Proliferation Of Vascular Endothelial Cells Research Articles

The VEGFR2/mTOR/S6K1 pathway involved in the angiogenic effects of roxarsone in vitro and in vivo

Roxarsone, an organoarsenic compound used in poultry industry to increase weight gain, is widely used as a feed additive in some developing countries. Roxarsone has a low absorption rate and is mostly excreted with feces, which could pose a risk to human health through environmental and animal food routes. Roxarsone has been demonstrated to have tumor-promoting and proangiogenic effects. Herein, we report the role of VEGFR2/mTOR/S6K1 signaling in roxarsone-promoted vessel endothelial cell growth and angiogenesis in the Matrigel plug model and the mouse B16 cell tumor transplantation model. In angiogenesis-related experiments in vitro, 1.0 μM roxarsone significantly increased the activity, proliferation, migration, and tube formation of rat vascular endothelial cells. In addition, 1.0 μM roxarsone upregulated the protein levels of mTOR, phosphorylated mTOR, S6K1, and phosphorylated S6K1 and significantly increase the expression of Mtor and S6k1 mRNA. Rapamycin and SU5416 significantly inhibited the effects of 1.0 μM roxarsone on cell growth. Furthermore, the weight, volume, and CD31 expression of B16-F10 xenografts and Matrigel plugs in mice were upregulated by 25 mg/kg roxarsone. The protein and mRNA levels of mTOR, S6K1 and its phosphorylated protein were significantly increased in the roxarsone treatment group in xenografts. SU5416 and a short hairpin RNA targeting Vegfr2 significantly reduced roxarsone-promoted xenograft and Matrigel plug growth. In summary, this study indicated that the VEGFR2/mTOR/S6K1 signaling plays a regulatory role in roxarsone-mediated promotion angiogenesis and enhanced tumor growth.

Exosomes Derived from AT2R-Overexpressing BMSC Prevent Restenosis After Carotid Artery Injury by Attenuating the Injury-Induced Neointimal Hyperplasia

Restenosis is a severe complication after percutaneous transluminal coronary angioplasty which limits the long-term efficacy of the intervention. In this study, we investigated the efficiency of exosomes derived from AT2R-overexpressing bone mesenchymal stem cells on the prevention of restenosis after carotid artery injury. Our data showed that AT2R-EXO promoted the proliferation and migration of vascular endothelial cells and maintained the ratio of eNOS/iNOS. On the contrary, AT2R-EXO inhibited the proliferation and migration of vascular smooth muscle cells. In vivo study proved that AT2R-Exo were more effectively accumulated in the injured carotid artery than EXO and Vehicle-EXO controls. AT2R-EXO treatment could improve blood flow of the injured carotid artery site more effectively. Further analysis revealed that AT2REXO prevents restenosis after carotid artery injury by attenuating the injury-induced neointimal hyperplasia. Our study provides a novel and more efficient exosome for the treatment of restenosis diseases after intervention.

Old and New Aspects of H. pylori-Associated Inflammation and Gastric Cancer.

H. pylori is involved in the development of 80% of gastric cancers and 5.5% of all malignant conditions worldwide. Its persistence within the host’s stomach causes chronic inflammation, which is a well-known hallmark of carcinogenesis. A wide range of cytokines was reported to be involved in the initiation and long-term persistence of this local and systemic inflammation. IL-8 was among the first cytokines described to be increased in patients with H. pylori infection. Although, this cytokine was initially identified to exert a chemoattracting effect that represents a trigger for the activation of inflammatory cells within H.-pylori-infected mucosa, more recent studies failed in encountering any association between IL-8 and H. pylori infection. IL-6 is a multifunctional, pleiotropic and multipotent cytokine involved in mediating the interaction between innate and adaptive immunity with a dichotomous role acting as both a proinflammatory and an anti-inflammatory cytokine depending on the signaling pathway. IL-1α functions as a promoter of angiogenesis and vascular endothelial cell proliferation in gastric carcinoma since it is closely related to H.-pylori-induced inflammation in children. IL-1β is an essential trigger and enhancer of inflammation. The association between a low IL-1β level and an increased TNF-α level might be considered a risk factor for peptic ulcer disease in the setting of H. pylori infection. IL-10 downregulates both cytotoxic inflammatory responses and cell-mediated immune responses. H. pylori uses the immunosuppressive role of IL-10 to favor its escape from the host’s immune system. TGFβ is a continuous inflammatory mediator that promotes the adherence of H. pylori to the host’s cells and their subsequent colonization. The role of H.-pylori-induced inflammatory responses in the onset of gastric carcinogenesis seems to represent the missing puzzle piece for designing effective preventive and therapeutic strategies in patients with H.-pylori-associated gastric cancer.

Bie-Jia-Ruan-Mai-Tang, a Chinese Medicine Formula, Inhibits Retinal Neovascularization in Diabetic Mice Through Inducing the Apoptosis of Retinal Vascular Endothelial Cells.

Proliferative diabetic retinopathy (PDR) is one of the main complications of diabetes, mainly caused by the aberrant proliferation of retinal vascular endothelial cells and the formation of new blood vessels. Traditional Chinese medicines possess great potential in the prevention and treatment of PDR. Bie-Jia-Ruan-Mai-Tang (BJ), a Chinese medicine formula, has a good therapeutic effect on PDR clinically; however, the mechanism of action involved remains unclear. Therefore, we investigated the effect of BJ on PDR through in vitro and in vivo experiments. A diabetic mouse model with PDR was established by feeding a high-fat–high-glucose diet combined with an intraperitoneal injection of streptozotocin (STZ), while high-glucose-exposed human retinal capillary endothelial cells (HRCECs) were employed to mimic PDR in vitro. The in vivo experiments indicated that BJ inhibited the formation of acellular capillaries, decreased the expression of VEGF, and increased the level of ZO-1 in diabetic mice retina. In vitro experiments showed that high glucose significantly promoted cell viability and proliferation. However, BJ inhibited cell proliferation by cycle arrest in the S phase, thus leading to apoptosis; it also increased the production of ROS, decreased the mitochondrial membrane potential, reduced the ATP production, and also reduced the expressions of p-PI3K, p-AKT, and Bcl-xL, but increased the expressions of Bax and p-NF-κB. These results suggest that BJ induces the apoptosis of HRCECs exposed to high glucose through activating the mitochondrial death pathway by decreasing the PI3K/AKT signaling and increasing the NF-κB signaling to inhibit the formation of acellular capillaries in the retina, thus impeding the development of PDR.

A Delayed Dynamical Model Describing the Effect of Tumor-Induced Vascular Endothelial Growth Factor on Angiogenesis: Backward Bifurcations and Global Dynamics

Dynamic models have been successfully used for the prediction of long-term evolutionary behavior of the growth of tumor cells. In this paper, based on previous research, time delay in the process of the growth of tumor cells is further considered and a class of dynamic models with two-time delays and general functional response function is proposed. This model describes the effect of tumor-induced vascular endothelial growth factor (VEGF) on angiogenesis. First, the model is reduced to a two-dimensional one by means of the quasi-steady-state approximation method. This model has forward and backward bifurcations of the equilibria. Then, local stability of all equilibria, global stability of the tumor cell-free equilibrium and the vascular endothelial cell-free equilibrium, and the persistence of this model are studied in detail. It is found that time delay of tumor-induced vascular endothelial cells proliferation does not change local stability of the equilibria, while time delay associated with the growth of tumor cells can lead to the existence of Hopf bifurcation periodic solutions.

Knocking Out of CEACAM1 Can Reduce Oxidative Stress and Promote Cell Proliferation in the HPMVECs under Hypoxia.

Pulmonary hypertension (PH) induced by hypoxia is common in clinical practice and often suggests a poor prognosis. The oxidative stress and proliferation of pulmonary vascular endothelial cells caused by hypoxia are the major mechanisms involved in the pathophysiology of PH. It has been reported in recent years that the carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) promotes angiogenesis. In this study, normal human pulmonary microvascular endothelial cells (HPMVECs) and HPMVECs with stable knockout of CEACAM1 by CRISPR-Cas9 were subjected to oxygen-glucose deprivation/reperfusion (OGD/R) to induce hypoxic conditions. JC-1, ROS, and cell cycle profile were analyzed for each cell line and controls, using flow cytometry. A tube formation assay was used to detect angiogenesis, along with expression levels of CEACAM1, TNF-α, VEGF, VEGFR-2, p-P38/P38, and CyclinD1 proteins (to distinguish profiles of angiogenic growth and cell proliferation). We observed increased expression of CEACAM1 in HPMVECs after OGD/R, while ROS production was reduced and mitochondrial membrane potential was increased after OGD/R in CEACAM1−/− HPMVECs. Furthermore, we observed increased cell division in CEACAM−/− HPMVECs, accompanied by enhanced angiogenesis and reduced TNF-α protein expression and increased VEGF, VEGFR-2, and CyclinD1 expression. Together, these data suggest that upregulation of CEACAM1 in HPMVECs under hypoxic conditions may damage cells by increasing oxidative stress and inhibiting cell proliferation.

Therapeutic Effect and Mechanism of Negative Pressure Wound Therapy with Huoxue Shengji Decoction Instillation for Chronic Skin Ulcers.

Background Negative pressure wound therapy (NPWT) with instillation (NPWTi) is a new treatment for chronic skin ulcers (CSUs), but the choice of perfusate is still investigated. The clinical application of Huoxue Shengji (HXSJ) decoction has been proved to promote the formation of granulation. The formation of fresh granulation, angiogenesis, and proliferation of vascular endothelial cells are closely related. The purpose of this study was to observe the clinical efficacy of NWPT with HXSJ decoction instillation in the treatment of CSUs and to explore the potential mechanism by which HXSJ decoction promotes proliferation of vascular endothelial cells at the cellular level. Methods In the clinical study, the random number table was used to divide the patients into three groups (patients were numbered by visit time and assigned a random number and grouped by the remainder after the random number was divided by 3, and when the number of patients in one group reached 20, the enrolment of this group is stopped), including NPWT combined with HXSJ decoction instillation (group A), NPWT combined with normal saline instillation (group B), and NPWT (group C). Related indexes were examined, including the wound cavity volume, bacterial culture, histopathology examination, time periods of debridement, repair methods, and the time of ulcer healing. In the basic research, the effect of HXSJ decoction on the proliferation of HUVECs was analysed by CCK-8 assay and RT-PCR and western blot were used to quantify the VEGF and VEGFR-2 expression in the relevant signalling pathway. Results There was no significant difference in the improvement rate of invasive cavity volume (P > 0.05) between groups A and B, but a significant difference was observed between groups A and C (P < 0.05). There was no significant difference in microbial reduction among groups (all P > 0.05). Histopathological examination showed that the microvascular count in group A was significantly higher than that in groups B and C (both P < 0.01) and there was no statistical difference between groups B and C (P > 0.05). There were no significant differences in the number of invasive lesions and repair methods among the groups (all P > 0.05). The healing time of group A was significantly faster than those of groups B and C (compared to group B, P < 0.05; compared to group C, P < 0.01), and there was no statistical difference between groups B and C (P > 0.05). In the cellular experiments, concentration screening was performed and 125 μg/mL HXSJ decoction showed the most significant effect on the proliferation of HUVECs and also enhanced the expression of VEGF and VEGFR-2. Conclusion HXSJ decoction can enhance the expression of VEGF and VEGFR-2 and promote the proliferation of HUVECs. Treatment with NWPT with HXSJ decoction instillation can further reduce the wound cavity volume; meanwhile, it can promote blood vessel formation in ulcer wounds, thus accelerating the healing of CSUs.

The Functions and Mechanisms of Basic Fibroblast Growth Factor in Tendon Repair.

Tendon injury is a disorder of the musculoskeletal system caused by overuse or trauma, which is characterized by pain and limitations in joint function. Since tendon healing is slowly and various treatments are generally ineffective, it remains a clinically challenging problem. Recent evidences suggest that basic fibroblast growth factor (bFGF) not only plays an important role in tendon healing, but also shows a positive effect in laboratory experimentations. The purpose of this review is to summarize the effects of bFGF in the tendon healing. Firstly, during the inflammatory phase, bFGF stimulates the proliferation and differentiation of vascular endothelial cells to foster neovascularization. Furthermore, bFGF enhances the production of pro-inflammatory factors during the early phase of tendon healing, thereby accelerating the inflammatory response. Secondly, the cell proliferation phase is accompanied by the synthesis of a large number of extracellular matrix components. bFGF speeds up tendon healing by stimulating fibroblasts to secrete type III collagen. Lastly, the remodeling phase is characterized by the transition from type III collagen to type I collagen, which can be promoted by bFGF. However, excessive injection of bFGF can cause tendon adhesions as well as scar tissue formation. In future studies, we need to explore further applications of bFGF in the tendon healing process.

Total flavones from Sceptridium ternatum alleviate pulmonary hypertension through inhibiting the proliferation of vascular endothelial cells.

BackgroundSceptridium ternatum is a traditional Chinese medicine that is prescribed to treat respiratory diseases in China. Our previous study confirmed that total flavones from Sceptridium ternatum (FST) have preventive and therapeutic effects on pulmonary hypertension (PH). The present study sought to investigate the mechanism underpinning the therapeutic efficacy of FST in PH.MethodsCell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assays, real-time quantitative PCR (RT-qPCR), western blot, flow cytometry, high-throughput sequencing, and bioinformatics analysis were performed to study the therapeutic mechanism of FST in PH at the gene, cell, and animal levels.ResultsThe results showed that FST could inhibit the proliferation of both human pulmonary artery smooth muscle cells (HPASMCs) and human pulmonary microvascular endothelial cells (HPMECs), and downregulate the expression of HIF1α and HIF2α, which are the key factors in the pathogenesis and occurrence of PH. FST could also inhibit the activation of the downstream JAK2-STAT3 signaling pathway and upregulate the expression of the negative regulator SOCS1. Vascular endothelial cell and smooth muscle cell proliferation was inhibited and the symptoms of PH were relieved by FST.ConclusionsThe findings of this study offer important clues for the identification of new molecular targets in FST treatment and the development of treatment strategies for PH.

The Effect of Bone Marrow Mesenchymal Stem Cells-Exosomes (BMSC-EXO) on Tumor Angiogenesis and Its Mechanism in Ovarian Cancer Microenvironment

In ovarian cancer microenvironment, BMSC cells can differentiate into a variety of stem cells, thereby reducing the damage to tissues, and this effect lies in the exosomal substances secreted by BMSC cells. Then, in ovarian cancer microenvironment, whether BMSC-exo exhibited an effect on angiogenesis at the tumor site, and its possible molecular mechanism remains unclear. BALA nude mice and ovarian cancer tumor tissues were collected to isolate vascular endothelial cells which were then assigned into Control group, 40 μg/ml BMSC-exo group, 80 μg/ml BMSC-exo group, 120 μg/ml BMSC-exo group in the presence of Wnt/β-catenin inhibitor (PNU-74654) followed by analysis of proliferation and migration of ovarian cancer vascular endothelial cells (OCVECs) and the angiogenesis. 40 μg/ml and 80 μg/mlBMSC-exo group showed significantly higher cell proliferation than control group with higher cell number in 80 μg/ml BMSC-exo group than 40 μg/ml BMSC-exo group (P &lt; 0.05). The number of cell migration after BMSC-exo treatment was increased (P &lt; 0.05) and the tumor tissue showed obvious angiogenesis with more CD31-positive cells (P &lt; 0.05). PNU-74654 group showed significantly downregulated Wnt and β-catenin proteins (P &lt; 0.05) and lower cell number and higher migration rate of vascular endothelial cells (P &lt; 0.05). In conclusion, exosomes secreted by BMSC can repair damaged tissues possibly through activation of Wnt/β-catenin signaling pathway.

Fabrication and biological evaluation of polyether ether ketone(PEEK)/bioceramic composites

The repair of vascularized bone defects represents a significantly clinical challenge, and vascular regeneration is one of the necessary factors to promote bone tissue regeneration. To effectively repair large bone defects, new bone tissue must regenerate with a rich vascular network. Therefore, the development of biomaterials that can promote the regeneration of vascularized bone tissue is currently receiving attention from researchers. In this study, Li–Ca–Si bioceramics (LCS) containing Li, Ca, and Si elements was developed, then LCS was compounded with PEEK to prepare PEEK+10% LCS, PEEK+20% LCS, PEEK+30% LCS, and the effect of LCS-PEEK composite biomaterials on the proliferation and angiogenic ability of human umbilical vascular endothelial cells (HUVECs) further explored by Cell Counting Kit-8 (CCK-8), scanning electron microscope (SEM), quantitative real-time PCR (QPCR), Western Blotting and enzyme linked immunosorbent assay (ELISA). The results showed that HUVECs inoculated on 30%LCS ​+ ​PEEK material exhibited the best proliferation ability. And the adhesion ability of endothelial cells on PEEK gradually increased with the increase of LCS contents. Furthermore, the angiogenic ability of HUVECs on LCS-PEEK composites was examined using QPCR and Western blotting, and the results showed that the expression of angiogenic-related genes and proteins of HUVECs on PEEK composites gradually increased with increasing LCS concentration. These results demonstrated that the angiogenic ability of HUVECs was effectively stimulated by LCS-modified PEEK materials. The present results indicate that the PEEK material can be modified with bioceramics to promote angiogenesis, and this study lay the foundation for the subsequent development of scaffolds that promote vascularized bone tissue regeneration.

Update on Treatment of Infantile Hemangiomas: What's New in the Last Five Years?

Among benign vascular tumors of infancy, hemangiomas are the commonest, affecting approximately 5–10% of one-year-old children. They are derived from a benign proliferation of vascular endothelial cells (VECs) in the mesoderm and may arise anywhere on the body around 1–2 weeks after birth. Infantile hemangiomas (IHs) are characterized by an early proliferative phase in the first year followed by a spontaneous progressive regression within the following 5 years or longer. IH prevalence is estimated to be 5%–10% in one-year-old children and commonly affects female, Caucasian and low-birth weight infants. Although most of them spontaneously regress, approximately 10% requires treatment to prevent complications due to the site of occurrence such as bleeding, ulceration, cosmetically disfigurement, functional impairment, or life-threatening complications. For over 30 years, steroids have represented the first-line treatment for IHs, but recently topical or systemic β-blockers are increasingly being used and recognized as effective and safe. A search for “Cutaneous infantile hemangioma” [All Fields] AND “Treatment” [All Fields] was performed by using PubMed and EMBASE databases. Treatment of IHs with labeled drugs, such as oral propranolol, but also with off-label drugs, such as topical β-blockers, including topical timolol and carteolol, steroids, itraconazole or sirolimus, with a focus on formulations types and adverse events were described in our review. We also discussed the benefits of pulsed dye laser and the treatment of IHs with involvement of central nervous system, namely the PHACE and LUMBAR syndrome.

Promotion of corneal angiogenesis by sensory neuron-derived calcitonin gene-related peptide

The normal cornea has no blood vessels but has abundant innervation. There is emerging evidence that sensory nerves, originated from the trigeminal ganglion (TG) neurons, play a key role in corneal angiogenesis. In the current study, we examined the role of TG sensory neuron-derived calcitonin gene-related peptide (CGRP) in promoting corneal neovascularization (CNV). We found that CGRP was expressed in the TG and cultured TG neurons. In the cornea, minimal CGRP mRNA was detected and CGRP immunohistochemical staining was exclusively co-localized with corneal nerves, suggesting corneal nerves are likely the source of CGRP in the cornea. In response to intrastromal suture placement and neovascularization in the cornea, CGRP expression was increased in the TG. In addition, we showed that CGRP was potently pro-angiogenic, leading to vascular endothelial cell (VEC) proliferation, migration, and tube formation in vitro and corneal hemangiogenesis and lymphangiogenesis in vivo. In a co-culture system of TG neurons and VEC, blocking CGRP signaling in the conditioned media of TG neurons led to decreased VEC migration and tube formation. More importantly, subconjunctival injection of a CGRP antagonist CGRP8-37 reduced suture-induced corneal hemangiogenesis and lymphangiogenesis in vivo. Taken together, our data suggest that TG sensory neuron and corneal nerve-derived CGRP promotes corneal angiogenesis.

Bioactive Fish Scale Scaffolds with MSCs-Loading for Skin Flap Regeneration.

Skin flap transplantations are common methods for covering and repairing tissue defects in surgery, while the survival rates of these skin flaps are still low due to the vascular crisis and necrosis. To improve this situation, herein a novel biohybrid scaffold is proposed by integrating the advantages of anisotropic fish scales and mesenchymal stem cells (MSCs) for skin flap regeneration. The fish scale scaffold is obtained through its decellularization and decalcification processes, which reserved intact collagen, glycosaminoglycan, and other endogenous growth factors for MSCs and human vascular endothelial cells proliferation. As the scaffold maintains intrinsic anisotropic structures on both surfaces, the proliferative cells can be elongated along the aligned structures on the fish scale, which endow them the capacity to differentiate into multiple directions. Based on these features, it is demonstrated from an in vivo experiment that the MSCs‐loading fish scale scaffolds can effectively convert the activated inflammatory macrophages into anti‐inflammatory properties, reduce the inflammation around the flap, and improve the survival rate. These results indicate that the MSCs‐loading fish scale scaffold is suitable and has the potential for skin flap regeneration and functional recovery.

Adipose-Derived Stem Cells Exosomes Improve Fat Graft Survival by Promoting Prolipogenetic Abilities through Wnt/β-Catenin Pathway.

Autologous fat grafting has been widely used in plastic surgery in recent years, but the unstable retention of fat graft has always been a key clinical problem. Adipose tissue has poor tolerant to ischemia, so the transplanted adipose tissue needs to rebuild blood supply at an early stage in order to survive stably. Our previous study has found that comparing to human foreskin fibroblast exosome (HFF-Exo), human adipose-derived stem cells exosome (hADSC-Exo) can significantly improve the proliferation of vascular endothelial cells and the angiogenic effect of artificial dermal preconstructed flaps. Therefore, the ability of hADSC-Exo to improve the retention of adipose grafts and its potential regenerative mechanism aroused our strong interest. In this study, we applied hADSC-Exo and HFF-Exo to adipose grafts and explored the potential regeneration mechanism through various means such as bioinformatics, immunofluorescence, immunohistochemistry, and adipogenic differentiation. The results showed that hADSC-Exo can significantly promote grafts angiogenesis and adipogenic differentiation of ADSC to improve the retention of fat grafts and may downregulate the Wnt/β-catenin signaling pathway to promote the adipogenic differentiation. In summary, our results provide a theoretical basis for the clinical translation of hADSC-Exo in fat grafting.

Upregulation of endothelial hypoxia‐inducible factor‐2 alpha in animals with pulmonary hypertension

IntroductionIdiopathic pulmonary arterial hypertension (IPAH) is a life‐threatening disease with no cure. Pulmonary vascular remodeling due to increased pulmonary artery smooth muscle (PASMC) and lung vascular endothelial cell (LVEC) proliferation is a major cause for the elevated pulmonary vascular resistance (PVR) and pulmonary arterial pressure (PAP) in patients with IPAH. We have previously demonstrated that endothelial hypoxia‐inducible factor‐2α (HIF‐2α) contributes to the development of pulmonary vascular remodeling in LVEC isolated from IPAH patients. Moreover, HIF‐2α is involved in the initiation of endothelial‐to‐mesenchymal transition (EndMT) by upregulating Snai1 and Snai2 (EndMT drivers). However, the exact role of HIF‐2α in the development and progression of pulmonary hypertension (PH) remains elusive. We aimed to investigate whether endothelial HIF‐2α is involved in pulmonary vascular remodeling in animals with hypoxia/sugen‐induced PH (SuHx‐PH) and monocrotaline‐induced PH (MCT‐PH).MethodsHypoxia/sugen‐PH (SuHx‐PH) model in mice was induced by exposing animals to the combination of normobaric hypoxia (10% O2) and sugen 5416 (20 mg/kg, i.p., weekly) for 6 weeks. Monocrotaline‐MCT‐PH model in rats was induced by single administration of MCT (60 mg/kg, s.c.) followed by experimental measurements after 28 days. Body weight (BW) was collected from all animals weekly. Hemodynamic parameters including right ventricular systolic pressure (RVSP), mean pulmonary arterial pressure (mPAP), the Fulton index (FI), right ventricular (RV) contractility, heart rate (HR) were measured to establish PH. The pulmonary artery (PA) wall thickness was estimated by H&amp;E staining. The protein expression of Snai1 and HIF‐2α was determined by Western blot and immunocytochemistry. Normal human LVEC was treated with TGF‐β1 for 7 days to induce EndMT. LVEC isolated with patients with IPAH was treated with HIF‐2α inhibitor Compound 2 for 8‐48 hrs.ResultsExposure of mice to the SuHx (6 weeks) or rats to MCT (4 weeks) resulted in the significant increase of RVSP, mPAP, RV contractility, and FI compared to control animals. We did not detect any changes in HR between corresponded groups. BW was decreased by 7% after the first week of the SuHx treatment in mice. By the end of 6 weeks BW was significantly lower by 12% in SuHx mice compared with normoxic animals. BW in MCT‐treated rats was 5% lower after the first week and at the end of experiment compared to vehicle‐treated animals. Pulmonary vascular remodeling estimated by PA wall thickness was enhanced in both SuHx‐PH mice and MCT‐PH rats. The protein expression of HIF‐2α and Snai1 was higher in lung tissues isolated from SuHx‐PH mice and MCT‐PH rats compared to controls. Moreover, HIF‐2α and Snai1 was activated in normal human LVEC treated with TGF‐β1 (10ng/ml) for 7 days. Additionally, HIF‐2α inhibitor, Compound 2 (30µM) was able to downregulate Snai1 protein expression in LVEC isolated from IPAH patients after 16 hours.ConclusionsOur results indicate that HIF‐2α is involved in pulmonary vascular remodeling in animals with PH. Our studies support the premise that targeting HIF‐2α would be a novel therapeutic approach for the treatment of IPAH and other forms of PH.

Deletion of MicroRNA-21 Impairs Neovascularization Following Limb Ischemia: From Bedside to Bench.

With an increasing prevalence, peripheral arterial disease (PAD), cause by atherosclerosis is a new threat to public health beyond coronary artery disease and involves aberrant vascular endothelial cell proliferation and angiogenesis. The degree of vascular remodeling is influenced by the processes described. MicroRNA-21 (miR-21) has been found to play a critical role in cellular functions, including angiogenesis. Nevertheless, the effect of miR-21 on endothelial cells in response to hypoxia is largely unknown. Using wild-type C57BL/6J and miR-21–/– mice, we compared the capability of angiogenesis in response to hindlimb hypoxic/ischemia. In an in vitro study, we further studied whether overexpression of miR-21 mitigates hypoxia-induced apoptosis and impaired angiogenesis. Also, we prospectively collected the sera of patients with limb ischemia and followed the clinical information, including major adverse limb events (MALEs). Using laser Doppler perfusion imaging and CD31 staining, compared with miR-21–/– mice, wild-type mice expressed a significantly higher capability of angiogenesis and less apoptosis following 28 days of hindlimb hypoxic/ischemic surgery. In our in vitro study, after 24 h of hypoxia, proliferation, migration, and tube formation were significantly impaired in cells treated with the miR-21 inhibitor but rescued by the miR-21 mimic. Mechanistically, by suppressing PTEN/PI3K/AKT, miR-21 promoted angiogenesis and suppressed apoptosis in endothelial cells post hypoxia. In patients with limb ischemia, the high expression of circulating miR-21 was associated with less subsequent MALE. Collectively, miR-21 could be a biomarker associated with the endogenous ability of angiogenesis and reflect subsequent MALE in patients. Additionally, abolishing miR-21 impairs angiogenesis and promotes apoptosis post limb ischemia. Further studies are required to elucidate the clinical applications of miR-21.

Spinal epidural capillary hemangioma: A systematic literature review and an illustrative case

BackgroundSpinal hemangiomas are rare vascular malformations resulting from proliferation of vascular endothelial cells. The cavernous form is the most common and represents 5-12% of spinal vascular malformations, while the capillary form is rare. Case DescriptionA 56-year-old patient with no past medical history presented with progressive spinal cord compression symptoms localizing to the T10 level with MRC grade 4 proximal paraparesis. Preoperative MRI demonstrated a well-delineated, dumbbell-shaped, epidural lesion, without bony involvement, resulting in spinal cord compression at the T7 and T8 levels. The patient underwent gross total surgical resection of the lesion. At the one month follow up, the patient's strength improved to MRC grade 5, and sensation had fully returned. The histopathological diagnosis was a capillary hemangioma. Exclusively epidural capillary hemangiomas are extremely rare with only 26 cases reported in the literature. They are mainly located at the thoracic level (T4-T6). The MRI features include a well-circumscribed mass, hyperintense on T2-weighted sequence in 92% of cases, isointense on T1-weighted sequence in 88% of cases, and homogeneous contrast enhancement in 100% of cases. No tumor recurrence has been observed after gross total surgical removal. ConclusionsWhen evaluating progressive spinal cord compression by a purely epidural spinal lesion, the differential diagnosis should include capillary hemangioma, in addition to schwannoma, meningioma, and lymphoma. Early and complete surgical removal is the first line treatment.

Residue of thiram in food, suppresses immune system stress signals and disturbs sphingolipid metabolism in chickens

Thiram, a well-known sulfur containing organic compound is frequently and extensively used in agriculture because of high biological activity to control different pests. In certain cases, due to long persistence in the environment pesticides and other environmental contaminants induce undesirable toxic impacts to public health and environment. To ascertain the potential mechanisms of toxicity of thiram on different immune organs of broilers, a total of 100 one-day-old chicks were obtained and randomly divided into two groups including thiram group (50 mg/kg) and untreated control group. Thymus and spleen tissues were collected at the age of 14 days from the experimental birds. At necropsy level, thymus was congested, enlarged and hyperemic while spleen had no obvious lesions. The results on mechanisms (apoptosis and autophagy) of immunotoxicity showed significantly increased expression of bax, caspase3, cytc, ATG5, beclin1 and p62 in spleen of treated mice. Results indicated significantly decreased expression of m-TOR and bcl2 to activate apoptosis and autophagy. The expressions of bax, p53 and m-TOR were up-regulated in the thymus while the expressions of ATG5 and Beclin1 were down-regulated to mediate cell apoptosis and inhibit autophagy. The results on different metabolome investigation showed that the sphingolipid metabolism in the thymus of chicks exposed to thiram was disrupted resulting in up-regulation of metabolites related to cell membrane components such as SM, galactosylceramide and lactosylceramide. The results of our experimental research suggest that thiram can interfere with the sphingolipid metabolism in thymus and angiogenesis, inhibit the proliferation of vascular endothelial cells to induce potential toxic effects in chicken.

In Vivo Evaluation of Gamma-Irradiated and Heparin-Immobilized Small-Diameter Polycaprolactone Vascular Grafts with VEGF in Aged Rats.

The effectiveness of small-diameter vascular grafts depends on their antithrombogenic properties and ability to undergo accelerated endothelialization. The extreme hydrophobic nature of poly(ε-caprolactone) (PCL) hinders vascular tissue integration, limiting its use in medical implants. To enhance the antithrombogenicity of PCL as a biomaterial, we grafted 2-aminoethyl methacrylate (AEMA) hydrochloride onto the PCL surface using gamma irradiation; developed a biodegradable heparin-immobilized PCL nanofibrous scaffold using gamma irradiation and N-(3-dimethylaminopropyl)-N′-ethyl carbodiimide hydrochloride/N-hydroxysuccinimide reaction chemistry; and incorporated vascular endothelial growth factor (VEGF) into the scaffold to promote vascular endothelial cell proliferation and prevent thrombosis on the vascular grafts. We assessed the physicochemical properties of PCL, heparin-AEMA-PCL (H-PCL), and VEGF-loaded heparin-AEMA-PCL (VH-PCL) vascular grafts using scanning electron microscopy, attenuated total reflection–Fourier transform infrared spectroscopy, toluidine blue O staining, and fibrinogen adsorption and surface wettability measurement. In addition, we implanted the vascular grafts into 24-month-old Sprague Dawley rats and evaluated them for 3 months. The H-PCL and VH-PCL vascular grafts improved the recovery of blood vessel function by promoting the proliferation of endothelial cells and preventing thrombosis in clinical and histological evaluation, indicating their potential to serve as functional vascular grafts in vascular tissue engineering.