The transcriptomic profiling of scleral fibroblasts remains largely unexplored. To elucidate their heterogeneity, we performed single-cell RNA sequencing (scRNA-seq) on primary infant scleral fibroblasts.

Neurogenesis is a biological process in which new neurons are generated from neural stem cells (NSCs) in specific neural niches in the brain. Impaired neurogenesis, characterized by the progressive loss of neurons, leads to cognitive and motor disabilities and is a hallmark of central nervous system (CNS) diseases. Conversely, enhancing neurogenesis has been shown to alleviate the symptoms of CNS diseases. Apolipoprotein E (APOE) is a protein that plays various biological roles in CNS diseases. Emerging research indicates that APOE is involved in adult neurogenesis, which is crucial for maintaining the neural progenitor pool in the dentate gyrus (DG) and synaptic activity. Therefore, APOE could be a therapeutic target for promoting neurogenesis in the treatment and intervention of CNS diseases. In this context, we present a comprehensive overview of the clinical evidence supporting the role of APOE in CNS diseases on the basis of a meta-analysis. We also discuss the neurogenic potential of APOE, which has significant implications not only for understanding the biological underpinnings of neurological diseases but also for developing novel treatment strategies for CNS diseases.

In the present study, we aim to identify novel molecular targets for sensitizing Breast cancer stem cells (BCSCs) to common antitumor treatments. MicroRNAs (miRNAs) play key roles in pivotal cellular processes. Therefore, modulating the expression of these miRNAs may lead to increased sensitivity of BCSCs to current treatments or overcome their therapeutic resistance. Due to their pivotal roles in the regulation of apoptosis (via BCL2) and chemoresistance (via ABCG2) and their differential expression in BCSCs (compared to non-BCSCs), miR-34a and miR-328 were selected for analysis.

Most investigations of resin embedded biological samples by transmission electron microscopy (TEM) have been performed in TEM bright-field mode where the electron beam transmits through the sample. Modern TEMs can also be used in scanning TEM mode (STEM) where the beam scans across the sample. The preferred detector for STEM mode is the high-angle annular dark-field (HAADF) detector. The aim of this study was to compare image quality of resin embedded biological samples such as yeast (Saccharomyces), algae (Chlorella, Haematococcus), plant leaves (Nicotiana), human cells (MCF7), and animal tissue (mouse liver and brain) between TEM bright-field and STEM-HAADF mode. Generally, images taken in STEM-HAADF mode showed better image quality in terms of contrast, brightness, and signal-to-noise ratio. Samples of sections that did not receive postcontrasting with uranyl acetate or lead citrate appeared significantly less grainy. Specifically, STEM-HAADF mode resulted in significantly better image quality of algae cells, MCF7, and liver cells that did not receive postcontrasting. Artifacts visible in TEM mode were absent in STEM-HAADF mode. Thus, we can conclude that STEM-HAADF mode has significant advantages when investigating resin embedded biological samples that have little contrast or sections that did not receive postcontrasting rendering postcontrasting of sections unnecessary.

Cell progenitor to progeny transitions depend on precise transcriptional mechanisms to adjust gene expression. The sterile alpha motif-containing 1 protein (SAMD1) regulates a shift in transcriptional activity during embryonic stem cell exit from pluripotency. SAMD1 interacts with and facilitates the activity of the histone H3 lysine demethylating enzyme LSD1. SAMD1 is expressed throughout many biological systems, but its role in hematopoiesis is unknown. In human and mouse hematopoietic stem/progenitor cells, we tested the role of SAMD1 in hematopoiesis and erythropoiesis using loss-of-function approaches. SAMD1 promoted expression of critical drivers of hematopoiesis, including the GATA2 transcription factor, while opposing erythroid programs. Loss of SAMD1 in ex vivo differentiating cells increased erythroid and megakaryocyte differentiation and altered the landscape of histone H3K4 methylation genome-wide. Cohorts of SAMD1-repressed genes are linked to erythropoietic activities. SAMD1 expression promoted ERK signaling via SCF/Kit stimulation in progenitor populations. In erythroid precursor cells, SAMD1 co-occupies chromatin with LSD1 and GATA factors. Whereas SAMD1 downregulates H3K4me2 levels genome-wide, contributing to gene repression, SAMD1 also elevates transcription at select sites. To test Samd1 function in hematopoiesis, we performed competitive transplant experiments in mice. Samd1 knockdown hematopoietic stem cells (HSCs) contributed more to peripheral blood mononuclear cells versus control HSCs. Our results establish SAMD1 as a coordinator of H3K4 methylation and stem/progenitor activity in hematopoiesis and erythropoiesis.

Terminal duct lobular unit (TDLU) involution has been linked to decreased breast cancer (BCa) risk in some studies. Whether the number/activity of breast stem cells (SCs) in non-cancerous tissue may influence TDLU involution is unknown. We examined the associations of CD44, CD24, and ALDH1A1 SC markers with TDLU involution.

Olfactory sensory neurons (OSNs) in the olfactory epithelium (OE) are continuously replaced by neuroregeneration from basal stem cells. Acute inflammation destroys OSNs, causing hyposmia or anosmia, but leaves the basal stem cells intact. We previously found that ciliary neurotrophic factor (CNTF) is highly expressed in horizontal basal cells (HBCs) and the CNTF receptor is in globose basal cells (GBCs), which are the actively dividing cells that normally replace dying OSNs. Here, we investigated the role of CNTF in basal stem cell proliferation/differentiation and smell function recovery following methimazole-induced acute inflammatory OE injury. Methimazole increased inflammatory markers, TNFα, IL-6, and CD45, and depleted OSNs in the OE at 3 and 5 days. Simultaneously, CNTF and the GBC marker Mash1 were upregulated, suggesting that HBCs produced more CNTF, as validated using primary HBC cultures, to promote GBC proliferation. Methimazole increased GBC proliferation, as shown by the number of BrdU-labeled GBCs in CNTF+/+, but not in CNTF-/- littermate mice. Also, CNTF+/+ mice had higher levels of neuroregeneration and better smell function recovery than CNTF-/- littermates. This indicates that CNTF promotes GBC proliferation and promotes OE neuroregeneration and smell functional recovery. This study identifies the regenerative role of CNTF in HBCs and reveals the therapeutic potential to target CNTF signaling to improve olfactory neuroregeneration and functional recovery following injury.

Mechanical processing techniques to isolate the stromal vascular fraction (SVF) may optimize clinical translation of cell-based therapeutics. Therefore, the purpose of this study was to develop a technique for intraoperative isolation of SVF for immediate therapeutic use with the primary aim of enhancing bone healing at irradiated fracture sites.

This comprehensive review delves into the pivotal role of intestinal epithelial cells in the context of various diseases. It provides an in-depth analysis of the diverse types and functions of these cells, explores the influence of multiple signaling pathways on their differentiation, and elucidates their critical roles in a spectrum of diseases. The significance of the gastrointestinal tract in maintaining overall health is extremely important and cannot be exaggerated. This complex and elongated organ acts as a crucial link between the internal and external environments, making it vulnerable to various harmful influences. Preserving the normal structure and function of the gut is essential for well-being. Intestinal epithelial cells serve as the primary defense mechanism within the gastrointestinal tract and play a crucial role in preventing harmful substances from infiltrating the body. As the main components of the digestive system, they not only participate in the absorption and secretion of nutrients and the maintenance of barrier function but also play a pivotal role in immune defense. Therefore, the health of intestinal epithelial cells is of vital importance for overall health.

Skeletal stem cells (SSCs) have been isolated from various tissues, including periosteum and bone marrow, where they exhibit key functions in bone biology and hematopoiesis, respectively. The role of periosteal SSCs (P-SSCs) in bone regeneration and healing has been extensively studied, but their ability to contribute to the bone marrow stroma is still under debate. In the present study, we characterized a mouse whole bone transplantation model that mimics the initial bone marrow necrosis and fatty infiltration seen after injury. Using this model and a lineage tracing approach, we observed the migration of P-SSCs into the bone marrow after transplantation. Once in the bone marrow, P-SSCs are phenotypically and functionally reprogrammed into bone marrow mesenchymal stem cells (BM-MSCs) that express high levels of hematopoietic stem cell niche factors such as Cxcl12 and Kitl. In addition, using ex vivo and in vivo approaches, we found that P-SSCs are more resistant to acute stress than BM-MSCs. These results highlight the plasticity of P-SSCs and their potential role in bone marrow regeneration after bone marrow injury.

Prenatal alcohol exposure (PAE) affects embryonic development, causing a variable fetal alcohol spectrum disorder (FASD) phenotype with neurodevelopmental disorders and birth defects. To explore the effects of PAE on gastrulation, we used an in vitro model with subchronic moderate (20 mM) and severe (70 mM) ethanol exposures during the differentiation of human embryonic stem cells into germ layer cells. We analysed genome-wide gene expression (mRNA sequencing), DNA methylation (EPIC Illumina microarrays), and metabolome (non-targeted LC-MS) of the endodermal, mesodermal, and ectodermal cells. The largest number of ethanol-induced alterations were observed in endodermal cells, whereas the most prominent changes were in ectodermal cells. Methionine metabolism and genes of the major signaling pathways involved in gastrulation and body patterning were affected by ethanol in all germ layers. Many of the altered genes, including BMP4, FGF8, SIX3, and LHX2, have previously been associated with PAE and phenotypes of FASD, like defects in heart and corpus callosum development as well as holoprosencephaly. Our findings support the early origin of alcohol-induced developmental disorders and strengthen the role of methionine cycle in the etiology of FASD.

We developed a novel approach for generating rat offspring using rat embryonic stem (ES) cell-derived sperm produced in mice with the blastocyst complementation method. By optimizing culture conditions, we established naïve male rat ES cells from two transgenic rat strains expressing EGFP and Venus fluorescence, respectively. The pluripotency of these cells was confirmed by the formation of germline chimeras. These ES cells were then injected into blastocysts of germ cell-deficient mice, which resulted in chimeric mice with the ability to produce rat-derived sperm. Histological analysis confirmed the presence of seminiferous tubules and spermatozoa, which are morphologically characteristic of rats, in the chimeric testes. To evaluate the fertilization potential of the chimeric mouse sperm, we performed intracytoplasmic sperm injection (ICSI) to rat oocytes and successfully produced viable offspring carrying ES cell-derived traits. This method eliminates concerns regarding host cell contribution, as all sperm in the chimeras originate from rats, enabling the use of nonfluorescent cells. Furthermore, the absence of competition with host cells is expected to enhance sperm production efficiency. By utilizing germ cell-deficient mice as recipients, this approach offers a cost-effective and efficient strategy for generating genetically modified rats, addressing key limitations in rat ES cell-based genetic engineering.

Stem cells play a pivotal role in the malignant behavior of gastric cancer (GC), complicating its treatment and prognosis. However, the regulatory mechanisms of GC stem cells (GCSCs) remain poorly understood. DAZ-associated protein 1 (DAZAP1), a splicing regulator linked to various malignancies, has an unclear role in GC. This study investigated DAZAP1's impact on GC stemness and its mechanisms. DAZAP1 promoted tumor progression in GCSCs, as shown by sphere formation assays and stemness marker analysis. Functional enrichment analysis suggested that DAZAP1 enhanced tumor stemness by promoting oxidative phosphorylation (OXPHOS), which was validated through Seahorse assays and measurements of mitochondrial potential. Transmission electron microscopy and immunofluorescence analyses demonstrated that DAZAP1 promoted mitophagy. RNA immunoprecipitation and PCR analysis revealed that DAZAP1 regulated the splicing and expression of the mitophagy-related gene ULK1 through nonsense-mediated mRNA decay. Rescue experiments showed that overexpression of ULK1 reversed the suppression of GC stemness and OXPHOS levels induced by DAZAP1 silencing. Our findings indicate that DAZAP1 reduces ULK1 decay, thereby activating mitophagy and enhancing OXPHOS to fulfill the metabolic demands of cancer stem cells. These findings highlight the therapeutic potential of DAZAP1 as a target for treating GC.

Dry age-related macular degeneration (AMD) is a leading cause of untreatable vision loss. In advanced cases, retinal pigment epithelium (RPE) cell loss occurs alongside photoreceptor and choriocapillaris degeneration. We hypothesized that an RPE-patch would mitigate photoreceptor and choriocapillaris degeneration to restore vision. An induced pluripotent stem cell-derived RPE (iRPE) patch was developed using a clinically compatible manufacturing process by maturing iRPE cells on a biodegradable poly(lactic-co-glycolic acid) (PLGA) scaffold. To compare outcomes, we developed a surgical procedure for immediate sequential delivery of PLGA-iRPE and/or PLGA-only patches in the subretinal space of a pig model of laser-induced outer retinal degeneration. Deep learning algorithm-based optical coherence tomography (OCT) image segmentation verified preservation of the photoreceptors over the areas of PLGA-iRPE-transplanted retina and not in laser-injured or PLGA-only-transplanted retina. Adaptive optics imaging of individual cone photoreceptors further supported this finding. OCT-angiography revealed choriocapillaris regeneration in PLGA-iRPE- and not in PLGA-only-transplanted retinas. Our data, obtained using clinically relevant techniques, verified that PLGA-iRPE supports photoreceptor survival and regenerates choriocapillaris in a laser-injured pig retina. Sequential delivery of two 8 mm2 transplants allows for testing of surgical feasibility and safety of the double dose. This work allows one surgery to treat larger and noncontiguous retinal degeneration areas.

While sexual reproduction is a general feature of animals, fissiparity and budding are relatively uncommon modes of asexual reproduction by which a fragment from a parent becomes an independent organism. Unlike unitary development, tumor cells can be included in the detached fragment destined to become offspring. Although fragmentation facilitates the vertical transmission of parental tumor cells to nascent progeny, this process requires significantly fewer cell replications than development from a zygote. The former is a risk factor for cancer, while the latter reduces oncogenic mutations during replication, indicating that two opposite effects of carcinogenesis are involved in fragmentation. If fragmentation can significantly reduce the number of cell replications for the development and a small portion of parental cancer is transmitted to the offspring during fragmentation, consecutive fragmentation across generations can gradually diminish the cancer risk of offspring, which I term fragmentational purging. On the other hand, consecutive fragmentation may aggravate the cancer risk of the progeny, a process of fragmentational accumulation. The model results imply that fragmentational purging does not necessarily guarantee the evolution of fragmentation, nor does fragmentational accumulation ensure its exclusion. Other relevant factors including juvenile susceptibility of sexual reproduction and loss of genetic diversity stemming from asexual reproduction can influence the selective advantage of fragmentation. Furthermore, owing to the common features of stemness and self-renewal, the existence of pluripotent adult stem cells required for fragmentation could be coupled with elevated cancer risk. The model results across diverse parameters and the associated mathematical analyses highlight multifaceted evolutionary trajectories toward fragmentation. Further investigation of cancer-suppression strategies that fragmentational animals employ could provide insights into regenerative medicine and cancer therapy.

Osteogenic differentiation of mesenchymal stem cells (MSCs) was strongly correlated with the progression of congenital tibial pseudoarthrosis (CPT). Activation of ferroptosis inhibited osteogenic differentiation of MSCs. ELAV-like RNA binding protein 1 (ELAVL1) is a key factor in promoting ferroptosis. This study aimed to elucidate the mechanism of ELAVL1 in the osteogenic differentiation of CPT periosteum-derived MSCs. Osteogenic differentiation of CPT periosteum-derived MSCs was detected by ARS and ALP staining. Fe2+ content and lipid reactive oxygen species content were measured using commercial kits. Molecular interactions were verified using RIP, RNA pulldown, and Co-IP. The ubiquitination level of homeobox gene D8 (HOXD8) was detected using Co-IP. Expression of ELAVL1 and tripartite motif containing 21 (TRIM21) was upregulated in CPT periosteum-derived MSCs, whereas HOXD8 expression was downregulated. Moreover, knockdown of ELAVL1 or TRIM21 inhibited ferroptosis and promoted osteogenic differentiation of CPT MSCs. TRIM21 overexpression reversed the effect caused by knockdown of ELAVL1. Mechanistically, ELAVL1 upregulated TRIM21 by increasing the stability of TRIM21, which ubiquitinated and degraded HOXD8. ELAVL1 bound to TRIM21, which promoted ubiquitination and degradation of HOXD8, thereby promoting ferroptosis to inhibit osteogenic differentiation of CPT MSCs.

Rotator cuff (RC) tears affect many individuals around the globe. Ambiguity of rotator cuff repair surgical outcomes is currently a limitation that is associated with fat accumulation and atrophy in the rotator cuff muscles. To improve the efficacy of rotator cuff repairs, a deeper understanding of the root causes is required. Traditionally, the term "fat infiltration" has been used to described fatty changes in muscle after rotator cuff tears. This paper introduces the concept of fat expansion as a more appropriate description for the appearance of fatty rotator cuff tear pathological changes. Furthermore, the contribution of fibroadipogenic progenitor (FAP) cells to pathological changes associated with rotator cuff injuries is presented to characterize the molecular basis of impairment. Lastly, the field of regenerative engineering is discussed as a promising solution to the pathological changes associated with rotator cuff tears.

Conditioned medium of umbilical cord mesenchymal cells is a rich environment in various growth factors and cytokines, the use of which causes self-improvement and self-renewal in damaged tissues.

Stem cell therapy is a promising area of regenerative medicine, offering potential treatments for various life-threatening disorders. Stem cells are classified based on their differentiation potential into totipotent, pluripotent, and multipotent stem cells. Among them, mesenchymal stem cells (MSCs) are widely used in regenerative medicine due to their tissue regeneration capabilities and ability to differentiate into multiple cell types. Stem cells are being explored for treating neurodegenerative disorders like Parkinson's, Alzheimer's, Huntington's, and amyotrophic lateral sclerosis (ALS). These conditions result from progressive neuronal degeneration, leading to irreversible damage. Challenges such as cell survival, immune rejection, tumor formation, and ethical concerns related to embryonic stem cells need to be addressed. Nanotechnology is emerging as a tool for enhancing stem cell therapy, improving targeted delivery and effectiveness. Nanoparticles possess the ability to create microenvironments as substrates, facilitate targeted administration, and enable real-time, precise imaging of stem cells. This review explores the integration of stem cells and nanotechnology as regenerative medicine tool for neurodegenerative disease treatment, analyzing current strategies and therapeutic approaches. Integrating nanotechnology with stem cell therapy may significantly improve targeted delivery and enhance regenerative outcomes for neurodegenerative disorders.

Knee osteoarthritis (OA) is a degenerative joint disorder with limited non-surgical treatment options. Adipose-derived mesenchymal stem cell (AD-MSC) therapy has emerged as a promising regenerative approach; however, the comparative efficacy and safety of autologous versus allogeneic AD-MSCs remain unclear. This systematic review and network meta-analysis (NMA) evaluated the effectiveness and safety of intra-articular AD-MSCs in adults with Kellgren-Lawrence Grade II-IV knee OA. A comprehensive search identified eight randomized controlled trials that compared high-dose autologous, high-dose allogeneic, and low-dose allogeneic AD-MSCs to placebo or standard care interventions, such as hyaluronic acid, corticosteroids, or physical therapy. The primary outcomes were pain relief, assessed by the Visual Analog Scale (VAS), and functional improvement, measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), at three, six, and 12 months. Treatment rankings were determined using Surface Under the Cumulative Ranking (SUCRA) probabilities. High-dose autologous AD-MSCs ranked highest for pain relief at three, six, and 12 months (VAS SUCRA: 75.99%, 82.27%, 81.65%), while high-dose allogeneic AD-MSCs ranked highest for functional improvement at six and 12 months (WOMAC SUCRA: 74.6%, 71.71%). Low-dose allogeneic AD-MSCs consistently ranked lowest for both outcomes. Adverse event analysis indicated that low-dose allogeneic AD-MSCs had the highest risk of adverse effects (SUCRA: 22.24%), followed by high-dose allogeneic AD-MSCs (26.52%). In contrast, high-dose autologous AD-MSCs ranked safer (SUCRA: 54.08%). Serious adverse events were rare and unrelated to treatment, and consistency testing confirmed no significant inconsistencies in the NMA framework. Overall, high-dose autologous AD-MSCs provided sustained pain relief over 12 months, while high-dose allogeneic AD-MSCs demonstrated superior long-term functional improvement. These findings support a two-phase treatment model in which autologous AD-MSCs offer early and prolonged symptom relief, and allogeneic AD-MSCs assist in long-term joint recovery. Overall, AD-MSC therapy was well tolerated and may represent a viable, personalized, non-surgical knee OA management strategy.