JAK2 V617F -Mediated Clonal Hematopoiesis Accelerates Pathological Remodeling in Murine Heart Failure

Janus kinase 2 (valine to phenylalanine at residue 617) (JAK2 ^V617F ) mutations lead to myeloproliferative neoplasms associated with elevated myeloid, erythroid, and megakaryocytic cells. Alternatively these same mutations can lead to the condition of clonal hematopoiesis with no impact on blood cell counts. Here, a model of myeloid-restricted JAK2 ^V617F expression from lineage-negative bone marrow cells was developed and evaluated. This model displayed greater cardiac inflammation and dysfunction following permanent left anterior descending artery ligation and transverse aortic constriction. These data suggest that JAK2 ^V617F mutations arising in myeloid progenitor cells may contribute to cardiovascular disease by promoting the proinflammatory properties of circulating myeloid cells.

Hematopoietic loss of Y chromosome leads to cardiac fibrosis and heart failure mortality

Hematopoietic mosaic loss of Y chromosome (mLOY) is associated with increased risk of mortality and age-related diseases in men, but the causal and mechanistic relationships have yet to be established. Here, we show that male mice reconstituted with bone marrow cells lacking the Y chromosome display increased mortality and age-related profibrotic pathologies including reduced cardiac function. Cardiac macrophages lacking the Y chromosome exhibited polarization toward a more fibrotic phenotype, and treatment with a transforming growth factor β1-neutralizing antibody ameliorated cardiac dysfunction in mLOY mice. A prospective study revealed that mLOY in blood is associated with an increased risk for cardiovascular disease and heart failure-associated mortality. Together, these results indicate that hematopoietic mLOY causally contributes to fibrosis, cardiac dysfunction, and mortality in men.

Tet2-mediated clonal hematopoiesis in nonconditioned mice accelerates age-associated cardiac dysfunction

Clonal hematopoiesis of indeterminate potential is prevalent in elderly individuals and associated with increased risks of all-cause mortality and cardiovascular disease. However, mouse models to study the dynamics of clonal hematopoiesis and its consequences on the cardiovascular system under homeostatic conditions are lacking. We developed a model of clonal hematopoiesis using adoptive transfer of unfractionated ten-eleven translocation 2-mutant (Tet2-mutant) bone marrow cells into nonirradiated mice. Consistent with age-related clonal hematopoiesis observed in humans, these mice displayed a progressive expansion of Tet2-deficient cells in multiple hematopoietic stem and progenitor cell fractions and blood cell lineages. The expansion of the Tet2-mutant fraction was also observed in bone marrow-derived CCR2+ myeloid cell populations within the heart, but there was a negligible impact on the yolk sac-derived CCR2- cardiac-resident macrophage population. Transcriptome profiling revealed an enhanced inflammatory signature in the donor-derived macrophages isolated from the heart. Mice receiving Tet2-deficient bone marrow cells spontaneously developed age-related cardiac dysfunction characterized by greater hypertrophy and fibrosis. Altogether, we show that Tet2-mediated hematopoiesis contributes to cardiac dysfunction in a nonconditioned setting that faithfully models human clonal hematopoiesis in unperturbed bone marrow. Our data support clinical findings that clonal hematopoiesis per se may contribute to diminished health span.

Expression of vascular endothelial growth factor (VEGF) during folliculogenesis and corpus luteum formation in the human ovary

Vascular endothelial growth factor (VEGF) has been suggested to be involved in angiogenesis and microvascular hyperpermeability. We examined immunohistochemically the expression of VEGF in the granulosa and theca cells, along with that of proliferating cell nuclear antigen (PCNA), in the vascular endothelium during the course of follicular development and corpora lutea formation in human ovaries. The immunolocalization of VEGF in these cells was compared with that of another putative angiogenic factor, basic fibroblast growth factor (bFGF). The granulosa cells in the primordial and primary follicles were VEGF negative, but at the preantral stage, the granulosa cells showed weakly positive immunostaining for VEGF. However, the VEGF immunostaining in the granulosa cells was weak throughout the folliculogenesis. In contrast, the theca interna cells of developing follicles showed strong staining for VEGF, which was well correlated with the PCNA positivity in the vascular endothelial cells in the thecal layer. In the atretic follicles, the granulosa and theca cells were VEGF negative. In the corpora lutea, VEGF was strongly expressed in both granulosa and theca lutein cells in the early luteal phase when the PCNA positivity in the endothelium increased, but the VEGF staining in these cells became weak in the mid- and late luteal phases. Accordingly, the PCNA positivity in the vascular endothelium was well correlated with the expression of VEGF in the theca cells during follicular development and atresia, and that in the granulosa and theca lutein cells in corpora lutea formation and regression. In addition, the immunolocalization of VEGF was different from that of bFGF.

Involvement of a dysfunctional dopamine-D1/N-methyl-d-aspartate-NR1 and Ca2+/calmodulin-dependent protein kinase II pathway in the impairment of latent learning in a model of schizophrenia induced by phencyclidine

Continuous ingestion of phencyclidine (PCP) in humans produces long-lasting schizophrenic-like cognitive dysfunction. Although a malfunction of dopaminergic and/or glutamatergic neurotransmission is implicated in the etiology of schizophrenia, involvement of the dopaminergic-glutamatergic neurotransmission in the cognitive dysfunction induced by repeated PCP treatment is minor. We demonstrated that mice treated with PCP (10 mg/kg/day s.c.) for 14 days displayed an impairment of latent learning in a water-finding task and of learning-associated phosphorylation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and NR1 in the prefrontal cortex even after drug withdrawal. The infusion of a CaMKII inhibitor and NR1 antisense oligonucleotide into the prefrontal cortex produced an impairment of latent learning and decrease of learning-associated phosphorylation of CaMKII, which were observed in the PCP-treated mice. Exogenous NMDA-induced CaMKII activation was not observed in slices of the prefrontal cortex prepared from mice treated repeatedly with PCP. The potentiation of NMDA receptor function by the infusion of glycine into the prefrontal cortex ameliorated these impairments in mice treated repeatedly with PCP. The high potassium-stimulated release of dopamine from the prefrontal cortex was less extensive in the PCP-treated than saline-treated mice. The infusion of a dopamine-D1 receptor agonist into the prefrontal cortex attenuated the impairment of latent learning and decrease of learning-associated NR1 phosphorylation in the PCP-treated mice, suggesting a functional linkage between glutamatergic and dopaminergic signaling. These findings indicate that repeated PCP treatment impairs latent learning through a prefrontal cortical dysfunction of NMDA-CaMKII signaling, which is associated with dopaminergic hypofunction.

Molecular Damage in Aging

Cellular metabolism generates molecular damage affecting all levels of biological organization. Accumulation of this damage over time is thought to play a central role in the aging process, but damage manifests in diverse molecular forms complicating its assessment. Insufficient attention has been paid to date to the role of molecular damage in aging-related phenotypes, particularly in humans, in part because of the difficulty in measuring its various forms. Recently, omics approaches have been developed that begin to address this challenge, because they are able to assess a sizeable proportion of age-related damage at the level of small molecules, proteins, RNA, DNA, organelles and cells. This review describes the concept of molecular damage in aging and discusses its diverse aspects from theoretical models to experimental approaches. Measurement of multiple types of damage enables studies of the role of damage in human aging outcomes and lays a foundation for testing interventions to reduce the burden of molecular damage, opening new approaches to slowing aging and reducing its consequences.

Wnt5a-Mediated Neutrophil Recruitment Has an Obligatory Role in Pressure Overload-Induced Cardiac Dysfunction

BACKGROUND

Although the complex roles of macrophages in myocardial injury are widely appreciated, the function of neutrophils in nonischemic cardiac pathology has received relatively little attention.

METHODS

To examine the regulation and function of neutrophils in pressure overload-induced cardiac hypertrophy, mice underwent treatment with Ly6G antibody to deplete neutrophils and then were subjected to transverse aortic constriction.

RESULTS

Neutrophil depletion diminished transverse aortic constriction-induced hypertrophy and inflammation and preserved cardiac function. Myeloid deficiency of Wnt5a, a noncanonical Wnt, suppressed neutrophil infiltration to the hearts of transverse aortic constriction-treated mice and produced a phenotype that was similar to the neutropenic conditions. Conversely, mice overexpressing Wnt5a in myeloid cells displayed greater hypertrophic growth, inflammation, and cardiac dysfunction. Neutrophil depletion reversed the Wnt5a overexpression-induced cardiac pathology and eliminated differences in cardiac parameters between wild-type and myeloid-specific Wnt5a transgenic mice.

CONCLUSIONS

These findings reveal that Wnt5a-regulated neutrophil infiltration has a critical role in pressure overload-induced heart failure.

Kinase-interacting substrate screening is a novel method to identify kinase substrates

Protein kinases play pivotal roles in numerous cellular functions; however, the specific substrates of each protein kinase have not been fully elucidated. We have developed a novel method called kinase-interacting substrate screening (KISS). Using this method, 356 phosphorylation sites of 140 proteins were identified as candidate substrates for Rho-associated kinase (Rho-kinase/ROCK2), including known substrates. The KISS method was also applied to additional kinases, including PKA, MAPK1, CDK5, CaMK1, PAK7, PKN, LYN, and FYN, and a lot of candidate substrates and their phosphorylation sites were determined, most of which have not been reported previously. Among the candidate substrates for Rho-kinase, several functional clusters were identified, including the polarity-associated proteins, such as Scrib. We found that Scrib plays a crucial role in the regulation of subcellular contractility by assembling into a ternary complex with Rho-kinase and Shroom2 in a phosphorylation-dependent manner. We propose that the KISS method is a comprehensive and useful substrate screen for various kinases.

Search for specific markers of neoplastic epithelial duct and myoepithelial cell lines established from human salivary gland and characterization of their growth in vitro

The neoplastic epithelial duct cells human salivary gland (HSG) and myoepithelial cells human pleomorphic adenoma (HPA) established from human salivary gland were examined by the immunoperoxidase method for the presence of specific antigens such as carcinoembryonic antigen (CEA), S-100 protein, secretory component (SC), lactoferrin (LF), and myosin. Isolation of the cells and their morphologic features were reported previously. Consequently, the presence of CEA, SC, and LF in the HSG cells was demonstrated. The HPA cells were identified to express the specific antigens reactive to anti-S-100 protein, anti-myosin and anti-CEA sera in addition to the presence of oxytocin receptor. When the two cell lines were co-cultured in monolayer culture or within the sponge matrix, a large number of ductlike or tubular structures were formed in an optimal ratio of 1:2 in HSG and HPA cells, whereas the cultures of HSG cells only grew with occasional formation of ductlike structure. In addition, in HSG and HPA cells in an area with their contact in the mixed cultures, CEA staining was intensified as compared with the culture of HSG or HPA cells only and further S-100 protein was detected in HSG cells, whereas S-100 protein was not detected in the culture of HSG cells only. These findings strongly suggest that the intercalated duct and myoepithelial cells from human salivary gland propagate with their interaction together in the expression of specific antigens such as CEA and S-100 protein or in the morphogenesis of salivary gland epithelial cells.

Immunogenic cell death by oncolytic herpes simplex virus type 1 in squamous cell carcinoma cells

Molecules essential for the induction of immunogenic cell death (ICD) are called damage-associated molecular patterns (DAMPs). The effects of oncolytic herpes simplex virus type 1 (HSV-1) on the production of DAMPs were examined in squamous cell carcinoma (SCC) cells. The cytopathic effects of HSV-1 RH2 were observed in mouse SCCVII cells infected at a high multiplicity of infection (MOI), and the amounts of viable cells were decreased. After being infected with RH2, ATP and high mobility group box 1 (HMGB1) were released extracellulary, while calreticulin (CRT) translocated to the cell membrane. A flow-cytometric analysis revealed an increase in the number of annexin-V and propidium iodide (PI)-stained cells; and the amount of cleaved poly (ADP-ribose) polymerase (PARP) was increased. The killing effect of RH2 was reduced by pan-caspase inhibitor z-VAD-fmk and the caspase-1 inhibitor z-YVAD-fmk, suggesting the involvement of apoptosis and pyroptosis. In C3H mice bearing synergic SCCVII tumors, the growth of tumors injected with the supernatant of RH2-infected cells was less than that of tumors injected with phosphate-buffered saline (PBS). These results indicate that oncolytic HSV-1 RH2 produces DAMPs from SCC cells to induce cell death. This may contribute to the enhancement of tumor immunity by oncolytic HSV-1.

The Cancer Therapy-Related Clonal Hematopoiesis Driver Gene Ppm1d Promotes Inflammation and Non-Ischemic Heart Failure in Mice

[Figure: see text].

Generation of cells with phenotypes of both intercalated duct-type and myoepithelial cells in human parotid gland adenocarcinoma clonal cells grown in athymic nude mice

A neoplastic epithelial cell line was established from nude mice tumors grown after transplantation of surgical specimens from a human parotid gland adenocarcinoma. This cell line, which had ultrastructure similarities to salivary intercalated duct cells, was found by immunohistochemical techniques to contain amylase, but myosin was not detected. Ultrastructurally, cells of an intermediate type between intercalated ductal and myoepithelial cells were found in the transplanted tumors. Moreover, the expression of myosin in addition to the presence of amylase was detected in the tumors. These findings indicate that some transplanted tumor cells appear to be differentiating towards myoepithelial cells.

Human chorionic gonadotropin (hCG) inhibits cisplatin-induced apoptosis in ovarian cancer cells: possible role of up-regulation of insulin-like growth factor-1 by hCG

Gonadotropins have been suggested to play a role in the development or progression of ovarian cancer, and we have previously reported the expression of luteinizing hormone/ human chorionic gonadotropin (LH/hCG) receptor in 40% of epithelial ovarian carcinomas. To examine the biological effect of LH/hCG on ovarian cancer cells, apoptosis induced by cisplatin with or without hCG treatment was investigated in 2 ovarian cancer cell lines, OVCAR-3 and SK-OV-3. Stimulation of cell proliferation by hCG was also studied. In addition, to analyze further the mechanism of hCG signaling involved in apoptosis-inhibition, we examined the expression of LH/hCG receptors and the regulation by hCG for apoptosis-inhibitory pathways, such as the bcl-2/bax system and the insulin-like growth factor-1 (IGF-1)/IGF-1 receptor (IGFR) system. hCG did not increase cell proliferation in either cell line. However, hCG treatment suppressed cisplatin-induced apoptosis by 58% in the OVCAR-3 cells, as shown by immunofluorescent staining and quantitation of DNA fragmentation. LH/hCG receptor mRNA was expressed only in OVCAR-3, and no apoptosis-inhibitory effect of hCG was observed in the SK-OV-3 cells that did not express the receptor. In the OVCAR-3 cells, hCG significantly increased mRNA expression of IGF-1, but did not change mRNA levels of bcl-2/bax. Our findings suggest that LH/hCG influences the chemosensitivity of ovarian cancer cells through an apoptosis-inhibitory signal possibly via up-regulation of IGF-1 expression.

Clonal Hematopoiesis: A New Step Linking Inflammation to Heart Failure

Heart failure is a common disease with poor prognosis that is associated with cardiac immune cell infiltration and dysregulated cytokine expression. Recently, the clonal expansion of hematopoietic cells with acquired (i.e., nonheritable) DNA mutations, a process referred to as clonal hematopoiesis, has been reported to be associated with cardiovascular diseases including heart failure. Mechanistic studies have shown that leukocytes that harbor these somatic mutations display altered inflammatory characteristics that worsen the phenotypes associated with heart failure in experimental models. In this review, we summarize recent epidemiological and experimental evidence that support the hypothesis that clonal hematopoiesis-mediated immune cell dysfunction contributes to heart failure and cardiovascular disease in general.

TP53-mediated therapy-related clonal hematopoiesis contributes to doxorubicin-induced cardiomyopathy by augmenting a neutrophil-mediated cytotoxic response

Therapy-related clonal hematopoiesis (t-CH) is often observed in cancer survivors. This form of clonal hematopoiesis typically involves somatic mutations in driver genes that encode components of the DNA damage response and confer hematopoietic stem and progenitor cells (HSPCs) with resistance to the genotoxic stress of the cancer therapy. Here, we established a model of TP53-mediated t-CH through the transfer of Trp53 mutant HSPCs to mice, followed by treatment with a course of the chemotherapeutic agent doxorubicin. These studies revealed that neutrophil infiltration in the heart significantly contributes to doxorubicin-induced cardiac toxicity and that this condition is amplified in the model of Trp53-mediated t-CH. These data suggest that t-CH could contribute to the elevated heart failure risk that occurs in cancer survivors who have been treated with genotoxic agents.

Therapy for oral squamous cell carcinoma by tegafur and streptococcal agent OK-432 in combination with radiotherapy: Association of the therapeutic effect with differentiation and apoptosis in the cancer cells

Twenty patients with oral squamous cell carcinoma having mainly stage II or III lesions without distant metastasis, were treated with tegafur and streptococcal agent, OK-432, in combination with radiotherapy. As a consequence, 16 cases among the treated 20 cases showed complete remission by this therapy alone. Especially, we have found that the squamous cell carcinoma arising in non-keratinizing oral epithelium rather than in keratinizing oral epithelium has better response to this therapy. Among the 16 cases with complete remission (CR) by the current therapy, 10 cases were histopathologically diagnosed as well-differentiated squamous cell carcinoma and six cases as moderately differentiated squamous cell carcinoma. When we examined immunohistochemically the expression of various antigens such as proliferating cell nuclear antigen (PCNA), p53 and LeY or the presence of DNA fragmentation by nick-end labelling in the biopsy materials taken at the first visit to our clinic from 20 patients treated with the current therapy, the CR group showed a significantly increased LeY expres-sion level ( p< 0.05) and DNA fragmentation rate (p< 0.05) as compared with the partial response (PR, n= 3) + no change (NC, n= 1) group. On the other hand, the CR group with respect to PCNA expression level was significantly decreased as compared with the PR + NC group ( p< 0.05). From these findings, it can be considered that the therapy for oral squamous cell carcinoma by UFT and OK-432 in combination with radiotherapy is very effective, which may be associated with differentiation or apoptosis in oral squamous carcinoma cells. In addition, we present the clinical findings and results of immunohistochemical staining for the biopsy materials obtained from four CR cases treated with the current therapeutic method.

Combination effect of adenovirus-mediated pro-apoptotic bax gene transfer with cisplatin or paclitaxel treatment in ovarian cancer cell lines

To develop a novel therapeutic strategy for ovarian cancer, we constructed a recombinant adenovirus which highly expresses pro-apoptotic Bax protein and examined its therapeutic effect on a series of ovarian cancer cell lines: A2780, A2780/cDDP, OVCAR-3 and SK-OV-3. A recombinant adenovirus carrying the Bax-alpha gene (AxCALNKYbax) induced high expression of the Bax-alpha protein in all the cell lines. The cytotoxic effect of Bax was observed in three ovarian cancer cell lines: the per cent reduction in the number of cells was 40.0% for cisplatin-sensitive A2780, 50.0% for cisplatin-resistant A2780/cDDP, and 64.8% for marginally cisplatin-resistant OVCAR-3. In contrast, it was only 12.3% for cisplatin-resistant SK-OV-3. Cisplatin-resistant A2780/cDDP had a p53 mutation and exhibited attenuated Bax induction after cisplatin treatment, which may explain why supplementation of Bax was effective in this chemoresistant ovarian cancer. Combination with cisplatin or paclitaxel enhanced the cytotoxic effect of Bax induction in all but one cell line including cisplatin-resistant A2780/cDDP. It appears that adenovirus-mediated Bax induction, with or without combination with conventional chemotherapy, useful strategy for the treatment of ovarian cancer.

Inhibition of herpes simplex virus replication by genistein, an inhibitor of protein-tyrosine kinase

Genistein, an inhibitor of protein-tyrosine kinase, inhibited the replication of herpes simplex virus type 1 (HSV-1) at genistein concentrations of more than 25 microM, whereas the related compounds, which do not inhibit protein-tyrosine kinases, did not affect the replication of HSV-1. In the presence of genistein, the phosphorylation of tyrosine residues in specific viral polypeptides was markedly reduced. These results indicate that the phosphorylation of tyrosine residues in viral polypeptides may be essential for the replication of HSV-1.

Parametrial involvement in endometrial carcinomas: its incidence and correlation with other histological parameters

To identify the incidence and spread pattern of parametrial involvement in endometrial carcinomas, resected parametria in 91 patients who underwent radical or modified radical hysterectomy with pelvic lymphadenectomy were histologically examined. The relationship between parametrial involvement and other histopathological features including histological type, tumor grade, depth of myometrial invasion, lymph-vascular space invasion, cervical involvement, adnexal metastasis, and lymph node metastasis was studied. Parametrial involvement was histologically demonstrated in 12 (13.2%) of the 91 cases. There were 2 patterns of spread: direct invasion of cancer cells to the parametrial connective tissue (5 cases) and lymphatic involvement within the parametrium (7 cases). According to the FIGO surgical stage, parametrial involvement was found in none (0%) of 48 patients in Stage I, 3 (11.5%) of 26 in Stage II, and 9 (52.9%) of 17 in Stage III. Among histopathological variables, the presence of parametrial involvement was significantly correlated with deep myometrial invasion and lymph-vascular space invasion in the myometrium. Multivariate analysis revealed that parametrial involvement significantly contributed to the poor prognosis in Stage II and III patients.

Small cell undifferentiated carcinoma of the minor salivary gland containing exocrine, neuroendocrine, and squamous cells

The light microscopic, electron microscopic and immunohistochemical features of a small cell undifferentiated carcinoma of the minor salivary gland are presented. The tumor was composed predominantly of undifferentiated small cells with focally admixed neuroendocrine, exocrine and squamous cells, occasionally arranged in an organoid manner. The presence of vasoactive intestinal polypeptide in the tumor was found immunohistochemically. In addition, the tumor cells stained with Grimelius' impregnation. Immunohistochemically the tumor contained cells that reacted positively with the antibodies to carcinoembryonic antigen, 66K keratin polypeptide, or human salivary amylase. These findings indicate that a small cell undifferentiated carcinoma of the minor salivary gland, reported here, exhibits focally multidirectional differentiation as well as neuroendocrine cell derivation.

Induction of endonuclease G-mediated apopotosis in human oral squamous cell carcinoma cells by protein kinase C inhibitor safingol

PKC inhibitor safingol suppressed the growth of human oral squamous cell carcinoma (SCC) cells significantly at concentrations that inhibit PKC isoforms. Safingol inhibited the translocation of PKC following treatment with 12-o-tetradecanoylphorbol 13-acetate (TPA) in PKC alpha-EGFP-transfected cells, but not in PKC beta-EGFP- transfected cells, indicating selective inhibition for PKC alpha in oral SCC cells. Flow cytometric analysis and DNA analysis by agarose gel electrophoresis revealed an increase in the proportion of sub-G(1) cells and DNA fragmentation in safingol-treated cells. Mitochondrial membrane potential was decreased, and cytochrome c was released from mitochondria. However, the safingol-induced cell death was not accompanied by activation of caspase 3 and cleavage of poly (ADP-ribose) polymerase (PARP). The broad-spectrum caspase inhibitor BD-fmk failed to prevent safingol-induced cell death. Another apoptogenic factor endonuclease G, but not apoptosis-inducing factor (AIF), was also released from mitochondria and translocated to the nucleus. These results suggest that PKC alpha inhibitor safingol induces an endonuclease G- mediated apoptosis in a caspase-independent manner.

Effect of dibutyryl cyclic AMP on morphologic features and biologic markers of a human salivary gland adenocarcinoma cell line in culture

Dibutyryl cyclic AMP (dB-cAMP) has marked effects on the growth, morphologic features, and biologic markers of a human salivary gland adenocarcinoma cell line in culture. A cell line with ultrastructure and biologic markers specific to the intercalated duct cells of human salivary glands was cultivated in the presence of dB-cAMP. Major alterations, such as process formation and expression of myofilaments and oxytocin receptor in addition to myosin and S-100 protein, were observed in those cells with a phenotype similar to myoepithelial cells. Both the anchorage-independent and anchorage-dependent growths were markedly suppressed in the presence of dB-cAMP. After the removal of dB-cAMP from the culture, the treated cells returned rapidly to the phenotype of the untreated cells. These findings indicate that reversible differentiation into the myoepithelial cells of a human salivary gland adenocarcinoma cell line occurs in growth medium containing dB-cAMP.

ESE-1 inhibits the invasion of oral squamous cell carcinoma in conjunction with MMP-9 suppression

OBJECTIVES

Matrix metalloproteinases (MMPs) regulated by ets transcription factors facilitate carcinoma cell invasion. An ets family member, ESE-1, is expressed specifically in epithelial tissues, but its association with MMPs is obscure. In this study, we investigated whether ESE-1 regulates invasion of oral squamous cell carcinoma (SCC) via transcriptional activity of MMP-9.

METHODS

HSC-3 and KB were used as human oral SCC lines. The expression of ESE-1 and MMP-9 was detected by in situ hybridization and immunohistochemistry. Invasion assay, gelatin zymography and Northern blotting were used to detect the invasion activity, the gelatinolytic activity and the expression of MMP-9 in the ESE-1 transfectants. Luciferase assays and mutation analysis were used for the transcriptional analysis of MMP-9 promoter region by ESE-1.

RESULTS

ESE-1 was expressed in the intermediate layer but not in the invasive area, in which MMP-9 was expressed, in the oral SCC tissues. ESE-1 suppressed invasion activity and 92 kDa gelatinolytic activity in HSC-3 as a result of transfection. ESE-1 regulates MMP-9 expression in a negative manner and the ets binding site on the MMP-9 promoter contributed to suppression by ESE-1.

CONCLUSIONS

These findings indicate that ESE-1 negatively regulates the invasion of oral SCC via transcriptional suppression of MMP-9.

Enhancement of systemic tumor immunity for squamous cell carcinoma cells by an oncolytic herpes simplex virus

RH2 is a neurovirulent γ134.5 gene-deficient herpes simplex virus type 1 (HSV-1) with a lytic ability in human squamous cell carcinoma (SCC) cells; it is related to spontaneously occurring HSV-1 mutant HF10. The effect of RH2 on SCC was examined using a syngeneic C3H mouse model. After infection of mouse SCCVII cells with RH2, cell viability was decreased at first, but recovered by prolonged culture, indicating the limited replication of RH2. The antitumor ability of RH2 was examined using a bilateral SCCVII tumor model. The growth of the RH2-injected tumors was suppressed compared with that of phosphate-buffered saline-injected tumors. Moreover, the growth of contralateral tumor of RH2-treated mice was also suppressed significantly. The splenocytes of C3H mice treated with RH2 lysed more SCCVII cells than NFSaY83 cells and YAC-1 cells. The cytotoxicity of the splenocytes on SCCVII cells was significantly greater than that of splenocytes from tumor-bearing mice. Removal of CD8(+) T cells from splenocytes decreased their cell killing activity remarkably. The antitumor effect of RH2 on SCCVII xenografts in nude mice was not demonstrated. These results indicate that RH2 exhibited a suppressive effect on mouse SCC, even if the replication of RH2 was limited. This is ascribed to the ability of RH2 to enhance existing tumor-specific cytotoxic T lymphocyte activity.

Protein Kinase N Promotes Stress-Induced Cardiac Dysfunction Through Phosphorylation of Myocardin-Related Transcription Factor A and Disruption of Its Interaction With Actin

BACKGROUND

Heart failure is a complex syndrome that results from structural or functional impairment of ventricular filling or blood ejection. Protein phosphorylation is a major and essential intracellular mechanism that mediates various cellular processes in cardiomyocytes in response to extracellular and intracellular signals. The RHOA-associated protein kinase (ROCK/Rho-kinase), an effector regulated by the small GTPase RHOA, causes pathological phosphorylation of proteins, resulting in cardiovascular diseases. RHOA also activates protein kinase N (PKN); however, the role of PKN in cardiovascular diseases remains unclear.

METHODS

To explore the role of PKNs in heart failure, we generated tamoxifen-inducible, cardiomyocyte-specific PKN1- and PKN2-knockout mice by intercrossing the αMHC-CreERT2 line with Pkn1^flox/flox and Pkn2^flox/flox mice and applied a mouse model of transverse aortic constriction- and angiotensin II-induced heart failure. To identify a novel substrate of PKNs, we incubated GST-tagged myocardin-related transcription factor A (MRTFA) with recombinant GST-PKN-catalytic domain or GST-ROCK-catalytic domain in the presence of radiolabeled ATP and detected radioactive GST-MRTFA as phosphorylated MRTFA.

RESULTS

We demonstrated that RHOA activates 2 members of the PKN family of proteins, PKN1 and PKN2, in cardiomyocytes of mice with cardiac dysfunction. Cardiomyocyte-specific deletion of the genes encoding Pkn1 and Pkn2 (cmc-PKN1/2 DKO) did not affect basal heart function but protected mice from pressure overload- and angiotensin II-induced cardiac dysfunction. Furthermore, we identified MRTFA as a novel substrate of PKN1 and PKN2 and found that MRTFA phosphorylation by PKN was considerably more effective than that by ROCK in vitro. We confirmed that endogenous MRTFA phosphorylation in the heart was induced by pressure overload- and angiotensin II-induced cardiac dysfunction in wild-type mice, whereas cmc-PKN1/2 DKO mice suppressed transverse aortic constriction- and angiotensin II-induced phosphorylation of MRTFA. Although RHOA-mediated actin polymerization accelerated MRTFA-induced gene transcription, PKN1 and PKN2 inhibited the interaction of MRTFA with globular actin by phosphorylating MRTFA, causing increased serum response factor-mediated expression of cardiac hypertrophy- and fibrosis-associated genes.

CONCLUSIONS

Our results indicate that PKN1 and PKN2 activation causes cardiac dysfunction and is involved in the transition to heart failure, thus providing unique targets for therapeutic intervention for heart failure.