DigitalUM :: Browsing by Subject "Neutrophils"

Browsing by Subject "Neutrophils"

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Open Access
Alterations in liver parenchyma after sialoadenectomy in mice, Contribution of neutrophils and macrophages to the removal of damaged hepatocytes
(Murcia : F. Hernández, 2008) Viladrich, Meritxel; Sánchez, Olga; Soley, María; Ramírez, Ignasi
Surgical excision of submandibular salivary glands (sialoadenectomy) alters cell turnover in mice liver. Here we show that the liver of adult mice contained scattered leukocyte infiltration foci whose size was in the range of the diameter of hepatocytes. The number of infiltration foci in the liver increased soon after sialoadenectomy and remained high for several weeks. Neutrophils were recruited on dying hepatocytes soon after the initiation of the apoptotic process. Kupffer cells appeared later in the process. Just 2 days after sialoadenectomy, the number of type I infiltration foci (corresponding to the first stage) had increased 5-fold. Since these alterations in liver structure are coincident with a transient decrease in plasma EGF concentration, we studied whether inhibition of EGF receptor by means of genistein injection produced a similar effect. After three days of genistein administration, the number of type I infiltration foci increased 3.5-fold. Sialoadenectomized mice were more susceptible than controls to endotoxin shock. While 90% of shamoperated mice survived a burst of 100 μ g lipopolysaccharide/Kg (combined with D-galactosamine 750 mg/Kg), only 50% of sialoadenectomized mice survived. The surviving sialoadenectomized mice recovered more slowly than the controls, as indicated by the high plasma alanine transaminase activity a week after the burst. We conclude that (i) neutrophils and macrophages participate in the process of apoptotic hepatocyte removal in a sequential manner; (ii) although the alteration of liver structure induced by sialoadenectomy is mild, it has delayed consequences on the ability of the liver to deal with aggressive insults.
Open Access
An overview of the structural and functional aspects of immune cells in teleosts
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Mokhtar, Doaa M.; Abdelhafez, Enas A.
The immune system of fish consists of two main components, innate and adaptive immunities. Innate immunity is non-specific and acts as the primary line of protection against pathogen invasion, while adaptive immunity is more specific to a certain pathogen/following adaptation. The adaptive immune system consists of the humoral and cellular components. Cytotoxic T-lymphocyte cells are the major component of the cellular immunity that frequently kills viral-, bacterial- or parasitic-infected cells. According to the anatomical location, the mucosal-associated lymphoid tissue (MALT) in teleost fish subdivides into gutassociated lymphoid tissue (GALT), gill-associated lymphoid tissue (GIALT), and skin-associated lymphoid tissue (SALT). The MALTs contain various leukocytes; including, but not limited to, lymphocytes (T and B cells), plasma cells, macrophages, and granulocytes. Macrophages are multifunctional cells that are mainly involved in the immune response, including; phagocytosis and degradation of foreign antigens, tissue remodeling, and production of cytokines, chemokines and growth factors. An interesting feature of teleost macrophages is their ability to form melanomacrophage centers (MMC) in the hemopoietic tissues. Dendritic cells, rodlet cells, mast cells, eosinophilic granular cells (ECGs), telocytes, osteoclasts, club cells, as well as, barrier cells have been recorded in many fish species and have many immunological roles. This paper aims to summarize the current knowledge of the immune cells present in fish tissues serving as anatomical and physiological barriers against external hazards. Increased knowledge of fish immune systems will facilitate the development of novel vaccination strategies in fish.
Open Access
Bovine oviduct epithelial cells suppress the phagocytic activity of neutrophils towards sperm but not for bacteria in vitro: Immunofluorescence and electron microscopic observations
(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2020) Marey, Mohamed Ali; Matsukawa, Haruhisa; Sasaki, Motoki; Ezz, Mohamed Aboul; Yousef, Mohamed Samy; Takahashi, Ken-ichi; Miyamoto, Akio
Previously, we reported that polymorpho- nuclear neutrophils (PMNs) are constantly existent in the bovine oviduct fluid during the pre-ovulatory stage under physiological conditions. Moreover, incubation of PMNs with bovine oviduct epithelial cells-conditioned medium (BOEC-CM) resulted in suppression of their phagocytic activity for sperm. During pathophysiological conditions, cows may be inseminated by infected semen which exposes oviductal PMNs to allogenic sperm simultaneously with pathogens. This study aimed to visually investigate the role of oviduct epithelium in regulating the phagocytic behavior of PMNs toward sperm as a physiological stimulus, with Escherichia coli (E. coli) as a pathological stimulus. In our experiment, PMNs were incubated for 2 h in BOEC-CM. Phagocytosis was then assayed by co-incubation of these PMNs either with sperm, E. coli, or latex beads. BOEC- CM significantly suppressed the direct phagocytosis of PMNs for sperm, but did not affect their phagocytic activity for E. coli or latex beads. Additionally, an investigation with scanning electron microscopy revealed that BOEC-CM suppressed the formation of DNA-based neutrophil extracellular traps (NETs) for sperm entanglement. BOEC-CM did not alter NETs formation towards E. coli. A quantification of NETs formation using an immunofluorescence microscopy showed that the areas of NETs formation for E. coli were significantly larger than those formed for sperm. Our data clearly show that the bovine oviduct, through secretions, protects sperm from phagocytosis by PMNs and eliminates bacterial dissemination through maintaining the phagocytic activity of PMNs towards bacteria
Open Access
Emerging relationship between CFTR, actin and tight junction organization in cystic fibrosis airway epithelium
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2017) Castellani, Stefano; Favia, Maria; Guerra, Lorenzo; Carbone, Anna Lucia; Abbattiscianni, Anna Claudia; Di Gioia, Sante; Casavola, Valeria; Conese, Massimo
Cystic fibrosis (CF), one of the most common genetic disorders affecting primarily Caucasians, is due to mutations in the CF Transmembrane Conductance Regulator (CFTR) gene, encoding for a chloride channel also acting as regulator of other transmembrane proteins. In healthy subjects, CFTR is maintained in its correct apical plasma membrane location via the formation of a multiprotein complex in which scaffold proteins (such as NHERF1) and signaling molecules (such as cAMP and protein kinases) guarantee its correct functioning. In CF, a disorganized and dysfunctional airway epithelium brings an altered flux of ions and water into the lumen of bronchioles, consequent bacterial infections and an enormous influx of inflammatory cells (mainly polymorphonuclear neutrophils) into the airways. Recent evidence in healthy airway cells supports the notion that CFTR protein/function is strictly correlated with the actin cytoskeleton and tight junctions status. In CF cells, the most frequent CFTR gene mutation, F508del, has been shown to be associated with a disorganized actin cytoskeleton and altered tight junction permeability. Thus, the correct localization of CFTR on the apical plasma membrane domain through the formation of the scaffolding and signaling complex is likely fundamental to determine a physiological airway epithelium. The correction of CFTR mutations by either gene or drug therapies, as well as by stem cell-based interventions, can determine the resumption of a physiological organization of actin stress fibers and TJ structure and barrier function, further indicating the close interrelationship among these processes.
Open Access
HM13 is a predictive biomarker of metastasis and neutrophil infiltration in colorectal cancer
(Universidad de Murcia, Histología e Histopatología, 2025) Yanbing Ren; Ying Mao; Xiao Yuan; Biología Celular e Histología
Background. High levels of histo-compatibility minor 13 (HM13) have been related to the progression of several cancers. Here, we investigated the function of HM13 in colorectal cancer (CRC). Methods. HM13 expression, clinicopathology analysis, and its influence on survival were analyzed in multiple public databases (TCGA, TIMER2.0, and GEPIA). HM13 mRNA and protein levels in CRC cells were examined by qRT-PCR and western blot, respectively. CCK-8, Transwell, wound-healing, and adhesion assays were used to measure cell proliferation, migration, invasion, and adhesion in HM13-overexpressed and -silenced cells. The relationship between HM13 expression and neutrophil infiltration was also analyzed. CRC xenograft mouse models were used for in vivo verification of HM13 function. Results. In this study, TCGA dataset analysis revealed that elevated HM13 levels correlated with malignant progression and worse survival outcomes in CRC. Cell migration, proliferation, invasion, and adhesion were suppressed through the knockdown of sh-HM13 and enhanced through HM13 overexpression. Additionally, HM13 expression significantly correlated with the infiltration level of neutrophils in CRC in TCGA and TIMER analyses. HM13 levels were also positively correlated with myeloperoxidase (MPO) levels. In addition, in vivo studies further confirmed that MPO overexpression partially abolished the inhibition of tumor growth by sh-HM13 in CRC. Conclusion. The results suggested that high HM13 expression in CRC could promote tumor growth and metastasis by reducing neutrophil infiltration and may serve as a useful target in the treatment of metastatic CRC.
Open Access
Inflammatory cells induce neointimal growth in a rat arterial autograft model
(Murcia : F. Hernández, 2002) Jurado, F.; Bellón, J.M.; Rodríguez, M.; Corrales, C.; Buján, J.
Subendothelial invasion by leukocytes is a sign of intimal thickening in arteriosclerosis and in the response of a vessel to mechanical damage. Our study was designed to establish whether these cells are implicated in the formation of a neointima in an autologous arterial graft model in the rat and to evaluate the effects of cyclosporin A (CsA). Three study groups were established according to whether the animals were treated with CsA-Cp (Sandimmun)®, CsA-Et (ethanol vehicle) or received no treatment (control group). Both drug forms were administered (5 mg/kg/day, s.c.) from 4 days prior to surgery until the time of sacrifice. Antibodies specific for lymphocytes (CD4, CD8), monocytes/macrophages-ED1, smooth muscle a-actin and the von Willebrand factor (vWF) were used to identify the cells in the grafted arterial wall. In control grafts, the neointima had formed by 2 weeks postimplant. However, the cells comprising this layer generally presented no positivity whatsoever towards the antibodies employed. At 50 days, the new layer was observed to be formed by a vWF-positive endothelium and a-actin-positive cells. In all three groups, several polymorphonuclear (PMN) cells adhered to the denuded luminal surface from 7 days onwards. In the treated animals, neutrophils and monocytes were seen to infiltrate intimal and medial layers during the later postimplant stages. Around the third week post-implant, the neointima had reached the grafted segment from the distal portion of the recipient artery, and by 50 days it was similar to that seen in control specimens. Our findings suggest that: a) neutrophils play a role in neointimal thickening in this arterial autograft model; and b) CsA promotes the adhesion and infiltration of neutrophils in the injured arterial wall.
Open Access
Myeloid cell distribution and activity in multiple sclerosis
(Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Moliné-Velázquez, Verónica; Vila-del Sol, Virginia; de Castro, Fernando; Clemente, Diego
Multiple sclerosis (MS) is a demyelinating disease in which an exacerbated immune response provokes oligodendrocyte loss and demyelination, the hallmarks of this neurological disease. The destruction of myelin due to the uncontrolled activity of the invading immune cells leads to the formation of MS plaques. Among the different leukocytes that participate in the immune response associated with MS, the role of myeloid cells has been analyzed extensively (i.e. macrophages, dendritic cells -DCs- and neutrophils). Hence, in this review we will summarize what is known about the distribution, expression and markers available to study myeloid cells, and their histopathology, not only in a standard animal model of MS (autoimmune experimental encephalomyelitis -EAE) but also in MS tissue. In this review, we will not only refer to mature myeloid cells but also to the undifferentiated and almost unexplored myeloid-derived suppressor cells (MDSCs). The active role of MDSCs in the prompt resolution of an immune episode is gaining importance, yet is still the subject of some debate. Finally, the similarities and differences between MS and EAE are discussed, particularly in terms of myeloid cell phenotype, activity and the markers used.
Open Access
Neutrophils as a source of cytokines in inflammation
(Murcia : F. Hernández, 1999) Matsukawa, A.; Yoshinaga, M.
The recruitment of neutrophils into inflammatory foci is a fundamental process observed in inflammation. The function of neutrophils has long been regarded only as an effector cell that kills the invading pathogens. Recent evidence has demonstrated that neutrophils are capable of producing inflammatory cytokines. The findings are, however, mainly based on the findings obtained in vitro. It has not been fully elucidated if neutrophils could synthesize and secrete cytokines in vivo. Animal models of inflammation are essential to address the issue and provide insight into the involvement of neutrophils in producing cytokines.
Open Access
Role of prostaglandin E2 receptor subtypes in ovarian follicle growth in the rat in vivo. Correlation with interleukin-8 and neutrophils
(Murcia : F. Hernández, 2005) El-Nefiawy, N.; Abdel-Hakim, K.; Kanayama, N.; Terao, T.
This study was conducted to elucidate the role of three of prostaglandin E2 (PGE2) receptor subtype (EP2, EP3, and EP4) agonists in the process of follicular growth. The influence of these agonists on ovarian expression of intimately related factors to follicle development (neutrophils and interleukin-8 (IL- 8)) was also investigated. Immature female Wistar rats were injected once with these agonists and killed 48 hours later. Another group of rats were injected pregnant mare serum gonadotrophin. For evaluation of follicle growth, morphometric assessment of antral and ovulatory follicles was performed in serial ovarian sections. The study demonstrated that, EP2 and EP4 agonists showed the maximum follicle counts and diameters versus the control. EP2 and EP4 agonists mimicked PMSG induced follicle growth. Injection of the three agonists induced neutrophil infiltration into theca layer. EP4 agonist showed the most intense ovarian neutrophil accumulation. In addition, dense ovarian IL-8 expression was observed only after EP4 agonist injection. Conclusions: Our data suggests that: 1) EP2 and EP4 receptors are the key PGE2 receptors engaged in follicle growth. 2) Ovarian IL-8 expression and neutrophil infiltration are chiefly mediated via the EP4 receptor. EP2 and EP4 receptor agonists may be candidates for promising reagents that induce follicle maturation in clinical or agricultural fields. This knowledge could provide numerous targets for manipulation of fertility.
Open Access
The microanatomy of calcium stores in human neutrophils, Relationship of structure to function
(Murcia : F. Hernández, 1997) Pettit, E.J.; Davies, E.V.; Hallett, M.B.
As changes in cytosoiic free ca2+ play key roles in coupling responses in neutrophils, it is important to locate and identify ca2+ storage sites within these cells. Here, recent data is presented which highlights the functional link between rnicroanatomical structure and cell signailing function. Fluorescent opticai probes for cytosolic free ca2+ have been used, together with organelle specific markers. We present evidence from conventional fluorescence microscopy, together with ratiometric and confocal laser scanning fluorescence microscopy, which pin-points two celiular locations for ca2+ within the neutrophil; one within the nuclear lobes, and the other towards the ceii periphery. Knowledge of these two locations provides a clear insight into how signailing in this cell type is regulated and provides a framework for explaining how specific stimuli act to produce specific responses.
Open Access
Ultrastructural study of ovine pulmonary pasteurellosis, involvement of neutrophils and macrophages
(Murcia : F. Hernández, 2001) Gázquez, A.; Redondo, E.; Martínez, S.; Gómez, L.
Pasteurellosis is a common infectious disease characterised by fibrinous pneumonia and involving neutrophils and macrophages. This study aimed to determine the timing and extent of the pathogenic involvement of these cell elements in lesions induced in experimentally-infected lambs. A concentration of approximately 3 x 1 0 ~ba cterialml. was inoculated into 30 two-month-old disease-free Merino lambs. Five lambs were assigned to each of five experimental batches, slaughtered on days 1, 3,7, 11 and 15 following intratracheal inoculation, and to one control batch inoculated with a sterile solution. One control animal was slaughtered at the same time as each experimental batch. More characteristic lesions occur in bronchioles, peribronchial tissue and alveoli and are characterised by fibrinous processes. From the start of the experiment, epithelial-cell disruption and loss of microvilli were apparent; cell debris, desquamate cells and bacterial elements were observed in bronchiolar lumina, embedded in a fibrillar granular material. Alveolar structures displayed fewer neutrophils and macrophages, containing phagocytic vacuoles. Laminar bodies were apparent in type 11 pneumocytes. The interseptal area contained similar cell types, as well as abundant edema. In the course of the experiment, macrophage numbers increased in al1 the areas involved, with signs of intense phagocytic activity. The final phase of the experiment was characterised by a mild interseptal infiltrate and by clear alveolar lumina.
Open Access
Vitamin E prevents neutrophil accumulation and attenuates tissue damage in ischemic-reperfused human skeletal muscle
(Murcia : F. Hernández, 1997) Formigli, L.; Ibba-Manneschi, L.; Tani, A.; Gandini, E.; Adembri, C.; Pratesi, C.; Novelli, G.P.; Zecchi-Orlandini, S.
Neutrophil accumulation and the consequent production of oxygen-derived free radicals are involved in the pathogenesis of Ischemia-Reperfusion syndrome. In this study we investigated whether a treatment with Vitamin E, which has antioxidant properties, could attenuate the tissue damage by interfering with the influx of neutrophils within the ischemic and reperfused human skeletal muscle. To this purpose, patients undergoing aortic crossclamping during the surgical repair of aortic abdominal aneurysm were studied as a model of ischemiareperfusion of the lower limb muscles. Muscle biopsies from the right femoral quadriceps of patients not receiving and receiving Vitamin E pretreatment before surgery were taken: a) after the induction of anaesthesia, as control samples, and b) after a period of ischemia followed by 30 min of reperfusion. The tissue samples were either routinely processed for morphological study and immunohistochemical analysis to detect an altered expression of specific endothelial adhesion proteins, such as E-selectin and ICAM-1. The results obtained showed that Vitamin E administration was able to prevent the accumulation of neutrophils within the ischemic and reperfused muscle. This beneficia1 effect of Vitamin E was due to its ability to hinder the expression of E-selectin and ICAM-1, molecules known to increase the adhesiveness of endothelium to circulating neutrophils. After treatment with Vitamin E a marked attenuation of the reperfusion injury was also evident. In conclusion, Vitamin E treatment may be considered a valuable tool for protection against the ischemiareperfusion damage of human skeletal muscle.

Browsing by Subject "Neutrophils"

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