Secretion Of Angiogenic Factors Research Articles

Dual Effects of Resveratrol on the Expression and Secretion of Angiogenic Factors.

Angiogenesis is an essential process in the growth, development, and transition of tumors from dormancy to proliferating state. Resveratrol (RSV), as a natural polyphenolic compound, is claimed to be effective in regulating angiogenesis. This study aimed to evaluate the impact of RSV onthe angiogenesis process in HUVECs (human umbilical vein endothelial cells) alone and co-cultured with Jurkat cells. The effects of RSV on HUVECs and Jurkat cell viability and apoptosis were measured by MTT and Annexin-V/PI methods. HUVECs were co-cultured with pre-treated Jurkat cells and incubated for 24 h, 48 h and 72 h. The angiogenesis process in HUVECs and Jurkat cells alone and in co-culture models was investigated by analyzing the expression of VEGF, VEGFR-2, and Interleukin-8 (IL-8) employing qPCR and ELISA. RSV at low concentration (40 µM) had no significant effects on apoptosis rate of HUVECs, but higher concentrations (80-160 µM) increased apoptosis in co-culture method and HUVECs alone. RSV significantly reduced VEGFR2 and IL-8 gene expression also, IL-8 protein concentration in HUVECs, but the effects of this drug in the HUVECs-Jurkats co-culture were different. Expression of VEGF in Jurkat cells increased following treatment with RSV. RSV had direct anti-angiogenic effects on HUVECs. Unexpectedly its indirect effects were not significant on HUVECs-Jurkats co-culture. Results of our study showed, RSV may be effective in anti-angiogenesis therapy, but in some situations, it may induce angiogenesis. So, appropriate concentrations should achieve to minimize the unpredicted effects of RSV.

The Chinese Herbal Formula Ruyan Neixiao Cream Inhibits Angiogenesis of Precancerous Breast Lesions via Regulation of Ras/Raf/MEK/ERK Signaling Pathway.

Ruyan Neixiao Cream (RUc) is a traditional Chinese herbal formula which can effectively inhibit the angiogenesis of breast precancerous lesions. In order to reveal the specific mechanism, we carried out experiments in vitro and in vivo. We found that the conditioned medium of MCF-10AT cells treated with RUc transdermal solution (RUt) could significantly inhibit the proliferation, migration, invasion, tube formation of HUVECs and the capillary formation of rat aortic rings. RUt may down-regulate the expression of VEGF, MMP2, and MMP9 in MCF-10AT medium by down-regulating miR-21 and up-regulating TIMP-3 and RECK. We further confirmed in rats that the microvascular density of precancerous lesions decreased significantly after external use of RUc, which may be related to the inhibition of Ras/Raf/MEK/ERK signaling pathway related proteins. Presumptively, RUc may inhibit the angiogenesis of breast precancerous lesions by inhibiting Ras/Raf/MEK/ERK signaling pathway, thus relieving the inhibition of miR-21 on TIMP-3 and RECK, then down-regulating the secretion of angiogenic factors.

Discovery of Salidroside-Derivated Glycoside Analogues as Novel Angiogenesis Agents to Treat Diabetic Hind Limb Ischemia.

Therapeutic angiogenesis is a potential therapeutic strategy for hind limb ischemia (HLI); however, currently, there are no small-molecule drugs capable of inducing it at the clinical level. Activating the hypoxia-inducible factor-1 (HIF-1) pathway in skeletal muscle induces the secretion of angiogenic factors and thus is an attractive therapeutic angiogenesis strategy. Using salidroside, a natural glycosidic compound as a lead, we performed a structure-activity relationship (SAR) study for developing a more effective and druggable angiogenesis agent. We found a novel glycoside scaffold compound (C-30) with better efficacy than salidroside in enhancing the accumulation of the HIF-1α protein and stimulating the paracrine functions of skeletal muscle cells. This in turn significantly increased the angiogenic potential of vascular endothelial and smooth muscle cells and, subsequently, induced the formation of mature, functional blood vessels in diabetic and nondiabetic HLI mice. Together, this study offers a novel, promising small-molecule-based therapeutic strategy for treating HLI.

Angiogenic factors could help us to define patients obtaining complete response with undetectable minimal residual disease in untreated CLL patients treated by FCR: results from the CLL2010FMP, a FILO study

Angiogenesis is in a constant balance between pro and anti-angiogenic factors. Neoangiogenesis, implicated in metastatic spreading is characterized in solid cancers, but fairly new in chronic lymphocytic leukemia (CLL). We hypothesize that secretion of angiogenic factors could be correlated to the pathogenesis of CLL, and therefore predict the outcome of patients. We investigated concentrations of 22 cytokines and chemokines in 137 non-del 17p B-CLL patients, treated with a fludarabine-cyclophosphamide-rituximab (FCR)-based regimen. We constructed a biomarker index defining different risk groups based on lymphocyte count, the intensity of CD20 antigen on CD19+ cells, Ang-2, and PDGF-BB plasma concentrations at diagnosis. Four groups were defined, exhibiting specific molecular signatures and correlated with progression-free survival of patients. Our results suggest that we can determine at diagnosis of non-del 17p B-CLL patients, those with a very high probability of progression-free survival, independently of IGVH mutational status and residual disease at the end of treatment.

Co-culture of BMSCs and HUVECs with simvastatin-loaded gelatin nanosphere/chitosan coating on Mg alloy for osteogenic differentiation and vasculogenesis

Mg alloys are increasingly being investigated as a versatile and economical alternative for developing bone repair implants because of their high mechanical strength, wide availability, adjustable structure and properties. In this study, magnesium alloy WE43 is coated on both sides with gelatin nanosphere/chitosan (GNs/CTS), a coating enhanced by incorporating simvastatin (SIM). SIM-loaded GNs/CTS coated magnesium alloy can promote the osteogenic differentiation of bone mesenchymal stem cells (BMSCs). BMSCs and human umbilical vein endothelial cells (HUVECs) are co-cultured through transwell systems. The release of SIM from the coating is found to increase the secretion of chemokine and angiogenic factors from BMSCs, which promote the migration and tube formation of HUVECs, respectively. Bone morphogenetic protein secreted by HUVECs is seen to increase by the release of SIM from the coating, promoting the osteogenic differentiation of BMSCs. The secretion of chemokines from HUVECs promote the migration of BMSCs. The coated magnesium alloy substrate loaded with SIM is found to regulate the osteogenic differentiation of BMSCs. The study of the paracrine interaction between BMSCs and HUVECs proves that the applied coating promotes both osteogenic differentiation and vascularization, thus demonstrating a new approach for the design of bone repair materials based on magnesium alloys.

Anti-senescence ion-delivering nanocarrier for recovering therapeutic properties of long-term-cultured human adipose-derived stem cells

BackgroundHuman adipose-derived stem cells (hADSCs) have been used in various fields of tissue engineering because of their promising therapeutic efficacy. However, the stemness of hADSCs cannot be maintained for long durations, and their therapeutic cellular functions, such as paracrine factor secretion decrease during long-term cell culture. To facilitate the use of long-term-cultured hADSCs (L-ADSCs), we designed a novel therapeutic anti-senescence ion-delivering nanocarrier (AIN) that is capable of recovering the therapeutic properties of L-ADSCs. In the present study, we introduced a low-pH-responsive ion nanocarrier capable of delivering transition metal ions that can enhance angiogenic paracrine factor secretion from L-ADSCs. The AINs were delivered to L-ADSCs in an intracellular manner through endocytosis.ResultsLow pH conditions within the endosomes induced the release of transition metal ions (Fe) into the L-ADSCs that in turn caused a mild elevation in the levels of reactive oxygen species (ROS). This mild elevation in ROS levels induced a downregulation of senescence-related gene expression and an upregulation of stemness-related gene expression. The angiogenic paracrine factor secretion from L-ADSCs was significantly enhanced, and this was evidenced by the observed therapeutic efficacy in response to treatment of a wound-closing mouse model with conditioned medium obtained from AIN-treated L-ADSCs that was similar to that observed in response to treatment with short-term-cultured adipose-derived stem cells.ConclusionsThis study suggests a novel method and strategy for cell-based tissue regeneration that can overcome the limitations of the low stemness and therapeutic efficacy of stem cells that occurs during long-term cell culture.Graphical

Enhancing the Angiogenic and Proliferative Capacity of Dermal Fibroblasts with Mulberry (Morus alba. L) Root Extract.

Enhancing blood flow and cell proliferation in the hair dermis is critical for treating hair loss. This study was designed to aid the development of alternative and effective solutions to overcome alopecia. Specifically, we examined the effects of Morus alba. L root extract (MARE, which has been used in traditional medicine as a stimulant for hair proliferation) on dermal fibroblasts and other cell types found in the epidermis. We first optimized the concentration of MARE that could be used to treat human dermal fibroblasts (HDFs) without causing cytotoxicity. After optimization, we focused on the effect of MARE on HDFs since these cells secrete paracrine factors related to cell proliferation and angiogenesis that affect hair growth. Conditioned medium (CM) derived from MARE-treated HDFs (MARE HDF-CM) was used to treat human umbilical vein endothelial cells (HUVECs) and hair follicle dermal papilla cells (HFDPCs). Concentrations of MARE up to 20 wt% increased the expression of proliferative and anti-apoptotic genes in HDFs. MARE HDF-CM significantly improved the tubular structure formation and migration capacity of HUVECs. Additionally, MARE HDF-CM treatment upregulated the expression of hair growth-related genes in HFDPCs. CM collected from MARE-treated HDFs promoted the proliferation of HFDPCs and the secretion of angiogenic paracrine factors from these cells. Since it can stimulate the secretion of pro-proliferative and pro-angiogenic paracrine factors from HDFs, MARE has therapeutic potential as a hair loss preventative.

Abstract 2646: Implication of different anti-angiogenic treatments on in vitro vascular tube formation in triple negative inflammatory breast cancer cell lines

Abstract Introduction: Inflammatory breast cancer (IBC) is the most aggressive breast cancer in women and female dogs (IMC, Inflammatory mammary cancer) with a poor prognosis. Both IBC and IMC are highly angiogenic, lymphangiogenic and lymphangioinvasive. The aim of this study was to evaluate the effect of different anti-angiogenic treatments in the in vitro formation of vascular-like structures as well as cell secretion of different angiogenic and lymphangiogenic factors (VEGFA, VEGFC, VEGFD) and interleukin-8 (IL-8) in culture media. Material and Methods: For in vitro tube formation assay, culture human SUM149 cells and canine IPC-366 cells were divided into a control group, treated with DMSO, and 4 experimental groups treated with 1.5 μM of VEGF, SU5416 (anti-VEGFR, VEGF B20-4.1.1 (anti-VEGF) and celecoxib (NSAID), respectively, for 4 h at 37ºC in 5% CO2 conditions. Images were taken every 2 hours. Incomplete networks were excluded, and vessel-like tube structures were counted using the Image J Angiogenesis Analyzer software. Data were represented as average percentage relative to control ± SD. Results: VEGF and celecoxib treatment significantly augmented the formation of vascular-like tube structures respect to control group in both cell lines. However, VEGF B20-4.1.1 and SU5416 decreased the formation of vascular-like tube structures but not significantly. Conditionate media of IPC-366 and SUM149-treated cells with VEGF had significantly decreased VEGFA levels. In contrast, celecoxib treatment, reduced VEGFD levels and increased VEGFC in both cell lines. VEGF B20-4.1.1 addition increased VEGFA levels in culture media and SU5416 significantly diminished VEGFD concentrations. No significant differences in IL-8 levels were found for any treatment. Conclusions: Increased VEGFC levels after celecoxib treatment suggest a switch from a proangiogenic state toward a lymphangiogenic state. Neutralization of VEGF by VEGF B20-4.1.1 enhances the secretion of VEGFA and VEGFC by tumor cells inhibiting angiogenesis and lymphangenesis. Citation Format: Sara Caceres, Angela Alonso-Diez, Belen Crespo, Eduardo ESpinosa, Beatriz Madaruiaga, Gema Silvan, Maria J. Illera, Juan Carlos Illera. Implication of different anti-angiogenic treatments on in vitro vascular tube formation in triple negative inflammatory breast cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2646.

Cannabinoids orchestrate cross-talk between cancer cells and endothelial cells in colorectal cancer.

Medical marijuana has been approved by the FDA for treating chemotherapy-induced nausea and vomiting. However, less is known about its direct effects on tumor cells and the tumor microenvironment. In this study, RNA-sequencing datasets in the NCBI GEO repository were first analyzed; upregulation of cannabinoid receptors was observed in both primary and metastatic colorectal cancer (CRC) tumor tissues. An increase of cannabinoid receptors was also found in patients with CRC, azoxymethane/dextran sulfate sodium-induced CRC and CRC metastatic mouse models. Δ9-Tetrahydrocannabinol (Δ9-THC)-induced tumor progression in both primary and metastatic mouse models and also increased angiogenesis. A human growth factor antibody array indicated that Δ9-THC promoted the secretion of angiogenic growth factors in CRC, leading to the induction of tube formation and migration in human-induced pluripotent stem cell-derived vascular endothelial cells. The nuclear translocation of STAT1 played important roles in Δ9-THC-induced angiogenesis and tumor progression. Pharmacological treatment with STAT1 antagonist or abrogation of STAT1 with CRISPR/Cas9-based strategy rescued those effects of Δ9-THC in CRC. This study demonstrates that marijuana might increase the risk of CRC progression and that inhibition of STAT1 is a potential strategy for attenuating these side effects.

Inhibition of Angiogenic Factor Productions by Quercetin In Vitro and In Vivo.

Background: Angiogenesis is well known to be an important event in the tissue remodeling observed in allergic diseases. Although there is much evidence that quercetin, one of the most abundant dietary flavonoids, exerts anti-allergic effects in both human and experimental animal models of allergic diseases, the action of quercetin on angiogenesis has not been defined. Therefore, in this study, we first examined the action of quercetin on the secretion of angiogenic factors from murine mast cells in vitro. We also examined the action of quercetin on angiogenic factor secretion in the murine allergic rhinitis model in vivo. Methods: Mast cells (1 × 105 cells/mL) sensitized with ovalbumin (OVA)-specific murine IgE were stimulated with 10.0 ng/mL OVA in the presence or the absence of quercetin for 24 h. The concentrations of angiogenic factors, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), tumor necrosis factor-α, IL-6 and IL-8 in the supernatants were examined by ELISA. BALB/c male mice immunized with OVA were challenged intranasally with OVA every other day, starting seven days after the final immunization. These mice were then orally administered quercetin once a day for five days, starting seven days after the final immunization. Clinical symptoms were assessed by counting the number of sneezes and nasal rubbing behaviors during the 10 min period just after OVA nasal provocation. The angiogenic factor concentrations in the nasal lavage fluids obtained 6 h after nasal antigenic provocation were examined by ELISA. Results: Quercetin significantly inhibited the production of angiogenetic factors induced by IgE-dependent mechanisms at 5.0 µM or more. Oral administration of 25.0 mg/kg quercetin into the mice also suppressed the appearance of angiogenetic factors in nasal lavage fluids, along with the attenuation of nasal symptoms. Conclusions: These results strongly suggest that the inhibitory action of quercetin on angiogenic factor secretion may be implicated in the therapeutic action of quercetin on allergic diseases, especially allergic rhinitis.

Skeletal Muscle Extracellular Vesicles Regulate Endothelial Cells in a Fiber Type Dependent Manner

Introduction Skeletal muscle regulates endothelial cells (EC) via the secretion of angiogenic signaling factors, including extracellular vesicles (EV). Muscle can be characterized as predominantly oxidative (OXI) or glycolytic (GLY) depending on the expression of specific fiber types. OXI fibers have greater capillary density and secrete greater quantities of several angiogenic factors and EV, however it is unknown if EV signaling is regulated by fiber type. We hypothesized that EV released from OXI muscle (OXI-EV) induce a greater angiogenic response in cultured EC compared to EV from GLY muscle (GLY-EV). Methods From male CL57BL/6 mice, OXI muscle was isolated from red portions of the gastrocnemius and soleus; GLY muscle was isolated from white portions of the gastrocnemius and tibialis anterior. EVs were isolated using ultrafiltration-size exclusion chromatography. EV number and RNA content were measured. Human umbilical vein endothelial cells (HUVEC) were treated with OXI-EV or GLY-EV (10 μg/ml) for 24 h; and HUVEC functional angiogenic responses and molecular pathways related to angiogenesis were analyzed. Significance was established at P ≤ 0.05. Results OXI muscle released more EV than GLY muscle (OXI: 8.1x106; GLY: 4.6x106 particles/ml/mg muscle). Selected angiogenic mRNA (vascular endothelial growth factor (VEGF) A and B, angiopoietin (ANG) 1 and 2) and miRNAs (15a, 126, 133a) were not different between OXI-EV and GLY-EV, although there was a trend towards greater VEGFA in OXI-EV. In HUVEC, OXI-EV promoted greater tube formation (# of tubes: +34%; length: +20%), lowered intracellular superoxide (-58%), and trended (P < 0.10) toward greater growth (+22%) with no difference in migration compared to GLY-EVs. Treatment with OXI-EV promoted greater HUVEC endothelial nitric oxide synthase (eNOS) phosphorylation (+40%) and gene expression (+42%) compared to GLY-EV. In HUVEC, there was no difference in gene expression of VEGFA, VEGFB, ANG1, or Ang2 between OXI-EV and GLY-EV treatments. Conclusions EV from oxidative muscle demonstrate greater angiogenic potential than EV from glycolytic muscle consistent with greater capillarization of oxidative muscle. Thus, greater oxidative vs. glycolytic muscle capillarization is likely regulated in part by the combination of greater release of EV and greater EV angiogenic potential from oxidative muscle fibers.

Novel angiogenic metal nanoparticles controlling intracellular gene activation in stem cells

Metal and oxide nanoparticles (NPs) are attracting extensive attention in biomedical applications, including bioimaging and drug delivery. However, it is difficult to use these NPs as therapeutic agents for specific cell and tissue treatments because of limitations such as material oxidization and cell toxicity. Herein, we synthesized Cu-based angiogenic metal nanoparticles (Cu-AMNs), using a galvanic replacement reaction of Cu NPs and Au precursor, which stabilized and upregulated intracellular behaviors in human adipose-derived stem cells (hADSCs). Our novel therapeutic Cu-AMNs showed remarkable advantages in cell treatment, such as low mitochondrial damage, reduced ATP consumption, decreased cytotoxicity, mild reactive oxygen species generation with enhanced angiogenic paracrine factor secretion, and improved hypoxia inducible factor-1 alpha (HIF-1α) expression. Through the improved expression of HIF-1α, vascular endothelial growth factor (VEGF) secretion was prolonged for 3 days, even in re-attached hADSCs. In addition, Cu-AMNs improved other angiogenic factors and the amount of exocytosed Cu from hADSCs, resulting in strong development of tubular formation by human umbilical vein endothelial cells in vitro. Finally, transplantation of Cu-AMN-treated hADSCs in mice led to a significant in vivo increase in angiogenesis and blood perfusion in a mouse hindlimb ischemia model compared with conventional hADSC therapy.

Sodium alginate-bioglass-encapsulated hAECs restore ovarian function in premature ovarian failure by stimulating angiogenic factor secretion

BackgroundHuman amniotic epithelial cells (hAECs) exhibit a strong capability to restore ovarian function in chemotherapy-induced premature ovarian failure (POF). However, the therapeutic efficacy of hAECs is usually affected by the limited number and proliferative ability of grafted hAECs in target organs. The transplantation of stem cells encapsulated in sodium alginate-bioglass (SA-BG) composite hydrogel has recently been shown to be an effective strategy for tissue regeneration. The current study aims to investigate the therapeutic potential of hAECs or hAEC-derived conditioned medium (CM) encapsulated in SA-BG in mice with chemotherapy-induced POF.MethodsC57BL/6 mice were intraperitoneally injected with chemotherapy drugs to induce POF. hAECs or CM were harvested and encapsulated in SA-BG composite hydrogel, which were transplanted onto the injured ovaries of mice with POF. Follicle development, granulosa cell function, and ovarian angiogenesis were evaluated by morphological methods. To further elucidate the effect of SA-BG-encapsulated hAECs/CM on vascularization, the tube formation of human umbilical vein epithelial cells (hUVECs) was conducted in vitro. Cytokine array and ELISA were used to analyze and quantify the effects of bioactive components released by SA-BG on the secretion of angiogenic factors by hAECs.ResultsThe transplantation of SA-BG-encapsulated hAECs/CM restored follicle development, repaired granulosa cell function, and enhanced ovarian angiogenesis in POF mice. The further study showed that SA-BG significantly promoted the tube formation of hUVECs in vitro. Moreover, encapsulating hAECs could facilitate the effect of SA-BG on inducing the formation of the capillary tube in a paracrine manner. In addition, we found that SA-BG extracts significantly enhanced the viability of hAECs and stimulated the secretion of pro-angiogenic factors of hAECs. Notably, compared with SA-BG/CM, SA-BG/hAECs achieve better therapeutic effects, possibly because stimulation of BG enhanced the viability and paracrine capacity of hAECs.ConclusionsThe present study initially demonstrates that SA-BG-encapsulated hAECs or CM can exert a therapeutic effect on chemotherapy-induced POF mainly by protecting granulosa cell function and enhancing ovarian vascularization, which might provide a novel strategy for the delivery of hAECs for treating POF.

Porcine placenta extract improves high-glucose-induced angiogenesis impairment

BackgroundHigh glucose (HG)-induced reactive oxygen species (ROS) overproduction impairs angiogenesis that is one pivotal factor of wound healing process. Angiogenesis impairment induces delayed wound healing, whereby it eventually leads to amputation in cases of poorly controlled diabetes with diabetic ulceration. Porcine placenta extract (PPE) is a natural waste product that comprises plenty of bioactive agents including growth factors and antioxidants. It was reported as an effective compound that prevents ROS generation. The goal of this study was to investigate the in vitro effect of PPE on HG-induced ROS-mediated angiogenesis impairment.MethodsPrimary endothelial cells (HUVECs) and endothelial cell line (EA.hy926) were treated with HG in the presence of PPE. The endothelial cells (ECs) viability, intracellular ROS generation, migration, and angiogenesis were determined by MTT assay, DCFDA reagent, wound healing assay, and tube formation assay, respectively. Additionally, the molecular mechanism of PPE on HG-induced angiogenesis impairment was investigated by Western blot. The angiogenic growth factor secretion was also investigated by the sandwich ELISA technique.ResultsHG in the presence of PPE significantly decreased intracellular ROS overproduction compared to HG alone. HG in the presence of PPE significantly increased ECs viability, migration, and angiogenesis compared to HG alone by showing recovery of PI3K/Akt/ERK1/2 activation. HG in the presence of PPE also decreased ECs apoptosis compared to HG alone by decreasing p53/Bax/cleaved caspase 9/cleaved caspase 3 levels and increasing Bcl 2 level.ConclusionPPE attenuated HG-induced intracellular ROS overproduction that improved ECs viability, proliferation, migration, and angiogenesis by showing recovery of PI3K/Akt/ERK1/2 activation and inhibition of ECs apoptosis. This study suggests PPE ameliorated HG-induced ROS-mediated angiogenesis impairment, whereby it potentially provides an alternative treatment for diabetic wounds.

Syndecan-1 Overexpressing Mesothelioma Cells Inhibit Proliferation, Wound Healing, and Tube Formation of Endothelial Cells.

Simple SummaryThe transmembrane proteoglycan syndecan-1 (SDC-1) is an important mediator of cell-matrix interactions. The heparan sulfate side-chains of SDC-1 can bind to a multitude of growth factors, cytokines, and chemokines, thereby regulating a plethora of physiological and pathological processes, including angiogenesis. The extracellular region of SDC-1 can be released from the cell surface by the action of sheddases including matrix metalloproteinase-7 and 9, resulting in a soluble protein that is still active and can act as a competitive activator or inhibitor of the cell surface receptor. Accelerated shedding and loss of cell surface SDC-1 is associated with epithelial to mesenchymal transition (EMT) and achievement of a more invasive phenotype in malignant mesothelioma (MM). Transfection with SDC-1 reverts the morphology in epithelioid direction and inhibits the proliferation and migration of MM cells. This study aimed to investigate the role of SDC-1 in angiogenesis. We demonstrate that overexpression and silencing of SDC-1 alters the secretion of angiogenic proteins in MM cells. Upon SDC-1 overexpression, several factors collectively inhibit the proliferation, wound closure, and tube formation of endothelial cells, whereas SDC-1 silencing only affects wound healing.Malignant mesothelioma (MM) is an aggressive tumor of the serosal cavities. Angiogenesis is important for mesothelioma progression, but so far, anti-angiogenic agents have not improved patient survival. Our hypothesis is that better understanding of the regulation of angiogenesis in this tumor would largely improve the success of such a therapy. Syndecan-1 (SDC-1) is a transmembrane heparan sulfate proteoglycan that acts as a co-receptor in various cellular processes including angiogenesis. In MM, the expression of SDC-1 is generally low but when present, SDC-1 associates to epithelioid differentiation, inhibition of tumor cell migration and favorable prognosis, meanwhile SDC-1 decrease deteriorates the prognosis. In the present study, we studied the effect of SDC-1 overexpression and silencing on MM cells ability to secrete angiogenic factors and monitored the downstream effect of SDC-1 modulation on endothelial cells proliferation, wound healing, and tube formation. This was done by adding conditioned medium from SDC-1 transfected and SDC-1 silenced mesothelioma cells to endothelial cells. Moreover, we investigated the interplay and molecular functional changes in angiogenesis in a co-culture system and characterized the soluble angiogenesis-related factors secreted to the conditioned media. We demonstrated that SDC-1 over-expression inhibited the proliferation, wound healing, and tube formation of endothelial cells. This effect was mediated by a multitude of angiogenic factors comprising angiopoietin-1 (Fold change ± SD: 0.65 ± 0.07), FGF-4 (1.45 ± 0.04), HGF (1.33 ± 0.07), NRG1-β1 (1.35 ± 0.08), TSP-1 (0.8 ± 0.02), TIMP-1 (0.89 ± 0.01) and TGF-β1 (1.35 ± 0.01). SDC-1 silencing increased IL8 (1.33 ± 0.06), promoted wound closure, but did not influence the tube formation of endothelial cells. Pleural effusions from mesothelioma patients showed that Vascular Endothelial Growth Factor (VEGF) levels correlate to soluble SDC-1 levels and have prognostic value. In conclusion, SDC-1 over-expression affects the angiogenic factor secretion of mesothelioma cells and thereby inhibits endothelial cells proliferation, tube formation, and wound healing. VEGF could be used in prognostic evaluation of mesothelioma patients together with SDC-1.

Preservation of microvascular integrity and immunomodulatory property of prevascularized human mesenchymal stem cell sheets.

Prevascularization is essential to ensure the viability, functionality, and successful integration of tissue-engineered three-dimensional (3D) constructs with surrounding host tissues after transplantation. Human mesenchymal stem cell (hMSC) sheet can be prevascularized by coculturing with endothelial cells (ECs), and then be further used as building blocks for engineering 3D complex tissues. In addition, predifferentiation of hMSCs into a tissue-specific lineage in vitro has been proven to promote graft engraftment and regeneration. However, it is unclear if the prevascularized hMSC sheets can still maintain their microvascular integrity as well as the immune-regulatory properties after their tissue-specific differentiation. The objective of this study was to investigate the effects of differentiation cues on the microvascular structure, angiogenic factor secretion, and immunogenic responses of prevascularized hMSC sheets. The results showed that upon coculturing with ECs, hMSC sheets successfully formed microvascular network, while maintaining hMSCs' multi-lineage differentiation capability. The next step, osteogenic and adipogenic induction, damaged the preformed microvascular structures and compromised the angiogenic factor secretion ability of hMSCs. Nonetheless, this effect was mitigated by adjusting the concentration of differentiation factors. The subcutaneous transplantation in an immunocompetent rat model demonstrated that the osteogenic differentiated prevascularized hMSC sheet preserved its microvascular structure and immunomodulatory properties comparable to the undifferentiated prevascularized hMSC sheets. This study suggested that a balanced and optimal differentiation condition can effectively promote the tissue-specific predifferentiation of prevascularized hMSC sheet while maintaining its immunomodulatory and tissue integration properties.

Dual Ion Releasing Nanoparticles for Modulating Osteogenic Cellular Microenvironment of Human Mesenchymal Stem Cells.

In this study we developed a dual therapeutic metal ion-releasing nanoparticle for advanced osteogenic differentiation of stem cells. In order to enhance the osteogenic differentiation of human mesenchymal stem cells (hMSCs) and induce angiogenesis, zinc (Zn) and iron (Fe) were synthesized together into a nanoparticle with a pH-sensitive degradation property. Zn and Fe were loaded within the nanoparticles to promote early osteogenic gene expression and to induce angiogenic paracrine factor secretion for hMSCs. In vitro studies revealed that treating an optimized concentration of our zinc-based iron oxide nanoparticles to hMSCs delivered Zn and Fe ion in a controlled release manner and supported osteogenic gene expression (RUNX2 and alkaline phosphatase) with improved vascular endothelial growth factor secretion. Simultaneous intracellular release of Zn and Fe ions through the endocytosis of the nanoparticles further modulated the mild reactive oxygen species generation level in hMSCs without cytotoxicity and thus improved the osteogenic capacity of the stem cells. Current results suggest that our dual ion releasing nanoparticles might provide a promising platform for future biomedical applications.

Cotransplantation of mesenchymal stem cells and endothelial progenitor cells for treating steroid-induced osteonecrosis of the femoral head.

Steroid‐induced osteonecrosis of the femoral head (ONFH) is characterized by decreased osteogenesis, angiogenesis, and increased adipogenesis. While bone tissue engineering has been widely investigated to treat ONFH, its therapeutic effects remain unsatisfactory. Therefore, further studies are required to determine optimal osteogenesis, angiogenesis and adipogenesis in the necrotic area of the femoral head. In our study, we developed a carboxymethyl chitosan/alginate/bone marrow mesenchymal stem cell/endothelial progenitor cell (CMC/ALG/BMSC/EPC) composite implant, and evaluated its ability to repair steroid‐induced ONFH. Our in vitro studies showed that BMSC and EPC coculture displayed enhanced osteogenic and angiogenic differentiation. When compared with single BMSC cultures, adipogenic differentiation in coculture systems was reduced. We also fabricated a three‐dimensional (3D) CMC/ALG scaffold for loading cells, using a lyophilization approach, and confirmed its good cell compatibility characteristics, that is, high porosity, low cytotoxicity and favorable cell adhesion. 3D coculture of BMSCs and EPCs also promoted secretion of osteogenic and angiogenic factors. Then, we established an rabbit model of steroid‐induced ONFH. The CMC/ALG/BMSC/EPC composite implant was transplanted into the bone tunnel of the rabbit femoral head after core decompression (CD) surgery. Twelve weeks later, radiographical and histological analyses revealed CMC/ALG/BMSC/EPC composite implants had facilitated the repair of steroid‐induced ONFH, by promoting osteogenesis and angiogenesis, and reducing adipogenesis when compared with CD, CMC/ALG, CMC/ALG/BMSC and CMC/ALG/EPC groups. Thus, our data show that cotransplantation of BMSCs and EPCs in 3D scaffolds is beneficial in treating steroid‐induced ONFH.

The interaction of stem cells and vascularity in peripheral nerve regeneration.

The degree of nerve regeneration after peripheral nerve injury can be altered by the microenvironment at the site of injury. Stem cells and vascularity are postulated to be a part of a complex pathway that enhances peripheral nerve regeneration; however, their interaction remains unexplored. This review aims to summarize current knowledge on this interaction, including various mechanisms through which trophic factors are promoted by stem cells and angiogenesis. Angiogenesis after nerve injury is stimulated by hypoxia, mediated by vascular endothelial growth factor, resulting in the growth of pre-existing vessels into new areas. Modulation of distinct signaling pathways in stem cells can promote angiogenesis by the secretion of various angiogenic factors. Simultaneously, the importance of stem cells in peripheral nerve regeneration relies on their ability to promote myelin formation and their capacity to be influenced by the microenvironment to differentiate into Schwann-like cells. Stem cells can be acquired through various sources that correlate to their differentiation potential, including embryonic stem cells, neural stem cells, and mesenchymal stem cells. Each source of stem cells serves its particular differentiation potential and properties associated with the promotion of revascularization and nerve regeneration. Exosomes are a subtype of extracellular vesicles released from cell types and play an important role in cell-to-cell communication. Exosomes hold promise for future transplantation applications, as these vesicles contain fewer membrane-bound proteins, resulting in lower immunogenicity. This review presents pre-clinical and clinical studies that focus on selecting the ideal type of stem cell and optimizing stem cell delivery methods for potential translation to clinical practice. Future studies integrating stem cell-based therapies with the promotion of angiogenesis may elucidate the synergistic pathways and ultimately enhance nerve regeneration.

Adaptations of the human placenta to hypoxia: opportunities for interventions in fetal growth restriction.

The placenta is the functional interface between the mother and the fetus during pregnancy, and a critical determinant of fetal growth and life-long health. In the first trimester, it develops under a low-oxygen environment, which is essential for the conceptus who has little defense against reactive oxygen species produced during oxidative metabolism. However, failure of invasive trophoblasts to sufficiently remodel uterine arteries toward dilated vessels by the end of the first trimester can lead to reduced/intermittent blood flow, persistent hypoxia and oxidative stress in the placenta with consequences for fetal growth. Fetal growth restriction (FGR) is observed in ∼10% of pregnancies and is frequently seen in association with other pregnancy complications, such as preeclampsia (PE). FGR is one of the main challenges for obstetricians and pediatricians, as smaller fetuses have greater perinatal risks of morbidity and mortality and postnatal risks of neurodevelopmental and cardio-metabolic disorders. The aim of this review was to examine the importance of placental responses to changing oxygen environments during abnormal pregnancy in terms of cellular, molecular and functional changes in order to highlight new therapeutic pathways, and to pinpoint approaches aimed at enhancing oxygen supply and/or mitigating oxidative stress in the placenta as a mean of optimizing fetal growth. An extensive online search of peer-reviewed articles using PubMed was performed with combinations of search terms including pregnancy, placenta, trophoblast, oxygen, hypoxia, high altitude, FGR and PE (last updated in May 2020). Trophoblast differentiation and placental establishment are governed by oxygen availability/hypoxia in early pregnancy. The placental response to late gestational hypoxia includes changes in syncytialization, mitochondrial functions, endoplasmic reticulum stress, hormone production, nutrient handling and angiogenic factor secretion. The nature of these changes depends on the extent of hypoxia, with some responses appearing adaptive and others appearing detrimental to the placental support of fetal growth. Emerging approaches that aim to increase placental oxygen supply and/or reduce the impacts of excessive oxidative stress are promising for their potential to prevent/treat FGR. There are many risks and challenges of intervening during pregnancy that must be considered. The establishment of human trophoblast stem cell lines and organoids will allow further mechanistic studies of the effects of hypoxia and may lead to advanced screening of drugs for use in pregnancies complicated by placental insufficiency/hypoxia. Since no treatments are currently available, a better understanding of placental adaptations to hypoxia would help to develop therapies or repurpose drugs to optimize placental function and fetal growth, with life-long benefits to human health.