Beyond endothelial cells: Vascular endothelial growth factors in heart, vascular anomalies and placenta

Involvement of mitochondrial dynamics and mitophagy in diabetic endothelial dysfunction and cardiac microvascular injury

Endothelial cells (ECs), found in the innermost layer of blood vessels, are crucial for maintaining the structure and function of coronary microcirculation. Dysregulated coronary microcirculation poses a fundamental challenge in diabetes-related myocardial microvascular injury, impacting myocardial blood perfusion, thrombogenesis, and inflammation. Extensive research aims to understand the mechanistic connection and functional relationship between cardiac EC dysfunction and the development, diagnosis, and treatment of diabetes-related myocardial microvascular injury. Despite the low mitochondrial content in ECs, mitochondria act as sensors of environmental and cellular stress, influencing EC viability, structure, and function. Mitochondrial dynamics and mitophagy play a vital role in orchestrating mitochondrial responses to various stressors by regulating morphology, localization, and degradation. Impaired mitochondrial dynamics or reduced mitophagy is associated with EC dysfunction, serving as a potential molecular basis and promising therapeutic target for diabetes-related myocardial microvascular injury. This review introduces newly recognized mechanisms of damaged coronary microvasculature in diabetes-related microvascular injury and provides updated insights into the molecular aspects of mitochondrial dynamics and mitophagy. Additionally, novel targeted therapeutic approaches against diabetes-related microvascular injury or endothelial dysfunction, focusing on mitochondrial fission and mitophagy in endothelial cells, are summarized.

Transcriptomics Provides Novel Insights into the Regulatory Mechanism of IncRNA HIF1 A-AS1 on Vascular Smooth Muscle Cells

INTRODUCTION

Thoracic aortic aneurysm is a potentially fatal disease with a strong genetic contribution. The dysfunction of vascular smooth muscle cells (VSMCs) contributes to the formation of this aneurysm. Although previous studies suggested that long non-coding ribonucleic acid (RNA) hypoxia inducible factor 1 α-antisense RNA 1 (HIF1A-AS1) exerted a vital role in the progression and pathogenesis of thoracic aortic aneurysm, we managed to find a new regulatory mechanism of HIF1A-AS1 in VSMCs via transcriptomics.

METHODS

Cell viability was detected by the cell counting kit-8 assay. Cell apoptosis was assessed by Annexin V-fluorescein isothiocyanate/propidium iodide double staining. Transwell migration assay and wound healing assay were performed to check the migration ability of HIF1A-AS1 on VSMCs. The NextSeq XTen system (Illumina) was used to collect RNA sequencing data. Lastly, reverse transcription-quantitative polymerase chain reaction confirmed the veracity and reliability of RNA-sequencing results.

RESULTS

We observed that overexpressing HIF1A-AS1 successfully promoted apoptosis, significantly altered cell cycle distribution, and greatly attenuated migration in VSMCs, further highlighting the robust promoting effects of HIF1A-AS1 to thoracic aortic aneurysm. Moreover, transcriptomics was implemented to uncover its underlying mechanism. A total of 175 differently expressed genes were identified, with some of them enriched in apoptosis, migration, and cell cycle-related pathways. Intriguingly, some differently expressed genes were noted in vascular development or coagulation function pathways.

CONCLUSION

We suggest that HIF1A-AS1 mediated the progression of thoracic aortic aneurysm by not only regulating the function of VSMCs, but also altering vascular development or coagulation function.

Role of Angiopoietic Coronary Endothelial Dysfunction in the Pathogenesis of Ischemic Cardiomyopathy

BACKGROUND

The angiopoietic endothelial dysfunction in ischemic cardiomyopathy (ICMP) remains unexplored.

AIM

The identification of the imbalance of endothelial dysfunction mediators and the number of endothelial progenitor (EPC) and desquamated (EDC) cells in patients with coronary heart disease (CHD) with and without ICMP.

METHODS

A total of 87 patients (47 with ICMP and 40 without ICMP) were observed. The content of EPCs (CD14⁺CD34⁺VEGFR2⁺) in vein blood and EDCs (CD45^-CD146⁺) in the blood from the coronary sinus and cubital vein was determined by flow cytometry. The contents of HIF-1α and HIF-2α in vein blood as well as that of ADMA and endothelin-1 in sinus plasma and angiopoietin-2, MMP-9 and galectin-3 in both samples were assessed using ELISA, and VEGF, PDGF, SDF-1 and MCP-1 contents using immunofluorescence.

RESULTS

ADMA and endothelin-1 levels in the sinus blood were comparable between the patient groups; a deficiency of HIF-1α and excess of HIF-2α were detected in the vein blood of ICMP patients. The EDC content in the vein blood increased in CHD patients regardless of ICMP, and the concentrations of VEGF-A, VEGF-B, PDGF, MCP-1, angiopoietin-2, and MMP-9 were normal. In ICMP patients, vein blood was characterized by an excess of galectin-3 and sinus blood by an excess of EDCs, angiopoietin-2, MMP-9 and galectin-3.

CONCLUSION

ICMP is accompanied by angiopoietic endothelial dysfunction.

Value of 3D ultrasound flow imaging combined with serum AFP, β-hCG, sFlt-1 and CK in the diagnosis of placenta accreta

PURPOSE

To analyze the diagnostic value of placenta three-dimensional (3D) energy blood flow parameters combined with maternal serum AFP, β-hCG, sFlt-1 and CK levels for PA.

METHODS

30 pregnant women with PA and 30 pregnant women with normal placenta were randomly selected in the Affiliated Maternal and Child Health Hospital of Nantong University from January 2021 to December 2021. Thereafter, the 3D energy ultrasound was applied to detect the placenta VI, FI and VFI. Moreover, the diagnostic value of different parameters combined with serum AFP, β-hCG, sFlt-1 and CK levels for PA was analyzed.

RESULTS

Multivariate analysis results indicated that, gravidity > 2 and with/without placenta previa were the independent risk factors for PA (P < 0.05). In PA group, the AFP, β-hCG, CK, placenta VI, FI and VFI values were higher than those in non-PA group, while sFlt-1 was apparently lower than that in non-PA group. With the increase in PA degree, the serum AFP, β-hCG and CK levels increased. Meanwhile, serum sFlt-1 level was negatively correlated with PA degree. Serum AFP, β-hCG, sFlt-1, CK and placenta VFI showed prediction potency for PA, and their combined detection attained the optimal diagnostic value for predicting PA. ROC curve analysis suggested that, serum AFP, β-hCG, sFlt-1, CK and 3D ultrasound VFI value had the greatest AUC values in predicting PA, which might provide reference for the clinical diagnosis and disease evaluation of PA. Conclusion Serum AFP, β-hCG, sFlt-1, CK and placental VFI can increase the consistency in the diagnosis of PA. Serum markers combined with 3D ultrasound blood flow imaging can improve the sensitivity and specificity of prenatal diagnosis of PA, which provides an important reference for clinical diagnosis and treatment.

Effect of plasma-derived extracellular vesicles on angiogenesis and the ensuing proliferative diabetic retinopathy through a miR-30b-dependent mechanism

BACKGROUND/PURPOSE

Proliferative diabetic retinopathy (PDR) is a major diabetic microvascular complication, characterized by pathological angiogenesis. This study sets out to investigate the potential molecular mechanism in the angiogenesis during PDR.

METHODS

The expression of microRNA-30b (miR-30b) was quantified in a streptozotocin (STZ)-induced mouse model of PDR. The binding affinity between SIRT1 and miR-30b was then identified and validated. After transduction with In-miR-30b or combined with sh-SIRT1, high-glucose (HG)-induced retinal microvascular endothelial cells (RMECs) were co-cultured with extracellular vesicles (EVs) derived from the plasma of PDR mice (plasma-EVs). The proliferation and angiogenesis of RMECs were then detected in vitro.

RESULTS

miR-30b expression was upregulated in the retinal tissue of PDR mice. SIRT1 was a target gene of miR-30b and under the negative regulation by miR-30b in RMECs. In contrast, inhibition of miR-30b resulted in elevated SIRT1 expression, thus alleviating the angiogenesis of RMECs. miR-30b was enriched in the plasma-EVs and could be delivered to RMECs, in which miR-30b exerted pro-angiogenic effects. Furthermore, inhibition of miR-30b arrested the progression of PDR in mice by promoting the expression of SIRT1.

CONCLUSION

Collectively, the present study pinpointed the involvement of miR-30b delivered by plasma-EVs in PDR angiogenesis, thus laying the basis for the development of novel therapeutic targets for the treatment of PDR.

Angiotensin Receptor Blocker and Neprilysin Inhibitor Suppresses Cardiac Dysfunction by Accelerating Myocardial Angiogenesis in Apolipoprotein E-Knockout Mice Fed a High-Fat Diet

Materials and Methods

Male apolipoprotein E-knockout mice fed a high-fat diet were divided into control (CTL), valsartan (30 mg/kg) (VAL), sacubitril (30 mg/kg) (SAC), and valsartan plus sacubitril (30 mg/kg each) (VAL/SAC) groups after 4 weeks of prefeeding and were subsequently treated for 12 weeks.

Results

The VAL/SAC group exhibited significantly higher serum brain natriuretic peptide levels; more subtle changes in left ventricular systolic diameter, fractional shortening, and ejection fraction, and significantly higher expression levels of natriuretic peptide precursor B and markers of angiogenesis, including clusters of differentiation 34, vascular endothelial growth factor A, and monocyte chemotactic protein 1, than the CTL group.

Conclusions

Valsartan plus sacubitril preserved left ventricular systolic function in apolipoprotein E-knockout mice fed a high-fat diet. This result suggests that myocardial angiogenic factors induced by ARNI might provide cardioprotective effects.

Association of Systemic or Intravitreal Antivascular Endothelial Growth Factor (Anti-VEGF) and Impaired Wound Healing in Pediatric Patients: Collagen to the Rescue

BACKGROUND

Bevacizumab is a humanized monoclonal antibody to vascular endothelial growth factor (VEGF) that has been used as a systemic chemotherapy treatment of various malignancies in adults since 2000. It has been used for pediatric patients over the last decade. In addition, bevacizumab is used for neonatal intravitreal administration for retinopathy of prematurity, a major complication of preterm birth, characterized by incomplete and abnormal vascularization of the retina that can lead to retinal detachment and blindness without treatment.

CASES

The objective of this multiple case series is to report impaired wound healing seen in 3 adolescents and 1 premature neonate receiving bevacizumab and to propose collagen-based dermal template as a choice for the management of such wounds. The 3 adolescents were undergoing treatment of malignancies and developed wound healing complication within weeks of receiving anti-VEGF. The premature neonate experienced an extravasation and had a slow wound healing trajectory after receiving intravitreal administration of bevacizumab for retinopathy of prematurity. All wounds achieved closure following topical treatment with a collagen dermal template.

CONCLUSION

Use of bevacizumab is increasing in the pediatric population. Clinicians should be aware of compromised wound healing and higher likelihood of wound dehiscence after bevacizumab administration. We recommend waiting for at least 4 to 6 weeks between anti-VEGF administration (either systemic or vitreous) and elective surgical procedures, consistent with adult literature recommendations. If patient has an existing wound, we assert that bevacizumab should not be administered until that wound is healed. If wound healing is stalled, we recommend dermal template as a safe and effective accelerator of wound healing.

BMP6/TAZ-Hippo signaling modulates angiogenesis and endothelial cell response to VEGF

The BMP/TGFβ-Smad, Notch and VEGF signaling guides formation of endothelial tip and stalk cells. However, the crosstalk of bone morphogenetic proteins (BMPs) and vascular endothelial growth factor receptor 2 (VEGFR2) signaling has remained largely unknown. We demonstrate that BMP family members regulate VEGFR2 and Notch signaling, and act via TAZ-Hippo signaling pathway. BMPs were found to be regulated after VEGF gene transfer in C57/Bl6 mice and in a porcine myocardial ischemia model. BMPs 2/4/6 were identified as endothelium-specific targets of VEGF. BMP2 modulated VEGF-mediated endothelial sprouting via Delta like Canonical Notch Ligand 4 (DLL4). BMP6 modulated VEGF signaling by regulating VEGFR2 expression and acted via Hippo signaling effector TAZ, known to regulate cell survival/proliferation, and to be dysregulated in cancer. In a matrigel plug assay in nude mice BMP6 was further demonstrated to induce angiogenesis. BMP6 is the first member of BMP family found to directly regulate both Hippo signaling and neovessel formation. It may thus serve as a target in pro/anti-angiogenic therapies.

Comparison of Efficiency and Function of Vascular Endothelial Growth Factor Adenovirus Vectors in Endothelial Cells for Gene Therapy of Placental Insufficiency

Severe fetal growth restriction (FGR) affects 1:500 pregnancies, is untreatable and causes serious neonatal morbidity and death. Reduced uterine blood flow (UBF) and lack of bioavailable VEGF due to placental insufficiency is a major cause. Transduction of uterine arteries in normal or FGR sheep and guinea pigs using an adenovirus (Ad) encoding VEGF isoforms A (Ad.VEGF-A165) and a FLAG-tagged pre-processed short form D (DΔNΔC, Ad.VEGF-DΔNΔC-FLAG) increases endothelial nitric oxide expression, enhances relaxation and reduces constriction of the uterine arteries and their branches. UBF and angiogenesis are increased long term, improving fetal growth in utero. For clinical trial development we compared Ad.VEGF vector transduction efficiency and function in endothelial cells (ECs) derived from different species. We aimed to compare the transduction efficiency and function of the pre-clinical study Ad. constructs (Ad.VEGF-A165, Ad.VEGF-DΔNΔC-FLAG) with the intended clinical trial construct (Ad.VEGF-DΔNΔC) where the FLAG tag is removed. We infected ECs from human umbilical vein, pregnant sheep uterine artery, pregnant guinea pig aorta and non-pregnant rabbit aorta, with increasing multiplicity of infection (MOI) for 24 or 48 hours of three Ad.VEGF vectors, compared to control Ad. containing the LacZ gene (Ad.LacZ). VEGF supernatant expression was analysed by ELISA. Functional assessment used tube formation assay and Erk-Akt phosphorylation by ELISA. VEGF expression was higher after Ad.VEGF-DΔNΔC-FLAG and Ad.VEGF-DΔNΔC transduction compared to Ad.VEGF-A165 in all EC types (*p < 0.001). Tube formation was higher in ECs transduced with Ad.VEGF-DΔNΔC in all species compared to other constructs (***p < 0.001, *p < 0.05 with rabbit aortic ECs). Phospho-Erk and phospho-Akt assays displayed no differences between the three vector constructs, whose effect was, as in other experiments, higher than Ad.LacZ (***p < 0.001). In conclusion, we observed high transduction efficiency and functional effects of Ad.VEGF-DΔNΔC vector with comparability in major pathway activation to constructs used in pre-clinical studies, supporting its use in a clinical trial.

Pressure overload generates a cardiac-specific profile of inflammatory mediators

Mechanisms that contribute to myocardial fibrosis, particularly in response to left ventricular pressure overload (LVPO), remain poorly defined. To test the hypothesis that a myocardial-specific profile of secreted factors is produced in response to PO, levels of 44 factors implicated in immune cell recruitment and function were assessed in a murine model of cardiac hypertrophy and compared with levels produced in a model of pulmonary fibrosis (PF). Mice subjected to PO were assessed at 1 and 4 wk. Protein from plasma, LV, lungs, and kidneys were analyzed by specific protein array analysis in parallel with protein from mice subjected to silica-instilled PF. Of the 44 factors assessed, 13 proteins were elevated in 1-wk PO myocardium, whereas 18 proteins were found increased in fibrotic lung. Eight of those increased in 1-wk LVPO were not found to be increased in fibrotic lungs (CCL-11, CCL-12, CCL-17, CCL-19, CCL-21, CCL-22, IL-16, and VEGF). Additionally, six factors were increased in plasma of 1-wk LVPO in the absence of increases in myocardial levels. In contrast, in mice with PF, no factors were found increased in plasma that were not elevated in lung tissue. Of those factors increased at 1 wk, only TIMP-1 remained elevated at 4 wk of LVPO. Immunohistochemistry of myocardial vasculature at 1 and 4 wk revealed similar amounts of total vasculature; however, evidence of activated endothelium was observed at 1 wk and, to a lesser extent, at 4 wk LVPO. In conclusion, PO myocardium generated a unique signature of cytokine expression versus that of fibrotic lung.NEW & NOTEWORTHY Myocardial fibrosis and the resultant increases in myocardial stiffness represent pivotal consequences of chronic pressure overload (PO). In this study, cytokine profiles produced in a murine model of cardiac fibrosis induced by PO were compared with those produced in response to silica-induced lung fibrosis. A unique profile of cardiac tissue-specific and plasma-derived factors generated in response to PO are reported.

Tumor Angiogenesis and Anti-Angiogenic Strategies for Cancer Treatment

Angiogenesis is the process through which novel blood vessels are formed from pre-existing ones and it is involved in both physiological and pathological processes of the body. Furthermore, tumor angiogenesis is a crucial factor associated with tumor growth, progression, and metastasis. In this manner, there has been a great interest in the development of anti-angiogenesis strategies that could inhibit tumor vascularization. Conventional approaches comprise the administration of anti-angiogenic drugs that target and block the activity of proangiogenic factors. However, as their efficacy is still a matter of debate, novel strategies have been focusing on combining anti-angiogenic agents with chemotherapy or immunotherapy. Moreover, nanotechnology has also been investigated for the potential of nanomaterials to target and release anti-angiogenic drugs at specific sites. The aim of this paper is to review the mechanisms involved in angiogenesis and tumor vascularization and provide an overview of the recent trends in anti-angiogenic strategies for cancer therapy.

Serum vascular endothelial growth factor level is elevated in patients with impaired glucose tolerance and type 2 diabetes mellitus

Objective

This study was performed to investigate the serum vascular endothelial growth factor (VEGF) levels in Chinese patients with impaired glucose tolerance (IGT) and newly diagnosed type 2 diabetes mellitus (T2DM).

Methods

A total of 189 subjects (41 controls, 40 patients with IGT, and 108 patients with newly diagnosed T2DM) were recruited. Serum VEGF levels were determined by ELISA; other metabolic parameters were assessed by standard laboratory methods.

Results

There were significant differences in serum VEGF levels among the T2DM, IGT, and control groups (T2DM vs. controls: 72.00 [45.40, 98.35] pg/mL vs. 53.10 [36.30, 116.25] pg/mL; IGT vs. controls: 78.17 [55.52, 137.25] pg/mL vs. 53.10 [36.30, 116.25] pg/mL). Moreover, serum VEGF levels were positively associated with the homeostasis model assessment for insulin resistance (HOMA-IR) value. Multiple linear regression analysis indicated that the HOMA-IR value was an independent risk factor for elevated serum VEGF level.

Conclusions

Both IGT and T2DM patients exhibited increased serum VEGF levels, compared with controls; increased serum VEGF level was positively associated with the HOMA-IR value. Therefore, the increased serum VEGF level might partially result from increased insulin resistance in these patients.