Interleukin-2 is present in human blood vessels and released in biologically active form by heparanase

Interleukin-2 (IL-2) is a multifaceted cytokine with immunostimulatory and immunosuppressive properties. Our laboratory recently demonstrated that the availability of IL-2 is regulated, in part, by association with perlecan, a heparan sulfate proteoglycan. Given the abundance of perlecan in blood vessels, we asked whether IL-2 is present in vessel walls. Our results indicate that IL-2 is associated with endothelial and smooth muscle cells within the human arterial wall. This IL-2 is released by heparanase, and promotes the proliferation of an IL-2-dependent cell line. Given the presence of IL-2 in human arteries, we asked whether the large vessels of IL-2-deficient mice were normal. The aortas of IL-2-deficient mice exhibited a loss of smooth muscle cells, suggesting that IL-2 may contribute to their survival. In their entirety, these results suggest a here-to-fore unrecognized role of IL-2 in vascular biology, and have significant implications for both the immune and cardiovascular systems.     

Polymorphism of genes of the renin-angiotensin system ACE, AT1R, and AT2R in patients with pulmonary tuberculosis

The goal of this work was to verify the hypothesis about the possible role of some genes of the renin-angiotensin system in the innate immunity to tuberculosis. The insertion/deletion polymorphism (I/D) of the gene of the angiotensin-converting enzyme (ACE) is known to have an effect on the concentration of the angiotensin II in human body and also an indirect effect on various branches of metabolism. On the one hand, people with homozygote deletion of the ACE gene (DD genotype) are vulnerable to adiposity, arterial hypertension, hypercholesterolemia, and a number of other pathological conditions. On the other hand, it was shown that hypocholesterolemia is the general phenomenon for the patients with pulmonary tuberculosis (Perez-Guzman C. et al., Chest (2005)). In this work, we studied the I/D polymorphism of the gene ACE (genotypes DD, ID, and II), single nucleotide polymorphism (SNP) of the gene AT1R (1166 A/C), and SNP in 3123 positions of the gene AT2R (3123 A/C) in 200 patients with tuberculosis, 202 patients with essential hypertension, and 208 apparently healthy subjects. A group of patients with essential hypertension was used as a contrast group. According to the hypothesis stated above, the excess in the number of patients with the DD genotype (ACE) should be statistically significant in the group of patients with hypertension as compared to the group of patients with tuberculosis (chi2 = 9.64; chi2 = 0.0019; OR = 2.0; CI 1.2-3.3). There was a trend toward an increase in the rate of the DD genotype in the group of patients with tuberculosis relative to healthy subjects. Similar trend was observed in healthy subjects relative to the group of patients with hypertension. However, this difference was found to be statistically insignificant. The genotypes and allelotypes were compared in the group of patients with tuberculosis versus both the two control groups (healthy subjects and patients with hypertension). The significant difference from control was observed only in male rather than female patients with tuberculosis. It was shown that the greatest contribution to the distinction between groups was due to the genes ACE and AT2R. The combination of the genotypes of genes ACE and AT2R (ID+3123C) was met significantly more frequently in male patients with tuberculosis as compared to control group of healthy subjects (chi2 = 9.70; chi2 = 0.002; OR = 2.3; CI 1.2-4.3). The results obtained in this work are discussed in terms of the hypothesis stated above.     

Patterns of regeneration in vessels of human diseased muscle and skin

Regenerating vessels from 36 muscle biopsies and 12 skin biopsies pertaining to patients with the clinical and histological diagnosis of dermatomyositis-polymyositis and other inflammatory myopathies were described ultrastructurally. The following characteristics of vascular regeneration were encountered: a) alternation of thin and thick endothelial cells, b) superimposed segments of endothelial cytoplasm with formation of twisted intercellular junctions, c) long and complex intraluminal endothelial projections, d) discontinuous and porous perivascular basement lamina or multilaminated basement lamina. Some vessels featured only two or three of the mentioned characteristics. Endothelial fenestrations were occasionally encountered in the skin capillaries and were an exception in the muscle capillaries. In the skin there were aspects suggesting that intercalation of perivascular cells in the regenerating endothelial wall may occur. Most capillaries were in the final stage of regeneration.     

Immunolocalization of ACE2 and AT2 receptors in rabbit atherosclerotic plaques.

Evidence suggests that angiotensin type 2 receptor (AT2R) and angiotensin-converting enzyme 2 (ACE2) play a protective role in atherogenesis. These factors have not been identified in rabbit atherosclerotic plaques. Our goal was to localize ACE2 and AT2R in rabbit atherosclerotic tissues, and determine which cell types express these factors. New Zealand White rabbits were fed either a control diet or a 0.5% cholesterol diet (n=8/group) for 12 weeks. Paraffin-fixed thoracic aorta were serially sectioned and processed for immunohistochemistry using commercially available antibodies to ACE2, AT2R, RAM 11 (to identify macrophages), and alpha smooth muscle cell actin (alphaSMC) to identify smooth muscle cells and myofibroblasts. AT2R immunoreactivity, but not ACE2 immunoreactivity, was clearly present in endothelia overlying normal wall. However, both AT2R and ACE2 immunoreactivity were clearly present in endothelia overlying neo-intima formation and atherosclerotic plaques. Within plaques, both AT2R and ACE2 immunoreactivity were observed in macrophages and alphaSMC actin-positive cells. Examination of serial sections showed that the majority of cells were both ACE2- and AT2R-positive. Macrophages and alphaSMC actin-positive cells produce ACE2 and the AT2R in atherosclerotic plaques. Determining a role for these factors in the control of atherosclerosis will require additional studies.     

ACE2 expression and activity are enhanced during pregnancy

In the current study, we investigated the expression and activity of ACE2 during pregnancy in normotensive and hypertensive rats, focusing on the relative contribution of the uterus and the placentas, the kidney serving as a reference. We used the Sabra rat model of salt-sensitive hypertension. We confirmed a systemic vasodilatory state during the third trimester of pregnancy, as evidenced by a reduction in blood pressure, both in normotensive and hypertensive rats. At the time that blood pressure was reduced, ACE2 was expressed abundantly in the reproductive organs. The relative levels of ACE2 mRNA in the pregnant animal were placenta > kidneys > or = uterus and of ACE2 activity kidney > placenta > uterus. In the uterus and the placenta, ACE2 expression was unaffected by strain, salt-loading, or the level of blood pressure. ACE2 activity in the uterus of the nonpregnant rat was not affected by any of these variables either, but during pregnancy increased in salt-loaded animals. When estimating the total contribution of the uterus to ACE2 mRNA and activity during pregnancy, we found that the amount of ACE2 mRNA increased in both strains irrespective of diet, but that ACE2 activity increased only in salt-loaded animals. We further estimated the relative total contribution of the uterus, placentas, and kidneys to ACE2 expression and activity during pregnancy by adjusting for mass and number of organs and found that the placentas were the major contributors, followed by the kidney and the uterus. We conclude that during pregnancy, the placentas, in particular, but also the uterus, constitute important sources of ACE2, in addition to its normal production in the kidney, leading to an estimated twofold increase in total ACE2 activity. These data are consistent the hypothesis that transient ACE2 overexpression and increased activity during pregnancy may be important in modulating systemic, as well as local hemodynamics in the uteroplacental unit.     

Development of blood vessels in the human eyeball

Blood vessels of 167 eyeballs of human embryos and fetuses have been studied, using macro- microscopical, histological and morphometrical methods. Time of appearance and differentiation of blood vessels in the eye anlage has been determined. Topography and architecture of the vitreous body artery are described in detail, as well as the vascular tunic of the lens and the pupil membrane. Regularities and time of reversal development of the vascular formations mentioned are followed during the whole intrauterine development. The data obtained add to extend our knowledge on the role of disturbances of the normal morphogenesis of the eyeball blood bed in pathogenesis of its congenital diseases.     

TLR3 and TLR4 expression in healthy and diseased human endometrium

Background  

Toll-like receptors (TLRs) play an essential role in the innate immune system by initiating and directing immune response to pathogens. TLRs are expressed in the human endometrium and their regulation might be crucial for the pathogenesis of endometrial diseases.     

自发性高血压大鼠心脏中ACE,AT1R,ACE2和MasR表达变化的研究

目的：通过观察血管紧张素转化酶（ACE）和血管紧张素转化酶2（ACE2）在Wistar-京都种大鼠（WKY）和自发性高血压（SHR）大鼠心脏组织中表达的差异,探讨ACE与ACE2在自发性高血压大鼠高血压形成中的作用。方法：自由饲喂14周龄WKY和SHR雄性大鼠一周后,用BSN-II多通道无创测压系统测定大鼠收缩压（SBP）、舒张压（DBP）、心率（HR）并称重;放免法测定血浆中血管血管紧张素Ⅱ（AngII）含量;Real-time PCR测定心脏组织中ACE,ATI受体（ATIR）,ACE2和Mas受体（MasR）mRNA的表达水平;Western blot法检测心脏组织中ACE2的蛋白表达。结果：SHR大鼠SBP和DBP均显著高于WKY大鼠（P〈0.01）;两组大鼠心率和体重无显著差异（P〉0.05）;SHR大鼠血浆中AngII含量显著升高（P〈0.05）;与WKY大鼠相比,SHR大鼠心脏中ACE mRNA表达均显著升高（P〈0.05）,ACE2的mRNA和蛋白表达水平均显著下降（P〈0.05）;心脏组织中AT1R和MasR的mRNA表达没有显著性变化（P〉0.05）。结论：ACE与ACE2表达失调是SHR大鼠高血压形成的主要原因之一,其机理可能与局部组织RAS系统ACE-AngII-AT1R通路过度活跃,ACE2-Ang（1-7）-MasR通路相对不足有关。     

Rearranged mitochondrial genomes are present in human oocytes.

Using quantitative PCR, we have determined that a human oocyte contains approximately 100,000 mitochondrial genomes (mtDNAs). We have also found that some oocytes harbor measurable levels (up to 0.1%) of the so-called common deletion, an mtDNA molecule containing a 4,977-bp rearrangement that is present in high amounts in many patients with "sporadic" Kearns-Sayre syndrome (KSS) and progressive external ophthalmoplegia (PEO). This is the first demonstration that rearranged mtDNAs are present in human oocytes, and it provides experimental support for the supposition that pathogenic deletions associated with the ontogeny of sporadic KSS and PEO can be transmitted in the female germ line, from mother to child. The relevance of these finding to the accumulation of extremely low levels of deleted mtDNAs in both somatic and germ-line tissues during normal human aging is also discussed.     

C-terminal pro-ghrelin peptides are present in the human circulation

We provide the first evidence for the existence in human plasma of peptides derived from the 66 carboxyl-terminal amino acids of pro-ghrelin (C-ghrelin). C-ghrelin immunoreactivity in plasma was higher than ghrelin, and did not significantly correlate with body mass index in normal health. In patients with myocardial infarction, plasma levels of both ghrelin and C-ghrelin were significantly decreased (approximately 30%, P<0.05), whereas in patients with heart failure, C-ghrelin levels were significantly elevated (approximately 32%, P<0.05) compared with controls. HPLC coupled with RIA showed circulating C-ghrelin to be primarily of low molecular weight (M(r) approximately 3500), but in chronic heart failure, a higher molecular weight form (M(r) approximately 7500) is also present. This is the first evidence for potential circulating hormones derived from the carboxyl terminus of pro-ghrelin and for their modulation in cardiovascular diseases.     

Optical measurement of age-related calcification in human blood vessels

Vascular calcification is commonly associated with aging. Quantification of calcium accumulation in vessel walls is important in understanding the mechanisms of vascular calcification. To elucidate age-related change of calcification, site dependence of calcification, and the effect of hemodynamic stress on calcification, we measured calcium contents in various blood vessels with atomic emission spectrometry and simulated blood flow in the vessels by computational fluid dynamics. The content of calcium in the arteries increased progressively with aging while there is no change in the veins. The higher accumulation of calcium occurred in the arteries of the lower limb in comparison to the arteries of the upper limb. In the arterial bifurcation, there was the correlation at hemodynamic stress distribution and calcium content. The results of this study quantitatively support clinical findings of nonuniform calcification, and suggest that hemodynamic stress affects vascular calcification.     

Isolating and defining cells to engineer human blood vessels

A great deal of attention has been recently focused on understanding the role that bone marrow-derived putative endothelial progenitor cells (EPC) may play in the process of neoangiogenesis. However, recent data indicate that many of the putative EPC populations are comprised of various haematopoietic cell subsets with proangiogenic activity, but these marrow-derived putative EPC fail to display vasculogenic activity. Rather, this property is reserved for a rare population of circulating viable endothelial cells with colony-forming cell (ECFC) ability. Indeed, human ECFC possess clonal proliferative potential, display endothelial and not haematopoietic cell surface antigens, and display in vivo vasculogenic activity when suspended in an extracellular matrix and implanted into immunodeficient mice. Furthermore, human vessels derived became integrated into the murine circulatory system and eventually were remodelled into arterial and venous vessels. Identification of this population now permits determination of optimal type I collagen matrix microenvironment into which the cells should be embedded and delivered to accelerate and even pattern number and size of blood vessels formed, in vivo. Indeed, altering physical properties of ECFC-collagen matrix implants changed numerous parameters of human blood vessel formation, in host mice. These recent discoveries may permit a strategy for patterning vascular beds for eventual tissue and organ regeneration.     

不同年龄白发性高血压大鼠肾脏AT1R和AT2R的表达

目的本研究观察不同月龄自发性高血压大鼠（SHR）肾脏ALR和ALR表达,初步探讨AT1R和AT2R在高血压发生、发展过程中的可能作用。方法1月龄组（S1）、2月龄组（S2）、3月龄组（S3）、6月龄组（S6）和9月龄组（墨）雄性SHR共5组,每组各6只,各组均有相应月龄匹配的Wistar-Kyoto大鼠（WKY）作对照。采用RBP-I型大鼠血压心率测定仪测量大鼠尾动脉收缩压（SBP）;放免法测定血浆血管紧张素Ⅱ（AngⅡ）;免疫组化染色结合计算机图像分析方法测定肾脏AT1R和ALR表达水平。结果（1）SHR SBP随着月龄的增加而上升,S6后趋于稳定。（2）1个月后SHR血浆AngⅡ浓度均高于S1（P〈0.05）,而S2、S3、S6和S9之间无明显差别（P〉0.05）;1个月后SHR血浆AngⅡ浓度均高于相应配对的WKY组（P〈0.05）;而WKY各月龄组均无明显差别（P〉0.05）。（3）SHR肾脏AT1R随着月份的增加而增加（P〈0.05）,且高于相应配对的WKY组（P〈0.05）。SHR肾脏ABR随着月份的增加而降低,S6明显降低（P〈0.05）,S6和S9比较无明显差别（P〉0.05）;且均低于相应配对的WKY组（P〈0.05）。WKY各月龄组AT1R和AT2R无明显差别（P〉0.05）。结论SHR肾脏AT1R表达水平比WKY高,并随着年龄的增加而递增;AT2R表达水平比WKY低,并随着年龄的增加而降低。     

Differential vasoconstrictions induced by angiotensin II: role of AT1 and AT2 receptors in isolated C57BL/6J mouse blood vessels

Genetically altered mice are increasingly used as experimental models. However, ANG II responses in mouse blood vessels have not been well defined. Therefore, the aim of this study was to determine the role of ANG II in regulating major blood vessels in C57/BL6J mice with isometric force measurements. Our results showed that in mouse abdominal aorta ANG II induced a concentration-dependent contraction (EC50 4.6 nM) with a maximum contraction of 75.1 +/- 4.9% at 100 nM compared with that of 60 mM K+. Similarly, femoral artery also exhibited a contractile response of 76.0 +/- 3.4% to the maximum concentration of ANG II (100 nM). In contrast, ANG II (100 nM)-induced contraction was significantly less in carotid artery (24.5 +/- 6.6%) and only minimal (3.5 +/- 0.31%) in thoracic aorta. The nitric oxide synthase inhibitor N omega-nitro-L-arginine methyl ester and the AT2 antagonist PD-123319 failed to enhance ANG II-induced contractions. However, an AT1 antagonist, losartan (10 microM), completely inhibited ANG II (100 nM) response in abdominal aorta and carotid artery. An AT1 agonist, [Sar1]-ANG II (100 nM), behaved similarly to ANG II (100 nM) in abdominal aorta and carotid artery. RT-PCR analyses showed that mouse thoracic aorta has a significantly lower AT1 mRNA level than abdominal aorta. These results demonstrate that major mouse vessels exhibit differential contractions to ANG II, possibly because of varied AT1 receptor levels.     

NG2 and phosphacan are present in the astroglial scar after human traumatic spinal cord injury

Background

A major class of axon growth-repulsive molecules associated with CNS scar tissue is the family of chondroitin sulphate proteoglycans (CSPGs). Experimental spinal cord injury (SCI) has demonstrated rapid re-expression of CSPGs at and around the lesion site. The pharmacological digestion of CSPGs in such lesion models results in substantially enhanced axonal regeneration and a significant functional recovery. The potential therapeutic relevance of interfering with CSPG expression or function following experimental injuries seems clear, however, the spatio-temporal pattern of expression of individual members of the CSPG family following human spinal cord injury is only poorly defined. In the present correlative investigation, the expression pattern of CSPG family members NG2, neurocan, versican and phosphacan was studied in the human spinal cord.

Methods

An immunohistochemical investigation in post mortem samples of control and lesioned human spinal cords was performed. All patients with traumatic SCI had been clinically diagnosed as having "complete" injuries and presented lesions of the maceration type.

Results

In sections from control spinal cord, NG2 immunoreactivity was restricted to stellate-shaped cells corresponding to oligodendrocyte precursor cells. The distribution patterns of phosphacan, neurocan and versican in control human spinal cord parenchyma were similar, with a fine reticular pattern being observed in white matter (but also located in gray matter for phosphacan). Neurocan staining was also associated with blood vessel walls. Furthermore, phosphacan, neurocan and versican were present in the myelin sheaths of ventral and dorsal nerve roots axons. After human SCI, NG2 and phosphacan were both detected in the evolving astroglial scar. Neurocan and versican were detected exclusively in the lesion epicentre, being associated with infiltrating Schwann cells in the myelin sheaths of invading peripheral nerve fibres from lesioned dorsal roots.

Conclusion

NG2 and phosphacan were both present in the evolving astroglial scar and, therefore, might play an important role in the blockade of successful CNS regeneration. Neurocan and versican, however, were located at the lesion epicentre, associated with Schwann cell myelin on regenerating peripheral nerve fibres, a distribution that was unlikely to contribute to failed CNS axon regeneration. The present data points to the importance of such correlative investigations for demonstrating the clinical relevance of experimental data.