Histology and histopathology Vol.28, nº 2 (2013)
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- PublicationOpen AccessA comparative study of extracellular matrix remodeling in two murine models of emphysema(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2013) Lopes, F.D.T.Q.S.; Toledo, A.C.; Olivo, C.R.; Prado, C.M.; Leick, E.A.; Medeiros, M.C.; Santos, A.B.G.; Garippo, A.; Martins, M.A.; Mauad, T.A single instillation of porcine pancreatic elastase (PPE) results in significant airspace enlargement on the 28th day after instillation, whereas cigarette smoke (CS) exposure requires 6 months to produce mild emphysema in rodents. Considering that there are differences in the pathogenesis of parenchymal destruction in these different experimental models, it is likely that there may be different patterns of extracellular matrix (ECM) remodeling. To evaluate ECM remodeling, C57BL/6 mice were submitted to either a nasal drop of PPE (PPE 28 Days) or exposed for 6 months to cigarette smoke (CS 6 months). Control groups received either an intranasal instillation of saline solution (Saline 28 Days) or remained without any smoke inhalation for six months (Control 6 months). We measured the mean linear intercept and the volume proportion of collagen type I, collagen type III, elastin and fibrillin. We used emission-scanning confocal microscopy to verify the fiber distribution. Both models induced increased mean linear intercept in relation to the respective controls, being larger in the elastase model in relation to the CS model. In the CS model, emphysema was associated with an increase in the volume proportion of fibrillin, whereas in the PPE model there was an increase in the parenchymal elastin content. In both models, there was an increase in collagen type III, which was higher in the CS-exposed mice. We concluded that ECM remodeling is different in the two most used experimental models of emphysema.
- PublicationOpen AccessAberrant expression and association of VEGF and Dll4/Notch pathway molecules under hypoxia in patients with lung cancer(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2013) Yu, Shuang; Sun, Jianhua Sun; Zhang, Jingru; Xu, Xingfang; Li, Hong; Shan, Baozhong; Tian, Tian; Wang, Hongchun; Ma, Daoxin; Ji, ChunyanTumor angiogenesis plays important roles in the pathogenesis and prognosis of lung cancer. Both vascular endothelial growth factor (VEGF) and Dll4/Notch pathways are critical for angiogenesis, whereas their relationship under hypoxia in lung cancer remains unknown. Thus, in the present study, we evaluated the expression of VEGF and Dll4/Notch signaling molecules, and assessed their association with the microvessel density (CD31) and hypoxia (HIF1a) in lung cancer and normal lung tissues using immunohistochemical and Real-time RT-PCR techniques. Then, we investigated the biological function of Dll4 by transfecting Dll4 into HUVECs. In lung cancer tissues, Notch pathway molecules (HES1) and VEGF pathway molecules (VEGFR1 and VEGFR2) were significantly up-regulated, while the ratio of VEGFR1/VEGFR2 was decreased. CD31 and HIF1a were also found to be elevated in lung cancer. VEGFR1 was negatively correlated with Notch1 while positively correlated with Dll4. CD31 was positively correlated with HIF1a but negatively correlated with VEGFR1. Moreover, HIF1a was nearly positively correlated with HES1 in lung cancer tissues. After transfection, Dll4, Notch1 and VEGFR1 were up-regulated while VEGF and VEGFR2 were down-regulated in Dll4-transfected HUVECs compared with controls. Also, our findings suggest that the expression of VEGF and VEGFR2 increased gradually with the disease progression of lung cancer. In summary, VEGF and Notch signaling pathway molecules were overexpressed in lung cancer, which positively correlates with hypoxia (HIF1a) and angiogenesis (CD31). There might be a negative feedback loop between VEGF and Dll4/Notch signaling pathway in lung tumor angiogenesis.
- PublicationOpen AccessRat hair follicle-constituting cells labeled by a newly-developed somatic stem cell-recognizing antibody: a possible marker of hair follicle development(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2013) Ichikawa, Chisa; Izawa, Takeshi; Juniantito, Vetnizah; Tanaka, Miyuu; Hori, Mayuka; Tanaka, Katsuhiro; Takenaka, Shigeo; Kuwamura, Mitsuru; Yamate, Jyoji. A3 was generated as an antibody recognizing somatic stem cells in rat tissues. We investigated the distribution of A3-positive cells in developing rat hair follicles by immunolabeling. A3-positive cells began to be seen in the hair germ and peg in fetuses and neonates; the positive cells were epithelial cells above basal cells. Furthermore, A3-positive cells were seen in the outer root sheath adjacent to the bulge in mature hair follicles. Double immunofluorescence revealed that these A3- positive epithelial cells reacted to E-cadherin (for all epithelial elements) but not to CK15 (for basal cells/epithelial stem cells) or to nestin (for stem cells), indicating that A3-positive epithelial cells are suprabasal cells in the developing epidermic hair follicle. Additionally, spindle-shaped mesenchymal cells surrounding the hair peg and mature hair follicle reacted to A3; in double immunofluorescence, the A3-positive cells were located outside collagen type IV-positive glassy membrane, and reacted to vimentin (for mesenchmal cells), Thy-1 (for immature mesenchymal cells), CD34 (for stem cells) and nestin, but not to α- smooth muscle actin (for myofibroblasts); the positive cells were regarded as immature mesenchymal cells with stem cell nature in the connective tissue sheath of developing hair follicles. A3-positive epithelial and mesenchymal cells did not show proliferating activity. Collectively, it is considered that A3-positive cells seen in developing rat hair follicles may be quiescent postprogenitor cells with the potential to differentiate into either highly-differentiated epithelial or mesenchymal cells. A3 would become a useful antibody to know the kinetics of rat hair follicle-constituting cells.
- PublicationOpen AccessThe effect of glucagon and cyclic adenosine monophosphate on acute liver damage induced by acetaminophen(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2013) Kelava, Tomislav; Ćavar, Ivan; Vukojevic, Katarina; Saraga-Babić, Mirna; Čulo, FilipRecent investigations suggest that glucagon might have a potentially important hepatoprotective activity. We investigated the effect of glucagon in a model of acetaminophen-induced liver injury. CBA male mice were injected intraperitoneally with a lethal (300 mg/kg) or sublethal (150 mg/kg) dose of acetaminophen. The liver injury was assessed by observing the survival of mice, by liver histology and by measuring the concentration of alanine-aminotransferase (ALT). Inducible nitric oxide synthase (iNOS) and nuclear factor kappa B (NF-κB) protein expressions were determined immunohistochemically. Hepatic levels of reduced glutathione (GSH) and cyclic adenosine monophosphate (cAMP) were also measured. Results show that glucagon, dose and time dependently, protects against acetaminophen-induced hepatotoxicity. This protection was achieved with a dose of 0.5 mg/kg of glucagon given intraperitoneally 15 min before or 1 h after acetaminophen. Treatment of animals with acetaminophen elevated ALT and nitrite/nitrate concentration in the plasma, enhanced iNOS and NF-κB expression and reduced GSH and cAMP concentration in the liver. Animals treated with glucagon had higher hepatic cAMP level, lower ALT and nitrite/nitrate concentration in plasma and lower expression of iNOS in liver cells than animals in control group, whereas there was no difference in the expression of NF-κB. Glucagon did not prevent the loss of GSH content caused by acetaminophen. Our investigation indicates that glucagon has a moderately protective effect against acetaminophen-induced liver injury, which is, at least partially, mediated through the downregulation of iNOS and through the increase in hepatic cAMP content, but it is not mediated through the modulation of NF-κB activity.
- PublicationOpen AccessCrosstalk between endothelial cell and thrombus in chronic thromboembolic pulmonary hypertension: perspective(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2013) Sakao, Seiichiro; Tatsumi, KoichiroIt is generally accepted that chronic thromboembolic pulmonary hypertension (CTEPH) results from pulmonary emboli originating from deep vein thrombosis. However, this consensus opinion has been challenged, and the concept that some aspects of CTEPH exacerbation might result from a small-vessel disease leading to secondary thrombosis has been suggested. In addition to the effect of recurrent thromboembolism, a number of lines of clinical evidence indicate that progressive worsening is contributed to by remodeling in the small pulmonary arteries. Histopathological studies of the microvascular changes in CTEPH have identified vascular lesions similar to those seen in idiopathic pulmonary arterial hypertension (IPAH). Especially in in vitro and ex vivo experiments, pulmonary artery endothelial cells (ECs) in pulmonary hypertensive diseases are suggested to exhibit an unusual hyperproliferative potential with decreased susceptibility to apoptosis, indicating that dysfunctional ECs may contribute to the progression of the diseases. Although the degree and mechanisms of EC dysfunction as a contributor to CTEPH are unclear, EC dysfunction may occur in small arteries. Indeed, the cells stimulated by the microenvironment created by the unresolved clot may release substances that induce EC dysfunction. The EC dysfunctions in CTEPH may lead to disorders of the anti-coagulation properties in ECs and may result in additional clots in situ. Moreover, these may lead to the progression, not only of distal thrombus, but also of proximal clotting. This article reviews the pathobiological concepts of CTEPH and explains a crosstalk between EC dysfunction and in situ thrombi which may contribute to the vascular lesions of CTEPH.