CD73 complexes with emmprin to regulate MMP-2 production from co-cultured sarcoma cells and fibroblasts.

BACKGROUND: Interaction between cancer cells and fibroblasts mediated by extracellular matrix metalloproteinase inducer (emmprin, CD147) is important in the invasion and proliferation of cancer cells. However, the exact mechanism of emmprin mediated stimulation of matrix metalloprotease-2 (MMP-2) production from fibroblasts has not been elucidated. Our previous studies using an inhibitory peptide against emmprin suggested the presence of a molecule on the cell membrane which forms a complex with emmprin. Here we show that CD73 expressed on fibroblasts interacts with emmprin and is a required factor for MMP-2 production in co-cultures of sarcoma cells with fibroblasts. METHODS: CD73 along with CD99 was identified by mass spectrometry analysis as an emmprin interacting molecule from a co-culture of cancer cells (epithelioid sarcoma cell line FU-EPS-1) and fibroblasts (immortalized fibroblasts cell line ST353i). MMP-2 production was measured by immunoblot and ELISA. The formation of complexes of CD73 with emmprin was confirmed by immunoprecipitation, and their co-localization in tumor cells and fibroblasts was shown by fluorescent immunostaining and proximity ligation assays. RESULTS: Stimulated MMP-2 production in co-culture of cancer cells and fibroblasts was completely suppressed by siRNA knockdown of CD73, but not by CD99 knockdown. MMP-2 production was not suppressed by CD73-specific enzyme inhibitor (APCP). However, MMP-2 production was decreased by CD73 neutralizing antibodies, suggesting that CD73-mediated suppression of MMP-2 production is non-enzymatic. In human epithelioid sarcoma tissues, emmprin was immunohistochemically detected to be mainly expressed in tumor cells, and CD73 was expressed in fibroblasts and tumor cells: emmprin and CD73 were co-localized predominantly on tumor cells. CONCLUSION: This study provides a novel insight into the role of CD73 in emmprin-mediated regulation of MMP-2 production.

Intergenerational transmission of post-traumatic stress disorder in Australian Vietnam veterans' families.

OBJECTIVE: To assess the association between parental post-traumatic stress disorder (PTSD) and offspring PTSD and its specificity for other disorders in a non-clinical epidemiological cohort of Australian Vietnam veterans, their partners and their sons and daughters. METHOD: Veterans were interviewed twice, in 1992-1994 and 2005-2006; partners were interviewed in 2006-2007, and their offspring in 2012-2014. A total of 125 sons and 168 daughters were interviewed from 197 families, 137 of which also included partners who were the mothers of the children. Statistical analysis used multi-level modelling to compute odds ratios and 95% confidence intervals while controlling for clustering effects within families. Parent PTSD diagnoses were examined for associations with offspring trauma exposure, PTSD and other psychiatric diagnoses. RESULTS: Veteran PTSD increased the risk of PTSD and no other disorder in both sons and daughters; partner PTSD did not. Veteran depression was also a risk factor for sons' PTSD, and alcohol disorder was linked to alcohol dependence in sons and PTSD in daughters, but not when controlling for veteran PTSD. CONCLUSION: We conclude that PTSD in a Vietnam veteran father increases the risk specifically for PTSD in his sons and daughters.

Cooperative roles for emmprin and LYVE-1 in the regulation of chemoresistance for primary effusion lymphoma.

The Kaposi's sarcoma-associated herpesvirus is the causative agent of primary effusion lymphoma (PEL), for which cytotoxic chemotherapy represents the standard of care. The high mortality associated with PEL may be explained in part by resistance of these tumors to chemotherapy. The membrane-bound glycoprotein emmprin (CD147) enhances chemoresistance in tumors through effects on transporter expression, trafficking and interactions. Interactions between hyaluronan and hyaluronan receptors on the cell surface also facilitate emmprin-mediated chemoresistance. Whether emmprin or hyaluronan-receptor interactions regulate chemotherapeutic resistance for virus-associated malignancies is unknown. Using human PEL tumor cells, we found that PEL sensitivity to chemotherapy is directly proportional to expression of emmprin, the lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) and a drug transporter known as the breast cancer resistance protein/ABCG2 (BCRP), and that emmprin, LYVE-1 and BCRP interact with each other and colocalize on the PEL cell surface. In addition, we found that emmprin induces chemoresistance in PEL cells through upregulation of BCRP expression, and RNA interference targeting of emmprin, LYVE-1 or BCRP enhances PEL cell apoptosis induced by chemotherapy. Finally, disruption of hyaluronan-receptor interactions using small hyaluronan oligosaccharides reduces expression of emmprin and BCRP while sensitizing PEL cells to chemotherapy. Collectively, these data support interdependent roles for emmprin, LYVE-1 and BCRP in chemotherapeutic resistance for PEL.

A screening procedure for primary aldosteronism based on the Diasorin Liaison automated chemiluminescent immunoassay for direct renin.

BACKGROUND: Primary aldosteronism (PA), the most common secondary cause of hypertension, can be screened for using the aldosterone/renin ratio. This ratio is raised in PA and its accuracy depends on the ability to measure plasma renin at extremely low concentrations. METHODS: We compared two different procedures for assessing plasma renin. The conventional method, which measures plasma renin activity (PRA), is technically demanding and laborious, and the Diasorin Liaison method, which measures plasma renin concentration (PRC), is an automated immunoassay. Results from each method were used to calculate the aldosterone/renin ratio (ARR) and the performance of the Diasorin Liaison method compared with that of the conventional assay using receiver operator characteristic curves. RESULTS: The analytical and functional sensitivity of the PRC method were 2.1 and 5 microIU/mL, respectively. Intra- and inter-assay precision were <7.2% and 10.4%, respectively. There was significant (9%) prorenin interference. Samples with PRA > 1.0 ng/mL/h showed significant correlation with PRC (r = 0.93; P < 0.05; n = 146); however, with PRA < 1.0 ng/mL/h, no significant correlation occurred (r = 0.14; P < 0.05; n = 79). An aldosterone (pmol/L)/PRC(microIU/mL) ratio of >35, in patients with aldosterone >300 pmol/L, resulted in 100% sensitivity and 93% specificity, when compared with the commonly accepted aldosterone (pmol/L)/PRA (ng/mL/h) ratio of >750, in identifying patients who may suffer from PA. CONCLUSION: This study indicates the feasibility of using the automated PRC assay as a replacement for the conventional manual PRA assay in calculating the ARR as a first-line screen for PA.

Cancer incidence in patients with schizophrenia and their first-degree relatives - a meta-analysis.

OBJECTIVE: Controversy concerning cancer incidence in schizophrenia exists because of heterogeneous study findings. METHOD: A meta-analysis was performed on standardized incidence ratios (SIR) of cancer in patients with schizophrenia and first-degree relatives and compared with general population samples. RESULTS: The pooled overall cancer incidence in patients was not significantly increased (SIR = 1.05, CI 0.95-1.15). Lung cancer incidence was slightly increased (SIR = 1.31, CI 1.01-1.71), but was reduced after adjusting for smoking prevalence. The incidence of several cancers unrelated to smoking was reduced in patients. Breast cancer rates were significantly increased in female patients. The pooled overall cancer incidence in siblings (SIR = 0.89, CI 0.84-0.94) and parents (SIR = 0.90, CI 0.88-0.93) was significantly reduced. A meta-regression detected a significant relationship between cancer risk in the general population and relative risk in patients. CONCLUSION: The meta-analysis aided exploration of inconsistent study findings. There is a discrepancy between cancer risk exposure and cancer incidence in schizophrenia consistent with a protective effect.

Extracellular matrix metalloproteinase inducer regulates metalloproteinases in human uterine endometrium.

CONTEXT: Endometrial remodeling occurs during each menstrual cycle in women and also during the establishment of endometriosis. Both processes involve the production of metalloproteinases (MMPs) by uterine endometrial cells. OBJECTIVE: The objective of this study was to determine whether tissue remodeling and endometrial invasion involve activation of MMPs by extracellular matrix metalloproteinase inducer (EMMPRIN). MAIN OUTCOME MEASURES: EMMPRIN expression was examined by immunohistochemistry and real-time PCR in ectopic and eutopic endometria. For functional assays, human uterine fibroblasts were treated in the absence or presence of IL-1beta (10 ng/ml) or purified native EMMPRIN (0.5 or 1 microg/ml) for 24 h. Cellular RNA and conditioned medium were assayed by real-time PCR or immunoblotting. RESULTS: EMMPRIN protein localized to epithelial and fibroblast cells of eutopic and ectopic endometria. The pattern of localization was regulated by ovarian hormones. EMMPRIN mRNA levels varied throughout the menstrual cycle in parallel with the cyclic changes in estradiol. EMMPRIN treatment (0.5 microg/ml) of human uterine fibroblast cells stimulated MMP-1 (5.23-fold) and MMP-2 (8.55-fold), but not MMP-3, mRNA levels over levels in control cells (P < 0.05). EMMPRIN treatment (1 microg/ml) stimulated endogenous EMMPRIN (1.6-fold) mRNA levels (P > 0.05). IL-1beta stimulated MMP-1 (5.6-fold), MMP-2 (2.8-fold), and MMP-3 (75-fold) gene expression, but not EMMPRIN, over levels in control cells (P < 0.05). Both EMMPRIN and IL-1beta treatments stimulated MMP-1, -2, and -3, but not EMMPRIN protein secretion, with 0.5 microg/ml producing the greatest response. CONCLUSIONS: The ability of EMMPRIN to stimulate MMP secretion by endometrial fibroblasts indicates its potential role in uterine remodeling and the pathogenesis of endometriosis.

Communication across the divide. A trial of structured communication between general practice and emergency departments.

AIM: To evaluate the impact of structured form letters for general practitioner to emergency department (ED) communication. STUDY POPULATION: one hundred and fifty-five GPs with practices in the Liverpool local government area in metropolitan Sydney and patients referred by them to ED at Liverpool over five months from June to October 1998. DESIGN: randomised control trial of GPs as unit of randomisation; intervention GPs were encouraged to follow a structured proforma for their written communication with the ED. Control GPs were left to usual referral procedures. The ED was encouraged to fax a brief report back to GPs using the form. Impact measures: the quality of the referral letters was evaluated using a checklist that included: reason for referral; examination finding; medical history; investigations; psychosocial history; allergies; drugs given in the surgery and present medication. Surveys were sent every month to GPs to assess communication from the ED and adverse events observed by GPs. RESULTS: Most letters from GPs to the ED contained information on reasons for referral, medical history and examination findings. Reasons for referral were present in 95% of the intervention group GPs' letters compared with 99% of those of the control group. Investigations were included with 27% and present medications in 37%. Letters from GPs in the intervention group were more likely to contain a psychosocial history than those in the control group (13% compared with 1%). Most GPs reported receiving a letter from the ED although this was rarely by fax; most were brought to them by the patient. Phone calls were received by about one in five GPs each month. Most GPs found both of these to be useful. There were no differences between communication received by GPs in the intervention and control groups. CONCLUSION: This study demonstrates that improvements to communication between GPs and EDs are difficult and may require a systemic change within general practice and the hospital. Electronic systems may allow the sort of reciprocal communication required to establish and sustain improvement.

CD147 is a signaling receptor for cyclophilin B.

Cyclophilins A and B (CyPA and CyPB) are cyclosporin A binding proteins that can be secreted in response to inflammatory stimuli. We recently identified CD147 as a cell-surface receptor for CyPA and demonstrated that CD147 is an essential component in the CyPA-initiated signaling cascade that culminates in ERK activation and chemotaxis. Here we demonstrate that CD147 also serves as a receptor for CyPB. CyPB induced Ca(2+) flux and chemotaxis of CD147-transfected, but not control, CHO cells, and the chemotactic response of primary human neutrophils to CyPB was blocked by antibodies to CD147. These results suggest that CD147 serves as a receptor for extracellular cyclophilins.

Are survey measures of medical care utilisation misleading? A comparison of self-reported medical care consumption with actual medical care utilisation.

A substantial over-estimate of medical care consumption cost was found when estimates from self-report data from an epidemiological study were compared to actual cost data extracted from administrative records. Even though the few subjects who were actually provided with two or more services in the two-week self-report period substantially under-reported their medical care consumption, a large net over-estimate of medical care consumption was produced by the self-report data. This finding has important implications for use of self-report data from surveys such as the Australian Bureau of Statistics (ABS) National Health Survey for estimating health service consumption. By combining epidemiological survey data from the Australian Vietnam Veterans Health Study (AVVHS), with data on actual medical care for which the Health Insurance Commission (HIC) or the Department of Veterans' Affairs (DVA) paid benefits, we were able to directly compare self-reported medical care consumption with actual medical care utilisation. The comparison revealed that veterans' self-reports were a valid measure of relative medical care consumption because those who reported care over the past two weeks were much more likely to have been recent consumers than those who did not. This relationship became even stronger if the comparison of self-report was extended to data on benefits paid beyond the two-week self-report period. However, the HIC and DVA data confirmed only 51% of veterans self-reporting medical care consumption during the past two weeks actually received a service.

Tumorigenic potential of extracellular matrix metalloproteinase inducer.

Extracellular matrix metalloproteinase inducer (EMMPRIN), a glycoprotein present on the cancer cell plasma membrane, enhances fibroblast synthesis of matrix metalloproteinases (MMPs). The demonstration that peritumoral fibroblasts synthesize most of the MMPs in human tumors rather than the cancer cells themselves has ignited interest in the role of EMMPRIN in tumor dissemination. In this report we have demonstrated a role for EMMPRIN in cancer progression. Human MDA-MB-436 breast cancer cells, which are tumorigenic but slow growing in vivo, were transfected with EMMPRIN cDNA and injected orthotopically into mammary tissue of female NCr nu/nu mice. Green fluorescent protein was used to visualize metastases. In three experiments, breast cancer cell clones transfected with EMMPRIN cDNA were considerably more tumorigenic and invasive than plasmid-transfected cancer cells. Increased gelatinase A and gelatinase B expression (demonstrated by in situ hybridization and gelatin substrate zymography) was demonstrated in EMMPRIN-enhanced tumors. In contrast to de novo breast cancers in humans, human tumors transplanted into mice elicited minimal stromal or inflammatory cell reactions. Based on these experimental studies and our previous demonstration that EMMPRIN is prominently displayed in human cancer tissue, we propose that EMMPRIN plays an important role in cancer progression by increasing synthesis of MMPs.

CD147 facilitates HIV-1 infection by interacting with virus-associated cyclophilin A.

Cyclophilin A (CyPA) is specifically incorporated into the virions of HIV-1 and has been shown to enhance significantly an early step of cellular HIV-1 infection. Our preliminary studies implicated CD147 as a receptor for extracellular CyPA. Here, we demonstrate a role for CyPA-CD147 interaction during the early steps of HIV-1 infection. Expression of human CD147 increased infection by HIV-1 under one-cycle conditions. However, susceptibility to infection by viruses lacking CyPA (simian immunodeficiency virus or HIV-1 produced in the presence of cyclosporin A) was unaffected by CD147. Virus-associated CyPA coimmunoprecipitated with CD147 from infected cells. Antibody to CD147 inhibited HIV-1 entry as evidenced by the delay in translocation of the HIV-1 core proteins from the membrane and inhibition of viral reverse transcription. Viruses whose replication did not require CyPA (SIV or mutant HIV-1) were resistant to the inhibitory effect of anti-CD147 antibody. These results suggest that HIV-1 entry depends on an interaction between virus-associated CyPA and CD147 on a target cell.

Hyaluronan in morphogenesis.

Hyaluronan is a very large polysaccharide that is found in extracellular matrices, at the cell surface and inside cells. This review focuses on the functions of hyaluronan directly associated with the cell surface, where it is commonly present as the essential core of a highly hydrated pericellular matrix that contains several other components (hyaladherins) bound to hyaluronan. Three major molecular characteristics of hyaluronan contribute to its physiological functions: its unique hydrodynamic properties, its interactions with structural extracellular hyaladherins, and its instructive effects on cell signaling and behavior. Recent studies of hyaluronan-deficient mouse embryos illustrate the importance of each of these classes of function of hyaluronan. It is postulated that the morphogenetic effects of hyaluronan are due to its ability to act as a template for assembly of a multi-component, pericellular matrix as well as to its physical properties. This matrix would provide a hydrated environment in which cells are separated from structural barriers to morphogenetic changes and receive signals from hyaluronan itself and from associated factors.

Basigin (murine EMMPRIN) stimulates matrix metalloproteinase production by fibroblasts.

Analysis of basigin-null mice has shown that basigin is involved in several important physiological processes including reproductive, immune, and neural activities (Igakura et al., 1998, Dev Biol 194:152-165). However, its molecular mechanism of action in these processes has not yet been established. Our objective here is to determine whether basigin has functional properties similar to its apparent human tumor cell homolog, EMMPRIN, i.e., the ability to stimulate matrix metalloproteinase (MMP) production in fibroblasts (Guo et al. 1997, J Biol Chem 272:24-27). Mouse cells express two major forms of basigin that differ in their degree of glycosylation (molecular weights: 45 and 58 kDa) but, in similar fashion to human EMMPRIN, mouse tumor cells express higher levels of basigin than normal cells. We have used three different methods to show that basigin stimulates MMP expression in fibroblasts. First, recombinant basigin was partially purified from transfected CHO cells by affinity chromatography. This basigin preparation stimulates production of MMPs on addition to fibroblasts in culture. Second, co-culture of basigin-transfected CHO cells with fibroblasts gives rise to increased expression of MMPs as compared to control co-cultures. Third, we employed a novel approach in which a recombinant basigin adenovirus was constructed and used to infect the target fibroblasts, so that mutual stimulation between neighboring fibroblasts would be expected to result. In this method also, basigin stimulates production of MMPs. Finally, we showed that addition of basigin or EMMPRIN antibody, respectively, to recombinant basigin or EMMPRIN adenovirus-infected cells augments stimulation of MMP synthesis, implying that cross-linking of basigin/EMMPRIN in the membrane enhances activity. We conclude that murine basigin and human EMMPRIN have similar MMP-inducing activities and are functional homologs.

Suicide risk following child sexual abuse.

OBJECTIVE: To determine the suicide rate and prevalence of suicide attempts and suicidal ideation in 183 young people who had experienced child sexual abuse and to examine variables related to the abuse, which may correlate with suicide attempts or suicidal ideation. METHODS: Adolescents and young adults who had experienced child sexual abuse and individuals from a nonabused comparison group were asked about suicide attempts and suicidal ideation 5 and 9 years after intake to the study. Nine years after the abuse, a national death search was carried out to ascertain the number and causes of death in the 2 groups. Logistic regression was used to assess information on demographic and family functioning variables, the sexual abuse, notifications for other child abuse, criminal convictions, and out-of-home placements that were related to the outcome variables. RESULTS: Young people who had experienced child sexual abuse had a suicide rate that was 10.7 to 13.0 times the national Australian rates. There were no suicides in the control group. Thirty-two percent of the abused children had attempted suicide, and 43% had thought about suicide since they were sexually abused. CONCLUSIONS: Little information seems to be available to clinicians at the time of investigations for child sexual abuse in children that may identify those who are at increased risk of suicide. Abuse by an acquaintance, parental denial, or being angry with the child and not the abuser may predispose to suicide attempts but not necessarily to a completed suicide.

Regulation of glycogen synthesis by amino acids in cultured human muscle cells.

Insulin and a number of metabolic factors stimulate glycogen synthesis and the enzyme glycogen synthase. Using human muscle cells we find that glycogen synthesis is stimulated by treatment of the cells with lithium ions, which inhibit glycogen synthase kinase 3. Insulin further stimulates glycogen synthesis in the presence of lithium ions, an effect abolished by wortmannin and rapamycin. We report also that amino acids stimulate glycogen synthesis and glycogen synthase, these effects also being blocked by rapamycin and wortmannin. Amino acids stimulate p70(s6k) and transiently inhibit glycogen synthase kinase 3 without effects on the activity of protein kinase B or the mitogen-activated protein kinase pathway. Thus, the work reported here demonstrates that amino acid availability can regulate glycogen synthesis. Furthermore, it demonstrates that glycogen synthase kinase 3 can be inactivated within cells independent of activation of protein kinase B and p90(rsk).