Interleukin-1 induces the expression of vascular endothelial growth factor in human pericardial mesothelial cells

Acellular bovine pericardium as a biological dressing for treatment of cutaneous wounds of the distal limb in donkeys (Equus Asinus)

This research was performed to determine the impact of repeated topical dressing with acellular bovine pericardium (ABP) on healing distal limb wounds in donkeys. Twelve male clinically healthy donkeys were subjected to general anesthesia, and full-thickness wounds of six cm2 (2 × 3 cm) were created on the middle dorsolateral surface of the metacarpi. Two defects were made on each donkey’s forelimbs; the right limb was considered a control wound, and the left one was considered a treated wound. Moreover, the control wounds were irrigated with saline every three days postoperatively and bandaged with a standard dressing. The treated wounds were covered with ABP dressings. The ABP dressing was reapplied thrice at 7-, 14- and 21-days post-wound induction. In addition, the wound healing process was monitored clinically, histopathologically, and immunohistochemically of tissue as growth factor-β1, epidermal growth factor receptor, and vascular endothelial growth factor. Besides, the gene expression profile of angiogenic and myofibroblastic genes was applied as vascular endothelial growth factor-A, collagen type 3α1, fibroblast growth factor 7, and the transforming growth factor-β1.

The results revealed that the wounds treated with ABP healed more quickly than the control wounds. Additionally, the mean days required for healing were significantly shorter in the ABP-treated wounds (p < 0.05; 69.5 ± 1.6) compared to control wounds (86.3 ± 3). Furthermore, immunohistochemical and gene expression analyses were significantly improved in ABP wounds than in control wounds. In conclusion, ABP is considered a natural biomaterial and promotes the healing of distal limb wounds in donkeys if applied weekly during the first three-week post-wound induction.

The role of the metastasis suppressor gene KAI1 in melanoma angiogenesis

The tetraspan protein KAI1 (CD82) has been previously shown to have important roles in cell migration, invasion, and melanoma prognosis. In this study, we investigated the role of KAI1 regarding melanoma angiogenesis. KAI1 overexpression strongly suppressed the growth of the human umbilical vein endothelial cells and their tubular structure formation in vitro. Also, KAI1 was able to inhibit both interleukin-6 (IL-6) and VEGF at mRNA and protein levels. Using nude mice in the in vivo study, we showed that KAI1, through the regulation of ING4, inhibited blood vessel formation in matrigel plugs along with the downregulation of IL-6 and VEGF, and the recruitment of CD31-positive cells. Finally, we found that KAI1 was able to suppress the activity of a serine/threonine kinase Akt by suppressing Akt phosphorylation (Ser473). Taken together, our results suggested that KAI1 was able to suppress melanoma angiogenesis by downregulating IL-6 and VEGF expression, and the restoration of KAI1 functionality offered a new approach in human melanoma treatment.

The epicardium as a candidate for heart regeneration

The mammalian heart loses its regenerative capacity during early postnatal stages; consequently, individuals surviving myocardial infarction are at risk of heart failure due to excessive fibrosis and maladaptive remodeling. There is an urgent need, therefore, to develop novel therapies for myocardial and coronary vascular regeneration. The epicardium-derived cells present a tractable resident progenitor source with the potential to stimulate neovasculogenesis and contribute de novo cardiomyocytes. The ability to revive ordinarily dormant epicardium-derived cells lies in the identification of key stimulatory factors, such as Tβ4, and elucidation of the molecular cues used in the embryo to orchestrate cardiovascular development. myocardial infarction injury signaling reactivates the adult epicardium; understanding the timing and magnitude of these signals will enlighten strategies for myocardial repair.

Hippocampal neurogenesis after traumatic brain injury is mediated by vascular endothelial growth factor receptor-2 and the Raf/MEK/ERK cascade

Adult neurogenesis occurs in the subgranular zone of the hippocampal dentate gyrus, and can be modulated by physiological and pathological events. We examined the effect of vascular endothelial growth factor (VEGF), and the correlation between VEGF and the Raf/MEK/ERK cascade in neurogenesis after traumatic brain injury (TBI). The expression of VEGF and the phosphorylation level of Raf/MEK/ERK were analyzed by Western blot, and TBI-induced neurogenesis was determined by immunofluorescence labeling and confocal microscopic detection. Hippocampal VEGF began to increase after 12 h, and reached a peak at day 7. Along with the upregulation of VEGF, neurogenesis in the hippocampus also increased. Administration of the VEGF antisense oligodeoxynucleotide, or the VEGF receptor-2 antagonist SU1498 (10 μg, ICV), attenuated the phosphorylation of the MAPK cascade proteins and caused a decrease in neurogenesis in the hippocampus. Similarly, administration of the ERK inhibitor PD98059 (500 ng, ICV) also exhibited a suppressive effect on neurogenesis. Our results indicate that VEGF plays an important role in neurogenesis after TBI, and that the process involves VEGF receptor-2 and the Raf/MEK/ERK cascade.

Vascular endothelial growth factor, its soluble receptor, and hepatocyte growth factor: clinical and genetic correlates and association with vascular function

AIMS

Growth factors play an important role in regulating vascular function. Data are limited regarding clinical and genetic correlates of endothelial growth factors and their associations with vascular function.

METHODS AND RESULTS

We evaluated clinical and genetic correlates of circulating vascular endothelial growth factor A (VEGF), its soluble receptor sFlt-1, and hepatocyte growth factor (HGF) in 3754 Framingham Study participants. We also related the growth factors to measures of brachial artery function. Serum VEGF and HGF were higher and sFLt-1 was lower in women and smokers. VEGF and HGF were associated positively with body mass index; both displayed strong positive associations with the metabolic syndrome (P < 0.001) and its components. The heritabilities of VEGF, sFlt-1, and HGF were 78, 13, and 38%, respectively. VEGF and HGF were related positively to baseline brachial diameter (P < 0.01) and to baseline mean flow velocity (P < 0.001) in age- and sex-adjusted models, but the multivariable models failed to reach significance. None of the growth factors were related to flow-mediated dilation.

CONCLUSION

In our community-based sample, circulating VEGF and HGF demonstrated high heritabilities and a sexual dimorphism. Increased angiogenesis and greater endothelial cell turnover may underlie associations of these growth factors with risk factors including smoking.

Regional expression of the hypoxia-inducible factor (HIF) system and association with cardiomyocyte cell cycle re-entry after myocardial infarction in rats

Hypoxia-inducible factor (HIF)-1alpha and-2alpha have diverse actions on the myocardium, but the importance of direct effects on cardiac myocytes is unclear. To define their regional accumulation and association with cardiomyocyte cell cycle change after myocardial infarction (MI), a rat MI model was established by occluding the coronary arteries. To further prove a causative relationship between HIF and cell cycle regulation, cultured cardiomyocytes were transfected with adenoviral vectors carrying HIF-1alpha and HIF-2alpha. Two weeks after MI, both HIF-1alpha and HIF-2alpha mRNA were moderately increased in the infarcted left ventricle and noninfarcted left ventricle; HIF-2alpha amplification was also detected in areas of the interventricular septum and the right ventricle. In concordance with the changes in mRNA levels, immunohistochemistry signals of HIF-1alpha and HIF-2alpha were characterized by different regional distributions. In the myocardium adjacent to the infarcted tissue, a significant correlation between HIF-1alpha or HIF-2alpha and Ki-67 labeling index was observed (P < 0.001). Immunohistochemical double staining showed that HIF positive cardiomyocytes underwent DNA synthesis. Cardiomyocytes treated with HIF-1alpha or -2alpha expressed Ki-67, phosphohistone H3, and bromodeoxyuridine effectively in vitro. In conclusion, HIF-1alpha and HIF-2alpha had a distinct spatial expression pattern in a rat model of ischemic heart disease. Both HIF subunits might be potent stimuli for cardiomyocytes to re-enter the cell cycle and initiate DNA synthesis.