PROLIFERATION OF B AND T CELLS IN MIXED LYMPHOCYTE CULTURES

Electrophoretically fractionated CBA/Ca spleen T cells alone respond to allogeneic cells in one-way MLC and to PHA. They do not respond to E. coli LPS. B cells alone do not respond to allogeneic cells nor to PHA, but do respond to LPS. When karyotypically distinguishable syngeneic mixtures of T and B lymphocytes are stimulated with allogeneic cells, at the most 5% of mitoses on 5–9th culture day are of B cell origin. This indicates that B cells are not substantially recruited to proliferate in the MLC

Role of hyperpolarization-activated cyclic nucleotide-gated channel HCN2 in embryonic neural stem cell proliferation and differentiation

Funding Information: Supported by grants from the K. Albin Johansson foundation, the Magnus Ehrnrooth foundation, The Finnish Society of Sciences and Letters and the Medical Society of Finland. We are grateful for the laboratory assistance provided by Jarno Hörhä. Publisher Copyright: © 2022 The AuthorsHyperpolarization-activated cyclic nucleotide-gated channels (HCN channels) are involved in spontaneous activity in many electrically active cell types such as cardiomyocytes and neurons. In this study, the role of HCN channels in proliferation and migration of Nestin and Sox2 expressing embryonic neural progenitor cells (NPC) originating from the subventricular zone (SVZ) was examined. Immunostaining and PCR data showed that the HCN2 subtype was highly expressed in these cells. Patch clamp recordings revealed a hyperpolarization-activated current, which was sensitive to inhibitors of HCN channels. Using the fluorescence dye bis-(1,3-dibutylbarbituric acid)-trimethineoxonol (DiBAC(4)(3)) we found that a prompt reduction of the extracellular K+ concentration, or exposing the cells to acute hypoxia, induced an instant hyperpolarization in the whole cell population. Recovery from low K+ induced hyperpolarization after extracellular calcium removal, or by re-oxygenation of hypoxic cells, was sensitive to ZD7288, a HCN channel inhibitor. Treatment of neurosphere cultures from the SVZ with ZD7288 caused a significant and reversible inhibition of neurosphere formation from single cells indicating that proliferation of progenitor cells was reduced. Furthermore, the migration of neuronal cells from neurospheres was considerably retarded in the presence of ZD7288. The results suggest that HCN2 channels are involved in controlling the proliferation of NPC and that HCN2 channel-induced spontaneous electrical activity may trigger the motility response of neurosphere-derived neurons in concert with other ion channels. Furthermore, the response to hypoxia suggests that HCN2 channels may trigger the chemotactic response of NPC to ischemic brain regions seen in many studies.Peer reviewe

Antizyme inhibitor 2 (AZIN2) associates with better prognosis of head and neck minor salivary gland adenoid cystic carcinoma

cited By 0The key regulator of the polyamine biosynthetic pathway is ornithine decarboxylase (ODC). ODC is activated by antizyme inhibitor 1 (AZIN1) and 2 (AZIN2). AZIN1 and recently AZIN2 have been related to cancer; however, their functions in adenoid cystic carcinoma (ACC) have not been studied. We performed immunohistochemical study on minor salivary and mucous gland ACC tissue samples of patients treated at the Helsinki University Hospital (Helsinki, Finland) during 1974-2012. We scored AZIN1 and 2 immunoexpression in 42 and 45 tumor tissue samples, respectively, and correlated them with clinicopathological factors and survival. Enhanced AZIN2 expression was associated with better survival. In addition, both AZINs were seen more commonly in cribriform and tubular than in solid growth patterns. AZIN1 expression did not correlate with the studied clinicopathological factors. It seems that AZIN2 expression is higher in cancer tissue with secretory functions. In ACC tissue, high AZIN2 expression could be related to well-differentiated histological type which still has a functioning vesicle transportation system. Thus, AZIN2 could be a prognostic factor for better survival of ACC patients.Peer reviewe

Regulation of intracellular pH by electrogenic Na+/HCO3-co-transporters in embryonic neural stem cell-derived radial glia-like cells

A stroke causes a hypoxic brain microenvironment that alters neural cell metabolism resulting in cell membrane hyperpolarization and intracellular acidosis. We studied how intracellular pH (pH(i)) is regulated in differentiated mouse neural progenitor cells during hyperpolarizing conditions, induced by prompt reduction of the extra cellular K+ concentration. We found that the radial glia-like population in differentiating embryonic neural progenitor cells, but not neuronal cells, was rapidly acidified under these conditions. However, when extra cellular calcium was removed, an instant depolarization and recovery of the pH(i), back to normal levels, took place. The rapid recovery phase seen in the absence of calcium, was dependent on extracellular bicarbonate and could be inhibited by 50859, a potent Na/HCO3 cotransporter inhibitor. Immunostaining and PCR data, showed that NBCe1 (SLC4A4) and NBCn1 (SLC4A7) were expressed in the cell population and that the pH(i) recovery in the radial glial-like cells after calcium removal was mediated mainly by the electrogenic sodium bicarbonate transporter NBCe1 (SLC4A4). Our results indicate that extracellular calcium might hamper pH(i) regulation and Na/HCO3 cotransporter activity in a brain injury microenvironment. Our findings show that the NBC-type transporters are the main pH(i) regulating systems prevailing in glia-like progenitor cells and that these calcium sensitive transporters are important for neuronal progenitor cell proliferation, survival and neural stem cell differentiation.Peer reviewe

Tannic acid inhibits electrogenic Na+/HCO3- co-transporter activity in embryonic neural stem cell-derived radial glial-like cells

Self-renewing neural stem cells and progenitor cells are cell populations that generate radial glial cells and neurons through asymmetric division. Regulation of intracellular pH in stem cells with high metabolic activity is critical for both cell signaling and proliferation. We have recently found that a S0859-inhibitable electrogenic Na+/HCO3- co-transporter (NBCe1, Slc4a4), is the primary pH(i) regulatory mechanism in stem cell-derived radial glial-like cells. Here we show, by using the voltage-sensitive fluorescent dye DiBAC 4(3) and BCECF, a pH-sensitive dye, that an antioxidant, tannic acid (100 mu M), can inhibit potassium- and calcium-dependent rapid changes in membrane potential and NBCe1 mediated pH i regulation in brain-derived glial-like cells in vitro. Furthermore, neural stem cell differentiation and neurosphere formation (proliferation) were completely inhibited by tannic acid. The present study provides evidence that tannic acid is a natural inhibitor of NBCe1. It is tempting to speculate that tannic acid or related compounds that inhibits NBCe1-mediated pH(i) regulation in glial-like cells may also have bearing on the treatment of glial neoplasms. NeuroReport 31: 57-63 Copyright (c) 2019 The Author(s). Published by Wolters Kluwer Health, Inc.Peer reviewe

Impact of Astroprincin (FAM171A1) Expression in Oral Tongue Cancer

Astroprincin (APCN, FAM171A1) is a recently characterized transmembrane glycoprotein that is abundant in brain astrocytes and is overexpressed in some tumors. However, the expression and role of APCN is unknown in oral tongue squamous cell carcinoma (OTSCC). Aim of this study was to investigate the expression of APCN in OTSCC tissue samples and to analyze possible association of APCN with clinicopathological features and survival rates. This study included 76 patients treated for OTSCC. Expression of APCN in OTSCC tissue sections was examined by immunohistochemistry with a rabbit polyclonal antibody (MAP346) against APCN. All tumors were scored for intensity and percentage of APCN staining at the superficial, middle, and invasive front areas. High expression of APCN was significantly associated with increased tumor size (P = 0.013) and with OTSCC recurrence (P = 0.026). In this pilot study, we observed that the amount of APCN is associated with the size and recurrence of OTSCC. This finding suggests a role of APCN during OTSCC progression.Peer reviewe

Characterization of surface glycoproteins of mouse lymphoid cells

We have labeled exposed surface glycoproteins of mouse lymphoid cells by the galactose oxidase-tritated sodium borohydride technique. The labeled glycoproteins were separated by polyacrylamide slab gel electrophoresis and visualized by autoradiography (fluorography). The major thymocyte surface proteins have molecular weights of 170,000 and 125,000. Thymocytes from TL antigen-positive mouse strains showed an additional band with a molecular weight of 27,000. Highly purified T lymphocytes contain two major surface glycoproteins with molecular weights of 180,000 and 125,000. Purified B lymphocytes have one major surface glycoprotein with a molecular weight of 210,000. When T lymphocytes are stimulated in vitro by concanavalin A or phytohemagglutinin, the major proteins characteristic of T cells are relatively weakly labeled, but new components of lower molecular weights appear on the cell surface. A similar change is seen in B lymphocytes stimulated by Escherichia coli lipopolysaccharide. T lymphoblasts isolated from mixed lymphocyte cultures show a slightly different surface glycoprotein pattern. A polypeptide with a molecular weight of 57,000, which was labeled without enzymatic treatment by tritiated sodium borohydride alone, is strongly labeled in proliferating cells

Prevalence of cancer in relation to signs of periodontal inflammation

Funding Information: The study was supported by the Swedish Ministry of Health and Social Affairs (grant F84/ 189) and Karolinska Institutet, Stockholm, Sweden, and by grants from The Finnish Society of Sciences and Letters, the Finnish Medical Society, Finland, and the King Gustav V´s and Queen Victoria’ s Freemason´s Foundation, Sweden. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Publisher Copyright: © 2022 Meurman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.We investigated the associations between periodontal inflammation (gingivitis and periodontitis) and all-kind malignancies, specifically breast and prostate cancer, in a cohort followed-up for 30 years. The study hypothesis was based on the oral inflammation vs. systemic health paradigm. A sample of 2,168 subjects from an original cohort of 105,718 individuals from the greater Stockholm area in Sweden that had been followed since 1985 was investigated. Swedish national health registers were used in the study. Chi-square tests and logistic multiple regression analyses were conducted. The results showed that periodontitis was significantly associated with any cancer after adjusting for gender, age, income, and education (p = 0.015). The probability of getting cancer increased on average by 38% if the patient had periodontitis vs. had not; the odds ratio was 1.380 (95% confidence interval l.066-1.786). No significant association was observed between periodontitis and breast cancer (p = 0.608), while the association between periodontitis and prostate cancer tended towards significance (p = 0.082). However, no statistically significant difference was found between the observed and the calculated distribution of any cancer in gingivitis groups (p = 0.079). Thus, the study hypothesis was partly confirmed by showing a statistically significant association between periodontitis and any cancer.Peer reviewe

Downregulation of transcription factor GATA4 sensitizes human hepatoblastoma cells to doxorubicin-induced apoptosis

Hepatoblastoma, the most common type of pediatric liver cancer, is treated with a combination of surgery and chemotherapy. An essential drug in the treatment of hepatoblastoma is doxorubicin, which in high doses is cardiotoxic. This adverse effect is due to downregulation of cardiac expression of transcription factor GATA4, leading in turn to diminished levels of anti-apoptotic BCL2 (B-cell lymphoma 2) protein family members. GATA4 is also expressed in early fetal liver, but absent from normal postnatal hepatocytes. However, GATA4 is highly expressed in hepatoblastoma tissue. In this study, we assessed the role of GATA4 in doxorubicin-induced apoptosis of hepatoblastoma cells. Herein, we demonstrate that doxorubicin decreases GATA4 expression and alters the expression pattern of BCL2 family members, most profoundly that of BCL2 and BAK, in the HUH6 hepatoblastoma cell line. Silencing of GATA4 by siRNA prior to doxorubicin treatment sensitizes HUH6 cells to the apoptotic effect of this drug by further shifting the balance of BCL2 family members to the pro-apoptotic direction. Specifically, expression levels of anti-apoptotic BCL2 were decreased and pro-apoptotic BID were increased after GATA4 silencing. On the whole, our results indicate that since high endogenous levels of transcription factor GATA4 likely protect hepatoblastoma cells from doxorubicin-induced apoptosis, these cells can be rendered more sensitive to the drug by downregulation of GATA4.Peer reviewe