites including m6A-213, m6A-297, m6 A-780, and m6A-927, and it was detected mainly in cytoplasm of the SHF stem cells of cashmere goats. The integrated regulatory network analysis showed directly or indirectly complex regulatory relationships between m6A-circHECA of cashmere goats and its potential target molecules: miRNAs, mRNAs, and proteins. The regulatory network and pathway enrichment indicated that m6A-circHECA might play multiple roles in the SHF physiology process of cashmere goats through directly or indirectly interacting or regulating its potential target molecules. A higher methylation level of promoter region of HECA gene in SHFs of cashmere goats might cause the lower expression of m6A-circHECA. Conclusion: The m6A-circHECA might play multiple roles in SHF physiology process of cashmere goats through miRNA mediated pathways along with directly or indirectly interaction with its target proteins. The promoter methylation of m6A-circHECA host gene (HECA) most likely was implicated in its expression inhibition in SHFs of cashmere goats. [ABSTRACT FROM AUTHOR]

Introduction: Intercostal nerve transfer is a surgical technique used to restore function in patients with total brachial plexus injury. Stem cell and secretome therapy has been explored as a potential treatment for brachial plexus injuries. This study aimed to compare the functional and histologic outcome of intercostal nerve transfer to median nerve with local stem cells or secretome injection in total type brachial plexus injuries. Materials and methods: This was a double-blinded, randomized controlled study (RCT). We included patients with neglected total type brachial plexus injury (BPI) who underwent nerve transfer and local injection of either umbilical cord-derived mesenchymal stem cells (UC-MSC) or secretome into median nerve–flexor digitorum superficialis (FDS) neuromuscular junction (NMJ). We measured preoperative and 8-month postoperative FDS muscle strength, SF-36, DASH score, and histologic assessment. We then analyzed the difference outcome between those two groups. Result: A total of 15 patients were included in this study. Our study found that after nerve transfer and implantation with either UC-MSC or secretome, significant postoperative improvements were observed in physical functioning, role limitations, energy/fatigue, emotional well-being, social functioning, pain, general health, and DASH scores, particularly in the overall cohort and the secretome group. When we compared the mean difference of clinical outcome from preoperative to postoperative between UC-MSC and secretome groups, the UC-MSC group showed better improvement of health change in SF-36 subgroup compared to secretome group. From the analysis, there was no significant difference in the histologic outcomes (inflammation, regeneration, and fibrosis) in overall cohort between preoperative and postoperative cohort. There was also no significant difference in mean change of the histologic outcomes (inflammation, regeneration, and fibrosis) preoperative and postoperatively between UC-MSC and secretome groups. Discussion and conclusion: Implantation of either UC-MSC or secretome along with nerve transfer may provide clinical improvement, while to achieve histologic improvement, further conditioning should be performed. [ABSTRACT FROM AUTHOR]

Purpose: Periprosthetic joint infection is a complication of total joint arthroplasty with treatment costs over $1.6 billion dollars per year in the US with high failure rates. Therefore, generation of coatings that can prevent infection is paramount. Diamond-like carbon (DLC) is an ideal coating for implants as they are wear-resistant, corrosion-resistant, inert, and have a low friction coefficient. The purpose of this study was to test the efficacy of DLC surface treatment in prevention of biofilm on titanium discs infected with Staphylococcus aureus in vitro. Methods: Titanium alloy discs (n = 4 non-coated and n = 4 DLC-coated) were infected with 5 × 105 colony-forming units (CFU) of S. aureus for 2 weeks then analysed via crystal violet and scanning electron microscopy (SEM). Results: Crystal violet analysis yielded differences in the appearance of biofilm on implant surface where DLC-coated had a clumpier appearance but no difference in biofilm quantification. Interestingly, this clumpy appearance did lead to differences in SEM biofilm coverage where significantly less biofilm coverage was found on DLC-coated discs (81.78% vs. 54.17%, p < 0.003). Conclusion: DLC-coated titanium alloy implants may have preventative properties in S. aureus infection. Observing differences in biofilm coverage does warrant additional testing including CFU titration and biofilm kinetics with eventual use in an animal model of periprosthetic joint infection. [ABSTRACT FROM AUTHOR]

Acoustic manipulation or perturbation of biological soft matter has emerged as a promising clinical treatment for a number of applications within regenerative medicine, ranging from bone fracture repair to neuromodulation. The potential of ultrasound (US) endures in imparting mechanical stimuli that are able to trigger a cascade of molecular signals within unscathed cells. Particularly, low-intensity pulsed ultrasound (LIPUS) has been associated with bio-effects such as activation of specific cellular pathways and alteration of cell morphology and gene expression, the extent of which can be modulated by fine tuning of LIPUS parameters including intensity, frequency and exposure time. Although the molecular mechanisms underlying LIPUS are not yet fully elucidated, a number of studies clearly define the modulation of specific ultrasonic parameters as a means to guide the differentiation of a specific set of stem cells towards adult and fully differentiated cell types. Herein, we outline the applications of LIPUS in regenerative medicine and the in vivo and in vitro studies that have confirmed the unbounded clinical potential of this platform. We highlight the latest developments aimed at investigating the physical and biological mechanisms of action of LIPUS, outlining the most recent efforts in using this technology to aid tissue engineering strategies for repairing tissue or modelling specific diseases. Ultimately, we detail tissue-specific applications harnessing LIPUS stimuli, offering insights over the engineering of new constructs and therapeutic modalities. Overall, we aim to lay the foundation for a deeper understanding of the mechanisms governing LIPUS-based therapy, to inform the development of safer and more effective tissue regeneration strategies in the field of regenerative medicine. [ABSTRACT FROM AUTHOR]

Apoptosis is a regulated cell death that depends on caspases. It has mainly been studied as a mechanism for the removal of unwanted cells. However, apoptotic cells can induce fate or behavior changes of their neighbors and thereby participate in development. Here, we address the functions of apoptosis during metamorphosis of the cnidarian Hydractinia symbiolongicarpus. We describe the apoptotic profile during metamorphosis of the larva and identify Caspase3/7a , but no other executioner caspases, as essential for apoptosis in this context. Using pharmacological and genetic approaches, we find that apoptosis is required for normal head development. Inhibition of apoptosis resulted in defects in head morphogenesis. Neurogenesis was compromised in the body column of apoptosis-inhibited animals but there was no effect on the survival or proliferation of stem cells, suggesting that apoptosis is required for cellular commitment rather than for the maintenance of their progenitors. Differential transcriptomic analysis identifies TRAF genes as downregulated in apoptosis-inhibited larvae and functional experiments provide evidence that they are essential for head development. Finally, we find no major role for apoptosis in head regeneration in this animal, in contrast to the significance of apoptosis in Hydra head regeneration. [Display omitted] • A wave of apoptosis accompanies the initial phase of Hydractinia metamorphosis. • Caspase3/7a, but not other caspases, mediates apoptosis during metamorphosis. • Inhibition of apoptosis results in defective head development and neurogenesis. • Knockdown of TRAF genes phenocopies apoptosis inhibition. [ABSTRACT FROM AUTHOR]