Microglia at center stage: a comprehensive review about the versatile and unique residential macrophages of the central nervous system

Microglia cells are the unique residential macrophages of the central nervous system (CNS). They have a special origin, as they derive from the embryonic yolk sac and enter the developing CNS at a very early stage. They play an important role during CNS development and adult homeostasis. They have a major contribution to adult neurogenesis and neuroinflammation. Thus, they participate in the pathogenesis of neurodegenerative diseases and contribute to aging. They play an important role in sustaining and breaking the blood-brain barrier. As innate immune cells, they contribute substantially to the immune response against infectious agents affecting the CNS. They play also a major role in the growth of tumours of the CNS. Microglia are consequently the key cell population linking the nervous and the immune system. This review covers all different aspects of microglia biology and pathology in a comprehensive way

A novel in vitro human microglia model: Characterization of human monocyte-derived microglia

Microglia are the innate immune cells of the central nervous system. They help maintaining physiological homeostasis and contribute significantly to inflammatory responses in the course of infection, injury and degenerative processes. To date, there is no standardized simple model available to investigate the biology of human microglia. The aim of this study was to establish a new human microglia model. For that purpose, human peripheral blood monocytes were cultured in serum free medium in the presence of M-CSF, GM-CSF, NGF and CCL2 to generate monocyte-derived microglia (M-MG). M-MG were clearly different in morphology, phenotype and function from freshly isolated monocytes, cultured monocytes in the absence of the cytokines and monocyte-derived dendritic cells (M-DC) cultured in the presence of GM-CSF and IL-4. M-MG acquired a ramified morphology with primary and secondary processes. M-MG displayed a comparable phenotype to the human microglia cell line HMC3, expressing very low levels of CD45, CD14 and HLA-DR, CD11b and CD11c; and undetectable levels of CD40, CD80 and CD83, and a distinct pattern of chemokine receptors (positive for CCR1, CCR2, CCR4, CCR5, CXCR1, CXCR3, CX3CR1; negative for CCR6 and CCR7). In comparison with M-DC, M-MG displayed lower T-lymphocyte stimulatory capacity, as well as lower phagocytosis activity. The described protocol for the generation of human monocyte-derived microglia is feasible, well standardized and reliable, as it uses well defined culture medium and recombinant cytokines, but no serum or conditioned medium. This protocol will certainly be very helpful for future studies investigating the biology and pathology of human microglia

A Comparison Study of the Effects of Echinacea purpurea Ethanolic Extract and Mesna on Cyclophosphamide-Induced Macroscopic Fetal Defects in Rats

Objective(s)Quinazolinones are heterocyclic compounds, with biological and pharmacological activities, such asinhibiting some proteins, enzymes and reducing blood lipids.Materials and MethodsFollowing previous results of our group, effects of two new derivatives of quinazolinones9(3)-quinazolinone-2-propyl-2-phenylethyl (QPPE) and 9(3)-quinazolinone-2-ethyl-2–phenylethyl (QEPE)on livers, intestines and kidneys of newborn Balb/C mice were investigated. Pregnant mice were divided intofour groups of control, sham, experimental 1, treated with QPPE, and experimental 2, treated with QEPE.Experimental groups received 100 mg/kg body weight (most effective dose) of QPPE and QEPE, shamgroups received methyl cellulose 0.05% (the solvent) and control groups received distilled water,intraperitoneally (IP), on day 8 of gestation. Five days after birth, livers, intestines and kidneys wereremoved, fixed in formalin 10%, stained with hematoxylene and eosin for histological and pathologicalstudies.ResultsResults showed appearance of fatty changes in livers, an increase in diameters of hepatocytes and centralveins of livers, and reduction in the lengths of villi of proximal, middle and distal segments of newbornBalb/C mice intestines. Furthermore, there was a diminished diameter of the lumen of the proximal tubules,and average diameter of the lumen of distal tubules which led to an increase in the number of glomeruli cellsof newborn Balb/C mice kidneys.ConclusionRegarding inflammation in different parts of the kidneys, livers and intestines, our investigations suggest thatquinazolinones may have some toxic effects on embryos.Keywords: Abnormalities, Intestine, Kidney, Liver, Mice fetuses, Quinazolinone