Vascular Endothelial Growth Factor (VEGF) Expression in Human Pituitary Adenomas and Carcinomas

Vascular endothelial growth factor (VEGF) is a key mediator of endothelial cell proliferation, angiogenesis, and vascular permeability. Little is known about its expression in human pituitary adenomas. We examined 148 human pituitary adenomas for VEGF protein expression by immunohistochemistry. The strongest immunoreactivity was present in GH adenomas, corticotroph, silent corticotroph, silent subtype 3, and nononcocytic null cell adenomas. GH adenomas treated with octreotide strained less intensely than did untreated tumors. Relatively weak staining was present in PRL, gonadotroph, thyrotroph, and oncocytic null cell adenomas in the same sections showed evidence of down-regulation of VEGF protein expression in adenomas. Pituitary carcinomas usually had stronger staining than adenomas. In situ hybridization studies with oligonucleotide probes showed positive staining in all groups with stronger staining in GH, ACTH, TSH, and gonadotroph adenomas and in pituitary carcinomas. These results indicate that VEGF expression is more prominent in certain adenoma subtypes, that decreased expression occurs in adenomas as compared to nontumorous pituitary and that carcinomas show increased VEGF expression relative to adenomas suggesting up-regulation of VEGF during pituitary tumor progression.     

Pituitary Changes in Ataxia-Telangiectasia Syndrome: An Immunocytochemical,In Situ Hybridization,and DNA Cytometric Study of Three Cases

Ataxia-telangiectasia (AT) syndrome (cerebellar ataxia, oculocutaneous telangiectasias, immunodeficiency, susceptibility to infections, and neoplasia) is associated with cyto- and nucleomegaly in several organ systems. Our aim was to determine (1) whether such cellular abnormalities in the pituitary selectively involve specific cell types, and (2) the proliferation and DNA ploidy status of such cells. Three AT autopsy pituitaries were studied by histology, immunohistochemistry (pituitary hormones, MIB-1, p53 protein),in situ hybridization (pituitary hormones), and Feulgen stain image analysis for ploidy. Results indicated that, in adenohypophyses the scattered pleomorphic, bizarre nuclei were mainly those of somatotrophs and corticotrophs, growth hormone (GH), or adrenocorticotropic hormone (ACTH) immunoreactive and expressing the GH or ACTH gene, respectively. Cyto-and nucleomegaly were less frequent in other secretory cells but were also noted in pituicytes of the posterior lobe. Affected cells were immunonegative for MIB-1 and for p53 protein. Image morphometric DNA analysis showed the bizarre cells to be aneuploid with complex histogram patterns, including many nuclei with DNA contents >8 n. No adenomas were found. We conclude that in AT adenohypophyseal cells with cyto- and nucleomegaly, as well as pleomorphism, synthesize and store adenohypophyseal hormones, mainly GH or ACTH. They and affected pituicytes are nonproliferative and are aneuploid.     

人精浆中EGF与NPY测定的临床价值初探

目的:观察生育者与不育症者精浆中表皮生长因子(EGF)和神经肽Y(NPY)等多肽类物质水平及其对精子数量和功能的影响。方法:应用放射免疫分析(RIA)对110例不同原因引起的不育男性精浆中EGF和NPY等进行综合性测定和分析,同时与精液中精子的功能指标进行相关分析。结果:不育症组精浆EGF和NPY含量均明显高于生育组(P<0.01)。在不育症组中,随精子密度的减少,NPY浓度依次呈不断增高的趋势;在精子活动力与活动率正常组、非WBC精液组精浆EGF含量均低于不正常(或下降)组(P<0.05);NPY含量在精子活动率正常组、非WBC精液组均低于不正常(或下降)组(P<0.05)。结论:精浆中EGF和NPY含量增高或降低反映生殖系统局部的免疫状态和感染情况,其增高产生的毒性作用可影响精子的产生和精子的正常功能。检测精浆中EGF和NPY等含量可以反映男性不育症患者的状态,有利于帮助临床进行有针对性的治疗。     

Effects of All-Trans-Retinoic Acid (atRA) on Inducible Nitric Oxide Synthase (iNOS) Activity and Transforming Growth Factor Beta-1 Production in Experimental Anti-GBM Antibody-Mediated Glomerulonephritis

Sustained high output release of Nitric oxide (NO) as result of activation of inducible nitric oxide synthase (iNOS), and increased production of the antiproliferative/profibrotic cytokine transforming growth factor-1 (TGF-1) are well documented in glomerulonephritis. Modulation of iNOS activity and of TGF-1 production can therefore be viewed as anti-inflammatory strategies. The present study employed all-transretinoic acid (atRA) which is known to have anti-inflammatory effects and to modulate expression of iNOS and TGF-1, in order to explore its effect on iNOS enzyme activity and TGF-1 production in anti-GBM antibody induced glomerulonephritis. Glomerulonephritis was induced in Lewis rats by injection of anti-GBM antibody. A group of nephritic rats were given daily administration of atRA for 14–16 days. Extent of proteinuria was assessed by measuring urine protein and creatinine excretion. iNOS enzyme activity was measured by calculating conversion of L[¹⁴C]arginine to L-[¹⁴C]citrulline in glomerular protein lysates. Levels of TGF-1 in glomerular protein lysates were measured by quantitative ELISA. Levels of proliferating nuclear antigen (PCNA), TGF- receptor II (TGF-RII), and fibronectin were assessed by Western blot analysis. Glomerular iNOS activity in atRA treated nephritic animals was attenuated in comparison to that in nephritic controls that were not. Glomerular expression of PCNA was also reduced. Levels of TGF-1 were increased in glomeruli of atRA treated nephritic animals. In these animals, there was no change in glomerular levels of TGF- receptor II (TGF-RII) or fibronectin, and there was no reduction in urine protein excretion. These results suggest that atRA attenuates iNOS activity and proliferation in glomeruli of nephritic animals. The failure of atRA treatment to reduce proteinuria could be due to the increase in TGF-1 levels and to inhibition of iNOS-driven NO production.     

Pronephros and spleen cells from rainbow trout (Oncorhynchus mykiss) in vitro: Growth factors produced under the influence of mitogens

Supernatants or conditioned media (CM) were produced by rainbow trout pronephros cells (PNC) and spleen cell cultures (1×10⁶/ml), by addition of 20 g/ml phythaemagglutinin (PHA), 5 ng/ml 12-O-tetradecanoyl-phorbol-13-acetate (PHA) (for 2h), PHA together with PMA, 10% horse serum (HS), or 100 g/ml concanavalin A (ConA) after a culture of 7 days. Only PNC were effective growth factor producers. The effect of different concentrations of CM (5%–28%) on cell number was tested after a cultivation period of 14 days. PNC at a concentration of 1×10⁶/ml were cultured with various concentrations of CM and the proliferation was tested by the XTT-test (testing the dehydrogenase activity of the cells by formation of a formazan) after 10 days. CM produced by cells with PHA, PHA and PMA and HS increased the proliferation in a concentration-dependent manner. CM produced with PMA alone was effective in the XTT-test. There was no synergistic or additive effect of PMA with PHA. CM produced with ConA had no effect, although in the XTT-test a strong proliferation of PNC in presence of 100 g/ml ConA was observed. In a semisolid culture with collagen, CM treatment resulted in prevention of cell death and an increase in cell size but did not induce proliferation. All CM obtained from spleen cells had no effect. Stimulation of spleen cells by CM could be seen only in the XTT-test. PHA and HS trigger the PNC to release growth factors in vitro which stimulate cell growth and/or prevent cell death.     

An emerging role of neutrophils and NETosis in chronic inflammation and fibrosis in systemic lupus erythematosus (SLE) and ANCA-associated vasculitides (AAV): Implications for the pathogenesis and treatment

Neutrophils derive from hematopoietic stem cells (HSCs) with systemic inflammation driving their activation and differentiation to myeloid progenitors to ensure enhanced myelopoiesis. Epigenetic reprograming and re-education of these HSCs produces neutrophils primed towards elimination of pathogens and increased inflammatory response. Neutrophils -an important component of acute inflammation- are not present in chronic inflammatory tissues leading to the false assumption that they may not be as important for the latter. Activated neutrophils may release Neutrophil Extracellular Traps (NETs) during a distinct form of cell death, named NETosis; NETs are rich in bioactive molecules that promote thrombosis (including atherothrombosis), inflammation and fibrosis. Thus, although neutrophils may not be present in chronic inflammatory lesions, their remnants may amplify the inflammatory response beyond their short life-span in the tissues. Herein, we review current evidence supporting a role of neutrophils and NETosis in tissue injury and dysfunction in systemic autoimmunity using as disease paradigms Systemic Lupus Erythematosus (SLE) and the ANCA-associated vasculitides (AAV). We also discuss the mechanisms involved and their potential as targets for novel therapy and drug repositioning.