Calcitonin promotes mouse pre-implantation development: involvement of calcium mobilization and P38 mitogen-activated protein kinase activation.

The study was designed to examine the effects of calcitonin (CT) on the development of murine pre-implantation embryos and possible molecular mechanisms involved in the process. In the present study, the 2-cell embryos were treated with different concentration of CT in vitro for the indicated time and the results demonstrated that CT promoted the development of the pre-implantation embryos in a dosage-dependent manner by increasing the intracellular Ca(2+) level. Furthermore, the present study showed that CT significantly increased the expression of phospho-P38MAPK (Mitogen-Activated Protein Kinase) of the pre-implantation embryos by Western blots and pre-treatment of specific P38MAPK inhibitor significantly reduced the promotion effects of CT on the embryonic development in vitro culture. Moreover, the results of intrauterine horn injection showed that the average number of embryos implanted in CT-antibody or specific P38 MAPK inhibitor-treated uterus was significantly lower than that of the corresponding control, respectively. And the observation of tissue specimen suggested that some embryos were degenerated in CT-antibody or specific P38 MAPK inhibitor-treated uterus, and adipose vacuoles were present in the decidual cells. In conclusion, CT promoted the development of pre-implantation embryos and the intracellular Ca(2+) -dependent P38MAPK signal molecule was involved in the process.

Experimental study on total coliform violations in the complied NH2CL, O3, and UV treated municipal water supply system.

Water quality has become a severe concern on a global scale, owing mostly to the rapid increase of the nation's development. According to Malaysia's Natural Resources and Environment Ministry, poor water management is the primary cause of the country's water quality problems. Many river systems are polluted by home and industrial pollutants, according to the findings of research in Malaysia and comparable difficulties in a few other nations. Hence, the following are the research's goals: (1) To look into what is causing the infractions. (2) To undertake the inquiry, develop a thorough hypothesis. (3) To detect dangerous germs by sampling the most usually infected regions. (4) To develop a test for Total Coliform violations in chlorine-treated water at the water treatment plant and in water distribution systems. As a result, the most major barrier to ensuring the safe delivery of treated water to consumers and protecting human health from water-related diseases is the drinking water treatment process. As a result, practically all water treatment systems around the world, including those in the USA, use a chlorine-based procedure to disinfect the water system during treatment. According to studies, the ideal way of disinfecting treated water is both safe and beneficial. Any sort of pandemic or biologically caused disease has no societal implications. Many countries began to suffer in 2009 as a result of e-coli and total coliform contamination in their water systems, leading to ambiguity in disinfection methods. Some water from UNMC's coolers was within the guidelines, while some exceed them. Water coolers at Block E (614 m) and Block B (605 m), for example, measured 12 CFU/100 ml and 11 CFU/100 ml, respectively. Water coolers should be cleaned regularly to ensure that they perform correctly. Further, the microbial population was found to be higher at water storage tanks than that is at the water cooler. This demonstrates how a water cooler fulfils its purpose of filtering and trapping germs to provide clean drinking water.

Uptake of liposomes by cultured cardiomyocytes.

Small unilamellar liposomes (SUV) of different phospholipid/polymer composition were labeled with NBD-PC, which served as a bilayersituated fluorescence marker. Neonatal cardiomyocytes were incubated with liposomes and then the cell-associated fluorescence was measured. The factors influencing the liposome uptake by cardiomyocytes such as concentration of lipid, time of incubation, membrane fluidity of liposomes, charge lipid/polymer modification of liposomes and anoxia of cultured cardiomyocytes were investigated. The liposome uptake by cardiomyocytes increased dose-dependently and time-dependently. Liposome uptake was strongly influenced by the electrical charge and modified polymer. After 2 h incubation, the uptake of positively charged liposomes was 1.7-fold higher than that of negatively charged one and both higher than that of the neutral one. The presence of PE-PEG2000 distinctly reduced the liposome uptake and the difference between the uptake of charged and neutral liposome. Anoxia increased the uptake of liposome at the first hour (increased 20%), but after 2 h incubation the liposome uptake by hypoxia cellswas less than that of normoxia cells (decreased 18%). Mechanisms involved are also discussed.

Expression of macrophage colony-stimulating factor and its receptor in microglia activation is linked to teratogen-induced neuronal damage.

Prenatal exposure to teratogen agents is linked to the pathogenesis of neurodevelopment disorders, but the mechanisms leading to the neurodevelopmental disturbance are poorly understood. To elucidate this, an in vitro model of microglial activation induced by neuronal injury has been characterized. In this connection, exposure of primary microglial cells to the conditioned medium from the neuronal damage induced by teratogen, cyclophosphamide, is accompanied by a reactive microgliosis as assessed by reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, lectin histochemistry, double labeling immunohistochemistry and in situ hybridization. Our results showed that reactive microglia were capable of releasing various cytokines such as tumor necrosis factor-alpha, interleukin-1, interleukin-6, transforming growth factor-beta and nitric oxide. Also, we have shown that macrophage colony-stimulating factor (M-CSF) was in fact produced by the reactive microglia. Concomitant to this was the increased expression of M-CSF receptor in these cells following the teratogen-induced neuronal injury. The up-regulation of M-CSF receptor suggests that the cells are capable of responding to self-derived M-CSF in an autocrine fashion. Results with antibody neutralization further suggest that microglial proinflammatory response, as manifested by cytokine expression in culture, is mediated by M-CSF, which acts as a molecular signal that initiates a microglial reaction. We therefore suggest that microglial activation following cyclophosphamide treatment is not only a response to the neuronal damage, but is also a cause of the damage during pathogenesis of neurodevelopment disorders. To this end, the increased expression of M-CSF and its receptor on microglia would be directly linked to the active cell proliferation and proinflammatory response in the teratogen-induced injury.

Origin of microglia.

This paper reviews the various proposed hypotheses on the origin of microglia. The seminal study of del Rio-Hortega first stated that the cells were derived from the mesodermal pial cells that invaded the brain during embryonic development. Along with this was the description of precursor cells in the yolk sac in early development. Our results in the embryonic mouse brain have shown the occurrence of lectin-labelled precursor cells at the yolk sac that later appeared in the mesenchymal tissue associated with the neuroepithelium where they penetrated the nervous tissue to become the microglia. A second major view has held that microglia are of neuroectodermal origin; the cells either originate from glioblasts or the germinal matrix. Another school of thought is that microglia are derived from blood monocytes. In this connection, circulating monocytes enter the developing brain to assume the form as amoeboid microglia that subsequently evolve to become the ramified microglia. In traumatic brain lesions following an intravenous injection of colloidal carbon as a cytoplasmic marker for monocytes, it was found that carbon-labelled monocytes were the main source of brain macrophages, some of which transformed into microglia during the healing process. In conclusion, our results derived from the normal and altered brain development as well as from experimental lesions tend to favour the view of the monocytic nature of microglia. Recent studies by us also point to the possibility that some microglial cells may arise from the pial mesenchymal macrophages that appear to originate from the yolk sac precursors.

Induction of cytokine expression in the brain macrophages/amoeboid microglia of the fetal rat exposed to a teratogen.

Using in situ hybridization, RT-PCR, lectin histochemistry and immunohistochemistry, this study examined the time course expression and cellular localization of various cytokines including tumor necrosis factor-alpha (TNF-alpha), interleukins (IL-1, IL-6) and transforming growth factor-beta (TGF-beta) in fetal rat brain after a maternal injection of the teratogen cyclophosphamide (CP). Eight hours after CP injection, there was a marked increase in brain macrophages (BM)/amoeboid microglia (AM) in different areas of the fetal brain as determined by lectin histochemistry. Concomitant to this was the induction in mRNA level of TNF-alpha, which was progressively increased with time. TGF-beta mRNA was undetectable until 24 h had elapsed. Expression of IL-1 and IL-6 was undetectable at all stages. In situ hybridization combined with immunohistochemistry has shown the localization of TNF-alpha in BM/AM and neurons. Present results suggest that both TNF-alpha and TGF-beta are involved in the progression of neural damage in the fetal brain induced by the teratogen.

L-Cysteine promotes the proliferation and differentiation of neural stem cells via the CBS/H2S pathway.

Growing evidence has suggested that hydrogen sulfide (H2S) acts as a novel neuro-modulator and neuroprotective agent; however, it remains to be investigated whether H2S has a direct effect on neural stem cells (NSCs). We report here that NSCs expressed cystathionine ß synthase (CBS) and addition of exogenous H2S donor, L-cysteine, stimulated proliferation and increased the differentiation potential of NSCs to neurons and astroglia. Moreover, pre-treatment with aminooxyacetic acid, the inhibitor of CBS or knockdown of CBS in using siRNA, significantly attenuated the effects of L-cysteine on elevated H2S levels and the cell proliferation; it also effectively suppressed L-cysteine-induced neurogenesis and astrocytogenesis. Further analysis revealed that L-cysteine-induced proliferation was associated with phosphorylation of extracellular signal-regulated kinases 1/2 and differentiation with altered expression of differentiation-related genes. Taken together, the present data suggest that L-cysteine can enhance proliferation and differentiation of NSCs via the CBS/H2S pathway, which may serve as a useful inference for elucidating its role in regulating the fate of NSCs in physiological and pathological settings.

Roles of activated astrocytes in bone marrow stromal cell proliferation and differentiation.

Local microenvironment plays an important role in determining the fate choice of stem cells in the central nervous system (CNS). Astrocytes, a major component of local microenvironment in the CNS, have been demonstrated to influence the proliferation and neural differentiation of stem cells including neural stem/progenitor cells, embryonic stem cells and bone marrow stromal cells (BMSCs). However, it has remained to be ascertained if inflammation-activated astrocytes can affect the behavior of BMSCs. To this end, astrocyte-conditioned medium (ACM) was prepared in this study for treatment of BMSCs. The ACM derived from Wistar rat astrocytes stimulated by lipopolysaccharide for 12, 36 or 72 h, respectively, served as inflammatory ACM (12 h ACM, 36 h ACM and 72 h ACM), while that from unstimulated astrocytes was used as normal control astrocyte-conditioned medium (N-ACM). The results showed that the proliferation and neural differentiation of BMSCs grown in inflammatory ACM were significantly increased compared with those grown in N-ACM. The efficiency of BMSCs exposed to 36 h ACM was significantly greater than that of those exposed to 12 or 72 h ACM. Following neutralization of interleukin-6 (IL-6) of the ACM, both the proliferation and astrocytic differentiation of BMSCs were decreased; on the other hand, the neuronal differentiation was significantly increased. The present findings suggest that inflammation-activated astrocytes can facilitate the proliferation and neural differentiation of BMSCs and activated astrocytes at different phase after CNS injuries might have distinct effects on BMSCs. Moreover, astrocyte-derived IL-6 participates in the proliferation and neural differentiation of BMSCs.

Identification of differentially expressed genes in fetal rat forebrain exposed to a teratogen by cDNA microarray analysis.

In an attempt to understand the molecular basis underlying the neural tube defects induced by the teratogen, cyclophosphamide (CP), cDNA microarray analysis was carried out in neural tubes of embryos derived from normal and CP-treated rats. Genes found to have altered expression levels in CP-treated group were clustered into groups on the basis of their biological functions. The expression profile of different genes involved in transcription of molecules related to cell adhesion, inflammation, metabolism and neurotrophic factors pathways as well as in still undefined processes was differentially affected by the teratogen treatment. The most remarkable change was the up-regulation of genes related to an inflammatory process dominated by the fetal brain macrophages viz. amoeboid microglia. Amoeboid microglia/brain macrophage expansion, based on gene expression and histological analysis, was found to be vigorous at the subventricular region. The present results suggest that a vigorous inflammatory response involving amoeboid microglia/brain macrophages primarily is an important component in CP-induced prenatal development disorder.

Degradation kinetics of fluorouracil-acetic-acid-dextran conjugate in aqueous solution.

The degradation kinetics of fluorouracil-acetic-acid-dextran conjugate (FUAC-dextran) was investigated in various buffer solutions with different pH value and physiological saline solution at 60 degrees C and 37 degrees C, respectively. The hydrolytic reaction displayed pseudo-first-order degradation kinetics. Hydrolytic rate constant obtained was the function of pH value and independent of species of buffering agents. The smallest rate constant was observed at pH round 3.00. The activation energy of the hydrolytic reaction was estimated from Arrhenius equation as 88.73 +/- 6.00 kJ.mol-1. The special base catalytic degradation of the conjugate was observed from acidic to slight alkaline condition and the special base catalytic rate constants were calculated. The conjugate was more stable in physiological saline than that in buffer solution at pH 7.00 or 9.00 at 37 degrees C. The results revealed that the conjugate was stable in acidic condition and will degrade in alkaline condition.

Response of amoeboid microglia/brain macrophages in fetal rat brain exposed to a teratogen.

This study examined the time course response of amoeboid microglia/brain macrophages in the rat fetus induced by a single intraperitoneal injection of cyclophosphamide, a teratogen, into the mother rat at 13 days of gestation. Compared to the normal fetal brain, a marked increase in amoeboid microglia was observed in the telencephalon and diencephalon of experimental fetuses, especially in those killed at embryonic day 15. Conglomerations of microglia occurred in the dorsal and superior neuroepithelium of diencephalon, basal telencephalon, cortical neuroepithelium, and hippocampal formation as identified with OX-42, OX-18, and ED-1 by immunohistochemistry. Rhodamine isothiocynate (RhIc) as a tracer was injected via the tail vein into the pregnant rat to assess the phagocytic capability of these cells. Following the tracer injection, none of microglial cells in normal fetal brain was detectable. RhIc, however, was readily taken up by amoeboid microglia in fetal brain with injury insult. Double labeling has shown that the RhIc-labeled cells were immunoreactive with ED-1, OX-42, OX-18, and OX-6, confirming their microglial nature. Microglial proliferation was assessed by immunohistochemistry using bromodeoxyuridine, which showed a marked increase in mitotic activity. Confocal microscopic analysis revealed that a varying number of microglia coexpressed iNOS, macrophage colony-stimulating factor (M-CSF), and ICAM-1. RT-PCR analysis showed increased expression of M-CSF mRNA. Furthermore, colony-stimulating factor-1 receptor mRNA was localized in microglia by in situ hybridization. The present results suggest that NO along with M-CSF and ICAM-1 is involved in microglial proliferation in prenatal brain injury.