Browsing by Subject "Partial hepatectomy"

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    4-(3,4-dihydroxybenzoyloxymethyl)phenyl-O-β-D-glucopyranoside effect in liver regeneration
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2019) Firat, Tülin; Söyler, Gizem; Töre, Fatma; Șit, Mustafa; Kiyan, Aysu; Özgen, Ufuk; Kükner, Aysel
    Following an injury or resection, the mammalian liver has the capacity to regain its former volume and functioning by restoring itself. Studies have demonstrated that antioxidants play a role in hepatic regeneration. This study investigated the effect of 4-(3,4- dihydroxybenzoyloxymethyl)phenyl-O-ß-D-glucopyranoside (PG) obtained from Origanum micranthum on liver regeneration. Sixty Wistar Albino rats were used. In the sham-operated group, a midline abdominal laparotomy was performed without hepatectomy. In the partial hepatectomy (PHx) group, the median and left lateral lobes were removed. Rats in the PHx group received 20 mg/kg/day PG intraperitoneally before being sacrificed at 24, 48, and 72 hrs, and 7 days later. Liver tissues were collected for immunohistochemical analysis and electron microscopic evaluation. We found an increase in mitotic index, and the numbers of Ki-67 stained hepatocytes in all PHx early stage groups (24 hr, 48hr, 72 hr), but not in 7-day groups. The regeneration mediators eNOS, iNOS, TNF-α and NF-kB were shown to increase in PHx groups. This increase was more prominent dependening on time. In the PHx treatment (PHx+PG) groups, while eNOS was still high, iNOS, TNF-α and NF-kB had decreased. The apoptotic index was markedly high in the PHx groups; this was prevented by PG treatment. These findings were supported by the ultrastructural results. Our findings indicate that PG supports liver regeneration, hepatocyte proliferation, reduced liver damage, and inflammatory mediators following PHx.
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    Heat shock protein-GP96 as an innate sensor of damage and activator of autoreactive NKT and regulatory T cells during liver regeneration
    (Murcia : F. Hernández, 2008) Mrakovcic-Sutic, Ines; Jakovac, Hrvoje; Simin, Marija; Grebic, Damir; Cuk, Mira; Trobonjaca, Zlatko; Radosevic-Stasic, Biserka
    Tissue disintegration after injury leads, in the endoplasmic reticulum (ER), to activation of adaptive pathways known as the ER stress response. It is directed to the correction of unfolded proteins and to the activation of proteasome-dependent ER-associated degradation of the misfolded proteins, but induces also a rapid activation of natural and adaptive immunity, since a ER resident heat shock protein-gp96 acts not only as a molecular chaperone, but also as a strong adjuvant, able to cross-present the antigenic peptides onto MHC class I or MHC class II pathways. Analyzing its potential role in processes of normal growth, in mice subjected to 1/3 partial hepatectomy (pHx) we determined the tissue expression of gp96 protein and mRNA in regenerating liver, thymus and spleen, determining simultaneously the phenotypic profile and spontaneous cytotoxic activity of intrahepatic and splenic mononuclear lymphatic cells (MNLC) against NKT- and NK-cells sensitive targets (syngeneic thymocytes and YAC-1) in wild, perforin and FasL deficient mice. The data have shown that pHx induces fast overexpression of gp96 protein and mRNA in hepatocytes, spleen and thymus, with accumulation of CD3intermediate/NK1.1+/CD69+ cells (liver) and Foxp3+CD4+CD25+ cells (liver and thymus). Simultaneously, intrahepatic MNLC acquired the FasLdependent cytotoxic potential against NKT-sensitive targets and both, intrahepatic and splenic MNLC, acquired the perforin-dependent cytotoxic potential against NK-sensitive targets, implying that during the disturbance of morphostasis gp96 serves as a natural adjuvant for chaperoning antigenic self peptides into the immune surveillance pathways, resulting in activation of autoreactive NKT and regulatory cells, as well as NK cells. Moreover, cell cycle analysis revealed that G2+M phase of regenerating hepatocytes in PKO mice was translocated from the 1st to the 7th p. o. day, as well as that hepatocytes from FasL deficient mice were arrested in G0/G1 phase.