Search Results (532)

Bone integrity is maintained through continuous remodeling, orchestrated by the coordinated actions of osteocytes, osteoblasts, and osteoclasts. Once considered passive bystanders, osteocytes are now recognized as central regulators of this process, mediating biochemical signaling and mechanotransduction. Malfunctioning osteocytes contribute to serious skeletal disorders such as osteoporosis. Mesenchymal stromal cells (MSCs), multipotent stem cells capable of differentiating into osteoblasts, have emerged as promising agents for bone regeneration, primarily through the paracrine effects of their secreted exosomes. MSC-derived exosomes are nanoscale vesicles enriched with proteins, lipids, and nucleic acids that promote intercellular communication, osteoblast proliferation and differentiation, and angiogenesis. Notably, they deliver osteoinductive microRNAs (miRNAs) that influence osteogenic markers and support bone tissue repair. In vivo investigations validate their capacity to enhance bone regeneration, increase bone volume, and improve biomechanical strength. Additionally, MSC-derived exosomes regulate the immune response, creating pro-osteogenic and pro-angiogenic factors, boosting their therapeutic efficacy. Due to their cell-free characteristics, MSC-derived exosomes offer benefits such as diminished immunogenicity and minimal risk of off-target effects. These properties position them as promising and innovative approaches for bone regeneration, integrating immunomodulatory effects with tissue-specific regenerative capabilities. Full article

Platelet-rich plasma (PRP) is widely applied in veterinary regenerative medicine due to its rich composition of growth factors that promote tissue repair. However, the direct pro-angiogenic function of canine PRP (cPRP) has not been thoroughly validated through controlled in vitro and in vivo experimentation. Human umbilical vein endothelial cells (HUVECs) were used to assess cell proliferation, migration, and tube formation after exposure to cPRP. In addition, a rabbit corneal micropocket assay was employed to evaluate in vivo angiogenic responses. Treatment with 20% cPRP significantly enhanced HUVEC proliferation and migration and induced robust tube formation. In the in vivo model, we observed dose-dependent neovascularization, with the earliest vascular sprouting seen on day 1 in the 40% group. Both models consistently demonstrated that cPRP stimulates vascular development in a concentration-dependent manner. This study provides novel evidence of cPRP’s capacity to induce neovascularization, supporting its therapeutic value for treating nonhealing wounds in dogs, especially in cases involving chronic inflammation, aging, or immune dysregulation. These findings offer a scientific foundation for the broader clinical application of cPRP in veterinary regenerative practice. Full article

Nerve tissue damage is an unsolved problem in modern neurology and neurosurgery, which prompts the need to search for approaches to stimulate neuroprotection and regeneration of neural tissue. Earlier we have shown that the secretome of human mesenchymal stromal cells (MSCs) stimulates rat survival, reduces the severity of neurological deficits, and decreases the volume of brain damage in a hemorrhagic stroke model. A significant disadvantage of using the MSC secretome is the need to concentrate it (at least 5–10 fold) to achieve appreciable pharmacological activity. This increases the cost of obtaining clinically applicable amounts of secretome and slows down the clinical translation of this technology. Here, we created a number of genetically modified human MSC cultures, including immortalized MSCs and those with hyperexpression of brain-derived neurotrophic factor (BDNF) and urokinase-type plasminogen activator (uPA) and with suppressed expression of Von Hippel–Lindau tumor suppressor (VHL), and we evaluated the pharmacological activity of their secretomes in a model of intracerebral hemorrhage (ICH) in rats. The secretome of MSCs immortalized by hyperexpression of the catalytic subunit of human telomerase (hTERT) revealed neuroprotective activity indistinguishable from that of primary MSC cultures, yet it still required 10-fold concentration to achieve neuroprotective efficacy. The secretome of MSC culture with combined hyperexpression of BDNF and uPA and suppressed expression of Von Hippel–Lindau tumor suppressor even without additional concentration reduced the severity of neurological disorders and decreased brain lesion volume in the ICH model. The secretomes of MSCs with separate overexpression of BDNF and uPA or suppression of VHL had no such effect or, on the contrary, revealed a toxic effect in the ICH model. Presumably, this may be due to an imbalance in the representation of individual growth factors in the secretome of genetically modified MSCs, which individually may lead to undesirable effects in damaged nervous tissue, such as increased permeability of the blood–brain barrier (under the influence of pro-angiogenic factors) or neural cell apoptosis (due to an excess of neurotrophic factors). The obtained data show that genetic modification of MSC cultures can enhance or alter the therapeutic activity of their secretomes, which can be used in the creation of promising sources of biopharmaceutical substances. Full article

The tumor microenvironment (TME) is crucial for the onset, development, and resistance to treatment of lung cancer. The tumor microenvironment consisting of a complex array of immune cells, fibroblasts, endothelial cells, extracellular matrix elements, and signaling molecules, facilitates tumor growth and spread while inhibiting the body’s antitumor immune response. In lung cancer, tumor-associated macrophages, cancer-associated fibroblasts, mast cells, and dendritic cells interact through cytokines, chemokines, growth factors, and matrix metalloproteinases to create an immunosuppressive and proangiogenic milieu. Hypoxic conditions within the TME further enhance cancer cell adaptability through hypoxia-inducible factors (HIFs), promoting epithelial–mesenchymal transition, immune evasion, and metastasis. Moreover, miRNAs have emerged as key regulators of gene expression within the TME, offering novel insights into tumor behavior and potential therapeutic targets. Targeting dynamic interactions within the TME, particularly through the modulation of immune responses, angiogenesis, and stromal remodeling, offers promising avenues for precision pharmacological approaches. This review covers the current understanding of the lung TME, highlighting its impact on cancer pathophysiology and treatment strategies. Understanding and therapeutically reprogramming the TME may pave the way for personalized and more effective interventions for lung cancer treatment. Full article

Background: Subcutaneous pocket infection is a common morbidity associated with the integration of cardiac implantable electronic devices (CIEDs). A new antibiotic-eluting CIED bioenvelope has been developed as a prophylactic measure to mitigate infection and skin erosion caused by device migration. This study investigated the envelope’s regulatory properties in scar formation and vascularization. Methods: Fibroblasts were seeded on either plastic (n = 6) or small intestine submucosal extracellular matrix (SIS-ECM) (n = 6) for 24 h. The culture media were analyzed for proangiogenic and proinflammatory proteins with multiplex. Sham (n = 8) or SIS-ECM (n = 8) was randomly implanted into the dorsal subcutaneous pocket of mice. The implants were excised on day 7, cultured for 24 h, and the media analyzed. Rabbit models were implanted with either synthetic polymer HDPE (n = 12) or SIS-ECM (n = 11). The treatments were excised at weeks 2, 10, and 26 and then stained for analysis. Results: SIS-ECM significantly increased the fibroblasts’ paracrine release of proangiogenic and proinflammatory factors like VEGF-A (p < 0.05) and IL-6 (p < 0.05) compared with plastic. The murine tissue interacting with SIS-ECM released significantly more angiogenic proteins like VEGF-A (p < 0.05) than the sham. The histology analysis of rabbit subcutaneous tissue revealed a decreasing level of inflammation and fibrosis over time with SIS-ECM. Conclusions: The CIED bioenvelope elicited proangiogenic paracrine signaling and reduced fibrotic response in fibroblasts and animal models. Clinical translation of the CIED bioenvelope as an adjunct to regular prophylactic practice may be warranted in the future. Full article

The ocular surface is susceptible to a wide spectrum of inflammatory, degenerative, and neurotrophic diseases that can impair vision. The complex pathophysiology and limited therapeutic options associated with these conditions continue to pose significant clinical challenges. Nerve Growth Factor (NGF), a neurotrophin initially recognized for its role in neuronal survival and differentiation, has emerged as a key regulator of ocular surface homeostasis and repair. Beyond its neurotrophic functions, NGF is suggested to influence epithelial proliferation, immune responses, tear secretion, and angiogenesis. Experimental and clinical studies have implicated NGF in both the pathogenesis and potential treatment of various ocular surface diseases, including allergic conjunctivitis, neurotrophic keratopathy (NK), immune-mediated and herpetic keratitis, and dry eye disease (DED), as well as post-surgical corneal wound healing. Notably, recombinant human NGF (rhNGF, cenegermin) has been approved as the first topical biologic therapy for NK. Despite encouraging clinical outcomes, challenges such as high treatment costs, limited long-term data, and potential proangiogenic effects remain. This review consolidates current evidence on the role of NGF in ocular surface health and disease, highlighting its biological mechanisms, clinical applications, and future therapeutic potential. Full article

The role of periodontal ligament stem cells (PDLSCs) and dental pulp stem cells (DPSCs) in stimulating angiogenesis has been reported, but their angiogenetic potential has not been directly compared. In this work, paired PDLSCs and DPSCs, i.e., derived from the same donor, were tested for their immunophenotype and multi-differentiation capabilities, with particular emphasis on their pro-angiogenic activity. Flow cytometry was utilized to study the expression of mesenchymal stem cell, pericyte, and endothelial markers, while gene expression was evaluated through real-time PCR. The angiogenic potential was assessed recurring to tubulogenesis assay, co-cultures with Human Microvascular Endothelial Cell (HMEC-1), and VEGF-A quantification. The immunophenotype of DPSCs and PDLSCs was different in CD146+ and CD31+ cell subsets, but both cell types promoted HMEC-1 tubulogenesis in vitro. Consistently, VEGF-A gene expression level and its quantification in cell-conditioned media of PDLSCs and DPSCs was comparable between them, and both promoted the formation of vessel-like structures, when co-cultured with HMEC-1 cells. All together, these results showed the heterogeneity of PDLSCs and DPSCs, which are constituted of different cellular subsets, likely modulated by the microenvironmental cues. PDLSCs and DPSCs showed comparable pro-angiogenic activity, enhanced by the contemporary expression of angiogenic and chemotactic factors. Full article

Coronary artery disease (CAD) remains a leading cause of global morbidity and mortality despite advances in medical and interventional therapies. Mesenchymal stem cell (MSC) therapy has emerged as a promising regenerative approach for patients with refractory or non-revascularizable CAD. MSCs exhibit unique immunomodulatory, pro-angiogenic, and anti-fibrotic properties, primarily through paracrine mechanisms involving the secretion of cytokines, growth factors, and exosomal microRNAs. Clinical and preclinical studies have demonstrated improvements in myocardial perfusion, left ventricular ejection fraction (LVEF), and functional capacity following MSC-based interventions, particularly in patients with low baseline LVEF and heightened inflammation. Various MSC sources—including bone marrow, adipose tissue, and umbilical cord—offer distinct advantages, while delivery strategies such as intracoronary, intramyocardial, intravenous, and subcutaneous administration impact cell retention and efficacy. Advances in genetic modification, hypoxic preconditioning, and exosome-based therapies aim to enhance MSC survival and therapeutic potency. However, challenges persist regarding cell engraftment, cryopreservation effects, and inter-patient variability. Moving toward precision cell therapy, future approaches may involve stratifying patients by inflammatory status, ischemic burden, and comorbidities to optimize treatment outcomes. MSCs may not yet replace conventional therapies but are increasingly positioned to complement them within a personalized, regenerative framework for CAD management. Full article

Diabetic foot ulcers (DFU) represent a major complication of diabetes mellitus, affecting millions of patients worldwide and leading to high morbidity and amputation risks. The impaired healing process in DFU is driven by vascular insufficiency, neuropathy, chronic inflammation, and infections. Conventional treatments, including blood sugar control, wound debridement, and standard dressings, have shown limited efficacy in achieving complete healing. Recent advancements have introduced novel therapeutic approaches such as stem cell therapy, exosome-based treatments, and bioengineered scaffolds to accelerate wound healing and tissue regeneration. Mesenchymal stem cells (MSCs), particularly adipose-derived stem cells (ASCs), exhibit anti-inflammatory, pro-angiogenic, and immunomodulatory properties, enhancing wound repair. Additionally, exosomes derived from ASCs have demonstrated the ability to promote fibroblast proliferation, regulate inflammation, and stimulate angiogenesis. The integration of bioengineered scaffolds, including hydrogels, hyaluronic acid (HA), or micro-fragmented adipose tissue (MFAT), offers improved drug delivery mechanisms and a controlled healing environment. These scaffolds have been successfully utilized to deliver stem cells, growth factors, antioxidants, anti-glycation end products, anti-inflammatory and anti-diabetic drugs, or antimicrobial agents, further improving DFU outcomes. This review highlights the potential of combining novel 3D scaffolds with anti-diabetic drugs to enhance DFU treatment, reduce amputation rates, and improve patients’ quality of life. While promising, further clinical research is required to validate these emerging therapies and optimize their clinical application. Full article

This study developed electrosprayed deferoxamine (DFO)-loaded poly(lactic-co-glycolic acid) microspheres (DFO-MS) combined with a sucrose acetate isobutyrate (SAIB) depot (DFO-MS@SAIB) for bone-defect repair, targeting the coordinated regulation of angiogenesis and osteogenesis in vascularized bone regeneration—where new blood vessels support functional bone integration. In vitro/in vivo evaluations confirmed its dual pro-angiogenic and pro-osteogenic effects via HIF-1α pathway activation. Background/Objectives: Emerging evidence underscores the indispensability of vascularization in bone-defect repair, a clinical challenge exacerbated by limited intrinsic healing capacity. While autologous grafts and growth-factor-based strategies remain mainstream, their utility is constrained by donor-site morbidity, transient bioactivity, and poor spatiotemporal control over angiogenic–osteogenic coupling. Here, we leveraged DFO, a hypoxia-mimetic HIF-1α stabilizer with angiogenic potential, to engineer an injectable DFO-MS@SAIB depot. This system was designed to achieve sustained DFO release, thereby synchronizing vascular network formation with mineralized tissue regeneration in critical-sized defects. Methods: DFO-MS were fabricated via electrospraying and combined with SAIB (DFO-MS@S) to form an injectable sustained-release depot. Their physicochemical properties, including morphology, encapsulation efficiency, degradation, release kinetics, and rheology, were systematically characterized. In vitro, the angiogenic capacity of HUVECs co-cultured with DFO-MS was evaluated; conditioned HUVECs were then co-cultured with BMSCs to assess the BMSCs’ cytocompatibility and osteogenic differentiation. In vivo bone regeneration in a rat calvarial defect model was evaluated using micro-CT, histology, and immunohistochemistry. Results: The DFO-MS@SAIB system achieved sustained DFO release, stimulating HUVEC proliferation, migration, and tubulogenesis. In a Transwell co-culture model, pretreated HUVECs promoted BMSC migration and osteogenic differentiation via paracrine signaling involving endothelial-secreted factors (e.g., VEGF). HIF-1α pathway activation upregulated osteogenic markers (ALP, Col1a1, OCN), while in vivo experiments demonstrated enhanced vascularized bone regeneration, with significantly increased bone volume/total volume (BV/TV) and new bone area compared with controls. Conclusion: The DFO-MS@SAIB system promotes bone regeneration via sustained deferoxamine release and HIF-1α-mediated signaling. Its angiogenesis–osteogenesis coupling effect facilitates vascularized bone regeneration, thereby offering a translatable strategy for critical-sized bone-defect repair. Full article

Angiogenesis plays a crucial role in solid tumor growth. Ischemia and inflammation induce various angiogenic mediators, and patient metabolic conditions importantly influence this process. Macrophages closely interact with the vascular system and regulate angiogenesis through pro/anti-angiogenic factors. Traditionally, pro-angiogenic activity has been attributed to M2-like macrophages. We question this, as recent evidence suggests that also M1-like macrophages can be pro-angiogenic. Therefore, the aim is to identify the pro/anti-angiogenic gene expression profiles of human polarized macrophages unbiasedly. We also examine the effect of hyperglycemia on angiogenic gene expression, reflecting its role in diabetes and other metabolic conditions. Bioinformatic analysis was performed on the angiogenesis-related gene expression profiles of CD14+ monocyte-derived M1(IFN-γ)- and M2(IL-4)-polarized macrophages. The top differentially expressed genes were selected for validation. Macrophages were generated in vitro and polarized to M1(IFN-γ) and M2(IL-4/IL-6) cells under standard/hyperglycemic conditions. After immunophenotypic confirmation, selected gene expression was quantified using qPCR. IL-4 and IL-6 induce distinct M2-like phenotypes with mixed pro/anti-angiogenic gene expression. Remarkably, IFN-γ stimulation also increases several pro-angiogenic genes. Hyperglycemia affects the angiogenic expression profile in both M1- and M2-like macrophages, although distinctive identities remain intact. The pro-angiogenic phenotype is not limited to M2-polarized macrophages. Both M1- and M2-like macrophages express complex pro/anti-angiogenic gene profiles, which are only mildly influenced by hyperglycemia. Full article

Endothelial progenitor cells (EPC) are considered to support neovascularization and endothelial repair by being incorporated into newly formed or injured vessels and by improving vascularization in a paracrine manner by secreting proangiogenic factors. Here, we studied the role of gap junctional communication between EPC and endothelial cells in long-term co-cultures in vitro. The cultivation of endothelial cells together with mouse embryonic EPC (E 7.5) induced the spontaneous formation of angiogenic networks after 3–6 days consisting of both cell types, but not in the respective monocultures, whereas their respective cultivation on a basement matrix induced the formation of tube-like structures, as expected. The angiogenic network formation could not be mimicked by the incubation of endothelial cells with supernatants of EPC only. We therefore hypothesized that direct interaction and cell-cell communication is required to induce the angiogenic network formation in co-cultures with endothelial cells. Expression analysis demonstrated expression of the gap junctional protein connexin 43 (Cx43) in EPC. Moreover, dye injection studies as well as FACS analysis identified gap junctional communication between endothelial cells and EPC. The inhibition of gap junctions by pharmacological blockers significantly reduced the angiogenic network formation, confirming that gap junctional communication between both cell types is required for this process. Full article

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and lethal forms of cancer, characterized by a highly desmoplastic tumor microenvironment. One main risk factor is chronic pancreatitis (CP). Progression of CP to PDAC is greatly influenced by persistent inflammation promoting genomic instability, acinar–ductal metaplasia, and pancreatic intraepithelial neoplasia (PanIN) formation. Components of the extracellular matrix, including immune cells, can modulate this progression phase. This includes cells of the innate immune system, such as natural killer (NK) cells, macrophages, dendritic cells, mast cells, neutrophils, and myeloid-derived suppressor cells (MDSCs), either promoting or inhibiting tumor growth. On one hand, innate immune cells can trigger inflammatory responses that support tumor progression by releasing cytokines and growth factors, fostering tumor cell proliferation, invasion, and metastasis. On the other hand, they can also activate immune surveillance mechanisms, which can limit tumor development. For example, NK cells are cytotoxic innate lymphoid cells that are able to kill tumor cells, and active dendritic cells are crucial for a functioning anti-tumor immune response. In contrast, mast cells and MDSCs rather support a pro-tumorigenic tumor microenvironment that is additionally sustained by platelets. Once thought to play a role in hemostasis only, platelets are now recognized as key players in inflammation and cancer progression. By releasing cytokines, growth factors, and pro-angiogenic mediators, platelets help shape an immunosuppressive microenvironment that promotes fibrotic remodeling, tumor initiation, progression, metastasis, and immune evasion. Neutrophils and macrophages exist in different functional subtypes that can both act pro- and anti-tumorigenic. Understanding the complex interactions between innate immune cells, platelets, and early precursor lesions, as well as PDAC cells, is crucial for developing new therapeutic approaches that can harness the immune and potentially also the coagulation system to target and eliminate tumors, offering hope for improved patient outcomes. Full article

Brain glioma is one of the most common malignant tumors of brain tissue. It is characterized by rich vascularization, which indicates the significant participation of angiogenesis in its growth and development. In its first stages, the disease is very often asymptomatic, and late diagnosis significantly limits possibilities of treatment. Tumor angiogenesis, i.e., the formation of new vessels, requires the presence of angiogenic compounds that will enable tumor progression by creating a path for the supply of nutrients. The proangiogenic compounds involved in the development of glioma include hypoxia-inducible factor 1α (HIF-1α), angiopoietin-2 (ANG-2), and interleukin-1β (IL-1β). The aim of this study was to analyze changes in the levels of these proteins in plasma samples of patients diagnosed with brain glioma in stages G1 to G4, and in a control group, using SPRi biosensors. The results obtained in plasma were compared with the concentrations obtained during the analysis of tissue homogenates from patients with glioma in stages G2 to G4. A statistically significant difference in plasma concentrations was obtained between the patient group and the control group. The concentrations of the markers in tissue homogenate samples were statistically higher than in blood plasma. There was no significant effect of gender, diet, smoking, or the patient’s general health condition (Karnofsky score) on the course of the disease. These factors do not directly increase the risk of developing brain glioma. Full article

The cornea, a highly innervated and avascular ocular tissue, relies on intricate neuro-immune interactions to maintain homeostasis. Among key neuromediators, substance P (SP)—a neuropeptide belonging to the tachykinin family—plays a dual role in corneal physiology and pathology. This review synthesizes current knowledge on SP’s involvement in corneal innervation, epithelial homeostasis, immune regulation, neovascularization, and wound healing, while highlighting its dichotomous effects in both promoting tissue repair and exacerbating inflammation. SP, primarily signaling through the neurokinin-1 receptor (NK1R), influences corneal epithelial proliferation, barrier function, and wound healing by modulating cytokines, chemokines, and growth factors. However, its overexpression is linked to pain sensitization, inflammatory keratitis, and corneal neovascularization, driven by interactions with immune cells (e.g., mast cells, neutrophils) and pro-angiogenic factors (e.g., VEGF). Clinical studies demonstrate altered SP levels in dry eye disease, neurotrophic keratitis, and post-refractive surgery, correlating with nerve damage and ocular surface dysfunction. Emerging therapies targeting SP pathways- such as NK1R antagonists (e.g., fosaprepitant) and SP-IGF-1 combinations-show promise for treating neurotrophic ulcers but face challenges due to SP’s context-dependent actions. Future research should clarify the roles of NK2R/NK3R receptors and optimize SP-based interventions to balance its reparative and inflammatory effects. Understanding SP’s multifaceted mechanisms could advance the development of therapies for corneal diseases, particularly those involving sensory neuropathy and immune dysregulation. Full article