Changes In Vascular Pattern Research Articles

Growth-regulating factor 15-mediated vascular cambium differentiation positively regulates wood formation in hybrid poplar (Populus alba × P. glandulosa).

Hybrid poplars are industrial trees in China. An understanding of the molecular mechanism underlying wood formation in hybrid poplars is necessary for molecular breeding. Although the division and differentiation of vascular cambial cells is important for secondary growth and wood formation, the regulation of this process is largely unclear. In this study, mPagGRF15 OE and PagGRF15-SRDX transgenic poplars were generated to investigate the function of PagGRF15. RNA-seq and qRT-PCR were conducted to analyze genome-wide gene expression, while ChIP‒seq and ChIP-PCR were used to identified the downstream genes regulated by PagGRF15. We report that PagGRF15 from hybrid poplar (Populus alba × P. glandulosa), a growth-regulating factor, plays a critical role in the regulation of vascular cambium activity. PagGRF15 was expressed predominantly in the cambial zone of vascular tissue. Overexpression of mPagGRF15 (themutated version of GRF15 in the miR396 target sequence) in Populus led to decreased plant height and internode number. Further stem cross sections showed that the mPagGRF15 OE plants exhibited significant changes in vascular pattern with an increase in xylem and a reduction in phloem. In addition, cambium cell files were decreased in the mPagGRF15 OE plants. However, dominant suppression of the downstream genes of PagGRF15 using PagGRF15-SRDX showed an opposite phenotype. Based on the RNA-seq and ChIP-seq results, combining qRT-PCR and ChIP-PCR analysis, candidate genes, such as WOX4b, PXY and GID1.3, were obtained and found to be mainly involved in cambial activity and xylem differentiation. Accordingly, we speculated that PagGRF15 functions as a positive regulator mediating xylem differentiation by repressing the expression of the WOX4a and PXY genes to set the pace of cambial activity. In contrast, PagGRF15 mediated the GA signaling pathway by upregulating GID1.3 expression to stimulate xylem differentiation. This study provides valuable information for further studies on vascular cambium differentiation mechanisms and genetic improvement of the specific gravity of wood in hybrid poplars.

Sex Differences in renal ischemia-reperfusion injury following deletion of Netrin-1 in the kidney

Netrin-1, an angiogenic guidance cue, is heavily expressed in the kidney. Our lab has previously reported that deletion of Netrin-1 in Foxd1-positive stromal progenitors ( Foxd1 GC/+ Netrin1 fl/fl ) results in abnormal vascular patterning during kidney development, including a reduction in interlobar branching. It remains unknown how these changes in vascular patterning affect kidney function and physiology. In the current study, we hypothesized that changes in developmental patterning of the kidney vasculature would protect from renal ischemia-reperfusion injury in a sex-specific manner due to ischemic preconditioning to the kidney tubular cells. To test this hypothesis, we performed warm, bilateral ischemia-reperfusion by clamping the renal pedicles for 26-minutes in wild-type ( Netrin1 fl/fl or Netrin1 fl/+ )(3M, 3F), heterozygous ( Foxd1 GC/+ Netrin1 fl/+ ) (2M, 4F), and mutant ( Foxd1 GC/+ Netrin1 fl/fl ) (3M, 1F) male (M) and female (F) mice. Following 24-hours of reperfusion, blood and kidneys were collected for analysis of kidney injury markers. We found that plasma creatinine (p 2-wayANOVA =0.021) and blood urea nitrogen (p 2-wayANOVA =0.009) were decreased in female mice compared to male mice regardless of genotype. In both male and female mutant mice, there was a decrease in these markers of injury compared to heterozygous and wild-type control mice, although this did not reach statistical significance. In agreement, immunofluorescent staining of kidney injury marker 1 (KIM-1) indicated less tubular injury in female mice compared to males. These data suggest that female mice are less susceptible to ischemic injury than male mice despite both sexes having similar alterations in vascular patterning following deletion of Netrin-1. Further, our results indicate a protective effect of these developmental patterning changes due to Netrin-1 deletion. We suspect that changes in the vasculature in our mutant mice provide a preconditioning-like environment to mediate this effect. Future studies will investigate the underlying mechanisms which drive this injury phenotype between sexes. Understanding how renal vascular development impacts kidney injury is critical to the development of new therapeutic strategies to prevent the sustained injury following periods of ischemia. NIH R01DK121014 to LO This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstracts

Abstracts

Use of near-infrared indocyanine videoangiography and Flow 800 in the resectioning of a spinal cord haemangioblastoma

Haemangioblastomas are hypervascularized tumours. Their surgical management requires a complete resectioning and a prompt handling of the vascular inlets and outlets. The use of intraoperative indocyanine green video angiography (ICG-VAG) depicts the precise vascular pattern for the surgeon. Its use is safe and easy, and the procedure can be repeated during the operation. Here we present a case of spinal haemangioblastoma treated with the aid of intraoperative ICG-VAG and the Flow 800 software. The use of the Flow 800 allowed the surgeon to detect, at a glance, minimal changes in the vascular supply during the dissection.The colour-coded images generated by the Flow 800 increase the ICG-CAG sensitivity, improving the capability to detect changes in vascular patterns.

CONTRAST‐ENHANCED ULTRASONOGRAPHIC CHARACTERISTICS OF ADRENAL GLANDS IN DOGS WITH PITUITARY‐DEPENDENT HYPERADRENOCORTICISM

A noninvasive method for quantifying adrenal gland vascular patterns could be helpful for improving detection of adrenal gland disease in dogs. The purpose of this retrospective study was to compare the contrast-enhanced ultrasound (CEUS) characteristics of adrenal glands in 18 dogs with pituitary-dependent hyperadrenocorticism (PDH) vs. four clinically healthy dogs. Each dog received a bolus of the contrast agent (SonoVue®, 0.03 ml/kg of body weight) into the cephalic vein, immediately followed by a 5 ml saline flush. Dynamic contrast enhancement was analyzed using time-intensity curves in two regions of interest drawn manually in the caudal part of the adrenal cortex and medulla, respectively. In healthy dogs, contrast enhancement distribution was homogeneous and exhibited increased intensity from the medulla to the cortex. In the washout phase, there was a gradual and homogeneous decrease of enhancement of the adrenal gland. For all dogs with PDH, there was rapid, chaotic, and simultaneous contrast enhancement in both the medulla and cortex. Three distinct perfusion patterns were observed. Peak perfusion intensity was approximately twice as high (P < 0.05) in dogs with PDH compared with that of healthy dogs (28.90 ± 10.36 vs. 48.47 ± 15.28, respectively). In dogs with PDH, adrenal blood flow and blood volume values were approximately two- to fourfold (P < 0.05) greater than those of controls. Findings from the present study support the use of CEUS as a clinical tool for characterizing canine adrenal gland disease based on changes in vascular patterns.

Videocapillaroscopic Pattern of Alopecia Areata before and after Diphenylciclopropenone Treatment

Alopecia areata (AA) is an inflammatory skin disease the most effective therapy for which is diphenylcyclopropenone (DPCP). Videodermatoscopy and intra-vital capillaroscopy (IVCP) are two non-invasive techniques that help in the differential diagnosis of alopecias. It is known that, after DPCP therapy, there is a histologically proven significant increase of VEGF in hair follicle keratinocytes and a consequent increase in capillary vessels in the dermis of the same follicles. The aim of our study is to emphasize any clinical and videodermatoscopic-videocapillaroscopic changes after DPCP treatment in 20 patients affected by alopecia areata. Videodermatoscopic images and an intravital videocapillaroscopic analysis were performed at T0, T12 and T24 to emphasize clinical modifications and microscopic changes in vascular pattern before and after DPCP treatment. At T0, videodermatoscopy showed the presence of exclamation point hairs, hair follicles filled with hyperkeratotic plugs (yellow dots), hair follicles containing cadaverized hairs (black dots) and broken hairs. IVCP highlighted a pale scalp, and vessels were not visible. At 24 weeks (T24), videodermatoscopy revealed the disappearance or a statistically significant reduction of AA hallmarks and an increase of number of vellus hairs. Videocapillaroscopy showed a statistically significant increase of new vessels and, where neoangiogenesis were more marked, a major hair regrowth was evident. Our study emphasizes that, after DPCP therapy, neoangiogenesis is detectable by videocapillaroscopy and these new capillaries could be considered an initial positive attempt to compensate capillary loss of T0 alopecia areata images.

Dermoscopic Evolution of Vascular Pattern in Two Cases of Amelanotic Melanoma

Hypo/amelanotic skin lesions present a diagnostic chal-lenge, and dermoscopic analysis can often help in deter-mining whether a lesion is benign or malignant (1–3). The presence of a vascular pattern characterized by poly-morphic vessels, such as hairpin-like, pinpoint and linear irregular vessels, may be the only significant dermoscopic finding of amelanotic melanoma (AM) (4).As described previously, morphological changes in dermoscopic patterns have been associated with the characteristic evolution of benign melanocytic naevi after a long-term follow-up of 12 months (5, 6). Rapid and irregular modifications often suggest malignancy (6). The diagnosis of early-phase AM is especially challenging. We report here two cases of AM characterized by der-moscopic changes in vascular pattern observed during a follow-up period of 6–10 months after the initial visit.CASE REPORTS

VESGEN 2D: Automated, User‐Interactive Software for Quantification and Mapping of Angiogenic and Lymphangiogenic Trees and Networks

Quantification of microvascular remodeling as a meaningful discovery tool requires mapping and measurement of site-specific changes within vascular trees and networks. Vessel density and other critical vascular parameters are often modulated by molecular regulators as determined by local vascular architecture. For example, enlargement of vessel diameter by vascular endothelial growth factor (VEGF) is restricted to specific generations of vessel branching (Parsons-Wingerter et al., Microvascular Research72: 91, 2006). The averaging of vessel diameter over many successively smaller generations is therefore not particularly useful. The newly automated, user-interactive software VESsel GENeration Analysis (VESGEN) quantifies major vessel parameters within two-dimensional (2D) vascular trees, networks, and tree-network composites. This report reviews application of VESGEN 2D to angiogenic and lymphangiogenic tissues that includes the human and murine retina, embryonic coronary vessels, and avian chorioallantoic membrane. Software output includes colorized image maps with quantification of local vessel diameter, fractal dimension, tortuosity, and avascular spacing. The density of parameters such as vessel area, length, number, and branch point are quantified according to site-specific generational branching within vascular trees. The sole user input requirement is a binary (black/white) vascular image. Future applications of VESGEN will include analysis of 3D vascular architecture and bioinformatic dimensions such as blood flow and receptor localization. Branching analysis by VESGEN has demonstrated that numerous regulators including VEGF(165), basic fibroblast growth factor, transforming growth factor beta-1, angiostatin and the clinical steroid triamcinolone acetonide induce 'fingerprint' or 'signature' changes in vascular patterning that provide unique readouts of dominant molecular signaling.

High resolution imaging of fluorescein patterns in RCS rat retinae and their direct correlation with histology

To assess the progressive changes in the retinal vascular bed of dystrophic and non-dystrophic Royal College of Surgeons (RCS) rats, retinae, were visualised correlating in vivo fundus fluorescein angiography (FA) with histology. FA was performed in rats aged 5 weeks to 2 years, using a Zeiss confocal scanning laser ophthalmoscope (cSLO). After the final imaging session, a subset of retinae were prepared for flat-mount histology and the vascular bed was visualised using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) staining. While non-dystrophic rat retinae showed no substantive changes in vascular patterns with age and no demonstrable fluorescein leakage up to at least 1 year, dystrophic rat retinae showed abnormal vascular formations, demonstrable on FA and NADPH-d staining, which could be correlated in single retinae. Hyperfluorescent spots and late angiographic leakage were evident beginning at 10 weeks and progressed in severity with time: they were coincident in distribution with abnormal histological vascular complexes. The ability to monitor the same retina serially makes this approach a valuable tool for studying the dynamics of vascular change in the diseased retina, not only during the course of degeneration but also when assessing efficacy of potential therapeutic approaches.

Enhanced external counterpulsation in the management of patients with cardiovascular disease.

Studies over the past several decades support the hypothesis that enhanced external counterpulsation (EECP) can provide long-term benefits in patients with angina secondary to chronic coronary disease. Numerous non-sham controlled trials have recently been substantiated by a multicenter, randomized trial. Although the mechanism by which this mechanical treatment effects an alteration in cellular processes within the myocardium remains unclear, recent scientific investigations suggest that shear stress induced by chronic exposure to EECP might result in the release of a variety of growth factors and the subsequent stimulation of angiogenesis in the coronary beds. Ongoing clinical trials in patients with significant left ventricular dysfunction, an international registry, and additional clinical trials may help to elucidate further the role of this novel and unique therapy in our clinical armamentarium.

Binding of interleukin-8 to heparan sulphate enhances cervical maturation in rabbits.

Cervical ripening is a cytokine-triggered process with substantial remodelling of the cervical extracellular matrix. Interleukin-8 (IL-8) is an important cytokine in cervical maturation. Glycosaminoglycans are also included in this process, but their role in not clearly understood. The effects of heparan sulphate (HS), hyaluronic acid (HA), IL-8, HS + IL-8 and HA + IL-8 on biochemical properties of the cervix were examined in non-pregnant rabbits. The changes in vascular pattern with collagen structure of the cervices and immunohistochemical studies, together with the relative collagen concentrations, were determined. A reduction in relative collagen concentration was significant after HS + IL-8, IL-8 and HA + IL-8 treatment (all P < 0.0001). Gel electrophoresis analysis showed that IL-8 bound preferentially to HS than to HA. Neutrophils were significantly increased in number (P < 0.0001) and located predominantly beneath the glandular epithelium and around the blood vessels after HS + IL-8 treatment. HS + IL-8 treatment caused cervices to increase their water content and become oedematous. The collagen fibres were considerably dissociated, the interfibrillar spaces markedly dilated, and the blood vessels notably increased and dilated. We conclude that binding to HS enhances the activity of IL-8 in inducing cervical maturation.

Angiogenesis in uterine cervical intraepithelial neoplasia and squamous cell carcinoma: an immunohistochemical study.

Changes in vascular patterns aid in the colposcopic diagnosis of cervical neoplasia. We have studied vessels in 50 cases of normal cervix, cervical intraepithelial neoplasia (CIN I, II, III), and invasive carcinoma by two markers, Von-Willebrand factor (VWF) and ulex europaeus lectin I. With both markers, an increase in microvessel counts parallel to neoplastic progression was seen, with highest counts observed in CIN III. Average counts for ulex lectin and VWF increased from approximately 6 vessels per field in normal cervices to 15 vessels per field in CIN III. For each diagnostic group, comparable numbers of vessels were stained by both markers, with a slight preponderance of VWF in invasive carcinomas and of ulex lectin in noninvasive lesions. No correlation was found between microvessel count and human papilloma virus (HPV) by in situ hybridization. We conclude that enhanced microvessel density occurs in cervical neoplasia. The vessels are mostly blood vessels, not lymphatics. Therefore, the role of enhanced microvessel density in tumor spread remains to be proven.

Scanning electron microscopy of the capillary loops in the dermal papillae of the hand in primates, including man

The microvasculature of the skin of the hand in primates, including man, was examined by means of scanning electron microscopy of corrosion casts. In this study, the microvascular patterns and structures in different areas of the hand, and the changes in vascular patterns that occur with age, have been described. The typical structure of the capillary loops in the hand can be observed in the ball of the finger of the young adult monkey. The capillary loops were formed out of not just one capillary vessel, but two or three vessels. Each capillary vessel arose and divided into several branches at the papillae, and these became descending limbs. After the loop passed a hairpin turn, the descending limbs were 1.5 times larger than the ascending limbs in the intrapapillary portion, and they became extrapapillary venules. The descending limbs connected with the postcapillary venules in the postpapillary portion and with the horizontal network. The postcapillary venules fused with each other to form the primary and secondary venous arcades. The secondary venous arcades anastomosed with each other and flowed into the subpapillary venules, which run along the dermal furrow in the fingerprint. Changes in vascular patterns with age could be observed. In the infant fingerprint, the vascular systems had not yet differentiated, especially the venous system in the dermis. In the old adult finger, the capillary loops presented complicated features deviating due to aging.

Vascular changes in the lungs on the plain radiograph of the chest

Summary The normal anatomy of the pulmonary vessels is considered and correlated with the angiographic appearances. Some pathological conditions causing an alteration in the vascular pattern as seen on the plain films are considered and the changes are described. It is concluded that an appreciation of these changes in vascular pattern may indicate to the clinician the presence of local or distant disease.

Vascular Patterns in Immobilized, Denervated, or Devascularized Rabbit Limbs

Using an injection technique, the vascular pattern in the hind limbs of rabbits was studied by means of roentgenograms. The right hind limbs of these animals were immobilized by plaster cast, by cast and skeletal pins, and by internal pin fixation of the ankle and knee joints. In addition, denervation, femoral-artery ligation, and tenotomy were done in other animals. The changes in vascular pattern noted after cast immobilization were dilatation of the main arteries and increased vascularization about knee and ankle joints. After internal fixation alone similar changes occurred, except that there was no dilatation of the main arteries. Increased arborization of small muscle vessels was noted after femoral-artery ligation. Diminished vessel size and bizarre vascular patterns were noted after both denervation and tenotomy.