Search Results (431)

Testicular development and spermatogenesis are critical for male reproduction, but their molecular mechanisms in Dezhou donkeys remain understudied. This study used single-cell RNA sequencing (scRNA-seq) to analyze testicular tissues from Dezhou donkeys at juvenile (2 months), pre-pubertal (12 months), and mature (24 months) stages. A total of 24,606 high-quality cells were profiled, constructing a comprehensive single-cell transcriptional atlas. Unsupervised clustering identified nine major cell types: three germ cell subtypes (spermatogonia, spermatocytes, spermatids) and six somatic cell subtypes (Leydig cells, Sertoli cells, peritubular muscle cells, macrophages, endothelial cells, T cells). Key marker genes (AMH, TNP1, UTF1, ZMYND10) were validated by immunofluorescence. Pseudotemporal trajectory analysis revealed sequential germ cell differentiation (spermatogonia → spermatocytes → spermatids) and Sertoli cell maturation (immature → mature), while Leydig cells and peritubular muscle cells shared common progenitors. CellChat analysis identified critical ligand–receptor pairs in BMP, IGF, WNT, and FSH pathways, which regulate testicular development. This study provides the comprehensive single-cell transcriptional map of Dezhou donkey testicular development, elucidating key molecular mechanisms of germ and somatic cell maturation. The findings offer valuable insights into donkey reproductive biology, supporting breeding improvement and male infertility research. Full article

Physical inactivity contributes to type 2 diabetes (T2D), but the molecular links between exercise and metabolic improvement remain incompletely understood. We meta-analyzed genome-wide association studies of vigorous physical activity and T2D (combined n ≈ 1.95 million) and integrated eQTL/sQTL maps with single-cell and spatial transcriptomic datasets to connect genetic risk with tissues, cell types, and regulatory programs. Tissue and cell-type enrichment, colocalization, and network analyses were performed. Computational findings were further examined in male 10-week-old C57BL/6J mice with high-fat diet-induced diabetes. After 1 week of acclimatization, mice were randomly assigned to normal chow, high-fat diet, or high-fat diet plus exercise groups (n = 6 per group; high-fat diet with 60% of total energy from fat). The exercise intervention consisted of treadmill running (10 m/min for 50 min per day, 5 days per week, total 16 weeks), followed by metabolic phenotyping, skeletal muscle histology, bulk RNA sequencing, alternative splicing analysis, and RT-qPCR of Mau2 isoforms. Exercise- and T2D-associated variants showed joint enrichment in skeletal muscle and adipose eQTL/sQTL signals. Integrated single-cell analyses prioritized fibro-adipogenic progenitors and endothelial cells, and identified an extracellular matrix- and collagen-related module in fibro-adipogenic progenitors associated with both exercise and T2D. Mau2 emerged as a shared candidate gene with tissue-specific splicing signals. In diabetic mice, exercise improved glucose homeostasis and muscle fiber structure, and reduced Mau2 intron retention in skeletal muscle without changing total Mau2 expression. These findings support a multiscale framework linking exercise-responsive regulation to T2D-related tissue remodeling and splicing plasticity. Full article

Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) play essential roles in the brain, influencing neuronal and dendritic growth, as well as neurotransmission. These effects persist throughout life. Numerous studies in animals and humans have demonstrated the beneficial effects of GH therapy on memory and cognitive function, as well as on the restoration of neuronal function following injury. All nerve cells, including neurons, glia, endothelial, epithelial, and perivascular cells, are affected by the actions of GH/IGF-1. IGF-1, in particular, has been associated with cognitive function. The GH-IGF-1 axis increases the proliferation of neuronal progenitor cells and the formation of new neurons, oligodendrocytes, and astrocytes. In this study, we searched databases such as PubMed, Google Scholar, and Embase for human clinical trials evaluating the effect of growth hormone (GH) therapy on dementia, Alzheimer’s disease (AD), post-traumatic brain injury (PTI), and stroke. The following search terms were used: “GH and dementia,” “GH and Alzheimer’s disease,” “GH and TBI,” and “GH and stroke.” Inclusion criteria were all randomized controlled trials and observational studies. Exclusion criteria included the lack of cognitive and memory assessments. We found 28 articles. Most studies show the beneficial effects of GH therapy on memory and recovery of brain function after traumatic injury and stroke; however, consistent data are still lacking. The limited number of clinical trials, the small number of patients, and the lack of data on plasma levels of sex hormones that clearly contribute to brain function are limiting factors. This is the case, for example, with androgens. Other critical factors are dosage and treatment duration. Prolonged administration and supraphysiological doses are more effective in inducing positive clinical changes. Growth hormone (GH) therapy is a very promising intervention for preventing and treating dementia and early-stage Alzheimer’s disease, and it contributes significantly to the recovery of brain function in patients after traumatic injury and stroke. Further studies with more robust methodologies are needed to confirm these results. Full article

Background: Aging, especially after menopause, reduces the quantity and function of adult stem cells. Estrogen deficiency impairs proliferation, differentiation, and regenerative capacity. This study evaluated whether estrogen enhances endothelial differentiation of adipose-derived stromal cells (ADSCs) and improves therapeutic efficacy in critical limb ischemia (CLI). Methods: Male-derived ADSCs were assessed in vitro for endothelial differentiation using flow cytometry, biochemical assays, and angiogenesis analyses. Therapeutic effects were tested in a rat CLI model using endothelial-differentiated ADSCs (ED-ADSCs) with or without 17β-estradiol (E2). An ovariectomized (OVX) model examined estrogen deficiency and supplementation in vivo. Results: E2 promoted endothelial differentiation, increasing ERα/ERβ expression and activating PI3K/Akt/eNOS and MAPK signaling. This led to elevated VEGF expression, enhanced tube formation, and increased CD34⁺, KDR⁺, and CD31⁺ cell populations. In vivo, E2-pretreated ED-ADSCs significantly improved blood flow recovery. Estrogen deficiency reduced endothelial progenitor populations, which were restored by E2 supplementation. Conclusions: Estrogen modulates endothelial-associated characteristics and angiogenesis-related responses of ADSCs via ER-associated signaling, and may contribute to improved functional outcomes in ischemic conditions. E2 preconditioning may represent a potential strategy for stem cell-based therapy in estrogen-deficient settings. Full article

The aorta is the largest vascular conduit in humans, comprising three layers and a multitude of varying cell types collectively maintaining homeostasis and normal aortic wall function. Amongst these layers, the tunica adventitia is the external-most layer, where microvessels, termed vasa vasorum, can be found. These comprise pericytes and endothelial cells (ECs) and provide nourishment to the tunica adventitia and the outer media layers in the thoracic aorta. Adjacent to these microvessels, stem/progenitor group populations can be found, together forming a perivascular niche. Eventually, however, many of these cells and components can become dysregulated and contribute to development of thoracic aortic aneurysm (TAA). The purpose of this narrative review is to evaluate the recent literature related to marker gene expression in tunica adventitia pericytes, as well as the contribution of these populations to the development of aneurysm in the thoracic aorta. Pericytes in TAA generally exhibit phenotypic changes, which could be driven, in part, by loss of fibroblast growth factor (FGF) signaling. These changes eventually lead to vasa vasorum remodeling in the thoracic aorta, in turn contributing to the development of TAA. Full article

Hydrogel-based stem cell therapy uses different stem cells and bioactive molecules for wound healing in the treatment of diabetes and chronic burn wounds by accelerating angiogenesis, collagen deposition, and inhibition of inflammatory responses. Artificial vessels have already been used for patients with cardiovascular diseases, but most of them are polymeric, which can cause thrombosis and restenosis. 3D bioprinting combines cells, growth factors, and biomaterials to create a setting in which cells grow and differentiate into native tissue-like structures. The current study aimed to create a model of blood vessels using collagen and hyaluronic acid hydrogel combined with endothelial and muscle progenitor cells derived from amniotic mesenchymal stem cells using 3D bioprinting. A computer-aided design (CAD) software was employed to create the 3D models of a blood vessel model and printed using a 3D bioprinter with two printheads: one with bioink encapsulating endothelial progenitor cells and the second with bioink encapsulating smooth muscle progenitor cells. The blood vessel constructs were characterized morphologically and structurally by Fourier Transform Infrared (FTIR) Spectroscopy, thermogravimetric analysis (TGA), Scanning Electron Microscopy (SEM), immunohistochemistry, water uptake, and enzymatic degradation. Viability, proliferation, oxidative stress, vascular endothelial growth factor (VEGF) and nitric oxide (NO) production were assessed to demonstrate the cytocompatibility of the blood vessel constructs. Our results showed that collagen–hyaluronic acid hydrogels embedded with stem cells can be used for vascular constructs, meeting the desired requirements of biocompatibility and accuracy in reproducing the model created in the CAD software v1.0. Full article

Fetal skeletal muscle development involves coordinated interactions among myogenic, stromal, vascular, and immune compartments, yet the cellular and molecular programs guiding tissue maturation remain incompletely understood. To address this, we generated a high-resolution single-cell atlas of fetal female goat skeletal muscle and performed trajectory analysis, transcription factor activity profiling, and intercellular communication mapping. Unsupervised clustering identified RUNX2 mesenchymal progenitors, fibro-adipogenic progenitors (FAPs), myofibroblasts, endothelial cells, macrophages, differentiating myocytes, and mature skeletal muscle fibers, revealing a heterogeneous ecosystem in which stromal populations support myogenic progression and vascular and immune cells contribute to tissue organization. Pseudotime analysis traced a maturation continuum from differentiation-competent myocytes to contractile fibers, marked by sequential activation of extracellular matrix remodeling, cytoskeletal stabilization, and sarcomere assembly. KEGG and GO enrichment highlighted stage-specific engagement of ErbB, Hedgehog, and Hippo signaling, as well as cell cycle and ubiquitin-mediated proteolysis pathways, linking proliferation, differentiation, and structural maturation. Transcription factor profiling revealed early-stage proliferative and morphogenetically permissive states driven by E2F4/5, HMGA2, and HAND2, transitioning to late-stage differentiation, ECM remodeling, and tissue stabilization orchestrated by CEBPB, CREB3L1, ELK1, and E2F2. Cell–cell communication analysis showed a developmental redistribution of signaling authority, from ECM-driven, progenitor-centered networks to modular, structurally stabilized interactions. These findings define the cellular, transcriptional, and signaling framework orchestrating fetal skeletal muscle maturation. Full article

Clonal hematopoiesis refers to the clonal expansion of hematopoietic stem and progenitor cells, driven by somatic mutations. Major mutated genes in clonal hematopoiesis include genes involved in epigenetic regulation including DNA methylation and/or chromatin modification (e.g., DNMT3A, TET2, and ASXL1), tumor suppressors (e.g., TP53), signal transduction (e.g., JAK2), and RNA splicing (e.g., SF3B1 and SRSF2). Clonal hematopoiesis includes clonal hematopoiesis of indeterminate potential (CHIP), clonal cytopenia of unknown significance (CCUS), and myelodysplastic syndromes/neoplasms (MDS). CHIP occurs when the frequency of the variant allele equals or exceeds 2% (4% for X-linked genes in males) in the absence of cytopenias. CHIP is common among older persons and is associated with an increased risk of hematologic cancer. CHIP is also associated with an increased risk of atherosclerotic disease including acute myocardial infarction, stroke, cardiac failure, and abdominal aneurysm. Increasing evidence suggests that CHIP is associated with venous thromboembolic disease. Somatic mutations lead to proliferation of hematopoietic progenitor cells and their progeny, resulting in excessive activation of granulocytes and monocytes. It could be postulated that chronic inflammation caused by clonal expansion of myeloid cells carrying mutations in DNMT3A, TET2, and ASXL1 (“DTA”) genes may constitute an independent risk factor in clot formation and endothelial-cell damage. DTA mutations correlate with elevated proinflammatory cytokines such as IL-1β and IL-6 and enhanced activation of inflammasomes. Moreover, JAK2 mutations may have a direct role in the activation of platelets and coagulation. In vivo murine studies have demonstrated that activation of the JAK-STAT signaling pathway promotes neutrophil extracellular trap (NET) formation, contributing to a prothrombotic state. Insights from related clonal disorders such as paroxysmal nocturnal hemoglobinuria and the VEXAS syndrome support the concept that mutation-driven innate immune activation can directly perturb hemostatic balance. This review aims to summarize the association between clonal expansion of hematopoietic cells and thrombotic disease, and highlight how somatic mutations in hematopoietic cells may contribute to vascular disease and thrombogenesis. Full article

Diabetes mellitus is primarily caused by the loss or malfunction of insulin-producing β-cells, and although current therapies improve glycemic control, they do not restore physiologic insulin secretion. Advances in stem cell biology and organoid engineering have led to the development of pancreatic organoids and induced pluripotent stem cell (iPSC)-derived β-cells as promising platforms for disease modeling, drug testing, and regenerative medicine. Pancreatic organoids generated from ductal, acinar, or progenitor populations can recapitulate key anatomical and functional features of native pancreatic tissue, enabling studies of development, injury, and regeneration. In parallel, improvements in iPSC differentiation protocols have produced β-like cells capable of insulin secretion in response to glucose, although achieving full functional maturity remains a challenge. Bioengineering strategies, including biomaterial scaffolds, microfluidic platforms, endothelial co-culture systems, three-dimensional bioprinting, and CRISPR-based genome editing, have enhanced the stability, vascular compatibility, and functional performance of both organoid and iPSC-derived systems. Despite these advances, variability in differentiation efficiency, limited β-cell maturity, and poor long-term survival continue to hinder clinical translation. Together, pancreatic organoids and iPSC-derived β-cells represent complementary platforms that advance fundamental research and support the development of β-cell replacement therapies, with ongoing integration of bioengineering approaches expected to accelerate progress toward reproducible, scalable, and clinically relevant β-cell regeneration. Full article

Exosomes (EXs) mediate intercellular communication in the tissue microenvironment. We previously demonstrated that endothelial progenitor cell-derived exosomes (EPC-EXs) from exercised mice protect neurons and cerebral endothelial cells from hypoxia- and hypertension- induced injury ex vivo, suggesting their therapeutic potential in hypertensive ischemic injury. Here, we investigated whether exercise-conditioned EPC-EXs (ET-EPC-EXs) confer protection against acute ischemic injury. Hypertensive transgenic mice were divided into donor and recipient groups. Donor mice underwent treadmill exercise to generate ET-EPC-EXs. Recipient mice was subjected to middle cerebral artery occlusion and received ET-EPC-EXs via tail vein injection (2 × 10⁸/100 μL saline) two hours after stroke onset. Cerebral blood flow (CBF) was assessed, and brains were collected on day two for histological and molecular analyses. Our data showed that ET-EPC-EXs were robustly taken up by cerebral cells, predominantly in the penumbra in the ipsilateral hemisphere. ET-EPC-EXs reduced cell death and microglia activation and restored tight-junction proteins. Moreover, ET-EPC-EX treatment preserved CBF and improved sensorimotor function on day two post-stroke. Mechanistically, ET-EPC-EXs suppressed p38 activation, accompanied by reduced matrix metalloproteinase-3 and cytochrome c levels in the ipsilateral brain. Collectively, these findings demonstrate that EPC-EXs from exercise mice improve sensorimotor functions and confer protection in hypertensive ischemic brain injury, likely through attenuation of neuroinflammation and preservation of vascular integrity via modulation of the p38 signaling. Full article

Background: The prevalence of severe aortic stenosis (AS) is increasing, in accordance with a longer life expectancy. Aortic valve calcification is a multifactorial pathological process involving a complex interplay between different types of regenerative cellular and genetic factors. Among these cells, endothelial progenitor cells (EPCs) and their osteoblastic phenotype subpopulation (EPC-OCNs) have been implicated in vascular remodeling and disease progression. Objectives: To assess longitudinal changes in EPC and EPC-OCN levels in patients with severe symptomatic AS undergoing transcatheter aortic valve implantation (TAVI). Methods: In this prospective observational study, 65 patients with severe AS undergoing TAVI were enrolled. Circulating EPC and EPC-OCN levels were quantified by flow cytometry before the procedure, at 4 ± 1 days, and at 90 ± 29 days after TAVI. EPCs were defined by expression of CD133, CD34, and VEGFR-2. Results: Circulating EPC levels remained unchanged throughout the follow-up. In contrast, circulating EPC-OCNs increased significantly over time. Specifically, CD133+/VEGFR-2+/OCN+ cells rose from 2.50% to 6.25%, CD34+/VEGFR-2+/OCN+ from 2.04% to 4.05%, and VEGFR-2+/OCN+ from 1.46% to 3.01% (all p < 0.01). This suggests an osteogenic response to TAVI, while classical endothelial repair mechanisms were not systemically activated. Conclusions: EPC-OCNs increased significantly following TAVI, possibly reflecting ongoing tissue remodeling or calcification processes. In contrast, the stability of classical EPCs levels suggests limited systemic endothelial regeneration. These observations underscore the potential role of EPC-OCNs as markers or modulators of pre- and post-TAVI vascular remodeling. Full article

Obesity is increasingly recognized as a disease of dysregulated intercellular communication rather than merely an energy imbalance. Extracellular vesicles (EVs), membrane-bound nanoparticles (30–1000 nm) released by nearly all cell types, act as central mediators of this pathological crosstalk. In obesity, hypertrophic adipocytes, pro-inflammatory macrophages, and dysfunctional endothelial cells secrete EVs carrying altered cargo, including pro-inflammatory miRNAs (e.g., miR-34a, miR-155), bioactive lipids, and stress proteins, which propagate systemic metabolic dysfunction. Adipose tissue-derived EVs impair hepatic fatty acid oxidation, promote steatohepatitis, suppress pancreatic beta-cell insulin secretion, induce skeletal muscle insulin resistance via PPARγ repression, and contribute to endothelial dysfunction and atherosclerosis. EV-mediated adipocyte–macrophage crosstalk reinforces chronic adipose inflammation. Circulating EVs also provide biomarkers: subpopulation ratios, miRNA signatures, and tissue factor-positive EVs reflect disease severity, predict cardiovascular risk, and monitor therapeutic responses, with machine learning enhancing diagnostic precision. Therapeutically, EVs from mesenchymal stem cells, Wharton’s jelly MSCs, adipose progenitors, and M2 macrophages reverse insulin resistance, hepatic steatosis, and adipose inflammation in preclinical models. Engineering strategies improve EV potency and tissue targeting, and Phase I trials confirm safety, though manufacturing and cost remain barriers. Preclinical and early clinical studies of MSC-EVs confirm a favorable safety profile, though manufacturing scalability and cost remain barriers to widespread clinical adoption. Overall, EVs represent both diagnostic tools and therapeutic vehicles in precision obesity medicine, offering a pathway from symptom management toward true disease remission. Full article

Background: In an earlier murine model of myocardial infarction (MI), we showed that CD8 cells and myeloid dendritic cells (mDCs) infiltrate the infarcted myocardium within the first week. However, in humans, the spatial interplay between CD8⁺ T cells and dendritic cells in the spatial context of human myocardial infarction remains underexplored. Objective: In the present study, we applied spatial transcriptomics and functional assays to characterize immune–stromal dynamics in infarcted myocardium and peripheral blood. Methods & Results: Spatial transcriptomics analysis of infarcted human myocardium at days 2 and 6 post-MI, combined with peripheral blood flow cytometry and EPC colony-forming assays, was performed. Cell composition, pathway enrichment, and cell-to-cell communication analyses were conducted to map immune–stromal cells’ dynamics across time points. Spatial mapping identified dynamic shifts in immune, fibroblast, and endothelial populations, with fibroblasts and endothelial cells remaining abundant throughout. CD8⁺ T cells accumulated in ischemic regions while their circulating levels declined. Gene Ontology and pathway analyses of CD8A⁺ transcripts revealed enrichment of proinflammatory and NF-κB survival programs. ITGAX/CD33/THBD⁺ APCs progressively increased within infarct zones, activating antigen-presentation and leukocyte chemotaxis pathways. Early (day 2) APC–endothelial crosstalk showed the strongest predicted recruitment signals for CD8⁺ T cells, which diminished by day 6. Finally, EPC colony-forming capacity showed a tendency for reduction in MI patients and inversely correlated with coronary lesion burden, indicating impaired vascular repair potential. Conclusions: This integrative spatial and functional study demonstrates that APC-driven CD8⁺ recruitment and EPC dysfunction are key features of human MI. Immune–endothelial niches facilitate early cytotoxic T-cell infiltration, while progenitor depletion limits vascular regeneration. These findings provide mechanistic insight into immune–vascular imbalance during infarct healing and highlight potential therapeutic targets to modulate inflammation and restore vascular repair. Full article

Background: High-density lipoproteins (HDL) exert protective effects on the endothelium, which are impaired in type 2 diabetes (T2D). Although monocyte-derived multipotential cells (MOMCs) can be differentiated into the endothelial lineage, it remains unclear whether HDL glycation, size, and composition could affect MOMCs differentiation. Methods: Twenty normoglycemic (49 years, 35% male), 20 prediabetic (52 years, 35% male), and 20 newly diagnosed T2D participants (51 years, 50% male) were recruited. HDL were isolated from each study group. The size, composition, and early, intermediate, or advanced glycation products of HDL were determined. CD14+ MOMCs were isolated from healthy volunteers and incubated with HDL from each group. Endothelial phenotypic expression was assessed by CD14⁺/KDR⁺ expression. Results: Compared with normoglycemic and prediabetic individuals, T2D patients had higher concentrations of early (4.4, 4.6, vs. 5.2 µmol/mg of protein, respectively; p = 0.049) and advanced (7.7, 8.7, vs. 14.3 µg-BSA-AGEs/mg of protein, respectively; p < 0.02) glycation products in HDL. HDL composition was similar among groups. The CD14+/KDR+ expression in MOMCs incubated with HDL from T2D patients was lower than that observed in prediabetes and normoglycemic individuals (46% vs. 52% and 61%, respectively; p = 0.002). Advanced glycation end products in HDL inversely correlated with CD14+/KDR+ cells (r = −0.418, p = 0.002), adjusting for other HDL characteristics. Conclusions: In T2D patients, increased HDL-advanced glycation impairs the endothelial phenotypic expression of MOMCs, independently of other HDL characteristics. Since advanced glycation leads to greater biological damage, these findings highlight the importance of preserving HDL integrity in T2D patients to support endothelial repair and potentially delay vascular complications. Full article

The history of stromal-derived factor-1 (SDF-1), alias CXCL12, started serendipitously and relatively late in the cytokine cDNA cloning era (1975–2000) and evolved at the biological level from progenitor cell-specific chemokine in the bone marrow to multifunctional cytokine with growth factor-like and tissue-regenerative activities. This evolution was parallelled by the integration of SDF-1/CXCL12 within the protein families of chemokines, cytokines and cell growth-promoting recombinant products having the potential for clinical applications. Here, we use this central position of CXCL12 as small signaling protein as an example for future developments in regenerative medicine. We provide context about SDF-1 biology within the field of skin wound healing research and how this compares with studies of other cytokines and growth factors. We also discuss whether SDF-1 formulations may be exemplary for other cytokines used for tissue regeneration. Normal skin wound healing is fraught with delays and complications in patients with specific underlying diseases, such as diabetes, hypertension and other elderly-related comorbidities, skin infections and accidental physical insults. Except for platelet-derived growth factor (PDGF), many cytokines, including vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF), have failed so far in clinical studies of skin wound healing. This is in part due to the fact that (i) the biology of tissue regeneration is complex and insufficiently studied, (ii) in vitro approaches hardly mimic in vivo situations and (iii) commonly used animal models of acute and chronic wounding do not perfectly match human skin wound regeneration. A review of critical cells and molecules in normal skin and their actions in wounded tissue and a balanced comparison of the recent literature are preambles for progress in wound repair. We define advantages and limitations of recent approaches and appeal for more research. In particular, the possibilities of cellular immunomodulation mediated by endogenous and exogenous SDF-1/CXCL12 as a key molecule for skin regeneration are reviewed. Furthermore, biomaterials and scaffolds for the delivery and use of cytokines in precision medicine and aspects of their biofabrication are outlined with SDF-1 as an example. Finally, we indicate how applications of dermatological SDF-1 formulations for skin wound healing may be tailored for applications in other acute and chronic inflammatory conditions and regenerative medicine. Thereby, SDF-1/CXCL12 is placed at the crossroads between recombinant products, cytokines, chemokines and growth factors and occupies a central position between regenerative biology and medicine. Full article