Angiogenesis and hypertension: an update

Cerebral hypoperfusion exacerbates vascular dysfunction after traumatic brain injury

Traumatic brain injuries are extremely common, and although most patients recover from their injuries many TBI patients suffer prolonged symptoms and remain at a higher risk for developing cardiovascular disease and neurodegeneration. Moreover, it remains challenging to identify predictors of poor long-term outcomes. Here, we tested the hypothesis that preexisting cerebrovascular impairment exacerbates metabolic and vascular dysfunction and leads to worse outcomes after TBI. Male mice underwent a mild surgical reduction in cerebral blood flow using a model of bilateral carotid artery stenosis (BCAS) wherein steel microcoils were implanted around the carotid arteries. Then, 30 days post coil implantation, mice underwent TBI or sham surgery. Gene expression profiles, cerebral blood flow, metabolic function, oxidative damage, vascular health and angiogenesis were assessed. Single nuclei RNA sequencing of endothelial cells isolated from mice after TBI showed differential gene expression profiles after TBI and BCAS, that were further altered when mice underwent both challenges. TBI but not BCAS increased mitochondrial oxidative metabolism. Both BCAS and TBI decreased cerebrovascular responses to repeated whisker stimulation. BCAS induced oxidative damage and inflammation in the vasculature as well as loss of vascular density, and reduced the numbers of angiogenic tip cells. Finally, intravascular protein accumulation was increased among mice that experienced both BCAS and TBI. Overall, our findings reveal that a prior vascular impairment significantly alters the profile of vascular health and function of the cerebrovasculature, and when combined with TBI may result in worsened outcomes.

Hypertension and Dental Implants: A Systematic Review and Meta-Analysis

PURPOSE

The aim of the present systematic review was to investigate the influence of hypertension on the dental implant failure rate.

METHODS

An electronic search was undertaken in four databases, plus a manual search of journals. The I2 statistic was used to check heterogeneity and the inverse-variance method was used for the meta-analysis. The estimate of relative effect for dichotomous outcome was expressed as an odds ratio (OR).

RESULTS

The review included 24 publications. There were 4874 implants (257 failures) placed in hypertensive patients and 16,192 implants (809 failures) placed in normotensive patients. A pairwise meta-analysis showed that implants in hypertensive patients did not have a higher risk of failure than implants placed in normotensive patients (OR 1.100, p = 0.671). The log OR of implant failure between hypertensive and normotensive patients did not significantly change with the follow-up time (p = 0.824).

CONCLUSIONS

This review suggests that implants in hypertensive patients do not present higher odds of failure in comparison to normotensive patients. However, further research on this topic, with the use of more rigorous criteria to diagnose patients as being hypertensive, as well as clearer information about the pharmacological management of the condition in the patients, is recommended.

Cyclophilin A: An Independent Prognostic Factor for Survival in Patients with Metastatic Colorectal Cancer Treated with Bevacizumab and Chemotherapy

Colorectal cancer (CRC) ranks as second most common cause of cancer-related deaths. The CRC management considerably improved in recent years, especially due to biological therapies such as bevacizumab. The lack of predictive or prognostic biomarkers remains one of the major disadvantages of using bevacizumab in the CRC management. We performed a prospective study to analyze the prognostic and predictive roles of three potential serum biomarkers (Cyclophilin A (CypA), copeptin and Tie2) investigated by ELISA in 56 patients with metastatic CRC undergoing bevacizumab and chemotherapy between May 2019 and September 2021 at baseline and after one and six months of therapy. We showed that low levels of CypA at baseline and after one month of treatment were associated with better overall survival (OS) (42 versus 24 months, p = 0.029 at baseline; 42 versus 25 months, p = 0.039 after one month). For copeptin and Tie2, Kaplan-Meier curves showed no correlation between these biomarkers and OS or progression-free survival. When adjusting for baseline and post-treatment factors, a multivariate Cox analysis showed that low values of CypA at baseline and after one month of treatment were independent prognostic factors for OS and correlated with a better prognosis in metastatic CRC patients.

Integrated Analysis of miRNA and mRNA Regulation Network in Hypertension

Hypertension is the most common chronic disease. Early diagnosis is helpful for early medical intervention. The miRNAs and the messenger RNAs (mRNAs) network may be valuable disease diagnosis markers. We aimed to explore the diagnostic value of the miRNA-mRNA network for hypertension patients. Data of miRNAs and mRNAs expression were obtained from the Gene Expression Omnibus database. The weighted gene co-expression network analysis was performed to screen hypertension-related gene modules, and these genes undergone functional enrichment analysis using "clusterProfiler" package. Differential expression analysis was applied on miRNAs expression profiles using "limma" package. TargetScanHuman and miRDB databases were used to select target mRNAs. Cytoscape software was used to visualize the miRNA-mRNA regulation network. P value < 0.05 was considered statistically significant after t test. There were 123 screened mRNAs which were enriched in 161 Gene ontology (GO) terms and 14 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Thirty-five differentially expressed miRNAs (DEMs) are found in the GSE75670. Totally 36 miRNA-mRNA pairs were obtained after the integrated analysis, and three mRNAs and the hsa-miRNA-5589-5p were identified as key joints. Hub genes, KIAA0513, ARID3A and LRPAP1, and key hsa-miRNA-5589-5p are potential diagnostic biomarkers for hypertension. Our findings are promising in the clinical application, conducive to early detection and prompt intervention of hypertension.

Proteomic mapping reveals dysregulated angiogenesis in the cerebral arteries of rats with early-onset hypertension

Hypertension is associated with the presence of vascular abnormalities, including remodeling and rarefaction. These processes play an important role in cerebrovascular disease development; however, the mechanistic changes leading to these diseases are not well characterized. Using data-independent acquisition-based mass spectrometry analysis, here we determined the protein changes in cerebral arteries in pre- and early-onset hypertension from the spontaneously hypertensive rat (SHR), a model that resembles essential hypertension in humans. Our analysis identified 125 proteins with expression levels that were significantly upregulated or downregulated in 12-week-old spontaneously hypertensive rats compared to normotensive Wistar Kyoto rats. Using an angiogenesis enrichment analysis, we further identified a critical imbalance in angiogenic proteins that promoted an anti-angiogenic profile in cerebral arteries at early onset of hypertension. In a comparison to previously published data, we demonstrate that this angiogenic imbalance is not present in mesenteric and renal arteries from age-matched SHRs. Finally, we identified two proteins (Fbln5 and Cdh13), whose expression levels were critically altered in cerebral arteries compared to the other arterial beds. The observation of an angiogenic imbalance in cerebral arteries from the SHR reveals critical protein changes in the cerebrovasculature at the early onset of hypertension and provides novel insights into the early pathology of cerebrovascular disease.

Common Yoga Protocol Increases Peripheral Blood CD34+ Cells: An Open-Label Single-Arm Exploratory Trial

Purpose

Physical inactivity can be a cause of various lifestyle disorders including atherosclerosis, diabetes, hypertension, and cardiovascular diseases (CVDs). Lifestyle modification by the inclusion of Yoga and similar activities has shown beneficial effects on disease prevention and psychological management. However, the molecular mechanism at the cellular level is unknown. This study aims to identify the molecular response at systemic level generated after three months of Common Yoga Protocol (CYP) practice.

Methods

A total of 25 healthy adult females were recruited for this study (25 to 55 years). After the drop out of 6 participants at baseline and 2 participants after 1 month; blood samples of 17 participants were assessed. Blood samples were assessed for lipid profile, CD34+ cell enumeration and angiogenesis markers (ie, VEGF, Angiogenin and BDNF) at baseline (before intervention), after one month and after three months of Common Yoga Protocol (CYP) practice. The psychological health of the participants was assessed at baseline and after three months of CYP practice. The psychological tests used were General Health Questionnaire (GHQ), State-Trait Anxiety Inventory (STAI), Trail Making Test A & B, Digit symbol test, Digit symbol substitution test.

Results

After 3 months of intervention, blood samples of 17 participants were collected and following results were reported (1) percentage of CD34+ cells increased significantly after 3 months of CYP practice (from 18.18±7.32 cells/μL to 42.48±18.83 cells/μL) (effect size: W, 0.40; 95% CI, p = 0.001) (2) neurogenesis marker, ie, BDNF showed a significant change with time after 3 months of CYP intervention (effect size: W, 0.431, 95% CI; p = 0.002), (3) HDL showed an increasing trend (non-significant) after three months of CYP practice (53.017±1.28 mg/dl to 63.94±5.66 mg/dl) (effect size: W, 0.122; 95% CI; p = 0.126) (4) General Health score (10.64 ± 3.53 to 6.52 ± 3.12) (effect size: d, 0.98; 95% CI; p = 0.001) along with visual and executive function improved (69.94±26.21 to 61.88±28.55 (time taken in seconds)) (effect size: d, 0.582; 95% CI; p = 0.036), also stress and anxiety showed reduction (effect size: d, 0.91; 95% CI; p = 0.002) (5) a significant positive correlation was found between: HDL with VEGF (r = 0.547, p = 0.023) and BDNF (r = 0.538, p = 0.039) after 3 months of intervention; also, a significant positive correlation was found between VEGF with BDNF (r = 0.818, p ≤ 0.001) and Angiogenin (r = 0.946, p ≤ 0.001), also, BDNF was also positively correlated with Angiogenin (r = 0.725, p = 0.002) at both 1 month and 3 months after intervention. Also, VEGF and BDNF showed a significantly negative correlation with stress and anxiety questionnaire after the intervention.

Conclusion

The current study provides insights into the molecular response to CYP practice at systemic level. The results suggest that CYP practice indeed increased CD34+ cells in peripheral blood and BDNF also showed a significant change after the intervention. An overall improvement in general health and psychology of the participants was also observed.

Genetic Deletion of the LINC00520 Homolog in Mouse Aggravates Angiotensin II-Induced Hypertension

(1) Background: Hypertension is a complex, multifactorial disease that is caused by genetic and environmental factors. Apart from genetic predisposition, the mechanisms involved in this disease have yet to be fully understood. We previously reported that LEENE (lncRNA enhancing endothelial nitric oxide expression, transcribed from LINC00520 in the human genome) regulates endothelial cell (EC) function by promoting the expression of endothelial nitric oxide synthase (eNOS) and vascular growth factor receptor 2 (VEGFR2). Mice with genetic deletion of the LEENE/LINC00520 homologous region exhibited impaired angiogenesis and tissue regeneration in a diabetic hindlimb ischemia model. However, the role of LEENE in blood pressure regulation is unknown. (2) Methods: We subjected mice with genetic ablation of leene and wild-type littermates to Angiotensin II (AngII) and monitored their blood pressure and examined their hearts and kidneys. We used RNA-sequencing to identify potential leene-regulated molecular pathways in ECs that contributed to the observed phenotype. We further performed in vitro experiments with murine and human ECs and ex vivo experiments with murine aortic rings to validate the select mechanism. (3) Results: We identified an exacerbated hypertensive phenotype of leene-KO mice in the AngII model, evidenced by higher systolic and diastolic blood pressure. At the organ level, we observed aggravated hypertrophy and fibrosis in the heart and kidney. Moreover, the overexpression of human LEENE RNA, in part, restored the signaling pathways impaired by leene deletion in murine ECs. Additionally, Axitinib, a tyrosine kinase inhibitor that selectively inhibits VEGFR suppresses LEENE in human ECs. (4) Conclusions: Our study suggests LEENE as a potential regulator in blood pressure control, possibly through its function in ECs.

No association of a Vascular endothelial growth factor A (VEGFA) gene polymorphism with pre-eclampsia among pregnant women in Uganda

BACKGROUND

Vascular endothelial growth factor A (VEGFA) is a major angiogenic factor that plays an important role in the formation of blood vessels during embryonic development. VEGFA has been implicated in the pathophysiology of pre-eclampsia (PE), since pre-eclamptic women present with reduced levels of free circulating VEGFA. The 3' untranslated region (3'-UTR) of the VEGFA gene consists of elements that regulate the transcription and hence expression of the VEGFA protein in circulation. Hence it is suggested that variations thereof could underlie the reduced VEGFA levels observed in pre-eclamptic women. The purpose of this study was to investigate presence of the + 936C/T polymorphism, a common single nucleotide polymorphism (SNP) in the 3'-UTR of the VEGFA gene, and determine its association with PE among pregnant women in Uganda.

RESULTS

There was no significant difference observed in the allele and genotype frequencies of the + 936C/T 3' UTR-VEGFA polymorphism between pre-eclamptic and normotensive pregnant women (P > 0.05). Additionally, there was no significant difference in the median plasma levels of free VEGFA among women with the wild type, CT and TT genotypes of the + 936C/T VEGFA polymorphism (median = 0.84 pg/mL (IQR = 0.39-1.41) Vs 1.05 (0.61-1.18) Vs 1.05 (1.05-1.05) respectively, p-value = 0.7161).

CONCLUSIONS

These study findings indicate that the + 936C/T 3' UTR-VEGFA polymorphism had no significant association with increased susceptibility to PE among women in Uganda. Further studies with a larger sample size are recommended.

Association of Cerebral Oxygenation During Exercise With Target Organ Damage in Middle-Aged Hypertensive and Normotensive Individuals

BACKGROUND

The brain is one of the main target organs affected by hypertension. Impaired cerebral oxygenation during exercise is an indicator of cerebral dysfunction. We aimed to investigate whether cerebral oxygenation during exercise correlates with subclinical markers of early target organ damage in a population of middle-aged, newly diagnosed hypertensive and healthy individuals.

METHODS

Carotid intima-media thickness (cIMT) was measured using ultrasound, arterial stiffness was estimated measuring the augmentation index and pulse wave velocity, and retinal vessel diameter was assessed via the central retinal-arteriolar and vein equivalent and retinal-arteriovenous ratio. Participants (n = 93) performed a 3-minute isometric handgrip exercise. Cerebral prefrontal oxygenation was measured continuously using near infrared spectroscopy. The average exercise responses in oxygenated hemoglobin (O2Hb), deoxygenated hemoglobin (HHb), and total hemoglobin (tHb) were assessed. Univariate analyses were performed; partial correlation was used to account for traditional cardiovascular risk factors to identify independent associations between cerebral-oxygenation indices and early markers of target organ damage.

RESULTS

Mean cIMT was negatively correlated with the average exercise response in cerebral oxygenation (rhoO2Hb = -0.348, PO2Hb = 0.001; rhotHb = -0.253, Pthb = 0.02). Augmentation index was negatively correlated with cerebral oxygenation during exercise (rhoO2Hb = -0.374, P < 0.001; rhotHb = -0.332, P = 0.02), whereas no significant correlation was observed between pulse wave velocity and cerebral-oxygenation indices. In the adjusted analysis, cerebral oxygenation was correlated with central retinal arteriolar diameter (CRAE r = 0.233, P = 0.043).

CONCLUSIONS

Our novel findings suggest that indices of lower cerebral oxygenation during a submaximal physical task are associated with markers of early, subclinical target organ damage, namely increased cIMT, arterial stiffness, and arteriolar retinal narrowing in newly diagnosed, untreated, hypertensive individuals.

Biological aspects in controlling angiogenesis: current progress

All living beings continue their life by receiving energy and by excreting waste products. In animals, the arteries are the pathways of these transfers to the cells. Angiogenesis, the formation of the arteries by the development of pre-existed parental blood vessels, is a phenomenon that occurs naturally during puberty due to certain physiological processes such as menstruation, wound healing, or the adaptation of athletes' bodies during exercise. Nonetheless, the same life-giving process also occurs frequently in some patients and, conversely, occurs slowly in some physiological problems, such as cancer and diabetes, so inhibiting angiogenesis has been considered to be one of the important strategies to fight these diseases. Accordingly, in tissue engineering and regenerative medicine, the highly controlled process of angiogenesis is very important in tissue repairing. Excessive angiogenesis can promote tumor progression and lack of enough angiogensis can hinder tissue repair. Thereby, both excessive and deficient angiogenesis can be problematic, this review article introduces and describes the types of factors involved in controlling angiogenesis. Considering all of the existing strategies, we will try to lay out the latest knowledge that deals with stimulating/inhibiting the angiogenesis. At the end of the article, owing to the early-reviewed mechanical aspects that overshadow angiogenesis, the strategies of angiogenesis in tissue engineering will be discussed.

Circulating Levels of MicroRNAs Associated With Hypertension: A Cross-Sectional Study in Male and Female South African Participants

MicroRNAs are non-coding, post-transcriptional regulators of gene expression and their dysregulation has been associated with development of various diseases, including hypertension. Consequently, understanding their role in the pathogenesis and progression of disease is essential. Prior research focusing on microRNAs in disease has provided a basis for understanding disease prognosis and offered possible channels for therapeutic interventions. Herein, we aimed to investigate possible differences in the expression profiles of five microRNAs in the blood of participants grouped on the basis of their hypertension status. This was done to elucidate the possible roles played by these microRNAs in the development of hypertension. Using quantitative reverse transcription polymerase chain reaction, we evaluated the expression levels of miR-126-3p, 30a-5p, 182-5p, 30e-3p, and 1299 in the whole blood of 1456 participants, normotensive (n = 573), screen-detected hypertensive (n = 304) and known hypertensive (n = 579). The expression of miR-126-3p and 182-5p was significantly higher in known hypertensives relative to both screen-detected hypertensives and normotensives, and also in screen-detected hypertensives vs normotensives. A significant association between the expression of miR-126-3p, 182-5p, and 30a-5p and known hypertension was also evident. This study demonstrated dysregulated miR-126-3p, 182-5p, and 30a-5p expression in hypertension, highlighting the possible efficacy of these microRNAs as targets for the diagnosis of hypertension as well as the development of microRNA-based therapies.

Intermittent hypoxia changes the interaction of the kinin-VEGF system and impairs myocardial angiogenesis in the hypertrophic heart

Intermittent hypoxia (IH) is a feature of obstructive sleep apnea (OSA), a condition highly associated with hypertension-related cardiovascular diseases. Repeated episodes of IH contribute to imbalance of angiogenic growth factors in the hypertrophic heart, which is key in the progression of cardiovascular complications. In particular, the interaction between vascular endothelial growth factor (VEGF) and the kallikrein-kinin system (KKS) is essential for promoting angiogenesis. However, researchers have yet to investigate experimental models of IH that reproduce OSA, myocardial angiogenesis, and expression of KKS components. We examined temporal changes in cardiac angiogenesis in a mouse IH model. Adult male C57BI/6 J mice were implanted with Matrigel plugs and subjected to IH for 1-5 weeks with subsequent weekly histological evaluation of vascularization. Expression of VEGF and KKS components was also evaluated. After 3 weeks, in vivo myocardial angiogenesis and capillary density were decreased, accompanied by a late increase of VEGF and its type 2 receptor. Furthermore, IH increased left ventricular myocardium expression of the B2 bradykinin receptor, while reducing mRNA levels of B1 receptor. These results suggest that in IH, an unexpected response of the VEGF and KKS systems could explain the reduced capillary density and impaired angiogenesis in the hypoxic heart, with potential implications in hypertrophic heart malfunction.

Hypertension impairs hypoxia-induced angiogenesis in men

OBJECTIVE

The inability of the organism to appropriately respond to hypoxia results in abnormal cell metabolism and function. Hypoxia-induced angiogenesis seems to be suppressed in experimental models of hypertension; however, this hypothesis has not been tested in humans. We examined changes in endothelial biomarkers and vascular chemoattraction/angiogenic capacity in response to isocapnic hypoxia in hypertensive men.

METHODS

Twelve normotensive (38 ± 10 years) and nine hypertensive men (45 ± 11 years) were exposed to 5-min trials of normoxia (21% O2) and isocapnic hypoxia (10% O2). During the last minute of each trial, venous blood was drawn. Endothelial progenitor cells (EPCs; CD45/CD34/VEGFR2), endothelial microvesicles (apoptotic EMVs, CD42b/CD31/AnnexinV; endothelial activation, CD62E/CD144), nitrite, vascular endothelial growth factor (VEGF), and stromal cell-derived factor 1 (SDF-1) were measured.

RESULTS

During normoxia, EPCs, nitrite, endothelial activation, and SDF-1 were similar between groups, whereas VEGF was lower (P = 0.02) and apoptotic EMVs tended to increase (P = 0.07) in hypertensive men. During isocapnic hypoxia, endothelial activation increased in both groups (normotensive, P = 0.007 vs. normoxia; hypertensive, P = 0.006 vs. normoxia), whereas EMVs were higher only in the hypertensive group (P = 0.03 vs. normotensive). EPCs (P = 0.01 vs. normoxia; P = 0.03 vs. hypertensive men), NO (P = 0.01 vs. normoxia; P = 0.04 vs. hypertensive), and VEGF (P = 0.02 vs. normoxia; P = 0.0005 vs. hypertensive) increased only in normotensive individuals in response to isocapnic hypoxia. SDF-1 did not change in either group.

CONCLUSION

These results suggest that hypertension-induced impairment in angiogenesis in response to isocapnic hypoxia is related to disrupted NO bioavailability, VEGF chemotactic signaling, and EPC mobilization.

Imbalance in the Levels of Angiogenic Factors in Patients with Acute and Chronic Central Serous Chorioretinopathy

BACKGROUND

The pathogenesis of central serous chorioretinopathy (CSC) remains a subject of intensive research. We aimed to determine correlations between plasma levels of selected angiogenic factors and different forms of CSC.

METHODS

Eighty patients were enrolled in the study including 30 with a chronic form of CSC, 30 with acute CSC, and 20 controls. Presence of active CSC was determined by fluorescein angiography (FA), indocyanine green angiography (ICGA), and swept-source optical coherence tomography (SS-OCT). Plasma concentrations of angiopoietin-1, endostatin, fibroblast growth factor, placental growth factor (PlGF), platelet-derived growth factor (PDGF-AA), thrombospondin-2, vascular endothelial growth factor (VEGF), VEGF-D, and pigment epithelium-derived factor were measured, and the results were compared between groups. Additionally, mean choroidal thickness (CT) was measured in all patients.

RESULTS

Levels of angiopoietin-1 (p = 0.008), PlGF (p = 0.045), and PDGF-AA (p = 0.033) differed significantly between the three groups. Compared with the controls, VEGF (p = 0.024), PlGF (p = 0.013), and PDGF-AA (p = 0.012) were downregulated in the whole CSC group, specifically PDGF-AA (p = 0.002) in acute CSC and angiopoietin-1 (p = 0.007) in chronic CSC. An inverse correlation between mean CT and VEGF levels was noted in CSC patients (rho = -0.27, p = 0.044).

CONCLUSIONS

Downregulated angiopoietin-1, VEGF, PDGF-AA, and PlGF levels may highlight the previously unknown role of the imbalanced levels of proangiogenic and antiangiogenic factors in the pathogenesis of CSC. Moreover, downregulated VEGF levels may suggest that choroidal neovascularization in CSC is associated with arteriogenesis rather than angiogenesis.

High-salt intake affects retinal vascular tortuosity in healthy males: an exploratory randomized cross-over trial

The retinal microcirculation is increasingly receiving credit as a relatively easily accessible microcirculatory bed that correlates closely with clinical cardiovascular outcomes. The effect of high salt (NaCl) intake on the retinal microcirculation is currently unknown. Therefore, we performed an exploratory randomized cross-over dietary intervention study in 18 healthy males. All subjects adhered to a two-week high-salt diet and low-salt diet, in randomized order, after which fundus photographs were taken and assessed using a semi-automated computer-assisted program (SIVA, version 4.0). Outcome parameters involved retinal venular and arteriolar tortuosity, vessel diameter, branching angle and fractal dimension. At baseline, participants had a mean (SD) age of 29.8 (4.4) years and blood pressure of 117 (9)/73 (5) mmHg. Overall, high-salt diet significantly increased venular tortuosity (12.2%, p = 0.001). Other retinal parameters were not significantly different between diets. Changes in arteriolar tortuosity correlated with changes in ambulatory systolic blood pressure (r = - 0.513; p = 0.04). In conclusion, high-salt diet increases retinal venular tortuosity, and salt-induced increases in ambulatory systolic blood pressure associate with decreases in retinal arteriolar tortuosity. Besides potential eye-specific consequences, both phenomena have previously been associated with hypertension and other cardiovascular risk factors, underlining the deleterious microcirculatory effects of high salt intake.

Fibulin-3 affects vascular endothelial function and is regulated by angiotensin II

OBJECTIVE

The aim of the present study was to investigate the effect of fibulin-3 on vascular endothelial function, and to explore the relevant underlying mechanism with regard to the involvement of angiotensin II (AngII).

METHODS

One hundred and eight patients with essential hypertension (EH) and 31 controls were included to measure the flow-mediated dilatation (FMD). Serum fibulin-3 and AngII were examined using enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay. Stable transfection of fibulin-3 was conducted on human umbilical vein endothelial cells (HUVECs) and SV40T-transformed HUVECs (PUMC-HUVEC-T1 cells). Cell counting kit-8 assay, cell cycle assay, wound healing assay, Transwell assay, apoptosis assay, and tube formation assay were subsequently performed. The expression of angiogenesis-associated genes [endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor A (VEGFA)] were measured by western blot analysis. HUVECs and PUMC-HUVEC-T1 cells were treated with AngII, and with or without an inhibitor of nuclear factor κB (NF-κB), BAY 11-7082. Pro-inflammatory cytokines [interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α)] were detected by ELISA. The expression levels of fibulin-3 and p65 were then measured by western blotting.

RESULTS

Lower levels of serum fibulin-3 were accompanied by poorer FMD and higher levels of serum AngII in patients with EH. Fibulin-3 overexpression promoted cell proliferation, migration, and angiogenesis, but led to an inhibition of apoptosis. By contrast, fibulin-3 downregulation inhibited cell proliferation, migration and angiogenesis, but promoted apoptosis. AngII induced inflammation and inhibited the expression of fibulin-3. BAY 11-7082 eliminated the inhibitory effect of AngII on fibulin-3.

CONCLUSIONS

Taken together, the results of the present study have shown that serum fibulin-3 may be a predictor of vascular endothelial function in patients with EH. Fibulin-3 gene may also have a beneficial role in repairing the vascular endothelium. Furthermore, the results also suggested that fibulin-3 gene was suppressed by AngII via the NF-κB signaling pathway.

Microvascular disease in chronic kidney disease: the base of the iceberg in cardiovascular comorbidity

Chronic kidney disease (CKD) is a relentlessly progressive disease with a very high mortality mainly due to cardiovascular complications. Endothelial dysfunction is well documented in CKD and permanent loss of endothelial homeostasis leads to progressive organ damage. Most of the vast endothelial surface area is part of the microcirculation, but most research in CKD-related cardiovascular disease (CVD) has been devoted to macrovascular complications. We have reviewed all publications evaluating structure and function of the microcirculation in humans with CKD and animals with experimental CKD. Microvascular rarefaction, defined as a loss of perfused microvessels resulting in a significant decrease in microvascular density, is a quintessential finding in these studies. The median microvascular density was reduced by 29% in skeletal muscle and 24% in the heart in animal models of CKD and by 32% in human biopsy, autopsy and imaging studies. CKD induces rarefaction due to the loss of coherent vessel systems distal to the level of smaller arterioles, generating a typical heterogeneous pattern with avascular patches, resulting in a dysfunctional endothelium with diminished perfusion, shunting and tissue hypoxia. Endothelial cell apoptosis, hypertension, multiple metabolic, endocrine and immune disturbances of the uremic milieu and specifically, a dysregulated angiogenesis, all contribute to the multifactorial pathogenesis. By setting the stage for the development of tissue fibrosis and end organ failure, microvascular rarefaction is a principal pathogenic factor in the development of severe organ dysfunction in CKD patients, especially CVD, cerebrovascular dysfunction, muscular atrophy, cachexia, and progression of kidney disease. Treatment strategies for microvascular disease are urgently needed.

Differences in Female and Male-to-Female Transgender Facial Skin Micro-Vessel Density

Importance: The risk of hematoma formation after rhytidectomy is gender associated and can lead to postoperative complications. The literature to help explain and elucidate the mechanism behind this gender-associated risk is poorly developed and requires further investigation. Objective: The objective of this study was to compare facial skin micro-vessel density of female and male-to-female (MTF) transgender patients undergoing rhytidectomy to better understand the mechanism of gender-correlated hematoma risk factors. The authors hypothesized that transgender patients would have higher micro-vessel density compared with female patients. Design, Setting, and Participants: This was a prospective histopathological analysis of pre- and post-auricular facial skin samples from patients undergoing primary rhytidectomy. Patient clinical data and skin samples were collected. Histopathological slides were prepared and stained with CD-31, a marker of vessel endothelium, followed by image analysis allowing for micro-vessel stained pixel counts and calculated pixel density comparisons at a single academic hospital. Female, MTF transgender, and male patients >18 years of age were studied. Exposure: Patients undergoing primary rhytidectomy between 2015 and 2018. Main Outcomes: Gender-associated pre- and post-auricular micro-vessel pixel density. Results: Forty-one patients contributed skin samples for analysis. Post-auricular micro-vessel pixel density was greater than pre-auricular density (mean difference post-pre 0.359 percentage points [p.p.], standard error [SE] = 0.135, p = 0.009). The mean post-auricular micro-vessel pixel density was 1.60% (SE = 0.13 p.p.), 2.16% (SE = 0.19 p.p.), and 2.77% (SE = 0.34 p.p.) for female, transgender, and male patients, respectively (p = 0.016). Pre-auricular micro-vessel pixel density showed no difference among females, males, and transgender patients (p = 0.30). Gender was a strong predictor of increased post-auricular micro-vessel pixel density on stepwise linear regression, but it did not predict pre-auricular micro-vessel density. Both preoperative hair removal and a history of hypertension were associated with increased pre-auricular micro-vessel density. Conclusions and Relevance: Facial skin micro-vessel density differs by gender, in addition to pre- and post-auricular locations in patients undergoing rhytidectomy.

Overlapping pathogenic signalling pathways and biomarkers in preeclampsia and cardiovascular disease

OBJECTIVES

Preeclampsia is a cardiovascular pregnancy complication that occurs in 5-10% of pregnancies and it can lead to a number of pregnancy complications including maternal and foetal death. Long-term, preeclampsia is associated with up to 8-fold increased risk of cardiovascular disease (CVD) for both mothers and their offspring. The lack of mechanistic data in relation to the causes or consequences of preeclampsia has prevented the development of effective therapeutic and monitoring strategies.

STUDY DESIGN

This study investigates common underlying mechanisms of preeclampsia and CVD, specifically hypertension and heart failure with preserved ejection fraction (HFpEF), using "in silico" approach of publicly available datasets. Integrated techniques were designed to mine data repositories and identify relevant biomarkers associated with these three conditions.

MAIN OUTCOMES MEASURES

The knowledge base tools were employed that enabled the analysis of these biomarkers to discover potential molecular and biological links between these three conditions.

RESULTS

Our bioinformatics "in silico" analyses of the publically available datasets identified 76 common biomarkers between preeclampsia, hypertension and HFpEF. These biomarkers were representative of 29 pathways commonly enriched across the three conditions which were largely related to inflammation, metabolism, angiogenesis, remodelling, haemostasis, apoptosis and the renin-angiotensin-aldosterone (RAAS) system.

CONCLUSIONS

This bioinformatics approach uses the wealth of scientific data available in public repositories to gain a deeper understanding of the overlapping pathogenic mechanisms of associated diseases, which could be explored as biomarkers or targets to prevent long-term cardiovascular complications such as hypertension and HFpEF following preeclampsia.

The role of exercise in the reversal of IGF-1 deficiencies in microvascular rarefaction and hypertension

Hypertension has been linked with peripheral and central reductions in vascular density, and with devastating effects on brain function. However, the underlying mechanisms in the relationship between blood pressure and cognitive impairment have yet to be fully elucidated. Here, we review compelling evidence from two lines of inquiry: one that links microvascular rarefaction with insulin-like growth factor 1 (IGF-1) deficiencies, and another which posits that vascular dysfunction precedes hypertension. Based on the findings from experimental and clinical studies, we propose that these lines of evidence converge, and suggest that age-related declines in IGF-1 concentrations precede microvascular rarefaction, initiate an increase in vascular resistance, and therefore are causally linked to onset of hypertension. Physical exercise provides a relevant model for supporting our premise, given the well-established effects of exercise in attenuating vascular dysfunction, hypertension, IGF-1 deficiency, and cognitive decline. We highlight here the role of exercise-induced increases in blood flow in improving vascular integrity and enhancing angiogenesis via the actions of IGF-1, resulting in reversal of rarefaction and hypertension, and enhancement of cerebral blood flow and cognition.

Urinary metal/metalloid levels in relation to hypertension among occupationally exposed workers

Occupational exposure to metals can have an adverse effect on the cardiovascular system. However, epidemiological studies of the associations of metals expose with hypertension among occupationally exposed workers were limited. The aim of this study was to investigate the potential association between urinary metal levels and the risk of hypertension among molybdenum miners and iron and steel foundry workers. The cross-sectional study had 395 participants. Urinary metal levels were determined by inductively coupled plasma mass spectrometry. Log-binomial regression model and two-piece-wise regression model were applied to assess the dose-response relationship between metal exposure and hypertension. We observed that increased prevalence ratios for hypertension among the quartile of urinary concentrations of molybdenum, arsenic and lead were positive (all P for trend <0.05). Compared with the lowest quartiles, participants in the highest quartiles of molybdenum, arsenic and lead had a 2.58-fold, 4.30-fold and 4.85-fold increased probability of having hypertension, respectively. In the threshold effect analyses, we found the relationship was nonlinear between urinary molybdenum, cobalt, cadmium, arsenic and lead concentrations and the prevalence of hypertension. In addition, Pb, Mo, As and Co may have joint effect, and a strong positive correlation with the prevalence of hypertension. Conversely, the association between the joint effect of Cd, Pb and Mo versus the prevalence of hypertension is not significant. We provide reference levels of molybdenum, cobalt, cadmium, arsenic and lead that can be used to assess the effects of occupational metal exposure on hypertension.

Cardiovascular optoacoustics: From mice to men - A review

Imaging has become an indispensable tool in the research and clinical management of cardiovascular disease (CVD). An array of imaging technologies is considered for CVD diagnostics and therapeutic assessment, ranging from ultrasonography, X-ray computed tomography and magnetic resonance imaging to nuclear and optical imaging methods. Each method has different operational characteristics and assesses different aspects of CVD pathophysiology; nevertheless, more information is desirable for achieving a comprehensive view of the disease. Optoacoustic (photoacoustic) imaging is an emerging modality promising to offer novel information on CVD parameters by allowing high-resolution imaging of optical contrast several centimeters deep inside tissue. Implemented with illumination at several wavelengths, multi-spectral optoacoustic tomography (MSOT) in particular, is sensitive to oxygenated and deoxygenated hemoglobin, water and lipids allowing imaging of the vasculature, tissue oxygen saturation and metabolic or inflammatory parameters. Progress with fast-tuning lasers, parallel detection and advanced image reconstruction and data-processing algorithms have recently transformed optoacoustics from a laboratory tool to a promising modality for small animal and clinical imaging. We review progress with optoacoustic CVD imaging, highlight the research and diagnostic potential and current applications and discuss the advantages, limitations and possibilities for integration into clinical routine.

Assessment of Migration of Human MSCs through Fibrin Hydrogels as a Tool for Formulation Optimisation

Control of cell migration is fundamental to the performance of materials for cell delivery, as for cells to provide any therapeutic effect, they must migrate out from the delivery material. Here the influence of fibrinogen concentration on the migration of encapsulated human mesenchymal stem cells (hMSCs) from a cell spheroid through fibrin hydrogels is tracked over time. Fibrin was chosen as a model material as it is routinely employed as a haemostatic agent and more recently has been applied as a localised delivery vehicle for potential therapeutic cell populations. The hydrogels consisted of 5 U/mL thrombin and between 5 and 50 mg/mL fibrinogen. Microstructural and viscoelastic properties of different compositions were evaluated using SEM and rheometry. Increasing the fibrinogen concentration resulted in a visibly denser matrix with smaller pores and higher stiffness. hMSCs dispersed within the fibrin gels maintained cell viability post-encapsulation, however, the migration of cells from an encapsulated spheroid revealed that denser fibrin matrices inhibit cell migration. This study provides the first quantitative study on the influence of fibrinogen concentration on 3D hMSC migration within fibrin gels, which can be used to guide material selection for scaffold design in tissue engineering and for the clinical application of fibrin sealants.

Argininosuccinate Lyase Deficiency Causes an Endothelial-Dependent Form of Hypertension

Primary hypertension is a major risk factor for ischemic heart disease, stroke, and chronic kidney disease. Insights obtained from the study of rare Mendelian forms of hypertension have been invaluable in elucidating the mechanisms causing primary hypertension and development of antihypertensive therapies. Endothelial cells play a key role in the regulation of blood pressure; however, a Mendelian form of hypertension that is primarily due to endothelial dysfunction has not yet been described. Here, we show that the urea cycle disorder, argininosuccinate lyase deficiency (ASLD), can manifest as a Mendelian form of endothelial-dependent hypertension. Using data from a human clinical study, a mouse model with endothelial-specific deletion of argininosuccinate lyase (Asl), and in vitro studies in human aortic endothelial cells and induced pluripotent stem cell-derived endothelial cells from individuals with ASLD, we show that loss of ASL in endothelial cells leads to endothelial-dependent vascular dysfunction with reduced nitric oxide (NO) production, increased oxidative stress, and impaired angiogenesis. Our findings show that ASLD is a unique model for studying NO-dependent endothelial dysfunction in human hypertension.

The superoxide dismutase mimetic tempol does not alleviate glucocorticoid-mediated rarefaction of rat skeletal muscle capillaries

Sustained elevations in circulating glucocorticoids elicit reductions in skeletal muscle microvascular content, but little is known of the underlying mechanisms. We hypothesized that glucocorticoid‐induced oxidative stress contributes to this phenomenon. In rats that were implanted with corticosterone (CORT) or control pellets, CORT caused a significant decrease in muscle glutathione levels and a corresponding increase in protein carbonylation, an irreversible oxidative modification of proteins. Decreased endothelial nitric oxide synthase and increased endothelin‐1 mRNA levels were detected after 9 days of CORT, and blood flow to glycolytic muscles was diminished. Control and CORT rats were treated concurrently with drinking water containing the superoxide dismutase mimetic tempol (172 mg/L) or the α‐1 adrenergic receptor antagonist prazosin (50 mg/L) for 6 or 16 days. Both tempol and prazosin alleviated skeletal muscle protein carbonylation. Tempol failed to prevent CORT‐mediated capillary rarefaction and was ineffective in restoring skeletal muscle blood flow. In contrast, prazosin blocked capillary rarefaction and restored skeletal muscle blood flow to control levels. The failure of tempol to prevent CORT‐induced skeletal muscle microvascular rarefaction does not support a dominant role of superoxide‐induced oxidative stress in this process. Although a decrease in protein carbonylation was observed with prazosin treatment, our data suggest that the maintenance of skeletal muscle microvascular content is related more closely with counteracting the CORT‐mediated influence on skeletal muscle vascular tone.

Macro- and Microelement Status in Animal and Human Hypertension: the Role of the ACE Gene I/D Polymorphism

Genetic factors that predispose to hypertension may contribute to element disturbances observed in hypertensive patients. We tested the hypothesis that the deletion allele of the angiotensin-converting enzyme (ACE) gene is associated with element imbalances in hypertension. The concentrations of elements in genetically predisposed to hypertension rats (SHRs) and their controls (WKY rats) were also examined. ICP-MS was used for elemental analysis of human hair and animal fur. Genotyping was performed by PCR. We also measured micronuclei frequency and distribution of peripheral blood leukocytes in cell cycle phases by flow cytometry and studied the correlations of these parameters with element contents. In general, the tendency for higher levels of toxic and lower levels of essential elements is observed in hypertension, specifically in patients carrying the D allele. Hypertensive men had significantly higher Be, V, Cr, As, Mo, Ag, Sb, and Na levels and lower Ca, Zn, Ba, and U levels compared with control subjects; the differences were not significant for Mg, Al, K, Mn, Fe, Co, Ni, Cu, Se, Cd, Tl, Pb, and Th. The D allele was associated with higher Be, Mo, and Th levels and lower Zn, Se, and Tl levels. The concentrations of Ca, Co, Mo and U were higher in SHR than those in the WKY rats. Mo, an antagonist of Cu, positively correlated with the S-phase cells, and Cu positively correlated with micronuclei frequency. The results suggest an involvement of the ACE I/D polymorphism in element imbalances in hypertension and attract attention to the possible significant role of genetic factors in Mo accumulation.

Ultrasonic evaluation of renal cortex arterial area enables differentiation between hypertensive and glomerulonephritis-related chronic kidney disease

PURPOSE

Identifying the primary etiology of cardio-renal syndrome in a timely manner remains an ongoing challenge in nephrology. We hypothesized that hypertensive kidney damage can be distinguished from chronic glomerulonephritis at an early stage of chronic kidney disease (CKD) using ultrasound (US) Doppler sonography.

METHODS

Fifty-six males (age 54 ± 15, BMI 28.3 ± 3.5 kg/m2) with hypertension and stable CKD at stages 2-4 [38 with essential hypertension (HT-CKD); 18 with glomerulonephritis (GN-CKD)] were studied. Blood tests, UACR, echocardiography, ABPM, carotid IMT, and an ultrasound dynamic tissue perfusion measurement (DTPM) of the renal cortex were performed.

RESULTS

HT-CKD patients had reduced proximal renal cortex perfusion as well as reduced total and proximal renal cortex arterial area. Proximal renal cortex arterial area ≤0.149 cm2 identified hypertension-related CKD with a sensitivity of 71% and a specificity of 78% (AUC 0.753, p < 0.001).

CONCLUSIONS

Evidence of diminished arterial vascularity or perfusion of renal proximal cortex, both derived from US Doppler, could be helpful in differentiating hypertensive nephropathy from glomerulonephritis-related CKD.

Sirtuin 3 Deficiency Accelerates Hypertensive Cardiac Remodeling by Impairing Angiogenesis

Background

Emerging evidence indicates that impaired angiogenesis may contribute to hypertension‐induced cardiac remodeling. The nicotinamide adenine dinucleotide–dependent deacetylase Sirtuin 3 (SIRT3) has the potential to modulate angiogenesis, but this has not been confirmed. As such, the aim of this study was to examine the relationship between SIRT3‐mediated angiogenesis and cardiac remodeling.

Methods and Results

Our experiments were performed on SIRT3 knockout and age‐matched wild‐type mice infused with angiotensin II (1400 ng/kg per minute) or saline for 14 days. After angiotensin II infusion, SIRT3 knockout mice developed more severe microvascular rarefaction and functional hypoxia in cardiac tissues compared with wild‐type mice. These events were concomitant with mitochondrial dysfunction and enhanced collagen I and collagen III expression, leading to cardiac fibrosis. Silencing SIRT3 facilitated angiotensin II–induced aberrant Pink/Parkin acetylation and impaired mitophagy, while excessive mitochondrial reactive oxygen species generation limited angiogenic capacity in primary mouse cardiac microvascular endothelial cells. Moreover, SIRT3 overexpression in cardiac microvascular endothelial cells enhanced Pink/Parkin‐mediated mitophagy, attenuated mitochondrial reactive oxygen species generation, and restored vessel sprouting and tube formation. In parallel, endothelial cell–specific SIRT3 transgenic mice showed decreased fibrosis, as well as improved cardiac function and microvascular network, compared with wild‐type mice with similar stimuli.

Conclusions

Collectively, these findings suggest that SIRT3 could promote angiogenesis through attenuating mitochondrial dysfunction caused by defective mitophagy.

Vasoactive peptides associate with treatment outcome ofbevacizumab-containing therapy in metastatic colorectal cancer

BACKGROUND

Hypertension is a common early adverse event of anti-angiogenic treatment of cancer and may associate with treatment response. However, blood pressure measurement as a surrogate response biomarker has methodological limitations, and predictive biomarkers of angiogenesis inhibitors are lacking. In disease associated with hypertension, vasoactive peptides have been linked to cardiovascular pressure load. Here, we have explored potential associations between circulating levels of vasoactive peptides and tumor response during bevacizumab-containing treatment of colorectal cancer.

MATERIAL AND METHODS

Metastatic colorectal cancer (mCRC) patients with available best objective response (ORR) and time to tumor progression (TTP) data were included from a randomized clinical trial investigating maintenance therapy after first line chemotherapy plus bevacizumab. Midregional-pro-adrenomedullin (MR-proADM), midregional-pro-atrial-natriuretic-peptide (MR-proANP), and C-terminal-prepro-vasopressin (Copeptin) vasoactive peptide concentrations were measured in plasma at baseline and after 6 weeks of chemotherapy and bevacizumab treatment (n = 97). We determined associations among clinical outcome (ORR and TTP), peptide levels, and hypertension (NCI-CTCAE 4.0 criteria), using Spearman's test, multiple linear regression, and Mann-Whitney's test.

RESULTS

Increasing levels of vasoactive peptides from baseline and after six weeks of treatment were associated with improved treatment outcome (MR-proADM: ORR, p = .0003; TTP, p = .05; MR-proANP: ORR, p = .05; TTP, p = .03; Copeptin: ORR, p = .10; TTP, p = .02). Patients with increasing levels of all three peptides (n = 28) versus increasing levels of one or two peptides (n = 59) showed a median TTP of 284 and 225 d, respectively (p = .02).

CONCLUSIONS

Our results suggest that increasing systemic levels of vasoactive peptides associate with improved tumor response and TTP in mCRC patients treated with a bevacizumab-containing regimen. These findings support the proposed link between the tumor vasculature and the cardiovascular system of the host. This should motivate further studies that investigate the potential role of vasoactive peptides as a novel class of dynamic biomarkers in the treatment of cancer.

Retinal Capillary Rarefaction in Patients with Type 2 Diabetes Mellitus

Purpose

In diabetes mellitus type 2, capillary rarefaction plays a pivotal role in the pathogenesis of end-organ damage. We investigated retinal capillary density in patients with early disease.

Methods

This cross-sectional study compares retinal capillary rarefaction determined by intercapillary distance (ICD) and capillary area (CapA), measured non-invasively and in vivo by scanning laser Doppler flowmetry, in 73 patients with type 2 diabetes, 55 healthy controls and 134 individuals with hypertension stage 1 or 2.

Results

In diabetic patients, ICD was greater (23.2±5.5 vs 20.2±4.2, p = 0.013) and CapA smaller (1592±595 vs 1821±652, p = 0.019) than in healthy controls after adjustment for differences in cardiovascular risk factors between the groups. Compared to hypertensive patients, diabetic individuals showed no difference in ICD (23.1±5.8, p = 0.781) and CapA (1556±649, p = 0.768).

Conclusion

In the early stage of diabetes type 2, patients showed capillary rarefaction compared to healthy individuals.

DLBS1033 REDUCES BLOOD PRESSURE OF HYPERTENSIVE WISTAR-STRAIN RATS

The purpose of this study was to determine the effects of DLBS1033 on blood pressure reduction in hypertension--induced wistar strain rats. Design used in this study was true experimental design. The study was conducted at Biomedical Laboratory, Physiology, Faculty of Dentistry, Jember University, and Clinical and Community Pharmacy Laboratory, Pharmacy Faculty, Jember University. Subjects were taken from male Wistar rats aged 2-3 months, weighing 150-200 grams, as many as 22 rats. Intervention samples were induced into hypertension by giving prednisone in a dose of 1.5 mg/kg/day orally and 2% NaCl followed DLBS1033 of 0.5 grams/kgbw/day orally in the treatment group. T test results on systolic blood pressure (p = 0.00), which was <0.05, showing significant differences in systolic blood pressure in treatment groups. It can be concluded that DLBS1033 can lower systolic blood pressure in wistar rats with induced hypertension using prednisone 1.5 mg/kgbw/day and NaCl 2%.

Diseases having an influence on inhibition of angiogenesis as risk factors of osteonecrosis of the jaw

Objectives

The objective of this study was to retrospectively investigate the association of diseases having an influence on inhibition of angiogenesis such as hypertension, diabetes mellitus type II, hypercholesterolemia, and rheumatoid arthritis (RA) with the development of osteonecrosis of the jaws.

Materials and Methods

The 135 patients were allocated into 4 groups of bisphosphonate-related osteonecrosis of the jaw (BRONJ) group (1A); non-BRONJ group (1B); osteonecrosis of the jaw (ONJ) group (2A); and control group (2B), according to histologic results and use of bisphosphonate. This retrospective study was conducted with patients who were treated in one institute from 2012 to 2013. Fisher's exact test and logistic regression analysis were used to analyze the odds ratios of diseases having an influence on inhibition of angiogenesis for development of ONJ.

Results

The effects of diabetes and hypertension were not statistically significant on development of ONJ. When not considering bisphosphonate use, RA exhibited a high odds ratio of 3.23 (P=0.094), while hyperlipidemia showed an odds ratio of 2.10 (P=0.144) for development of ONJ. More than one disease that had an influence on inhibition of angiogenesis showed a statistically significant odds ratio of 2.54 (P=0.012) for development of ONJ.

Conclusion

Patients without diseases having an influence on inhibition of angiogenesis were at less risk for developing ONJ.

Targeting endothelial connexin40 inhibits tumor growth by reducing angiogenesis and improving vessel perfusion

Endothelial connexin40 (Cx40) contributes to regulate the structure and function of vessels. We have examined whether the protein also modulates the altered growth of vessels in tumor models established in control mice (WT), mice lacking Cx40 (Cx40-/-), and mice expressing the protein solely in endothelial cells (Tie2-Cx40). Tumoral angiogenesis and growth were reduced, whereas vessel perfusion, smooth muscle cell (SMC) coverage and animal survival were increased in Cx40-/- but not Tie2-Cx40 mice, revealing a critical involvement of endothelial Cx40 in transformed tissues independently of the hypertensive status of Cx40-/- mice. As a result, Cx40-/- mice bearing tumors survived significantly longer than corresponding controls, including after a cytotoxic administration. Comparable observations were made in WT mice injected with a peptide targeting Cx40, supporting the Cx40 involvement. This involvement was further confirmed in the absence of Cx40 or by peptide-inhibition of this connexin in aorta-sprouting, matrigel plug and SMC migration assays, and associated with a decreased expression of the phosphorylated form of endothelial nitric oxide synthase. The data identify Cx40 as a potential novel target in cancer treatment.

Arterial Hypertension Is Characterized by Imbalance of Pro-Angiogenic versus Anti-Angiogenic Factors

OBJECTIVE

Hypertension is the most common cardiovascular disease and the main risk factor for stroke, peripheral arterial disease, arterial aneurysms and kidney disease. It has been reported recently that hypertensive patients and animals are characterized by decreased density of arterioles and capillaries in the tissues, called rarefaction. Rarefaction significantly increases peripheral resistance which results in elevated blood pressure, leads to vessel damage and induction of inflammation. Therefore, we hypothesized that hypertension is associated with decreased serum concentration of physiological pro-angiogenic factors and concomitant increased production of angiogenesis inhibitors.

MATERIALS AND METHODS

82 patients diagnosed with hypertension and 34 healthy volunteers were recruited to the study. Flow cytometry and enzyme-linked immunosorbent assay (ELISA) techniques were used to measure serum levels of the following cytokines: endostatin, vascular endothelial growth factor (VEGF), interleukin 8 (IL-8), angiogenin, and basic fibroblast growth factor (bFGF).

RESULTS

Hypertensive patients were characterized by increased serum concentration of endostatin which is an anti-angiogenic factor. In addition, hypertension was associated with decreased levels of physiological pro-angiogenic mediators such as: angiogenin and bFGF. The hypertensive group was also characterized by elevated levels of CRP, VEGF and IL-8 that are the hallmarks of inflammation.

CONCLUSIONS

Presented results show that hypertension is characterized by imbalance of pro-angiogenic and anti-angiogenic factors in the background of inflammation.

Elevated blood pressure in preterm-born offspring associates with a distinct antiangiogenic state and microvascular abnormalities in adult life

Preterm-born individuals have elevated blood pressure. We tested the hypothesis that this associates with an enhanced antiangiogenic circulating profile and that this association is mediated by variations in capillary density. We studied 204 adults aged 25 years (range, 20-30 years), of which 102 had been followed up prospectively since very preterm birth (mean gestational age, 30.3±2.5 weeks) and 102 were born term to uncomplicated pregnancies. A panel of circulating biomarkers, including soluble endoglin and soluble fms-like tyrosine kinase-1, were compared between groups and related to perinatal history and adult cardiovascular risk. Associations with cardiovascular phenotype were studied in 90 individuals who had undergone detailed assessment of microvascular, macrovascular, and cardiac structure and function. Preterm-born individuals had elevations in soluble endoglin (5.64±1.03 versus 4.06±0.85 ng/mL; P<0.001) and soluble fms-like tyrosine kinase-1 (88.1±19.0 versus 73.0±15.3 pg/mL; P<0.001) compared with term-born individuals, proportional to elevations in resting and ambulatory blood pressure, as well as degree of prematurity (P<0.05). Maternal hypertensive pregnancy disorder was associated with additional increases in soluble fms-like tyrosine kinase-1 (P=0.002). Other circulating biomarkers, including those of inflammation and endothelial activation, were not related to blood pressure. There was a specific graded association between soluble endoglin and degree of functional and structural capillary rarefaction (P=0.002 and P<0.001), and in multivariable analysis, there were capillary density-mediated associations between soluble endoglin and blood pressure. Preterm-born individuals exhibit an enhanced antiangiogenic state in adult life that is specifically related to elevations in blood pressure. The association seems to be mediated through capillary rarefaction and is independent of other cardiovascular structural and functional differences in the offspring.

Disturbed acid-base transport: an emerging cause of hypertension

Genome-wide association studies and physiological investigations have linked alterations in acid-base transporters to hypertension. Accordingly, Na⁺-coupled HCO⁻₃-transporters, Na⁺/H⁺-exchangers, and anion-exchangers have emerged as putative mechanistic components in blood pressure disturbances. Even though hypertension has been studied extensively over the last several decades, the cause of the high blood pressure has in most cases not been identified. Renal, cardiovascular, and neuronal dysfunctions all seem to play a role in hypertension development but their relative importance and mutual interdependency are still being debated. Multiple functional and structural alterations have been described in patients and animals with hypertension but it is typically unclear whether they are causes or consequences of hypertension or represent mechanistically unrelated associations. Perturbed blood pressure regulation has been demonstrated in several animal models with disrupted expression of acid-base transporters; and reciprocally, disturbed acid-base transport function has been described in hypertensive individuals. In addition to regulating intracellular and extracellular pH, Na⁺-coupled HCO⁻₃-transport, Na⁺/H⁺-exchange, and anion-exchange also contribute to water and electrolyte balance in cells and systemically. Since acid-base transporters are widely expressed, alterations in transport activities likely affect multiple cell and organ functions, and it is a significant challenge to determine the mechanisms linking perturbed acid-base transport function to hypertension. It is the purpose of this review to evaluate the current evidence for involvement of acid-base transporters in hypertension development and discuss the cellular and integrative mechanisms, which may link changes in acid-base transport to blood pressure disturbances.

Skeletal muscle microvasculature in the diagnosis of neuromuscular disease

Blood vessels are often overlooked in analyses of skeletal muscle biopsies. However, there are many vascular features in skeletal muscle biopsies that, when interpreted in the context of other histologic patterns and clinical history, provide useful information that allows muscle pathologists to narrow their differential diagnoses and provide more accurate guidance to treating physicians. Here, we provide a review of normal skeletal muscle vasculature with details of the ultrastructure of vessel walls. We discuss the vascular effects of factors common to many patients undergoing muscle biopsy, for example, diabetes mellitus, hypertension, and aging. We then discuss vascular findings relevant to diagnostic muscle biopsy evaluation, with current theories of pathogenesis and detailed descriptions of the important features.

Microvascular repair: post-angiogenesis vascular dynamics

Vascular compromise and the accompanying perfusion deficits cause or complicate a large array of disease conditions and treatment failures. This has prompted the exploration of therapeutic strategies to repair or regenerate vasculatures, thereby establishing more competent microcirculatory beds. Growing evidence indicates that an increase in vessel numbers within a tissue does not necessarily promote an increase in tissue perfusion. Effective regeneration of a microcirculation entails the integration of new stable microvessel segments into the network via neovascularization. Beginning with angiogenesis, neovascularization entails an integrated series of vascular activities leading to the formation of a new mature microcirculation, and includes vascular guidance and inosculation, vessel maturation, pruning, AV specification, network patterning, structural adaptation, intussusception, and microvascular stabilization. While the generation of new vessel segments is necessary to expand a network, without the concomitant neovessel remodeling and adaptation processes intrinsic to microvascular network formation, these additional vessel segments give rise to a dysfunctional microcirculation. While many of the mechanisms regulating angiogenesis have been detailed, a thorough understanding of the mechanisms driving post-angiogenesis activities specific to neovascularization has yet to be fully realized, but is necessary to develop effective therapeutic strategies for repairing compromised microcirculations as a means to treat disease.

Biomechanical factors as triggers of vascular growth

Haemodynamic factors influence all forms of vascular growth (vasculogenesis, angiogenesis, arteriogenesis). Because of its prominent role in atherosclerosis, shear stress has gained particular attention, but other factors such as circumferential stretch are equally important to maintain the integrity and to (re)model the vascular network. While these haemodynamic forces are crucial determinants of the appearance and the structure of the vasculature, they are in turn subjected to structural changes in the blood vessels, such as an increased arterial stiffness in chronic arterial hypertension and ageing. This results in an interplay between the various forces (biomechanical forces) and the involved vascular elements. Although many molecular mediators of biomechanical forces still need to be identified, there is plenty of evidence for the causal role of these forces in vascular growth processes, which will be summarized in this review. In addition, we will discuss the effects of concomitant diseases and disorders on these processes by altering either the biomechanics or their transduction into biological signals. Particularly endothelial dysfunction, diabetes, hypercholesterolaemia, and age affect mechanosensing and -transduction of flow signals, thereby underpinning their influence on cardiovascular health. Finally, current approaches to modify biomechanical forces to therapeutically modulate vascular growth in humans will be described.

Preserved capillary density of dorsal finger skin in treated hypertensive patients with or without type 2 diabetes

OBJECTIVES

Capillary rarefaction is a hallmark of untreated hypertension. Recent data indicate that rarefaction may be reversed by antihypertensive treatment in nondiabetic hypertensive patients. Despite the frequent association of diabetes with hypertension, nothing is known on the capillary density of treated diabetic patients with hypertension.

METHODS

We enrolled 21 normotensive healthy, 25 hypertensive only, and 21 diabetic (type 2) hypertensive subjects. All hypertensive patients were treated with a blocker of the renin-angiotensin system, and a majority had a home blood pressure ≤135/85 mmHg. Capillary density was assessed with videomicroscopy on dorsal finger skin and with laser Doppler imaging on forearm skin (maximal vasodilation elicited by local heating).

RESULTS

There was no difference between any of the study groups in either dorsal finger skin capillary density (controls 101 ± 11 capillaries/mm(2) , nondiabetic hypertensive 99 ± 16, diabetic hypertensive 96 ± 18, p > 0.5) or maximal blood flow in forearm skin (controls 666 ± 114 perfusion units, nondiabetic hypertensive 612 ± 126, diabetic hypertensive 620 ± 103, p > 0.5).

CONCLUSIONS

Irrespective of the presence or not of type 2 diabetes, capillary density is normal in hypertensive patients with reasonable control of blood pressure achieved with a blocker of the renin-angiotensin system.

Sodium nitrite therapy rescues ischemia-induced neovascularization and blood flow recovery in hypertension

Arterial hypertension is a major risk factor that can lead to complication of peripheral vascular disease due, in part, to endothelial dysfunction. Because sodium nitrite (SN) can be converted to nitric oxide (NO), which counteracts endothelial dysfunction, we explored the effect of nitrite on neovascularization following hind limb ischemia in different models of hypertension (HT). Chronic delivery of angiotensin II (Ang II, 400 ng/kg/min) or N(omega)-nitro-L-arginine-methyl-ester (L-NAME, 0.1 g/L) was used for a 2-week period to induce hypertension. Mice were subjected to femoral artery ligation-induced ischemia in the hind limb followed by treatment with SN (50 mg/L) for 2 weeks. SN significantly reduced systolic arterial blood pressure in mice receiving Ang II and L-NAME but had no effect in sham animals. After 2 weeks, blood flow and microangiography showed 60 % ± 1.0 recovery in sham compared with 40 % ± 1.3 in HT mice. Importantly, sham and HT mice treated with SN showed a 100 % blood flow recovery associated with normalization in capillary density. The inhibition of xanthine-oxido-reductase (allopurinol) or VEGFR (SU-5416) prevented the neovascularization in HT mice treated with SN. Cyclic GMP (cGMP) content in the hind limb was significantly increased in mice treated with SN compared with non-treated mice. Nitrite/nitrate content was only increased in the sham group treated with SN. Immunoprecipitation and Western blot analysis revealed an increase in eNOS/Akt/VEGFR phosphorylation in skeletal muscle from mice treated with SN compared with non-treated mice. Our findings indicate that SN therapy rescues the neovascularization and blood flow recovery in the ischemic hind limb of sham and HT mice likely through the Akt/NO/cGMP and VEGFR pathways.

Effects of aging on angiogenesis

Aging is a dominant risk factor for most forms of cardiovascular disease. Impaired angiogenesis and endothelial dysfunction likely contribute to the increased prevalence of both cardiovascular diseases and their adverse sequelae in the elderly. Angiogenesis is both an essential adaptive response to physiological stress and an endogenous repair mechanism after ischemic injury. In addition, induction of angiogenesis is a promising therapeutic approach for ischemic diseases. For these reasons, understanding the basis of age-related impairment of angiogenesis and endothelial function has important implications for understanding and managing cardiovascular disease. In this review, we discuss the molecular mechanisms that contribute to impaired angiogenesis in the elderly and potential therapeutic approaches to improving vascular function and angiogenesis in aging patients.

Wrapper-based selection of genetic features in genome-wide association studies through fast matrix operations

BACKGROUND

Through the wealth of information contained within them, genome-wide association studies (GWAS) have the potential to provide researchers with a systematic means of associating genetic variants with a wide variety of disease phenotypes. Due to the limitations of approaches that have analyzed single variants one at a time, it has been proposed that the genetic basis of these disorders could be determined through detailed analysis of the genetic variants themselves and in conjunction with one another. The construction of models that account for these subsets of variants requires methodologies that generate predictions based on the total risk of a particular group of polymorphisms. However, due to the excessive number of variants, constructing these types of models has so far been computationally infeasible.

RESULTS

We have implemented an algorithm, known as greedy RLS, that we use to perform the first known wrapper-based feature selection on the genome-wide level. The running time of greedy RLS grows linearly in the number of training examples, the number of features in the original data set, and the number of selected features. This speed is achieved through computational short-cuts based on matrix calculus. Since the memory consumption in present-day computers can form an even tighter bottleneck than running time, we also developed a space efficient variation of greedy RLS which trades running time for memory. These approaches are then compared to traditional wrapper-based feature selection implementations based on support vector machines (SVM) to reveal the relative speed-up and to assess the feasibility of the new algorithm. As a proof of concept, we apply greedy RLS to the Hypertension - UK National Blood Service WTCCC dataset and select the most predictive variants using 3-fold external cross-validation in less than 26 minutes on a high-end desktop. On this dataset, we also show that greedy RLS has a better classification performance on independent test data than a classifier trained using features selected by a statistical p-value-based filter, which is currently the most popular approach for constructing predictive models in GWAS.

CONCLUSIONS

Greedy RLS is the first known implementation of a machine learning based method with the capability to conduct a wrapper-based feature selection on an entire GWAS containing several thousand examples and over 400,000 variants. In our experiments, greedy RLS selected a highly predictive subset of genetic variants in a fraction of the time spent by wrapper-based selection methods used together with SVM classifiers. The proposed algorithms are freely available as part of the RLScore software library at http://users.utu.fi/aatapa/RLScore/.