Search Results (1,709)

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

Background: Diabetic foot ulcers (DFUs) are a serious complication of diabetes and are often difficult to treat. Hyperbaric oxygen therapy (HBOT) has been proposed as an adjunctive treatment to promote healing, but its long-term clinical and biological effects remain insufficiently characterized. This study aimed to evaluate the impact of HBOT on systemic biomarkers, local microvasculature, and clinical outcomes in patients with DFUs. Methods: In this non-randomized prospective study, 20 patients with ischemic DFUs were followed over a 36-month period. Fourteen received HBOT in addition to standard care, while six received standard care alone. Clinical outcomes—including DFU resolution, recurrence, lower extremity amputation (LEA), and mortality—were assessed alongside systemic inflammatory and angiogenic biomarkers and wound characteristics at baseline and at 3, 6, 12, and 36 months. CD31 immunostaining was performed on available tissue samples. Results: The two groups were comparable at baseline (mean age 62 ± 12 years; diabetes duration 18 ± 9 years). At 3 months, the HBOT group showed significant reductions in erythrocyte sedimentation rate and DFU size (p < 0.05), with downward trends observed in C-reactive protein (CRP), vascular endothelial growth factor (VEGF), and placental growth factor (PlGF), and an increase in stromal-derived factor-1 alpha (SDF1-α). No significant changes were observed in the control group. CD31+ microvessel density appeared to increase in HBOT-treated DFU tissue after one month, although the sample size was limited. Patients receiving HBOT had lower rates of LEA and mortality, improved wound healing, and sustained outcomes over three years. DFU recurrence rates were similar between groups. Conclusions: HBOT was associated with improved wound healing and favorable biomarker profiles in patients with treatment-resistant ischemic DFUs. While these findings are encouraging, the small sample size and non-randomized design limit their generalizability, highlighting the need for larger, controlled studies. Full article

Titanium–aluminum–vanadium (Ti6Al4V) is a material chosen for spine, orthopedic, and dental implants due to its combination of desirable mechanical and biological properties. Lasers have been used to modify metal surfaces, enabling the generation of a surface on Ti6Al4V with distinct micro- and nano-scale structures. Studies indicate that topography with micro/nano features of osteoclast resorption pits causes bone marrow stromal cells (MSCs) and osteoprogenitor cells to favor differentiation into an osteoblastic phenotype. This study examined whether the biological response of human MSCs to Ti6Al4V surfaces is sensitive to laser treatment-controlled micro/nano-topography. First, 15 mm diameter Ti6Al4V discs (Spine Wave Inc., Shelton, CT, USA) were either machined (M) or additively manufactured (AM). Surface treatments included no laser treatment (NT), nanosecond laser (Ns), femtosecond laser (Fs), or nanosecond followed by femtosecond laser (Ns+Fs). Surface wettability, roughness, and surface chemistry were determined using sessile drop contact angle, laser confocal microscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Human MSCs were cultured in growth media on tissue culture polystyrene (TCPS) or test surfaces. On day 7, the levels of osteocalcin (OCN), osteopontin (OPN), osteoprotegerin (OPG), and vascular endothelial growth factor 165 (VEGF) in the conditioned media were measured. M NT, Fs, and Ns+Fs surfaces were hydrophilic; Ns was hydrophobic. AM NT and Fs surfaces were hydrophilic; AM Ns and Ns+Fs were hydrophobic. Roughness (Sa and Sz) increased after Ns and Ns+Fs treatment for both M and AM disks. All surfaces primarily consisted of oxygen, titanium, and carbon; Fs had increased levels of aluminum for both M and AM. SEM images showed that M NT discs had a smooth surface, whereas AM surfaces appeared rough at a higher magnification. Fs surfaces had a similar morphology to their respective NT disc at low magnification, but higher magnification revealed nano-scale bumps not seen on NT surfaces. AM Fs surfaces also had regular interval ridges that were not seen on non-femto laser-ablated surfaces. Surface roughness was increased on M and AM Ns and Ns+Fs disks compared to NT and Fs disks. OCN was enhanced, and DNA was reduced on Ns and Ns+Fs, with no difference between them. OPN, OPG, and VEGF levels for laser-treated M surfaces were unchanged compared to NT, apart from an increase in OPG on Fs. MSCs grown on AM Ns and Ns+Fs surfaces had increased levels of OCN per DNA. These results indicate that MSCs cultured on AM Ns and AM Ns+Fs surfaces, which exhibited unique roughness at the microscale and nanoscale, had enhanced differentiation to an osteoblastic phenotype. The laser treatments of the surface mediated this enhancement of MSC differentiation and warrant further clinical investigation. Full article

Background/Objectives: Brain metastasis (BM) is a common and often early manifestation in lung adenocarcinoma (LUAD), yet its tumor microenvironment remains poorly defined at the time of initial diagnosis. This study aims to characterize early immune microenvironmental alterations in synchronous BM using spatial proteomic profiling. Methods: We performed digital spatial proteomic profiling using the NanoString GeoMx platform on formalin-fixed paraffin-embedded tissues from five treatment-naïve LUAD patients in whom BM was the initial presenting lesion. Paired primary lung and brain metastatic samples were analyzed across tumor and stromal compartments using 68 immune- and tumor-related protein markers. Results: Spatial profiling revealed distinct expression patterns between primary tumors and brain metastases. Immune regulatory proteins—including IDO-1, PD-1, PD-L1, STAT3, PTEN, and CD44—were significantly reduced in brain metastases (p < 0.01), whereas pS6, a marker of activation-induced T-cell death, was significantly upregulated (p < 0.01). These alterations were observed in both tumor and stromal regions, suggesting a more immunosuppressive and apoptotic microenvironment in brain lesions. Conclusions: This study provides one of the first spatially resolved proteomic characterizations of synchronous BM at initial LUAD diagnosis. Our findings highlight early immune escape mechanisms and suggest the need for site-specific immunotherapeutic strategies in patients with brain metastasis. Full article

Endometriosis is a disorder characterized by the presence of endometrial tissue outside the uterus, leading to dyspareunia, chronic pelvic pain, dysuria, and infertility. The latter has been related to implantation failure associated with alterations in decidualization, a process regulated by sex hormones such as progesterone. Membrane progesterone receptor β (mPRβ) exhibits a lower expression in endometriotic tissues than in normal endometrial ones. However, the role of mPRβ in decidualization is unknown. This work aimed to investigate whether mPRβ plays a role in the decidualization of endometrial stromal cells (ESCs) derived from women with and without endometriosis. The mPR agonist OrgOD-2 induced the gene expression of key decidualization markers (insulin-like growth factor binding protein 1, prolactin, transcription factor heart and neural crest derivatives-expressed transcript 2, and fork-head transcription factor) in healthy ESCs, eutopic (uterine cavity), and ectopic (outside of the uterine cavity) ESCs from women with endometriosis. Notably, the expression of the decidualization markers was lower in endometriotic cells than in healthy endometrial ones. An siRNA mediated knockdown of mPRβ reduced the expression of decidualization-associated genes in ESCs treated with a decidualization stimuli, regardless of whether cells were derived from healthy women or those with endometriosis. Our data suggest that progesterone, through mPRβ activation, regulates the decidualization process in endometrial stromal cells from women with and without endometriosis. Full article

In recent years, significant progress has been made in breast reconstructive surgery, particularly with the use of three-dimensional (3D) disassemblable scaffolds. Reconstructive plastic surgery aimed at restoring the shape and size of the mammary gland offers medical, psychological, and social benefits. Using autologous tissues allows surgeons to recreate the appearance of the mammary gland and achieve tactile sensations similar to those of a healthy organ while minimizing the risks associated with implants; 3D disassemblable scaffolds are a promising solution that overcomes the limitations of traditional methods. These constructs offer the potential for patient-specific anatomical adaptation and can provide both temporary and long-term structural support for regenerating tissues. One of the most promising approaches in post-mastectomy breast reconstruction involves the use of autologous cellular and tissue components integrated into either synthetic scaffolds—such as polylactic acid (PLA), polyglycolic acid (PGA), poly(lactic-co-glycolic acid) (PLGA), and polycaprolactone (PCL)—or naturally derived biopolymer-based matrices, including alginate, chitosan, hyaluronic acid derivatives, collagen, fibrin, gelatin, and silk fibroin. In this context, two complementary research directions are gaining increasing significance: (1) the development of novel hybrid biomaterials that combine the favorable characteristics of both synthetic and natural polymers while maintaining biocompatibility and biodegradability; and (2) the advancement of three-dimensional bioprinting technologies for the fabrication of patient-specific scaffolds capable of incorporating cellular therapies. Such therapies typically involve mesenchymal stromal cells (MSCs) and bioactive signaling molecules, such as growth factors, aimed at promoting angiogenesis, cellular proliferation, and lineage-specific differentiation. In our review, we analyze existing developments in this area and discuss the advantages and disadvantages of 3D disassemblable scaffolds for mammary gland reconstruction, as well as prospects for their further research and clinical use. Full article

The c-ErbB receptor family is a fundamental cell signaling system that regulates cell proliferation, motility, apoptosis, differentiation, and other key cellular functions. Overexpressed and mutated in some tumors, c-ErbB receptors play a pivotal role in their progression but are also present in many non-malignant cells, including those that are promising from the point of view of regenerative medicine, such as mesenchymal stromal cells (MSCs). The role of c-ErbB receptors in these cells is not clearly understood, and the data on their expression are sporadic. Therefore, the systemic characterization of c-ErbB receptor family expression in MSCs from a wide range of tissues is of high priority. Here, using RT-qPCR and Western blotting analysis, we evaluated the c-ErbB receptors expression pattern at the mRNA and protein levels in human MSCs isolated from six different tissues. We found that MSCs possess considerable EGFR and HER2 mRNA levels comparable to those in some malignant cells while showing trace HER3 and HER4 expression. However, EGFR but not HER2 was detected in MSCs at the protein level. We also show that the absence of HER2 protein is not associated with its rapid lysosomal degradation. We conclude that c-ErbB signaling in human MSCs is exclusively mediated by EGFR. Full article

Replicative or stress-induced senescence disrupts the functioning of multipotent mesenchymal stromal cells (MSCs) required for tissue renewal and regeneration. Aged MSCs demonstrate reduced proliferation, impaired differentiation, and aberrant secretory activity, defined as “senescence-associated secretory phenotype” (SASP). SASP is characterized by elevated secretion of proinflammatory cytokines and specific extracellular vesicles (SASP-EVs), which affect the cellular microenvironment and promote tissue dysfunction. However, molecular mechanisms responsible for senescent phenotype propagation remain largely obscure. Earlier, we demonstrated suppression of adipogenic differentiation and insulin sensitivity of young MSCs by SASP-EVs. In this study, we elucidated potential mechanisms underlying SASP-EVs’ effects on MSCs. Bioinformatic analysis revealed that insulin signaling components are the most probable targets of SASP-EVs microRNA cargo. We demonstrated that SASP-EVs downregulated intracellular AGO1 levels, but surprisingly, PTEN levels were upregulated. Specifically, the increase in PTEN content was provided by its nuclear fraction. We have found that the intracellular PTEN distribution in young MSCs treated by SASP-EVs was similar to senescent MSCs. Furthermore, PTEN upregulation was accompanied by increased PTENP1 expression—a molecular sponge for PTEN-targeting microRNAs. Our findings indicate that nuclear PTEN could be a hallmark of senescent MSCs, and SASP-EVs propagate the senescent phenotype in young MSCs by promoting PTEN nuclear localization. Full article

Background: Breast cancer, the most prevalent malignancy among women worldwide, exhibits significant heterogeneity, particularly in the tumor microenvironment (TME), which poses challenges for treatment. Spatial transcriptomics (ST) has emerged as a transformative technology, enabling gene expression analysis while preserving tissue spatial architecture. This provides unprecedented insights into tumor heterogeneity, cellular interactions, and disease mechanisms, offering a powerful tool for advancing breast cancer research and therapy. This review aims to synthesize the applications of ST in breast cancer research, focusing on its role in decoding tumor heterogeneity, characterizing the TME, elucidating progression and metastasis dynamics, and predicting therapeutic responses. We also explore how ST can bridge molecular profiling with clinical translation to enhance precision therapy. The key scientific concepts of review included the following: We summarize the technological advancements in ST, including imaging-based and sequencing-based methods, and their applications in breast cancer. Key findings highlight how ST resolves spatial heterogeneity across molecular subtypes and histological variants. ST reveals the dynamic interplay between tumor cells, immune cells, and stromal components, uncovering mechanisms of immune evasion, metabolic reprogramming, and therapeutic resistance. Additionally, ST identifies spatial prognostic markers and predicts responses to chemotherapy, targeted therapy, and immunotherapy. We propose that ST serves as a hub for integrating multi-omics data, offering a roadmap for precision oncology and personalized treatment strategies in breast cancer. Full article

We present a narrative review focusing on the therapeutic potential of mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) in regenerating bone defects, particularly those resulting from surgical treatment of malignant bone and soft tissue tumors. These large bone defects pose significant challenges for reconstruction and functional recovery, highlighting the need for innovative regenerative strategies. Background: MSCs, which can differentiate into various cell types, are known for their immunosuppressive properties and ability to promote tissue repair. MSC-EVs, rich in bioactive molecules like microRNAs and proteins, play a crucial role in bone regeneration by mediating intercellular communication and modulating inflammation. Methods: This narrative review compiles data from various studies, including systematic reviews and individual research, focusing on the application of MSC-EVs in bone defect treatment. It examines the characteristics, mechanisms of action, and therapeutic effects of MSC-EVs, as well as the microRNAs involved in bone regeneration. Results: The findings indicate that MSC-EVs can enhance both osteogenesis and angiogenesis, highlighting their potential as promising candidates for clinical applications in bone defects. However, many mechanisms remain unclear; therefore, further investigation is needed. Conclusions: The review emphasizes the potential of MSC-EVs in improving patient outcomes for severe bone defects. It also highlights future challenges, including formulation, standardization, safety, and delivery methods, particularly in conjunction with biomaterials. Overall, MSC-EVs represent a significant advancement in regenerative medicine for bone defects. Full article

Tissue engineering enables autologous reconstruction of human tissues, addressing limitations in tissue availability and immune compatibility. Several tissue engineering techniques, such as self-assembly, rely on or benefit from extracellular matrix (ECM) secretion by fibroblasts to produce biomimetic scaffolds. Models have been developed for use in humans, such as skin and corneas. Ascorbic acid (vitamin C, AA) is essential for collagen biosynthesis. However, AA is chemically unstable in culture, with a half-life of 24 h, requiring freshly prepared AA with each change of medium. This study aims to demonstrate the functional equivalence of 2-phospho-L-ascorbate (2PAA), a stable form of AA, for tissue reconstruction. Dermal, vaginal, and bladder stroma were reconstructed by self-assembly using tissue-specific protocols. The tissues were cultured in a medium supplemented with either freshly prepared or frozen AA, or with 2PAA. Biochemical analyses were performed on the tissues to evaluate cell density and tissue composition, including collagen secretion and deposition. Histology and quantitative polarized light microscopy were used to evaluate tissue architecture, and mechanical evaluation was performed both by tensiometry and atomic force microscopy (AFM) to evaluate its macroscopic and cell-scale mechanical properties. The tissues produced by the three ascorbate conditions had similar collagen deposition, architecture, and mechanical properties in each organ-specific stroma. Mechanical characterization revealed tissue-specific differences, with tensile modulus values ranging from 1–5 MPa and AFM-derived apparent stiffness in the 1–2 kPa range, reflecting the nonlinear and scale-dependent behavior of the engineered stroma. The results demonstrate the possibility of substituting AA with 2PAA for tissue engineering. This protocol could significantly reduce the costs associated with tissue production by reducing preparation time and use of materials. This is a crucial factor for any scale-up activity. Full article

Cardiac tissue engineering is a promising strategy to restore cardiac function in heart failure patients. Understanding the cardiac tissue architecture including the cardiac stroma is essential for developing not only advanced cardiac tissue engineering but also novel therapeutic strategies. One of the crucial components of the cardiac stroma is the myocardial vasculature. To enhance the spatial visualization of the cardiac stromal cytoarchitecture with a particular focus on myocardial vasculature, we performed 3D reconstructions of the murine cardiac micro vessels using Serial Block-Face Scanning Electron Microscopy (SBF-SEM). These analyses revealed that pericyte cell bodies were primarily oriented lengthwise and extended several cellular protrusions towards the endothelium. At capillary branching points, some pericytes made contact with both capillaries emerging from branching. In addition to pericytes that are completely encapsulated by the common basal lamina together with capillary endothelial cells, we identified other vascular-associated cells located outside this sheath. Based on marker expression, these cells were distinguished from fibroblasts and suggested to be telocytes. The vascular-associated cells formed electron-dense contact zones with endothelial cells, suggesting functional coupling between these both cell types. In conclusion, this study provides detailed three-dimensional visualizations of the cardiac stroma with a particular focus on cardiac microvasculature, offering enhanced insight into the cardiac stromal cytoarchitecture. Full article

Micro-fragmented adipose tissue (MFAT) is a promising autologous therapy for knee osteoarthritis. To avoid repeated liposuction procedures for its clinical application, MFAT obtained from patients with knee osteoarthritis was stored at −80 °C in a tissue bank. This study describes the preparation, cryopreservation, thawing, and washing, as well as comprehensive analysis of cell populations in fresh and MFAT thawed after two years. Immunophenotyping of both fresh and thawed MFAT showed a significant presence of endothelial progenitors and pericytes in the stromal vascular fraction. Viability before (59.75%) and after freezing (55.73%) showed no significant difference. However, the average cell count per gram of MFAT was significantly reduced in thawed samples (3.00 × 10⁵) compared to fresh ones (5.64 × 10⁵), likely due to processing steps. Thawed MFAT samples showed increased CD73 expression on the CD31^highCD34^high subset of EP and SA-ASC, as well as increased expression of CD105 on EP, the CD31^lowCD34^low subset of EP, pericytes, and SA-ASC. Microbiological testing confirmed 100% sterility, and double washing efficiently removed DMSO, confirming sample safety. Histological analysis revealed healthy, uniformly shaped adipocytes with intact membranes. This approach allows accurate estimation of cell yield for intra-articular injection, ensuring delivery of the target cell number into the knee. Quality control analysis confirms that cryopreserved MFAT retains high cellular and structural integrity, supporting its safety and suitability for clinical application. Full article

Deposition of intramuscular fat (IM), also known as marbling, is the deciding factor of beef quality grade in the U.S. Defining molecular mechanisms underlying the differential deposition of adipose tissue in distinct anatomical areas in beef cattle is key to the development of strategies for marbling enhancement while limiting the accumulation of excessive subcutaneous adipose tissue (SAT). The objective of this exploratory study was to define the IM and SAT transcriptional heterogeneity at the whole tissue and single-nuclei levels in beef steers. Longissimus dorsi muscle samples (9–11th rib) were collected from two finished beef steers at harvest to dissect matched IM and adjacent SAT (backfat). Total RNA from IM and SAT was isolated and sequenced in an Illumina NovaSeq 6000. Nuclei from the same samples were isolated by dounce homogenization, libraries generated with 10× Genomics, and sequenced in an Illumina NovaSeq 6000, followed by analysis via Cell Ranger pipeline and Seurat in RStudio (v4.3.2) By the expression of signature marker genes, single-nuclei RNA sequencing (snRNAseq) analysis identified mature adipocytes (AD; ADIPOQ, LEP), adipose stromal and progenitor cells (ASPC; PDGFRA), endothelial cells (EC; VWF, PECAM1), smooth muscle cells (SMC; NOTCH3, MYL9) and immune cells (IMC; CD163, MRC1). We detected six cell clusters in SAT and nine in IM. Across IM and SAT, AD was the most abundant cell type, followed by ASPC, SMC, and IMC. In SAT, AD made up 50% of the cellular population, followed by ASPC (31%), EC (14%), IMC (1%), and SMC (4%). In IM depot, AD made up 23% of the cellular population, followed by ASPC at 19% of the population, EC at 28%, IMC at 7% and SMC at 12%. The abundance of ASPC and AD was lower in IM vs. SAT, while IMC was increased, suggesting a potential involvement of immune cells on IM deposition. Accordingly, both bulk RNAseq and snRNAseq analyses identified activated pathways of inflammation and metabolic function in IM. These results demonstrate distinct transcriptional cellular heterogeneity between SAT and IM depots in beef steers, which may underly the mechanisms by which fat deposits in each depot. The identification of depot-specific cell populations in IM and SAT via snRNAseq analysis has the potential to reveal target genes for the modulation of fat deposition in beef cattle. Full article

Current treatment strategies for partial tendon tears often lack the capacity to promote true tissue regeneration and improve long-term clinical outcomes. This study tested the hypothesis that treatment of a partial defect in the rabbit common calcaneus tendon (CCT) with uncultured, unmodified, autologous, adipose-derived regenerative cells (UA-ADRCs) enables regenerative healing without scar formation. A full-thickness, 3 mm defect was produced in the midsubstance of the right gastrocnemius tendon, a component of the CCT, in adult female New Zealand white rabbits. Animals received either an injection of 28.3 × 10⁶ UA-ADRCs in 0.5 mL Ringer’s lactated solution (RLS) or saline, or RLS or saline alone as sham treatment. Tendons were analyzed 4 or 12 weeks post-treatment using histology, immunohistochemistry and non-destructive biomechanical testing. UA-ADRC-treated tendons showed newly formed connective tissue consistent with tendon regeneration, whereas sham-treated tendons developed scar tissue. Biomechanical testing showed significantly higher percent relaxation in UA-ADRC-treated tendons compared to sham controls (p < 0.05), indicating greater viscoelasticity characteristic of healthy or well-integrated tissue. Together, these findings suggest that UA-ADRC therapy may provide a regenerative, structure-modifying treatment for partial tendon tears. Full article