Angiogenic Potential of Tissue Engineered Cartilage From Human Mesenchymal Stem Cells Is Modulated by Indian Hedgehog and Serpin E1

Bioinformatics Analysis and Experimental Verification Define Different Angiogenesis Subtypes in Endometrial Carcinoma and Identify a Prognostic Signature

Increasing evidence indicates that peripheral blood vessels play a pivotal role in regulating tumor growth with the presence of new blood vessels facilitating tumor growth and metastasis. Nevertheless, the impact of specific molecule-mediated angiogenesis on the tumor immune microenvironment (TIME) and individual prognosis of uterine corpus endometrial carcinoma (UCEC) remains uncertain. The transcriptome information on 217 prognostic angiogenesis-related genes was integrated, and the angiogenesis patterns of 506 UCEC patients in The Cancer Genome Atlas (TCGA) cohort were comprehensively evaluated. We identified five angiogenic subtypes, namely, EC1, EC2, EC3, EC4, and EC5, which differed significantly in terms of prognosis, clinicopathological features, cancer hallmarks, genomic mutations, TIME patterns, and immunotherapy responses. Additionally, an angiogenesis-related prognostic risk score (APRS) was constructed to enable an individualized comprehensive evaluation. In multiple cohorts, APRS demonstrated a powerful predictive ability for the prognosis of UCEC patients. Likewise, APRS was confirmed to be associated with clinicopathological features, genomic mutations, cancer hallmarks, and TIME patterns in UCEC patients. The predictability of APRS for immune checkpoint inhibitor (ICI) therapy was also salient. Subsequently, the expression levels of four angiogenesis-related hub genes were verified by qRT-PCR, immunohistochemistry, and single-cell sequencing data analysis. The effects of four representative genes on angiogenesis were validated by Wound-Healing and Transwell assays, tube formation assay in vitro, and tumor xenograft model in vivo. This study proffered a new classification of UCEC patients based on angiogenesis. The established APRS may contribute to individualized prognosis prediction and immunotherapy selections that are better suited for UCEC patients.

CD62E- and ROS-Responsive ETS Improves Cartilage Repair by Inhibiting Endothelial Cell Activation through OPA1-Mediated Mitochondrial Homeostasis

Background: In the environment of cartilage injury, the activation of vascular endothelial cell (VEC), marked with excessive CD62E and reactive oxygen species (ROS), can affect the formation of hyaluronic cartilage. Therefore, we developed a CD62E- and ROS-responsive drug delivery system using E-selectin binding peptide, Thioketal, and silk fibroin (ETS) to achieve targeted delivery and controlled release of Clematis triterpenoid saponins (CS) against activated VEC, and thus promote cartilage regeneration. Methods: We prepared and characterized ETS/CS and verified their CD62E- and ROS-responsive properties in vitro. We investigated the effect and underlying mechanism of ETS/CS on inhibiting VEC activation and promoting chondrogenic differentiation of bone marrow stromal cells (BMSCs). We also analyzed the effect of ETS/CS on suppressing the activated VEC-macrophage inflammatory cascade in vitro. Additionally, we constructed a rat knee cartilage defect model and administered ETS/CS combined with BMSC-containing hydrogels. We detected the cartilage differentiation, the level of VEC activation and macrophage in the new tissue, and synovial tissue. Results: ETS/CS was able to interact with VEC and inhibit VEC activation through the carried CS. Coculture experiments verified ETS/CS promoted chondrogenic differentiation of BMSCs by inhibiting the activated VEC-induced inflammatory cascade of macrophages via OPA1-mediated mitochondrial homeostasis. In the rat knee cartilage defect model, ETS/CS reduced VEC activation, migration, angiogenesis in new tissues, inhibited macrophage infiltration and inflammation, promoted chondrogenic differentiation of BMSCs in the defective areas. Conclusions: CD62E- and ROS-responsive ETS/CS promoted cartilage repair by inhibiting VEC activation and macrophage inflammation and promoting BMSC chondrogenesis. Therefore, it is a promising therapeutic strategy to promote articular cartilage repair.

Modular, Vascularized Hypertrophic Cartilage Constructs for Bone Tissue Engineering Applications

Insufficient vascularization is a main barrier to creating engineered bone grafts for treating large and ischemic defects. Modular tissue engineering approaches have promise in this application because of the ability to combine tissue types and to localize microenvironmental cues to drive desired cell function. In direct bone formation approaches, it is challenging to maintain sustained osteogenic activity, since vasculogenic cues can inhibit tissue mineralization. This study harnessed the physiological process of endochondral ossification to create multiphase tissues that allowed concomitant mineralization and vessel formation. Mesenchymal stromal cells in pellet culture were differentiated toward a cartilage phenotype, followed by induction to chondrocyte hypertrophy. Hypertrophic pellets exhibited increased alkaline phosphatase activity, calcium deposition, and osteogenic gene expression relative to chondrogenic pellets. In addition, hypertrophic pellets secreted and sequestered angiogenic factors, and supported new blood vessel formation by co-cultured endothelial cells and undifferentiated stromal cells. Multiphase constructs created by combining hypertrophic pellets and vascularizing microtissues and maintained in unsupplemented basal culture medium were shown to support robust vascularization and sustained tissue mineralization. These results demonstrate a new in vitro strategy to produce multiphase engineered constructs that concomitantly support the generation of mineralize and vascularized tissue in the absence of exogenous osteogenic or vasculogenic medium supplements.

Strategies for Cartilage Repair in Osteoarthritis Based on Diverse Mesenchymal Stem Cells-Derived Extracellular Vesicles

Osteoarthritis (OA) causes disability and significant economic and social burden. Cartilage injury is one of the main pathological features of OA, and is often manifested by excessive chondrocyte death, inflammatory response, abnormal bone metabolism, imbalance of extracellular matrix (ECM) metabolism, and abnormal vascular or nerve growth. Regrettably, due to the avascular nature of cartilage, its capacity to repair is notably limited. Mesenchymal stem cells-derived extracellular vesicles (MSCs-EVs) play a pivotal role in intercellular communication, presenting promising potential not only as early diagnostic biomarkers in OA but also as efficacious therapeutic strategy. MSCs-EVs were confirmed to play a therapeutic role in the pathological process of cartilage injury mentioned above. This paper comprehensively provides the functions and mechanisms of MSCs-EVs in cartilage repair.

Combination of Phenethyl Isothiocyanate and Dasatinib Inhibits Hepatocellular Carcinoma Metastatic Potential through FAK/STAT3/Cadherin Signalling and Reduction of VEGF Secretion

Cancerous cells are characterised by their ability to invade, metastasise, and induce angiogenesis. Tumour cells use various molecules that can be targeted to reverse these processes. Dasatinib, a potent Src inhibitor, has shown promising results in treating hepatocellular carcinoma (HCC) in vitro and in vivo. However, its effectiveness is limited by focal adhesion kinase (FAK) activation. Isothiocyanates, on the other hand, are phytochemicals with broad anticancer activity and FAK inhibition capabilities. This study evaluated the synergistic effect of dasatinib and phenethyl isothiocyanate (PEITC) on HCC. The combination was tested using various assays, including MTT, adhesion, scratch, Boyden chamber, chorioallantoic membrane (CAM), and yolk sac membrane (YSM) assays to evaluate the effect of the drug combination on HCC metastatic potential and angiogenesis in vitro and in vivo. The results showed that the combination inhibited the adhesion, migration, and invasion of HepG2 cells and reduced xenograft volume in the CAM assay. Additionally, the combination reduced angiogenesis in vitro, diminishing the growth of vessels in the tube formation assay. The inhibition of FAK/STAT3 signalling led to increased E-cadherin expression and reduced VEGF secretion, reducing HCC metastatic potential. Therefore, a combination of PEITC and dasatinib could be a potential therapeutic strategy for the treatment of HCC.

Integration of Transcriptome and MicroRNA Profile Analysis of iMSCs Defines Their Rejuvenated State and Conveys Them into a Novel Resource for Cell Therapy in Osteoarthritis

Although MSCs grant pronounced potential for cell therapies, several factors, such as their heterogeneity restrict their use. To overcome these limitations, iMSCs (MSCs derived from induced pluripotent stem cells (iPSCs) have attracted attention. Here, we analyzed the transcriptome of MSCs, iPSCs and iMSCs derived from healthy individuals and osteoarthritis (OA) patients and explored miRNA-mRNA interactions during these transitions. We performed RNA-seq and gene expression comparisons and Protein-Protein-Interaction analysis followed by GO enrichment and KEGG pathway analyses. MicroRNAs' (miRNA) expression profile using miRarrays and differentially expressed miRNA's impact on regulating iMSCs gene expression was also explored. Our analyses revealed that iMSCs derivation from iPSCs favors the expression of genes conferring high proliferation, differentiation, and migration properties, all of which contribute to a rejuvenated state of iMSCs compared to primary MSCs. Additionally, our exploration of the involvement of miRNAs in this rejuvenated iMSCs transcriptome concluded in twenty-six miRNAs that, as our analysis showed, are implicated in pluripotency. Notably, the identified here interactions between hsa-let7b/i, hsa-miR-221/222-3p, hsa-miR-302c, hsa-miR-181a, hsa-miR-331 with target genes HMGA2, IGF2BP3, STARD4, and APOL6 could prove to be the necessary tools that will convey iMSCs into the ideal mean for cell therapy in osteoarthritis.

Mesenchymal-Stromal-Cell-Conditioned Media and Their Implication for Osteochondral Regeneration

Despite significant advances in biomedical research, osteochondral defects resulting from injury, an autoimmune condition, cancer, or other pathological conditions still represent a significant medical problem. Even though there are several conservative and surgical treatment approaches, in many cases, they do not bring the expected results and further permanent damage to the cartilage and bones occurs. Recently, cell-based therapies and tissue engineering have gradually become promising alternatives. They combine the use of different types of cells and biomaterials to induce regeneration processes or replace damaged osteochondral tissue. One of the main challenges of this approach before clinical translation is the large-scale in vitro expansion of cells without changing their biological properties, while the use of conditioned media which contains various bioactive molecules appears to be very important. The presented manuscript provides a review of the experiments focused on osteochondral regeneration by using conditioned media. In particular, the effect on angiogenesis, tissue healing, paracrine signaling, and enhancing the properties of advanced materials are pointed out.

In Vitro Mineralisation of Tissue-Engineered Cartilage Reduces Endothelial Cell Migration, Proliferation and Tube Formation

Tissue engineering bone via endochondral ossification requires the generation of a cartilage template which undergoes vascularisation and remodelling. While this is a promising route for bone repair, achieving effective cartilage vascularisation remains a challenge. Here, we investigated how mineralisation of tissue-engineered cartilage affects its pro-angiogenic potential. To generate in vitro mineralised cartilage, human mesenchymal stromal cell (hMSC)-derived chondrogenic pellets were treated with β-glycerophosphate (BGP). After optimising this approach, we characterised the changes in matrix components and pro-angiogenic factors by gene expression analysis, histology and ELISA. Human umbilical vein endothelial cells (HUVECs) were exposed to pellet-derived conditioned media, and migration, proliferation and tube formation were assessed. We established a reliable strategy to induce in vitro cartilage mineralisation, whereby hMSC pellets are chondrogenically primed with TGF-β for 2 weeks and BGP is added from week 2 of culture. Cartilage mineralisation determines loss of glycosaminoglycans, reduced expression but not protein abundance of collagen II and X, and decreased VEGFA production. Finally, the conditioned medium from mineralised pellets showed a reduced ability to stimulate endothelial cell migration, proliferation and tube formation. The pro-angiogenic potential of transient cartilage is thus stage-dependent, and this aspect must be carefully considered in the design of bone tissue engineering strategies.

Exosomes treating osteoarthritis: hope with challenge

Osteoarthritis (OA) has been proven as the second primary cause of pain and disability in the elderly population, impact patients both physically and mentally, as well as imposing a heavy burden on the global healthcare system. Current treatment methods, whether conservative or surgical, that aim at relieving symptoms can not delay or reverse the degenerative process in the structure. Scientists and clinicians are facing a revolution in OA treatment strategies. The emergence of exosomes brings hope for OA treatment based on pathology, which is attributed to its full potential in protecting chondrocytes from excessive death, alleviating inflammation, maintaining cartilage matrix metabolism, and regulating angiogenesis and subchondral bone remodeling. Therefore, we summarized the recent studies of exosomes in OA, aiming to comprehensively understand the functions and mechanisms of exosomes in OA treatment, which may provide direction and theoretical support for formulating therapeutic strategies in the future.

Tissue engineering in growth plate cartilage regeneration: Mechanisms to therapeutic strategies

The repair of growth plate injuries is a highly complex process that involves precise spatiotemporal regulation of multiple cell types. While significant progress has been made in understanding the pathological mechanisms underlying growth plate injuries, effectively regulating this process to regenerate the injured growth plate cartilage remains a challenge. Tissue engineering technology has emerged as a promising therapeutic approach for achieving tissue regeneration through the use of functional biological materials, seed cells and biological factors, and it is now widely applied to the regeneration of bone and cartilage. However, due to the unique structure and function of growth plate cartilage, distinct strategies are required for effective regeneration. Thus, this review provides an overview of current research on the application of tissue engineering to promote growth plate regeneration. It aims to elucidates the underlying mechanisms by which tissue engineering promotes growth plate regeneration and to provide novel insights and therapeutic strategies for future research on the regeneration of growth plate.

Mesenchymal Stem Cell Mechanisms of Action and Clinical Effects in Osteoarthritis: A Narrative Review

With the insufficient satisfaction rates and high cost of operative treatment for osteoarthritis (OA), alternatives have been sought. Furthermore, the inability of current medications to arrest disease progression has led to rapidly growing clinical research relating to mesenchymal stem cells (MSCs). The availability and function of MSCs vary according to tissue source. The three primary sources include the placenta, bone marrow, and adipose tissue, all of which offer excellent safety profiles. The primary mechanisms of action are trophic and immunomodulatory effects, which prevent the further degradation of joints. However, the function and degree to which benefits are observed vary significantly based on the exosomes secreted by MSCs. Paracrine and autocrine mechanisms prevent cell apoptosis and tissue fibrosis, initiate angiogenesis, and stimulate mitosis via growth factors. MSCs have even been shown to exhibit antimicrobial effects. Clinical results incorporating clinical scores and objective radiological imaging have been promising, but a lack of standardization in isolating MSCs prevents their incorporation in current guidelines.

The Releasate of Avascular Cartilage Demonstrates Inherent Pro-Angiogenic Properties In Vitro and In Vivo

OBJECTIVE

Cartilage is avascular and numerous studies have identified the presence of single anti- and pro-angiogenic factors in cartilage. To better understand the maintenance hyaline cartilage, we assessed the angiogenic potential of complete cartilage releasate with functional assays in vitro and in vivo.

DESIGN

We evaluated the gene expression profile of angiogenesis-related factors in healthy adult human articular cartilage with a transcriptome-wide analysis generated by next-generation RNAseq. The effect on angiogenesis of the releasate of cartilage tissue was assessed with a chick chorioallantoic membrane (CAM) assay as well as human umbilical vein endothelial cell (HUVEC) migration and proliferation assays using conditioned media generated from tissue-engineered cartilage derived from human articular and nasal septum chondrocytes as well as explants from bovine articular cartilage and human nasal septum. Experiments were done with triplicate samples of cartilage from 3 different donors.

RESULTS

RNAseq data of 3 healthy human articular cartilage donors revealed that the majority of known angiogenesis-related factors expressed in healthy adult articular cartilage are pro-angiogenic. The releasate from generated cartilage as well as from tissue explants, demonstrated at least a 3.1-fold increase in HUVEC proliferation and migration indicating a pro-angiogenic effect of cartilage. Finally, the CAM assay demonstrated that cartilage explants can indeed attract vessels; however, their ingrowth was not observed.

CONCLUSION

Using multiple approaches, we show that cartilage releasate has an inherent pro-angiogenic capacity. It remains vessel free due to anti-invasive properties associated with the tissue itself.