Angiogenesis induced by endothelial nitric oxide synthase gene through vascular endothelial growth factor expression in a rat hindlimb ischemia model

Optimizing transport methods to preserve function of self-innervating muscle cells for laryngeal injection

Objectives

Recently, our laboratory has discovered a self-innervating population of muscle cells, called motor endplate-expressing cells (MEEs). The cells innately release a wide variety of neurotrophic factors into the microenvironment promoting innervation when used as an injectable treatment. Unlike other stem cells, the therapeutic potential of MEEs is dependent on the cells' ability to maintain phenotypical cell surface proteins in particular motor endplates (MEPs). The goal of this study is to identify transport conditions that preserve MEE viability and self-innervating function.

Methods

Muscle progenitor cells (MPCs) of adult Yucatan pigs were cultured and induced to generate MEEs. Effects of short-term cryopreservation methods were studied on MPC and MEE stages. A minimally supplemented medium was investigated for suspension-mediated transport, and MEEs were loaded at a constant concentration (1 × 107 cells/mL) into plastic syringes. Samples were subjected to varying temperatures (4, 22, and 37°C) and durations (6, 18, 24, and 48 h), which was followed by statistical analysis of viability. Transport conditions maintaining viability acceptable for cellular therapy were examined for apoptosis rates and expression of desired myogenic, neurotrophic, neuromuscular junction, and angiogenic genes.

Results

Cryopreservation proved detrimental to our cell population. However, a minimally supplemented medium, theoretically safe for injection, was identified. Transport temperature and duration impacted cell viability, with warmer temperatures leading to faster death rates prior to the end of the study. Transport conditions did not appear to affect apoptotic rate. Any expression change of desirable genes fell within the acceptable range.

Conclusions

Transport state, medium, duration, and temperature must be considered during the transport of injectable muscle cells as they can affect cell viability and expression of integral genes. These described factors are integral in the planning of general cell transport and may prove equally important when the cell population utilized for laryngeal injection is derived from a patient's own initial muscle biopsy.

PDE9A Inhibition Improves Coronary Microvascular Rarefaction and Left Ventricular Diastolic Dysfunction in the ZSF1 Rat Model of HFpEF

OBJECTIVE

Heart failure with preserved ejection fraction (HFpEF) commonly arises from comorbid diseases, such as hypertension, obesity, and diabetes mellitus. Selective inhibition of phosphodiesterase 9A (PDE9A) has emerged as a potential therapeutic approach for treating cardiometabolic diseases. Coronary microvascular disease (CMD) is one of the key mechanisms contributing to the development of left ventricular (LV) diastolic dysfunction in HFpEF. Our study aimed to investigate the mechanisms by which PDE9A inhibition could ameliorate CMD and improve LV diastolic function in HFpEF.

METHODS AND RESULTS

The obese diabetic Zucker fatty/spontaneously hypertensive heart failure F1 hybrid (ZSF1) rat model of HFpEF was employed in which it was found that a progressively developing coronary microvascular rarefaction is associated with LV diastolic dysfunction when compared to lean, nondiabetic hypertensive controls. Obese ZSF1 rats had an increased cardiac expression of PDE9A. Treatment of obese ZSF1 rats with the selective PDE9A inhibitor, PF04447943 (3 mg/kg/day, oral gavage for 2 weeks), improved coronary microvascular rarefaction and LV diastolic dysfunction, which was accompanied by reduced levels of oxidative and nitrosative stress markers, hydrogen peroxide, and 3-nitrotyrosine. Liquid chromatography-mass spectrometry (LC-MS) proteomic analysis identified peroxiredoxins (PRDX) as downregulated antioxidants in the heart of obese ZSF1 rats, whereas Western immunoblots showed that the protein level of PRDX5 was significantly increased by the PF04447943 treatment.

CONCLUSIONS

Thus, in the ZSF1 rat model of human HFpEF, PDE9A inhibition improves coronary vascular rarefaction and LV diastolic dysfunction, demonstrating the usefulness of PDE9A inhibitors in ameliorating CMD and LV diastolic dysfunction through augmenting PRDX-dependent antioxidant mechanisms.

Low-intensity pulsed ultrasound modulates disease progression in the SOD1G93A mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease characterized by the progressive loss of motor neurons in the brain and spinal cord, and there are no effective drug treatments. Low-intensity pulsed ultrasound (LIPUS) has garnered attention as a promising noninvasive neuromodulation method. In this study, we investigate its effects on the motor cortex and underlying mechanisms using the SOD1G93A mouse model of ALS. Our results show that LIPUS treatment delays disease onset and prolongs lifespan in ALS mice. LIPUS significantly increases cerebral blood flow in the motor cortex by preserving vascular endothelial cell integrity and increasing microvascular density, which may be mediated via the ion channel TRPV4. RNA sequencing analysis reveals that LIPUS substantially reduces the expression of genes associated with neuroinflammation. These findings suggest that LIPUS applied to the motor cortex may represent a potentially effective therapeutic tool for the treatment of ALS.

Effects of Photobiomodulation Therapy on the Expression of Hypoxic Inducible Factor, Vascular Endothelial Growth Factor, and Its Specific Receptor: A Randomized Control Trial in Patients with Diabetic Foot Ulcer

Background: Impaired angiogenesis is a significant factor contributing to delayed healing in diabetic foot ulcers (DFUs) due to inadequate oxygenation. Objective: This study aimed to investigate the impact of photobiomodulation (PBM) using a Ga-As laser on the release of serum hypoxia-inducible factor 1-α (HIF-1α), vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor-2, and nitric oxide (NO) in diabetic patients with DFUs. Materials and methods: In this double-blind RCT, a total of 30 patients with grade II DFUs were enrolled. The patients were randomly divided into two groups: the PBM (n = 15) and the placebo (n = 15). In the PBM group, a Ga-As laser (904 nm, 2 J/cm2, 90 W) was given for 3 days/week for 4 weeks (11 sessions). In the placebo group, the power was turned off. Both groups received similar standard wound care. Before and after interventions, the levels of serum HIF-1α, VEGF, NO, and sVEGFR-2 were measured. In addition, the percentage decrease in the wound surface area (%DWSA) was measured. Results: Following the intervention, the results revealed that the PBM group had significantly lower levels of VEGF than the placebo group (p = 0.005). The %DWSA was significantly higher in the PBM group compared to the placebo group (p = 0.003). Moreover, VEGF showed a significant negative correlation with %DWSA (p < 0.001). Conclusions: The observed decrease in serum levels of VEGF and an increase in %DWSA, compared to the placebo group, suggests that PBM effectively improves angiogenesis. Furthermore, the significant correlation found between VEGF levels and %DWSA emphasizes the importance of evaluating wound surface in patients as a dependable indicator of enhanced wound angiogenesis. Clinical Trial Registration: NCT02452086.

Nitroprusside and metal nitroprusside nano analogues for cancer therapy

Sodium nitroprusside (SNP), U.S approved drug has been used in clinical emergency as a hypertensive drug for more than a decade. It is well established for its various biomedical applications such as angiogenesis, wound healing, neurological disorders including anti-microbial applications etc. Apart from that, SNP have been considered as excellent biomedical materials for its use as anti-cancer agent because of its behavior as NO-donor. Recent reports suggest that incorporation of metals in SNP/encapsulation of SNP in metal nanoparticles (metal nitroprusside analogues) shows better therapeutic anti-cancer activity. Although there are numerous reports available regarding the biological applications of SNP and metal-based SNP analogue nanoparticles, unfortunately there is not a single comprehensive review which highlights the anti-cancer activity of SNP and its derivative metal analogues in detail along with the future perspective. To this end, the present review article focuses the recent development of anti-cancer activity of SNP and metal-based SNP analogues, their plausible mechanism of action, current status. Furthermore, the future perspectives and challenges of these biomedical materials are also discussed. Overall, this review article represents a new perspective in the area of cancer nanomedicine that will attract a wider spectrum of scientific community.

Early Changes in Porcine Larynges Following Injection of Motor-Endplate Expressing Muscle Cells for the Treatment of Unilateral Vocal Fold Paralysis

OBJECTIVES

No curative injectable therapy exists for unilateral vocal fold paralysis. Herein, we explore the early implications of muscle-derived motor-endplate expressing cells (MEEs) for injectable vocal fold medialization after recurrent laryngeal nerve (RLN) injury.

METHODS

Yucatan minipigs underwent right RLN transection (without repair) and muscle biopsies. Autologous muscle progenitor cells were isolated, cultured, differentiated, and induced to form MEEs. Three weeks after the injury, MEEs or saline were injected into the paralyzed right vocal fold. Outcomes including evoked laryngeal electromyography (LEMG), laryngeal adductor pressure, and acoustic vocalization data were analyzed up to 7 weeks post-injury. Harvested porcine larynges were examined for volume, gene expression, and histology.

RESULTS

MEE injections were tolerated well, with all pigs demonstrating continued weight gain. Blinded analysis of videolaryngoscopy post-injection revealed infraglottic fullness, and no inflammatory changes. Four weeks after injection, LEMG revealed on average higher right distal RLN activity retention in MEE pigs. MEE-injected pigs on average had vocalization durations, frequencies, and intensities higher than saline pigs. Post-mortem, the MEE-injected larynges revealed statistically greater volume on quantitative 3D ultrasound, and statistically increased expression of neurotrophic factors (BDNF, NGF, NTF3, NTF4, NTN1) on quantitative PCR.

CONCLUSIONS

Minimally invasive MEE injection appears to establish an early molecular and microenvironmental framework to encourage innate RLN regeneration. Longer follow-up is needed to determine if early findings will translate into functional contraction.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:272-282, 2024.

Interleukin-30 subverts prostate cancer-endothelium crosstalk by fostering angiogenesis and activating immunoregulatory and oncogenic signaling pathways

BACKGROUND

Cancer-endothelial interplay is crucial for tumor behavior, yet the molecular mechanisms involved are largely unknown. Interleukin(IL)-30, which is expressed as a membrane-anchored cytokine by human prostate cancer (PC) cells, promotes PC vascularization and progression, but the underlying mechanisms have yet to be fully explored.

METHODS

PC-endothelial cell (EC) interactions were investigated, after coculture, by flow cytometry, transcriptional profiling, western blot, and ELISA assays. Proteome profiler phospho-kinase array unveiled the molecular pathways involved. The role of tumor-derived IL30 on the endothelium's capacity to generate autocrine circuits and vascular budding was determined following IL30 overexpression, by gene transfection, or its deletion by CRISPR/Cas9 genome editing. Clinical value of the experimental findings was determined through immunopathological study of experimental and patient-derived PC samples, and bioinformatics of gene expression profiles from PC patients.

RESULTS

Contact with PC cells favors EC proliferation and production of angiogenic and angiocrine factors, which are boosted by PC expression of IL30, that feeds autocrine loops, mediated by IGF1, EDN1, ANG and CXCL10, and promotes vascular budding and inflammation, via phosphorylation of multiple signaling proteins, such as Src, Yes, STAT3, STAT6, RSK1/2, c-Jun, AKT and, primarily CREB, GSK-3α/β, HSP60 and p53. Deletion of the IL30 gene in PC cells inhibits endothelial expression of IGF1, EDN1, ANG and CXCL10 and substantially impairs tumor angiogenesis. In its interaction with IL30-overexpressing PC cells the endothelium boosts their expression of a wide range of immunity regulatory genes, including CCL28, CCL4, CCL5, CCR2, CCR7, CXCR4, IL10, IL13, IL17A, FASLG, IDO1, KITLG, TNFA, TNFSF10 and PDCD1, and cancer driver genes, including BCL2, CCND2, EGR3, IL6, VEGFA, KLK3, PTGS1, LGALS4, GNRH1 and SHBG. Immunopathological analyses of PC xenografts and in silico investigation of 1116 PC cases, from the Prostate Cancer Transcriptome Atlas, confirmed the correlation between the expression of IL30 and that of both pro-inflammatory genes, NOS2, TNFA, CXCR5 and IL12B, and cancer driver genes, LGALS4, GNRH1 and SHBG, which was validated in a cohort of 80 PC patients.

CONCLUSIONS

IL30 regulates the crosstalk between PC and EC and reshapes their transcriptional profiles, triggering angiogenic, immunoregulatory and oncogenic gene expression programs. These findings highlight the angiostatic and oncostatic efficacy of targeting IL30 to fight PC.

Endothelium-Mimetic Surface Modification Improves Antithrombogenicity and Enhances Patency of Vascular Grafts in Rats and Pigs

We first identified thrombomodulin (TM) and endothelial nitric oxide (NO) synthase as key factors for the antithrombogenic function of the endothelium in human atherosclerotic carotid arteries. Then, recombinant TM and an engineered galactosidase responsible for the conversion of an exogenous NO prodrug were immobilized on the surface of the vascular grafts. Surface modification by TM and NO cooperatively enhanced the antithrombogenicity and patency of vascular grafts. Importantly, we found that the combination of TM and NO also promoted endothelialization, whereas it reduced adverse intimal hyperplasia, which is critical for the maintenance of vascular homeostasis, as confirmed in rat and pig models.

Migration of endothelial cells on the surface of anodized Ni-Ti stent strut

Background

Stent is widely regarded as the main treatment for curing cardiovascular diseases such as stenosis. Previous research has revealed that the damage of endothelial cells (EC), i.e., the components of endothelium, during stent implantation, could lead to severe complications, such as restenosis. To prevent restenosis, enhancements have been made to surface biocompatibility to accelerate the stent endothelialization process. Anodization on the Ni-Ti is a simple and efficient surface modification method to improve the biocompatibility of the Ni-Ti stent surfaces by enhancing the surface hydrophilicity, leading to an increase in the EC activities. The EC activity is known to be affected by the blood flow. Flow change by stent structure may result in EC dysfunctions, thereby leading to restenosis. It is thus essential to investigate the EC activities resulting from the anodization on the Ni-Ti surface under flow conditions.

Objective

To study the influence of the endothelialization process on the Ni-Ti stent surface through anodization. The EC attachment and morphology on the anodized stent strut were observed under both with and without the flow conditions.

Method

A parallel plate flow chamber was designed to generate a constant wall shear stress (WSS) to study the flow effect on the EC behavior. The hydrophilicity of the Ni-Ti stent strut surface was enhanced by a TiO2 layer fabricated via anodization. The EC distribution on the surface of the anodized nitinol stent strut was observed after 24 h of static (without flow) and flow exposure (with flow) experiment.

Results

Under the static condition, the EC density on the surface of the anodized Ni-Ti stent strut was higher compared with the control. Under the flow condition, the enhancement of the EC density on the surface of the stent strut with anodization was reduced. The EC demonstrates a long and thin spindle-shaped morphology under the flow condition.

Conclusion

Unlike the static condition, the EC is demonstrating a long and thin morphology in response to the flow under the flow condition. By improving the surface hydrophilicity, the anodization could enhance the EC migration onto the strut surface, and subsequently, accelerate the Ni-Ti stent endothelialization process. The improvement of the surface hydrophilicity is lower under the flow conditions when compared with the static conditions.

The eNOS isoform exhibits increased expression and activation in the main olfactory bulb of nNOS knock-out mice

The main olfactory bulb (MOB) is a neural structure that processes olfactory information. Among the neurotransmitters present in the MOB, nitric oxide (NO) is particularly relevant as it performs a wide variety of functions. In this structure, NO is produced mainly by neuronal nitric oxide synthase (nNOS) but also by inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS). The MOB is considered a region with great plasticity and the different NOS also show great plasticity. Therefore, it could be considered that this plasticity could compensate for various dysfunctional and pathological alterations. We examined the possible plasticity of iNOS and eNOS in the MOB in the absence of nNOS. For this, wild-type and nNOS knock-out (nNOS-KO) mice were used. We assessed whether the absence of nNOS expression could affect the olfactory capacity of mice, followed by the analysis of the expression and distribution of the NOS isoforms using qPCR and immunofluorescence. NO production in MOB was examined using both the Griess and histochemical NADPH-diaphorase reactions. The results indicate nNOS-KO mice have reduced olfactory capacity. We observed that in the nNOS-KO animal, there is an increase both in the expression of eNOS and NADPH-diaphorase, but no apparent change in the level of NO generated in the MOB. It can be concluded that the level of eNOS in the MOB of nNOS-KO is related to the maintenance of normal levels of NO. Therefore, our findings suggest that nNOS could be essential for the proper functioning of the olfactory system.

The Potential of PSMA as a Vascular Target in TNBC

Recent studies proving prostate-specific membrane antigen (PSMA) expression on triple-negative breast cancer (TNBC) cells and adjacent endothelial cells suggest PSMA as a promising target for therapy of until now not-targetable cancer entities. In this study, PSMA and its isoform expression were analyzed in different TNBC cells, breast cancer stem cells (BCSCs), and tumor-associated endothelial cells. PSMA expression was detected in 91% of the investigated TNBC cell lines. The PSMA splice isoforms were predominantly found in the BCSCs. Tumor-conditioned media from two TNBC cell lines, BT-20 (high full-length PSMA expression, PSMAΔ18 expression) and Hs578T (low full-length PSMA expression, no isoform expression), showed significant pro-angiogenic effect with induction of tube formation in endothelial cells. All TNBC cell lines induced PSMA expression in human umbilical vein endothelial cells (HUVEC). Significant uptake of radiolabeled ligand [⁶⁸Ga]Ga-PSMA was detected in BCSC1 (4.2%), corresponding to the high PSMA expression. Moreover, hypoxic conditions increased the uptake of radiolabeled ligand [¹⁷⁷Lu]Lu-PSMA in MDA-MB-231 (0.4% vs. 3.4%, under hypoxia and normoxia, respectively) and MCF-10A (0.3% vs. 3.0%, under normoxia and hypoxia, respectively) significantly (p < 0.001). [¹⁷⁷Lu]Lu-PSMA-induced apoptosis rates were highest in BT-20 and MDA-MB-231 associated endothelial cells. Together, these findings demonstrate the potential of PSMA-targeted therapy in TNBC.

Diabetes mellitus in peripheral artery disease: Beyond a risk factor

Peripheral artery disease (PAD) is one of the major cardiovascular diseases that afflicts a large population worldwide. PAD results from occlusion of the peripheral arteries of the lower extremities. Although diabetes is a major risk factor for developing PAD, coexistence of PAD and diabetes poses significantly greater risk of developing critical limb threatening ischemia (CLTI) with poor prognosis for limb amputation and high mortality. Despite the prevalence of PAD, there are no effective therapeutic interventions as the molecular mechanism of how diabetes worsens PAD is not understood. With increasing cases of diabetes worldwide, the risk of complications in PAD have greatly increased. PAD and diabetes affect a complex web of multiple cellular, biochemical and molecular pathways. Therefore, it is important to understand the molecular components that can be targeted for therapeutic purposes. In this review, we describe some major developments in enhancing the understanding of the interactions of PAD and diabetes. We also provide results from our laboratory in this context.

Neuronal nitric oxide synthase is required for erythropoietin stimulated erythropoiesis in mice

Introduction: Erythropoietin (EPO), produced in the kidney in a hypoxia responsive manner, is required for red blood cell production. In non-erythroid tissue, EPO increases endothelial cell production of nitric oxide (NO) and endothelial nitric oxide synthase (eNOS) that regulates vascular tone to improve oxygen delivery. This contributes to EPO cardioprotective activity in mouse models. Nitric oxide treatment in mice shifts hematopoiesis toward the erythroid lineage, increases red blood cell production and total hemoglobin. In erythroid cells, nitric oxide can also be generated by hydroxyurea metabolism that may contribute to hydroxyurea induction of fetal hemoglobin. We find that during erythroid differentiation, EPO induces neuronal nitric oxide synthase (nNOS) and that neuronal nitric oxide synthase is required for normal erythropoietic response. Methods: Wild type (WT) mice and mice with targeted deletion of nNOS (nNOS-/-) and eNOS (eNOS-/-) were assessed for EPO stimulated erythropoietic response. Bone marrow erythropoietic activity was assessed in culture by EPO dependent erythroid colony assay and in vivo by bone marrow transplantation into recipient WT mice. Contribution of nNOS to EPO stimulated cell proliferation was assessed in EPO dependent erythroid cells and in primary human erythroid progenitor cell cultures. Results: EPO treatment increased hematocrit similarly in WT and eNOS-/- mice and showed a lower increase in hematocrit nNOS-/- mice. Erythroid colony assays from bone marrow cells were comparable in number from wild type, eNOS-/- and nNOS-/- mice at low EPO concentration. Colony number increased at high EPO concentration is seen only in cultures from bone marrow cells of wild type and eNOS-/- mice but not from nNOS-/- mice. Colony size with high EPO treatment also exhibited a marked increase in erythroid cultures from wild type and eNOS-/- mice but not from nNOS-/- mice. Bone marrow transplant from nNOS-/- mice into immunodeficient mice showed engraftment at comparable levels to WT bone marrow transplant. With EPO treatment, the increase in hematocrit was blunted in recipient mice that received with nNOS-/- donor marrow compared with recipient mice that received WT donor marrow. In erythroid cell cultures, addition of nNOS inhibitor resulted in decreased EPO dependent proliferation mediated in part by decreased EPO receptor expression, and decreased proliferation of hemin induced differentiating erythroid cells. Discussion: EPO treatment in mice and in corresponding cultures of bone marrow erythropoiesis suggest an intrinsic defect in erythropoietic response of nNOS-/- mice to high EPO stimulation. Transplantation of bone marrow from donor WT or nNOS-/- mice into recipient WT mice showed that EPO treatment post-transplant recapitulated the response of donor mice. Culture studies suggest nNOS regulation of EPO dependent erythroid cell proliferation, expression of EPO receptor and cell cycle associated genes, and AKT activation. These data provide evidence that nitric oxide modulates EPO dose dependent erythropoietic response.

Endothelial cell-specific loss of eNOS differentially affects endothelial function

The endothelium maintains and regulates vascular homeostasis mainly by balancing interplay between vasorelaxation and vasoconstriction via regulating Nitric Oxide (NO) availability. Endothelial nitric oxide synthase (eNOS) is one of three NOS isoforms that catalyses the synthesis of NO to regulate endothelial function. However, eNOS’s role in the regulation of endothelial function, such as cell proliferation and migration remain unclear. To gain a better understanding, we genetically knocked down eNOS in cultured endothelial cells using sieNOS and evaluated cell proliferation, migration and also tube forming potential in vitro. To our surprise, loss of eNOS significantly induced endothelial cell proliferation, which was associated with significant downregulation of both cell cycle inhibitor p21 and cell proliferation antigen Ki-67. Knockdown of eNOS induced cell migration but inhibited formation of tube-like structures in vitro. Mechanistically, loss of eNOS was associated with activation of MAPK/ERK and inhibition of PI3-K/AKT signaling pathway. On the contrary, pharmacologic inhibition of eNOS by inhibitors L-NAME or L-NMMA, inhibited cell proliferation. Genetic and pharmacologic inhibition of eNOS, both promoted endothelial cell migration but inhibited tube-forming potential. Our findings confirm that eNOS regulate endothelial function by inversely controlling endothelial cell proliferation and migration, and by directly regulating its tube-forming potential. Differential results obtained following pharmacologic versus genetic inhibition of eNOS indicates a more complex mechanism behind eNOS regulation and activity in endothelial cells, warranting further investigation.

Detecting Intestinal Goblet Cells of the Broadgilled Hagfish Eptatretus cirrhatus (Forster, 1801): A Confocal Microscopy Evaluation

Simple Summary

The intestinal epithelium of fish, similar to mammals, consists mainly of enterocytes and goblet cells. Goblet cells play a key role in the secretion of mucus, which, in addition to promoting the digestion of nutrients, is the first protective barrier against bacteria, viruses, and pathogens. Our study aims to evaluate the presence, localization, and co-localization of 5-HT, TLR2, iNOS, and Piscidin1 in goblet cells of the intestine of Eptatretus cirrhatus. The results obtained by confocal microscopy show, for the first time, the positivity of goblet cells to the antibodies tested, suggesting the involvement of these cells in the intestinal immunity of broadgilled hagfish.

Abstract

The fish intestine operates as a complicated interface between the organism and the environment, providing biological and mechanical protections as a result of a viscous layer of mucus released by goblet cells, which serves as a barrier against bacteria, viruses, and other pathogens, and contributes to the functions of the immune system. Therefore, goblet cells have a role in preserving the health of the body by secreting mucus and acting as sentinels. The ancient jawless fish broadgilled hagfish (Eptatretus cirrhatus, Forster, 1801) has a very basic digestive system because it lacks a stomach. By examining the presence, localization, and co-localization of 5-HT, TLR2, iNOS, and Piscidin1, this study intends to provide insight into the potential immune system contributions arranged by the gut goblet cells of broadgilled hagfish. Our results characterize intestinal goblet cells of broadgilled hagfish, for the first time, with the former antibodies, suggesting the hypothesis of conservation of the roles played by these cells also in primitive vertebrates. Moreover, this study deepens the knowledge about the still little-known immune system of hagfish.

Cancer-Induced Metabolic Rewiring of Tumor Endothelial Cells

Simple Summary

Angiogenesis, the formation of new blood vessels from preexisting ones, is a complex and demanding biological process that plays an important role in physiological, as well as pathological conditions, including cancer. During tumor growth, the induction of angiogenesis allows tumor cells to grow, invade, and metastasize. Recent evidence supports endothelial cell metabolism as a critical regulator of angiogenesis. However, whether and how tumor endothelial cells rewire their metabolism in cancer remains elusive. In this review, we discussed the metabolic signatures of tumor endothelial cells and their symbiotic, competitive, and mechanical metabolic interactions with tumor cells. We also discussed the recent works that may provide a rationale for attractive metabolic targets and strategies for developing specific therapies against tumor angiogenesis.

Abstract

Cancer is a leading cause of death worldwide. If left untreated, tumors tend to grow and spread uncontrolled until the patient dies. To support this growth, cancer cells need large amounts of nutrients and growth factors that are supplied and distributed to the tumor tissue by the vascular system. The aberrant tumor vasculature shows deep morphological, molecular, and metabolic differences compared to the blood vessels belonging to the non-malignant tissues (also referred as normal). A better understanding of the metabolic mechanisms driving the differences between normal and tumor vasculature will allow the designing of new drugs with a higher specificity of action and fewer side effects to target tumors and improve a patient’s life expectancy. In this review, we aim to summarize the main features of tumor endothelial cells (TECs) and shed light on the critical metabolic pathways that characterize these cells. A better understanding of such mechanisms will help to design innovative therapeutic strategies in healthy and diseased angiogenesis.

A novel soluble epoxide hydrolase vaccine protects murine cardiac muscle against myocardial infarction

Myocardial infarction is still a life-threatening disease, even though its prognosis has been improved through the development of percutaneous coronary intervention and pharmacotherapy. In addition, heart failure due to remodeling after myocardial infarction requires lifelong management. The aim of this study was to develop a novel treatment suppressing the myocardial damage done by myocardial infarction. We focused on inhibition of soluble epoxide hydrolase to prolong the activation of epoxyeicosatrienoic acids, which have vasodilatory and anti-inflammatory properties. We successfully made a new vaccine to inactivate soluble epoxide hydrolase, and we have evaluated the effect of the vaccine in a rat myocardial infarction model. In the vaccinated group, the ischemic area was significantly reduced, and cardiac function was significantly preserved. Vaccine treatment clearly increased microvessels in the border area and suppressed fibrosis secondary to myocardial infarction. This soluble epoxide hydrolase vaccine is a novel treatment for improving cardiac function following myocardial infarction.

Endothelial Cell Distribution After Flow Exposure With Two Stent Struts Placed in Different Angles

Stent implantation has been a primary treatment for stenosis and other intravascular diseases. However, the struts expansion procedure might cause endothelium lesion and the structure of the struts could disturb the blood flow environment near the wall of the blood vessel. These changes could damage the vascular innermost endothelial cell (EC) layer and pose risks of restenosis and post-deployment thrombosis. This research aims to investigate the effect of flow alterations on EC distribution in the presence of gap between two struts within the parallel flow chamber. To study how the gap presence impacts EC migration and the endothelialization effect on the surface of the struts, two struts were placed with specific orientations and positions on the EC layer in the flow chamber. After a 24-h exposure under wall shear stress (WSS), we observed the EC distribution conditons especially in the gap area. We also conducted computational fluid dynamics (CFD) simulations to calculate the WSS distribution. High EC-concentration areas on the bottom plate corresponded to the high WSS by the presence of gap between the two struts. To find the relation between the WSS and EC distributions on the fluorescence images, WSS condition by CFD simulation could be helpful for the EC distribution. The endothelialization rate, represented by EC density, on the downstream sides of both struts was higher than that on the upstream sides. These observations were made in the flow recirculation at the gap area between two struts. On two side surfaces between the gaps, meaning the downstream at the first and the upstream at the second struts, EC density differences on the downstream surfaces of the first strut were higher than on the upstream surfaces of the second strut. Finally, EC density varied along the struts when the struts were placed at tilted angles. These results indicate that, by the presence of gap between the struts, ECs distribution could be predicted in both perpendicular and tiled positions. And tiled placement affect ECs distribution on the strut side surfaces.

eNOS controls angiogenic sprouting and retinal neovascularization through the regulation of endothelial cell polarity

The roles of nitric oxide (NO) and endothelial NO synthase (eNOS) in the regulation of angiogenesis are well documented. However, the involvement of eNOS in the sprouting of endothelial tip-cells at the vascular front during sprouting angiogenesis remains poorly defined. In this study, we show that downregulation of eNOS markedly inhibits VEGF-stimulated migration of endothelial cells but increases their polarization, as evidenced by the reorientation of the Golgi in migrating monolayers and by the fewer filopodia on tip cells at ends of sprouts in endothelial cell spheroids. The effect of eNOS inhibition on EC polarization was prevented in Par3-depleted cells. Importantly, downregulation of eNOS increased the expression of polarity genes, such as PARD3B, PARD6A, PARD6B, PKCΖ, TJP3, and CRB1 in endothelial cells. In retinas of eNOS knockout mice, vascular development is retarded with decreased vessel density and vascular branching. Furthermore, tip cells at the extremities of the vascular front have a marked reduction in the number of filopodia per cell and are more oriented. In a model of oxygen-induced retinopathy (OIR), eNOS deficient mice are protected during the initial vaso-obliterative phase, have reduced pathological neovascularization, and retinal endothelial tip cells have fewer filopodia. Single-cell RNA sequencing of endothelial cells from OIR retinas revealed enrichment of genes related to cell polarity in the endothelial tip-cell subtype of eNOS deficient mice. These results indicate that inhibition of eNOS alters the polarity program of endothelial cells, which increases cell polarization, regulates sprouting angiogenesis and normalizes pathological neovascularization during retinopathy.

Physical Gold Nanoparticle-Decorated Polyethylene Glycol-Hydroxyapatite Composites Guide Osteogenesis and Angiogenesis of Mesenchymal Stem Cells

In this study, polyethylene glycol (PEG) with hydroxyapatite (HA), with the incorporation of physical gold nanoparticles (AuNPs), was created and equipped through a surface coating technique in order to form PEG-HA-AuNP nanocomposites. The surface morphology and chemical composition were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), UV–Vis spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and contact angle assessment. The effects of PEG-HA-AuNP nanocomposites on the biocompatibility and biological activity of MC3T3-E1 osteoblast cells, endothelial cells (EC), macrophages (RAW 264.7), and human mesenchymal stem cells (MSCs), as well as the guiding of osteogenic differentiation, were estimated through the use of an in vitro assay. Moreover, the anti-inflammatory, biocompatibility, and endothelialization capacities were further assessed through in vivo evaluation. The PEG-HA-AuNP nanocomposites showed superior biological properties and biocompatibility capacity for cell behavior in both MC3T3-E1 cells and MSCs. These biological events surrounding the cells could be associated with the activation of adhesion, proliferation, migration, and differentiation processes on the PEG-HA-AuNP nanocomposites. Indeed, the induction of the osteogenic differentiation of MSCs by PEG-HA-AuNP nanocomposites and enhanced mineralization activity were also evidenced in this study. Moreover, from the in vivo assay, we further found that PEG-HA-AuNP nanocomposites not only facilitate the anti-immune response, as well as reducing CD86 expression, but also facilitate the endothelialization ability, as well as promoting CD31 expression, when implanted into rats subcutaneously for a period of 1 month. The current research illustrates the potential of PEG-HA-AuNP nanocomposites when used in combination with MSCs for the regeneration of bone tissue, with their nanotopography being employed as an applicable surface modification approach for the fabrication of biomaterials.

Molecular pathways underlying tissue injuries in the bladder with ketamine cystitis

Ketamine cystitis (KC) is a chronic bladder inflammation leading to urinary urgency, frequency, and pain. The pathogenesis of KC is complicated and involves multiple tissue injuries in the bladder. Recent studies indicated that urothelium disruption, lamina propria fibrosis and inflammation, microvascular injury, neuropathological alterations, and bladder smooth muscle (BSM) abnormalities all contribute to the pathogenesis of KC. Ketamine has been shown to induce these tissue injuries by regulating different signaling pathways. Ketamine can stimulate antiproliferative factor, adenosine triphosphate, and oxidative stress to disrupt urothelium. Lamina propria fibrosis and inflammation are associated with the activation of cyclooxygenase-2, nitric oxide synthase, immunoglobulin E, and transforming growth factor β1. Ketamine contributes to microvascular injury via the N-methyl-D aspartic receptor (NMDAR), and multiple inflammatory and angiogenic factors such as tumor necrosis factor α and vascular endothelial growth factor. For BSM abnormalities, ketamine can depress the protein kinase B, extracellular signal-regulated kinase, Cav1.2, and muscarinic receptor signaling. Elevated purinergic signaling also plays a role in BSM abnormalities. In addition, ketamine affects neuropathological alterations in the bladder by regulating NMDAR- and brain-derived neurotrophic factor-dependent signaling. Inflammatory cells also contribute to neuropathological changes via the secretion of chemical mediators. Clarifying the role and function of these signaling underlying tissue injuries in the bladder with KC can contribute to a better understanding of the pathophysiology of this disease and to the design of effective treatments for KC.

Regenerative medicine for radiation emergencies

Hiroshima University is a 'medical institution for tertiary radiation emergencies' and a 'medical support organization as a part of the International Atomic Emergency Agency Emergency Preparedness Response-Response and Assistance Network (IAEA EPR-RANET)'. To establish a system of regenerative medicine for radiation emergencies with treatment by implantation of various types of cells derived from induced pluripotent stem (iPS) cells, it is necessary to establish methods of defense against and treatment for radiation-induced damage from nuclear power plant accidents and nuclear terrorism. It is also necessary to develop cell therapy, cellular repair technology and regenerative biotechnology as regenerative medicine for radiation emergencies. Such applications have not been established yet. To develop a regenerative medical system, by using the existing one, for radiation emergencies, we will attempt to manage the cell-processing center to establish a safe and secured iPS cell bank for radiation medicine. By using this iPS cell bank as the central leverage, we will develop an education program for radiation emergency medicine and construct a network of regenerative medicine for radiation emergency medicine.

Estrogen-related receptor α is involved in angiogenesis and skeletal muscle revascularization in hindlimb ischemia

Skeletal muscle ischemia is a major consequence of peripheral arterial disease (PAD) or critical limb ischemia (CLI). Although therapeutic options for resolving muscle ischemia in PAD/CLI are limited, the issue is compounded by poor understanding of the mechanisms driving muscle vascularization. We found that nuclear receptor estrogen-related receptor alpha (ERRα) expression is induced in murine skeletal muscle by hindlimb ischemia (HLI), and in cultured myotubes by hypoxia, suggesting a potential role for ERRα in ischemic response. To test this, we generated skeletal muscle-specific ERRα transgenic (TG) mice. In these mice, ERRα drives myofiber type switch from glycolytic type IIB to oxidative type IIA/IIX myofibers, which are typically associated with more vascular supply in muscle. Indeed, RNA sequencing and functional enrichment analysis of TG muscle revealed that "paracrine angiogenesis" is the top-ranked transcriptional program activated by ERRα in the skeletal muscle. Immunohistochemistry and angiography showed that ERRα overexpression increases baseline capillarity, arterioles and non-leaky blood vessel formation in the skeletal muscles. Moreover, ERRα overexpression facilitates ischemic neo-angiogenesis and perfusion recovery in hindlimb musculature of mice subjected to HLI. Therefore, ERRα is a hypoxia inducible nuclear receptor that is involved in skeletal muscle angiogenesis and could be potentially targeted for treating PAD/CLI.

Therapeutic angiogenesis using zinc oxide nanoflowers for the treatment of hind limb ischemia in rat model

Critical limb ischemia (CLI) is considered as a severe type of peripheral artery diseases (PADs) which occurs due to the inadequate supply of blood to the limb extremities. CLI patients often suffer from extreme cramping pain, impaired wound healing, immobility, cardiovascular complications, amputation of the affected limb and even death. The conventional therapy for the treatment of CLI includes surgical revascularization as well as restoring angiogenesis using growth factor therapy. However, surgical revascularization is suitable for only a minor percentage of CLI patients and it is associated with high perioperative mortality rate. The use of growth factors is also limited in terms of their poor therapeutic angiogenesis potential as observed by the earlier clinical studies, which could be attributed to their poor bio-availability and non-specificity issues. Therefore, to outweigh the aforesaid disadvantages of the conventional strategies, there is an utmost need for the advancement of new alternative therapeutic biomaterials to treat CLI. Since past few decades, various research groups including ours have been involved in developing different pro-angiogenic nanomaterials. Among them, zinc oxide nanoflowers (ZONF), established in our laboratory, are considered as one of the potent nanoparticles to induce therapeutic angiogenesis. In our earlier studies, we have depicted that ZONF promote angiogenesis by inducing the formation of reactive oxygen species (ROS) and nitric oxide (NO) as well as activating Akt/MAPK/eNOS cell signaling pathways in the endothelial cells. Recently, we have also reported the therapeutic potential of ZONF to treat cerebral ischemia through their neuritogenic and neuroprotective properties, exploiting angio-neural cross talk. Considering the excellent pro-angiogenic properties of ZONF and importance of revascularization for the recovery of CLI, in this present study, we have comprehensively explored the therapeutic potential of ZONF in a rat hind limb ischemia model (established by ligating the femoral artery of hind limb), an animal model that mimics CLI in humans. The behavioural studies, laser Doppler perfusion imaging, histopathology, immunofluorescence as well as estimation of serum NO level depicted that the administration of ZONF could ameliorate the ischemic conditions in rats at a faster rate by promoting therapeutic angiogenesis to the ischemic sites. Altogether, the present study offers an alternative nanomedicine approach employing ZONF for the treatment of PADs.

Co-Culture of Primary Human Coronary Artery and Internal Thoracic Artery Endothelial Cells Results in Mutually Beneficial Paracrine Interactions

Although saphenous veins (SVs) are commonly used as conduits for coronary artery bypass grafting (CABG), internal thoracic artery (ITA) grafts have significantly higher long-term patency. As SVs and ITA endothelial cells (ECs) have a considerable level of heterogeneity, we suggested that synergistic paracrine interactions between CA and ITA ECs (HCAECs and HITAECs, respectively) may explain the increased resistance of ITA grafts and adjacent CAs to atherosclerosis and restenosis. In this study, we measured the gene and protein expression of the molecules responsible for endothelial homeostasis, pro-inflammatory response, and endothelial-to-mesenchymal transition in HCAECs co-cultured with either HITAECs or SV ECs (HSaVECs) for an ascending duration. Upon the co-culture, HCAECs and HITAECs showed augmented expression of endothelial nitric oxide synthase (eNOS) and reduced expression of endothelial-to-mesenchymal transition transcription factors Snail and Slug when compared to the HCAEC–HSaVEC model. HCAECs co-cultured with HITAECs demonstrated an upregulation of HES1, a master regulator of arterial specification, of which the expression was also exclusively induced in HSaVECs co-cultured with HCAECs, suggestive of their arterialisation. In addition, co-culture of HCAECs and HITAECs promoted the release of pro-angiogenic molecules. To conclude, co-culture of HCAECs and HITAECs results in reciprocal and beneficial paracrine interactions that might contribute to the better performance of ITA grafts upon CABG.

The importance of physiologic ischemia training in preventing the development of atherosclerosis: the role of endothelial progenitor cells in atherosclerotic rabbits

Objective

The aim of this study was to investigate the effects of physiologic ischemia training (PIT) on the proliferation of endothelial progenitor cells (EPCs) and the corresponding changes in the influencing factors in atherosclerotic rabbits, including vascular endothelial growth factor (VEGF) and nitric oxide (NO).

Materials and methods

Eighteen rabbits were assigned randomly to three groups: a high-fat diet (HD) group, an HD-with-training (HT) group, and a control group. Rabbits in the HD and HT groups were fed high-fat food and those in the HT group were administered PIT from the seventh week onward. Atherosclerotic plaques in the thoracic aorta were stained with Oil Red O and measured by Image-Pro Plus 6.0; VEGF expression was measured using an enzyme-linked immunosorbent assay and real-time PCR to determine both protein and mRNA levels. EPCs were counted using a fluorescence-activated cell sorter; NO in plasma was measured by the Griess reaction; and the levels of blood lipids were measured using a biochemical analyzer.

Results

More lipid-containing lesions were found in the HD group than in the HT group (P<0.01), whereas atherosclerotic plaques were not observed in the control group. In addition, the expression of VEGF, production of NO, and levels of blood lipids were consistent with the proportion of plaques. It is noteworthy that the proliferation of EPCs increased in the HT group throughout the 10 weeks, whereas those in the control and HD groups increased in the first 6 weeks and declined during the 10th week (P<0.01).

Conclusion

PIT may prevent the development of aortic atherosclerosis by promoting the proliferation of EPCs in atherosclerotic rabbits.

Estrogen Receptors and Estrogen-Induced Uterine Vasodilation in Pregnancy

Normal pregnancy is associated with dramatic increases in uterine blood flow to facilitate the bidirectional maternal–fetal exchanges of respiratory gases and to provide sole nutrient support for fetal growth and survival. The mechanism(s) underlying pregnancy-associated uterine vasodilation remain incompletely understood, but this is associated with elevated estrogens, which stimulate specific estrogen receptor (ER)-dependent vasodilator production in the uterine artery (UA). The classical ERs (ERα and ERβ) and the plasma-bound G protein-coupled ER (GPR30/GPER) are expressed in UA endothelial cells and smooth muscle cells, mediating the vasodilatory effects of estrogens through genomic and/or nongenomic pathways that are likely epigenetically modified. The activation of these three ERs by estrogens enhances the endothelial production of nitric oxide (NO), which has been shown to play a key role in uterine vasodilation during pregnancy. However, the local blockade of NO biosynthesis only partially attenuates estrogen-induced and pregnancy-associated uterine vasodilation, suggesting that mechanisms other than NO exist to mediate uterine vasodilation. In this review, we summarize the literature on the role of NO in ER-mediated mechanisms controlling estrogen-induced and pregnancy-associated uterine vasodilation and our recent work on a “new” UA vasodilator hydrogen sulfide (H₂S) that has dramatically changed our view of how estrogens regulate uterine vasodilation in pregnancy.

The Role of High-Density Lipoproteins in Endothelial Cell Metabolism and Diabetes-Impaired Angiogenesis

Diabetes mellitus affects millions of people worldwide and is associated with devastating vascular complications. A number of these complications, such as impaired wound healing and poor coronary collateral circulation, are characterised by impaired ischaemia-driven angiogenesis. There is increasing evidence that high-density lipoproteins (HDL) can rescue diabetes-impaired angiogenesis through a number of mechanisms, including the modulation of endothelial cell metabolic reprogramming. Endothelial cell metabolic reprogramming in response to tissue ischaemia is a driver of angiogenesis and is dysregulated by diabetes. Specifically, diabetes impairs pathways that allow endothelial cells to upregulate glycolysis in response to hypoxia adequately and impairs suppression of mitochondrial respiration. HDL rescues the impairment of the central hypoxia signalling pathway, which regulates these metabolic changes, and this may underpin several of its known pro-angiogenic effects. This review discusses the current understanding of endothelial cell metabolism and how diabetes leads to its dysregulation whilst examining the various positive effects of HDL on endothelial cell function.

Equine hydrallantois is associated with impaired angiogenesis in the placenta

INTRODUCTION

Hydrallantois is the excessive accumulation of fluid in the allantoic cavities during the last trimester of pregnancy, leading to abdominal wall hernias, cardiovascular shock, abortion, and dystocia. It has been postulated that hydrallantois is associated with structural and/or functional changes in the chorioallantoic membrane. In the present study, we hypothesized that angiogenesis is impaired in the hydrallantoic placenta.

METHOD

Capillary density in the hydrallantoic placenta was evaluated in the chorioallantois via immunohistochemistry for Von Willebrand Factor. Moreover, the expression of angiogenic genes was compared between equine hydrallantois and age-matched, normal placentas.

RESULTS

In the hydrallantoic samples, edema was the main pathological finding. The capillary density was significantly lower in the hydrallantoic samples than in normal placentas. The reduction in the number of vessels was associated with abnormal expression of a subset of angiogenic and hypoxia-associated genes including VEGF, VEGFR1, VEGFR2, ANGPT1, eNOS and HIF1A. We believe that the capillary density and the abnormal expression of angiogenic genes leads to tissue hypoxia (high expression of HIF1A) and edema. Finally, we identified a lower expression of genes associated with steroidogenic enzyme (CYP19A1) and estrogen receptor signaling (ESR2) in the hydrallantoic placenta.

DISCUSSION

Based on the presented data, we believe that formation of edema is due to disrupted vascular development (low number of capillaries) and hypoxia in the hydrallantoic placenta. The edema leads to further hypoxia and consequently, causes an increase in vessel permeability which leads to a gradual increase in interstitial fluid accumulation, resulting in an insufficient transplacental exchange rate and accumulation of fluid in the allantoic cavity.

CCL28-induced CCR10/eNOS interaction in angiogenesis and skin wound healing

Chemokines and their receptors play important roles in vascular homeostasis, development, and angiogenesis. Little is known regarding the molecular signaling mechanisms activated by CCL28 chemokine via its primary receptor CCR10 in endothelial cells (ECs). Here, we test the hypothesis that CCL28/CCR10 signaling plays an important role in regulating skin wound angiogenesis through endothelial nitric oxide synthase (eNOS)-dependent Src, PI3K, and MAPK signaling. We observed nitric oxide (NO) production in human primary ECs stimulated with exogenous CCL28, which also induced direct binding of CCR10 and eNOS resulting in inhibition of eNOS activity. Knockdown of CCR10 with siRNA lead to reduced eNOS expression and tube formation suggesting the involvement of CCR10 in EC angiogenesis. Based on this interaction, we engineered a myristoylated 7 amino acid CCR10-binding domain (Myr-CBD7) peptide and showed that this can block eNOS interaction with CCR10, but not with calmodulin, resulting in upregulation of eNOS activity. Importantly, topical administration of Myr-CBD7 peptide on mouse dermal wounds not only blocked CCR10-eNOS interaction, but also enhanced expression of eNOS, CD31, and IL-4 with reduction of CCL28 and IL-6 levels associated with improved wound healing. These results point to a potential therapeutic strategy to upregulate NO bioavailability, enhance angiogenesis, and improve wound healing by disrupting CCL28-activated CCR10-eNOS interaction.

Revascularization and limb salvage following critical limb ischemia by nanoceria-induced Ref-1/APE1-dependent angiogenesis

In critical limb ischemia (CLI), overproduction of reactive oxygen species (ROS) and impairment of neovascularization contribute to muscle damage and limb loss. Cerium oxide nanoparticles (CNP, or 'nanoceria') possess oxygen-modulating properties which have shown therapeutic utility in various disease models. Here we show that CNP exhibit pro-angiogenic activity in a mouse hindlimb ischemia model, and investigate the molecular mechanism underlying the pro-angiogenic effect. CNP were injected into a ligated region of a femoral artery, and tissue reperfusion and hindlimb salvage were monitored for 3 weeks. Tissue analysis revealed stimulation of pro-angiogenic markers, maturation of blood vessels, and remodeling of muscle tissue following CNP administration. At a dose of 0.6 mg CNP, mice showed reperfusion of blood vessels in the hindlimb and a high rate of limb salvage (71%, n = 7), while all untreated mice (n = 7) suffered foot necrosis or limb loss. In vitro, CNP promoted endothelial cell tubule formation via the Ref-1/APE1 signaling pathway, and the involvement of this pathway in the CNP response was confirmed in vivo using immunocompetent and immunodeficient mice and by siRNA knockdown of APE1. These results demonstrate that CNP provide an effective treatment of CLI with excessive ROS by scavenging ROS to improve endothelial survival and by inducing Ref-1/APE1-dependent angiogenesis to revascularize an ischemic limb.

Astragaloside IV protects against diabetic nephropathy via activating eNOS in streptozotocin diabetes-induced rats

BACKGROUND

Astragaloside IV (AS-IV) was reported to play a role in improving diabetic nephropathy (DN), however, the underlying mechanisms still remain unclear. The aim of the present study is to investigate whether AS-IV ameliorates DN via the regulation of endothelial nitric oxide synthase (eNOS).

METHODS

DN model was induced in Sprague-Dawley (SD) male rats by intraperitoneal injection of 65 mg/kg streptozotocin (STZ). Rats in the AS-IV treatment group were orally gavaged with 5 mg/kg/day or 10 mg/kg/day AS-IV for eight consecutive weeks. Body weight, blood glucose, blood urea nitrogen (BUN), Serum creatinine (Scr), proteinuria and Glycosylated hemoglobin (HbA1c) levels were measured. Hematoxylin-Eosin (HE) and Periodic Acid-Schiff (PAS) staining were used to detect the renal pathology. The apoptosis status of glomerular cells was measured by TUNEL assay. The phosphorylation and acetylation of eNOS were detected by western blot. The effects of AS-IV on high-glucose (HG)-induced apoptosis and eNOS activity were also investigated in human renal glomerular endothelial cells (HRGECs) in vitro.

RESULTS

Treatment with AS-IV apparently reduced DN symptoms in diabetic rats, as evidenced by reduced BUN, Scr, proteinuria, HbA1c levels and expanding mesangial matrix. AS-IV treatment also promoted the synthesis of nitric oxide (NO) in serum and renal tissues and ameliorated the phosphorylation of eNOS at Ser 1177 with decreased eNOS acetylation. Moreover, HG-induced dysfunction of HRGECs including increased cell permeability and apoptosis, impaired eNOS phosphorylation at Ser 1177, and decreased NO production, were all reversed by AS-IV treatment.

CONCLUSIONS

These novel findings suggest that AS-IV ameliorates functional abnormalities of DN through inhibiting acetylation of eNOS and activating its phosphorylation at Ser 1177. AS-IV could be served as a potential therapeutic drug for DN.

The Regulatory Roles of Non-coding RNAs in Angiogenesis and Neovascularization From an Epigenetic Perspective

Angiogenesis is a crucial process for organ morphogenesis and growth during development, and it is especially relevant during the repair of wounded tissue in adults. It is coordinated by an equilibrium of pro- and anti-angiogenic factors; nevertheless, when affected, it promotes several diseases. Lately, a growing body of evidence is indicating that non-coding RNAs (ncRNAs), such as miRNAs, circRNAs, and lncRNAs, play critical roles in angiogenesis. These ncRNAs can act in cis or trans and alter gene transcription by several mechanisms including epigenetic processes. In the following pages, we will discuss the functions of ncRNAs in the regulation of angiogenesis and neovascularization, both in normal and disease contexts, from an epigenetic perspective. Additionally, we will describe the contribution of Next-Generation Sequencing (NGS) techniques to the discovery and understanding of the role of ncRNAs in angiogenesis.

Bioinorganics and Wound Healing

Wound dressings and the healing enhancement (increasing healing speed and quality) are two components of wound care that lead to a proper healing. Wound care today consists mostly of providing an optimal environment by removing waste and necrotic tissues from a wound, preventing infections, and keeping the wounds adequately moist. This is however often not enough to re-establish the healing process in chronic wounds; with the local disruption of vascularization, the local environment is lacking oxygen, nutrients, and has a modified ionic and molecular concentration which limits the healing process. This disruption may affect cellular ionic pumps, energy production, chemotaxis, etc., and will affect the healing process. Biomaterials for wound healing range from simple absorbents to sophisticated bioactive delivery vehicles. Often placing a material in or on a wound can change multiple parameters such as pH, ionic concentration, and osmolarity, and it can be challenging to pinpoint key mechanism of action. This article reviews the literature of several inorganic ions and molecules and their potential effects on the different wound healing phases and their use in new wound dressings.

Transplantation of Human Umbilical Cord Blood-Derived Cellular Fraction Improves Left Ventricular Function and Remodeling After Myocardial Ischemia/Reperfusion

Rationale: Human umbilical cord blood (hUCB) contains diverse populations of stem/progenitor cells. Whether hUCB-derived nonhematopoietic cells would induce cardiac repair remains unknown. Objective: To examine whether intramyocardial transplantation of hUCB-derived CD45^-Lin^- nonhematopoietic cellular fraction after a reperfused myocardial infarction in nonimmunosuppressed rats would improve cardiac function and ameliorate ventricular remodeling. Methods and Results: Nonhematopoietic CD45^-Lin^- cells were isolated from hUCB. Flow cytometry and quantitative polymerase chain reaction were used to characterize this subpopulation. Age-matched male Fischer 344 rats underwent a 30-minute coronary occlusion followed by reperfusion and 48 hours later received intramyocardial injection of vehicle or hUCB CD45^-Lin^- cells. After 35 days, compared with vehicle-treated rats, CD45^-Lin^- cell-treated rats exhibited improved left ventricular function, blunted left ventricular hypertrophy, greater preservation of viable myocardium in the infarct zone, and superior left ventricular remodeling. Mechanistically, hUCB CD45^-Lin^- cell injection favorably modulated molecular pathways regulating myocardial fibrosis, cardiomyocyte apoptosis, angiogenesis, and inflammation in postinfarct ventricular myocardium. Rare persistent transplanted human cells could be detected at both 4 and 35 days after myocardial infarction. Conclusions: Transplantation of hUCB-derived CD45^-Lin^- nonhematopoietic cellular subfraction after a reperfused myocardial infarction in nonimmunosuppressed rats ameliorates left ventricular dysfunction and improves remodeling via favorable paracrine modulation of molecular pathways. These findings with human cells in a clinically relevant model of myocardial ischemia/reperfusion in immunocompetent animals may have significant translational implications.Visual Overview: An online visual overview is available for this article.

Narciclasine inhibits angiogenic processes by activation of Rho kinase and by downregulation of the VEGF receptor 2

The process of angiogenesis is involved in several pathological conditions, such as tumor growth or age-related macular degeneration. Although the available anti-angiogenic drugs have improved the therapy of these diseases, major drawbacks, such as unwanted side effects and resistances, still exist. Consequently, the search for new anti-angiogenic substances is still ongoing. Narciclasine, a plant alkaloid from different members of the Amaryllidaceae family, has extensively been characterized as anti-tumor compound. Beyond the field of cancer, the compound has recently been shown to possess anti-inflammatory properties. Surprisingly, potential actions of narciclasine on endothelial cells in the context of angiogenesis have been neglected so far. Thus, we aimed to analyze the effects of narciclasine on angiogenic processes in vitro and in vivo and to elucidate the underlying mechanism. Narciclasine (100-300 nM) effectively inhibited the proliferation, undirected and directed migration, network formation and angiogenic sprouting of human primary endothelial cells. Moreover, narciclasine (1 mg/kg/day) strongly reduced the VEGF-triggered angiogenesis in vivo (Matrigel plug assay in mice). Narciclasine mediated its anti-angiogenic effects in part by a RhoA-independent activation of the Rho kinase ROCK. Most importantly, however, the compound reduced the de novo protein synthesis in endothelial cells by approx. 50% without exhibiting considerable cytotoxic effects. As a consequence, narciclasine diminished the presence of proteins with a short half-life, such as the VEGF receptor 2, which is the basis for its anti-angiogenic effects. Taken together, our study highlights narciclasine as an interesting anti-angiogenic compound that is worth to be further evaluated in preclinical studies.

Promotion of angiogenesis by M13 phage and RGD peptide in vitro and in vivo

One of the most important goals of regenerative medicines is to generate alternative tissues with a developed vascular network. Endothelial cells are the most important cell type required in angiogenesis process, contributing to the blood vessels formation. The stimulation of endothelial cells to initiate angiogenesis requires appropriate extrinsic signals. The aim of this study was to evaluate the effects of M13 phage along with RGD peptide motif on in vitro and in vivo vascularization. The obtained results demonstrated the increased cellular proliferation, HUVECs migration, cells altered morphology, and cells attachment to M13 phage-RGD coated surface. In addition, the expression of Vascular Endothelial Growth Factor A (VEGF-A), VEGF Receptors 2 and 3, Matrix Metalloproteinase 9 (MMP9), and epithelial nitric oxide synthase (eNOS) transcripts were significantly upregulated due to the HUVECs culturing on M13 phage-RGD coated surface. Furthermore, VEGF protein secretion, nitric oxide, and reactive oxygen species (ROS) production were significantly increased in cells cultured on M13 phage-RGD coated surface.

Therapeutic strategies for enhancing angiogenesis in wound healing

The enhancement of wound healing has been a goal of medical practitioners for thousands of years. The development of chronic, non-healing wounds is a persistent medical problem that drives patient morbidity and increases healthcare costs. A key aspect of many non-healing wounds is the reduced presence of vessel growth through the process of angiogenesis. This review surveys the creation of new treatments for healing cutaneous wounds through therapeutic angiogenesis. In particular, we discuss the challenges and advancement that have been made in delivering biologic, pharmaceutical and cell-based therapies as enhancers of wound vascularity and healing.

Review of the Current Basic Science Strategies to Treat Critical Limb Ischemia

Critical limb ischemia (CLI) is a highly morbid disease with many patients considered poor surgical candidates. The lack of treatment options for CLI has driven interest in developing molecular therapies within recent years. Through these translational medicine studies in CLI, much has been learned about the pathophysiology of the disease. Here, we present an overview of the macrovascular and microvascular changes that lead to the development of CLI, including impairment of angiogenesis, vasculogenesis, and arteriogenesis. We summarize the randomized clinical controlled trials that have used molecular therapies in CLI, and discuss the novel imaging modalities being developed to assess the efficacy of these therapies.

KC21 Peptide Inhibits Angiogenesis and Attenuates Hypoxia-Induced Retinopathy

Desmogleins (Dsg2) are the major components of desmosomes. Dsg2 has five extracellular tandem cadherin domains (EC1-EC5) for cell-cell interaction. We had previously confirmed the Dsg2 antibody and its epitope (named KC21) derived from EC2 domain suppressing epithelial-mesenchymal transition and invasion in human cancer cell lines. Here, we screened six peptide fragments derived from EC2 domain and found that KR20, the parental peptide of KC21, was the most potent one on suppressing endothelial colony-forming cell (ECFC) tube-like structure formation. KC21 peptide also attenuated migration but did not disrupt viability and proliferation of ECFCs, consistent with the function to inhibit VEGF-mediated activation of p38 MAPK but not AKT and ERK. Animal studies showed that KC21 peptides suppressed capillary growth in Matrigel implant assay and inhibited oxygen-induced retinal neovascularization. The effects were comparable to bevacizumab (Bev). In conclusion, KC21 peptide is an angiogenic inhibitor potentially useful for treating angiogenesis-related diseases.

Associations between fetal size, sex and placental angiogenesis in the pig

Inadequate fetal growth cannot be remedied postnatally, leading to severe consequences for neonatal and adult development. It is hypothesized that growth restriction occurs due to inadequate placental vascularization. This study investigated the relationship between porcine fetal size, sex, and placental angiogenesis at multiple gestational days (GD). Placental samples supplying the lightest and closest to mean litter weight (CTMLW), male and female Large White X Landrace fetuses were obtained at GD30, 45, 60, and 90. Immunohistochemistry revealed increased chorioallantoic membrane CD31 staining in placentas supplying the lightest compared to those supplying the CTMLW fetuses at GD60. At GD90, placentas supplying the lightest fetuses had decreased CD31 staining in the chorioallantoic membrane compared to those supplying the CTMLW fetuses. The mRNA expression of six candidate genes with central roles at the feto-maternal interface increased with advancing gestation. At GD60, ACP5 expression was increased in placentas supplying the lightest compared to the CTMLW fetuses. At GD45, CD31 expression was decreased in placentas supplying the lightest compared to the CTMLW fetuses. In contrast, CD31 expression was increased in placentas supplying the lightest compared the CTMLW fetuses at GD60. In vitro endothelial cell branching assays demonstrated that placentas supplying the lightest and male fetuses impaired endothelial cell branching compared to placentas from the CTMLW (GD45 and 60) and female fetuses (GD60), respectively. This study has highlighted that placentas supplying the lightest and male fetuses have impaired angiogenesis. Importantly, the relationship between fetal size, sex, and placental vascularity is dynamic and dependent upon the GD investigated.

Platelet-derived growth factor-AA is a substantial factor in the ability of adipose-derived stem cells and endothelial progenitor cells to enhance wound healing

Nonhealing wounds with various forms of complications have been a major challenge for patients with different diseases, and few data are available regarding the clinical significance of platelet-derived growth factor-AA (PDGF-AA) in the enhanced wound healing with stem cells, and the precise molecular mechanism remains unclear. The study aims to investigate the role of PDGF-AA in adipose-derived stem cells (ASCs) and endothelial progenitor cells (EPCs) enhancing wound healing. In this study, ASCs and EPCs were applied to treat wounds in an animal wound model with a wound-healing assay. We knocked down PDGF-AA expression in ASCs using the PDGF-AA short hairpin RNA technique and investigated the related molecular mechanism. The wound model and wound-healing assay of the study showed that transplantation of ASCs could enhance wound healing. The results showed that the PDGF-AA knockdown ASC group had much less improvement of wound healing than other groups treated with wild-type ASCs in wound tissues. The regulation of PDGF-AA in ASCs may contribute to improve wound healing through the PI3K/Akt/eNOS signaling pathway. The data indicated that PDGF-AA might play a vital role in ASCs and EPCs enhancing wound healing, possibly by its effects on angiogenesis. It would be a potential approach using PDGF-AA for clinical treatment of chronic wounds.-Wu, L.-W., Chen, W.-L., Huang, S.-M., Chan, J. Y.-H. Platelet-derived growth factor AA is a substantial factor in the ability of adipose-derived stem cells and endothelial progenitor cells to enhance wound healing.

cGMP Signaling and Vascular Smooth Muscle Cell Plasticity

Cyclic GMP regulates multiple cell types and functions of the cardiovascular system. This review summarizes the effects of cGMP on the growth and survival of vascular smooth muscle cells (VSMCs), which display remarkable phenotypic plasticity during the development of vascular diseases, such as atherosclerosis. Recent studies have shown that VSMCs contribute to the development of atherosclerotic plaques by clonal expansion and transdifferentiation to macrophage-like cells. VSMCs express a variety of cGMP generators and effectors, including NO-sensitive guanylyl cyclase (NO-GC) and cGMP-dependent protein kinase type I (cGKI), respectively. According to the traditional view, cGMP inhibits VSMC proliferation, but this concept has been challenged by recent findings supporting a stimulatory effect of the NO-cGMP-cGKI axis on VSMC growth. Here, we summarize the relevant studies with a focus on VSMC growth regulation by the NO-cGMP-cGKI pathway in cultured VSMCs and mouse models of atherosclerosis, restenosis, and angiogenesis. We discuss potential reasons for inconsistent results, such as the use of genetic versus pharmacological approaches and primary versus subcultured cells. We also explore how modern methods for cGMP imaging and cell tracking could help to improve our understanding of cGMP’s role in vascular plasticity. We present a revised model proposing that cGMP promotes phenotypic switching of contractile VSMCs to VSMC-derived plaque cells in atherosclerotic lesions. Regulation of vascular remodeling by cGMP is not only an interesting new therapeutic strategy, but could also result in side effects of clinically used cGMP-elevating drugs.

TGF-β1/CD105 signaling controls vascular network formation within growth factor sequestering hyaluronic acid hydrogels

Cell-based strategies for the treatment of ischemic diseases are at the forefront of tissue engineering and regenerative medicine. Cell therapies purportedly can play a key role in the neovascularization of ischemic tissue; however, low survival and poor cell engraftment with the host vasculature following implantation limits their potential to treat ischemic diseases. To overcome these limitations, we previously developed a growth factor sequestering hyaluronic acid (HyA)-based hydrogel that enhanced transplanted mouse cardiosphere-derived cell survival and formation of vasculature that anastomosed with host vessels. In this work, we examined the mechanism by which HyA hydrogels presenting transforming growth factor beta-1 (TGF-β1) promoted proliferation of more clinically relevant human cardiosphere-derived cells (hCDC), and their formation of vascular-like networks in vitro. We observed hCDC proliferation and enhanced formation of vascular-like networks occurred in the presence of TGF-β1. Furthermore, production of nitric oxide (NO), VEGF, and a host of angiogenic factors were increased in the presence of TGF-β1. This response was dependent on the co-activity of CD105 (Endoglin) with the TGF-βR2 receptor, demonstrating its role in the process of angiogenic differentiation and vascular organization of hCDC. These results demonstrated that hCDC form vascular-like networks in vitro, and that the induction of vascular networks by hCDC within growth factor sequestering HyA hydrogels was mediated by TGF-β1/CD105 signaling.

Sildenafil improves blood perfusion in steroid-induced avascular necrosis of femoral head in rabbits via a protein kinase G-dependent mechanism

Objective

The aim of the study were to evaluate the effect of sildenafil against avascular necrosis of femoral head (ANFH) in a rabbit model, and to study the role of protein kinase G (PKG) pathway and vascular endothelial growth factor (VEGF) in ANFH.

Methods

Three weeks after inducing ANFH with methylprednisolone injection, 45 female adult New Zealand white rabbits were divided into three groups and treated as follows: group SI received daily intraperitoneal sildenafil with a dose of 10 mg/kg per day; group SD received daily sildenafil identically to group SI plus auricular vein injection DT3 (a specific PKG inhibitor); group NS received only normal saline. The blood perfusion function in the femoral head was measured by perfusion MRI and ink artery infusion. Bilateral femora heads were examined histopathologically for the presence of osteonecrosis; VEGF of tissue was examined by Western blot analysis; cGMP level and PKG activity were also measured.

Results

The incidence of ANFH in SI group was significantly lower than that observed in NS and SD groups (p < 0.05). VEGF in SI group was increased compared to NS group. cGMP level and PKG activity were also significantly different between NS and SI group (p < 0.05). However, these effects of sildenafil in SD group were all markedly inhibited by the administration of DT3 compared to SI group.

Conclusion

Sildenafil appear to increase the perfusion of femoral head by up-regulating VEGF through PKG pathway. The increased perfusion of femoral head could prevent ANFH.