VGLL3 confers slow-twitch muscle differentiation via PGC-1α expression in C2C12 myocytes.

Vestigial-like family member 3 (VGLL3) is a cofactor for the TEA-domain transcription factor (TEAD) family. Although VGLL3 influences myogenic differentiation, its involvement in slow- and fast-twitch fiber specification remains unknown. In this study, we established a cell line stably overexpressing VGLL3 and analyzed effects of VGLL3 on the myogenic differentiation of murine myoblast C2C12 cells. We found that VGLL3 expression promotes slow-twitch muscle differentiation. Mechanistically, VGLL3 expression induced the expression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), a master transcriptional regulator of slow-twitch muscle development. We also found that VGLL3 proteins are degraded by the proteasome, which causes switching of TEAD cofactors from VGLL3 to Yes-associated protein (YAP) and transcriptional coactivator with a PDZ-binding motif (TAZ). These results suggest that the balance between the two kinds of TEAD cofactors VGLL3 and YAP/TAZ controls muscle fiber-type specification.

Vestigial-like family member 3 stimulates cell motility by inducing high-mobility group AT-hook 2 expression in cancer cells.

Vestigial-like family member 3 (VGLL3) is a cofactor for TEA domain transcription factors (TEADs). Although VGLL3 is known to be highly expressed and stimulate cell proliferation in mesenchymal cancer cells, its involvement in mesenchymal phenotypes is largely unknown. In this study, we found that VGLL3 promotes epithelial-to-mesenchymal transition (EMT)-like phenotypic changes. We found that A549 human lung cancer cells stably expressing VGLL3 exhibit spindle-like morphological changes, reduction in the epithelial marker E-cadherin and induction of the mesenchymal marker Snail. Notably, VGLL3-expressing cells exhibited enhanced motility. The DNA-binding protein high-mobility group AT-hook 2 (HMGA2) was found to be a target of the VGLL3-TEAD4 complex, and HMGA2 knockdown repressed EMT-like phenotypic changes in VGLL3-expressing cells. VGLL3-dependent phenotypic changes are involved in transforming growth factor-ß (TGF-ß)-induced EMT progression. VGLL3 or HMGA2 knockdown repressed the motility of the mesenchymal breast cancer MDA-MB-231 cells. Importantly, high levels of VGLL3 expression were shown to have a positive correlation with poor prognosis in various human cancers, such as breast, colon, ovarian, head and neck, pancreatic, renal, gastric and cervical cancers. These results suggest that VGLL3 promotes EMT-like cell motility by inducing HMGA2 expression and accelerates cancer progression.

VGLL3 increases the dependency of cancer cells on de novo nucleotide synthesis through GART expression.

Vestigial-like family member 3 (VGLL3) is a member of the VGLL family that serves as cofactors for TEA-domain transcription factors. Although VGLL3 is involved in the proliferation of cancer cells, the molecular mechanisms underlying VGLL3-mediated cell proliferation remain largely unknown. In this study, we found that stable expression of VGLL3 in human lung cancer A549 cells affects glutamine metabolism and increases their dependency on de novo nucleotide synthesis for proliferation. Mechanistically, VGLL3 was found to induce the expression of GART, which encodes a trifunctional enzyme that catalyzes de novo purine synthesis from glutamine. GART knockdown and the glycinamide ribonucleotide synthase, aminoimidazole ribonucleotide synthase, and glycinamide ribonucleotide formyltransferase trifunctional protein (GART) inhibitor lometrexol repressed the proliferation and survival of A549 cells stably expressing VGLL3. Mesenchymal breast cancer BT549 cells and MDA-MB-231 cells showed high expression of VGLL3, and VGLL3 knockdown was found to reduce GART expression. Lometrexol also repressed the proliferation of these breast cancer cells, whereas addition of inosine monophosphate, an important metabolite downstream of GART, rescued this repression. Taken together, these results suggest that VGLL3 induces GART expression and thereby confers de novo nucleotide-dependent cell proliferation in cancer cells.

VGLL3 activates inflammatory responses by inducing interleukin-1α secretion.

Vestigial-like family member 3 (VGLL3), a member of the vestigial-like family, is a cofactor of the TEA-domain-containing transcription factor (TEAD). Although elevation in VGLL3 expression is associated with inflammatory diseases, such as inflammatory sarcomas and autoimmune diseases, the molecular mechanisms underlying VGLL3-mediated inflammation remain largely unknown. In this study, we analyzed the relationship between elevated VGLL3 expression and the levels of NF-κB, a transcription factor that plays a pivotal role in inflammation. NF-κB was found to be activated in a cell line stably expressing VGLL3. Mechanistically, VGLL3 was shown to promote the expression and secretion of the potent NF-κB-activating cytokine interleukin (IL)-1α, probably through its association with TEADs. As VGLL3 is a target of transforming growth factor ß (TGF-ß) signaling, we analyzed IL-1α induction upon TGF-ß stimulation. TGF-ß stimulation was observed to induce IL-1α secretion and NF-κB activation, and VGLL3 was associated with this phenomenon. The TGF-ß transcription factors Smad3 and Smad4 were shown to be necessary for inducing VGLL3 and IL-1α expression. Lastly, we found that VGLL3-dependent IL-1α secretion is involved in constitutive NF-κB activation in highly malignant breast cancer cells. Collectively, the findings suggested that VGLL3 expression and TGF-ß stimulation activate the inflammatory response by inducing IL-1α secretion.

Vestigial-like family member 3 (VGLL3), a cofactor for TEAD transcription factors, promotes cancer cell proliferation by activating the Hippo pathway.

Vestigial-like 3 (VGLL3) is a member of the VGLL family, whose members serve as cofactors for TEA domain-containing transcription factors (TEADs). TEADs promote tissue and tumor development together with the cofactors Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ). Although VGLL3 is involved in tumor cell proliferation, its relationship with TEADs and YAP/TAZ remains largely unknown. To close this research gap, here we established tumor cells stably expressing VGLL3 and found that they exhibit enhanced proliferation. Notably, YAP and TAZ were inactivated in the VGLL3-expressing cells, coinciding with activation of the Hippo pathway, which suppresses YAP/TAZ activities. VGLL3 in combination with TEADs promoted expression of the Hippo pathway components large tumor suppressor kinase (LATS2) and angiomotin-like 2 (AMOTL2). VGLL3 was highly expressed in malignant breast tumor cells and osteosarcoma cells, and VGLL3 knockdown increased nuclear localization of YAP and TAZ. Knockdown of LATS2 or AMOTL2, as well as VGLL3 knockdown, repressed proliferation of breast tumor cells. Together, these results suggest that VGLL3 together with TEADs promotes cell proliferation by activating the Hippo pathway through LATS2 and AMOTL2, leading to YAP/TAZ inactivation.

Forkhead box protein A1 confers resistance to transforming growth factor-ß-induced apoptosis in breast cancer cells through inhibition of Smad3 nuclear translocation.

Transforming growth factor-ß (TGF-ß) induces apoptosis of normal epithelial cells, such as mammary epithelium. Although breast cancer progression associates with acquisition of resistance to TGF-ß-induced apoptosis, the molecular mechanisms underlying this resistance are largely unknown. Here, we show that forkhead box protein A1 (FOXA1), which is known as a pioneer transcription factor, suppresses TGF-ß-induced apoptosis of estrogen receptor-positive breast cancer cells. FOXA1 is found to inhibit nuclear translocation of Smad3, a key transcription factor downstream of TGF-ß signaling, through suppression of the binding of Smad3 to the nuclear import receptor importin7. Furthermore, RNA sequencing analyses show that knockdown of FOXA1 upregulates Smad3-mediated proapoptotic gene expression. These results demonstrate that FOXA1 as a potent survival factor that suppresses TGF-ß-induced apoptosis by inhibiting Smad3 signaling in estrogen receptor-positive breast cancer cells. Thus, we provide evidence for the first time that FOXA1 localizing to the cytoplasm negatively regulates Smad3-induced apoptosis in TGF-ß-mediated signal transduction.

Analysis of the Correlation between the Myocardial Expression of DPP-4 and the Clinical Parameters of Patients with Heart Failure.

Dipeptidyl peptidase-4 (DPP-4) inhibitors are widely used as antidiabetic drugs. We recently reported that DPP-4 inhibition has beneficial effects on heart failure (HF) mice model. Furthermore, we confirmed that myocardial DPP-4 activity was significantly increased in HF mice compared with non-HF mice. The aim of this study was to investigate the level of myocardial CD26 (DPP-4) expression and its association to clinical parameters in HF patients.Endomyocardial biopsy (EMB) specimens (n = 33) were obtained from HF patients who were admitted to Chiba University Hospital from June 2006 to July 2012. EMB specimens were fixed in formaldehyde and stained with Masson's trichrome staining or with anti-CD26 antibody. Patients were divided into the high CD26 density (CD26-H) or low CD26 density groups (CD26-L). DPP-4 density was compared with blood brain natriuretic peptide (BNP) level and echocardiographic parameters at one year after EMB. Although there were no significant differences in echocardiographic parameters between the CD26-H group and CD26-L group, blood BNP levels were higher in the CD26-H group than in the CD26-L group at one year after EMB. Multivariate regression analysis showed that CD26 density was also an independent determinant of blood BNP levels at one year after EMB.The level of myocardial CD26 expression might be a predictive marker of prognosis in patients with HF.

The effects of dipeptidyl peptidase-4 on cardiac fibrosis in pressure overload-induced heart failure.

Dipeptidyl peptidase-4 (DPP-4) inhibitors are hypoglycemic agents. DPP-4 inhibitor has cardioprotective effects after transverse aortic constriction (TAC), but role of DPP-4 on cardiac fibrosis after TAC is not well known. Our aim was to determine the effects of DPP-4 on cardiac fibrosis in murine TAC model. Wild-type mice and DPP-4 knockout mice were subjected to TAC. Wild-type mice were then treated with vehicle or DPP-4 inhibitor. DPP-4 activities in serum and heart tissue were significantly increased at 2 weeks after TAC, but they were significantly decreased by DPP-4 inhibitor treatment. The inhibition of DPP-4 did not affect left ventricular hypertrophy, but improved cardiac function and decreased myocardial and perivascular fibrosis after TAC. The inhibition of DPP-4 decreased the collagen type III/I ratio in myocardium. These results suggest that DPP-4 inhibition ameliorates the progression of heart failure after TAC by changing the quality and quantity of cardiac fibrosis.

DPP-4 inhibition protects human umbilical vein endothelial cells from hypoxia-induced vascular barrier impairment.

Dipeptidyl peptidase-4 (DPP-4) inhibitors are relatively new class of anti-diabetic drugs. Some protective effects of DPP-4 on cardiovascular disease have been described independently from glucose-lowering effect. However, the detailed mechanisms by which DPP-4 inhibitors exert on endothelial cells remain elusive. The purpose of this research was to determine the effects of DPP-4 inhibitor on endothelial barrier function. Human umbilical vein endothelial cells (HUVECs) were cultured and exposed to hypoxia in the presence or absence of Diprotin A, a DPP-4 inhibitor. Immunocytochemistry of vascular endothelial (VE-) cadherin showed that jagged VE-cadherin staining pattern induced by hypoxia was restored by treatment with Diprotin A. The increased level of cleaved ß-catenin in response to hypoxia was significantly attenuated by Diprotin A, suggesting that DPP-4 inhibition protects endothelial adherens junctions from hypoxia. Subsequently, we found that Diprotin A inhibited hypoxia-induced translocation of NF-κB from cytoplasm to nucleus through decreasing TNF-α expression level. Furthermore, the tube formation assay showed that Diprotin A significantly restored hypoxia-induced decrease in number of tubes by HUVECs. These results suggest that DPP-4 inhibitior protects HUVECs from hypoxia-induced barrier impairment.

The effects of DPP-4 inhibitor on hypoxia-induced apoptosis in human umbilical vein endothelial cells.

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of oral hypoglycemic agents for patients with type 2 diabetes mellitus and have potential antiatherosclerotic properties. Meanwhile, it is unclear how DPP-4 inhibitors have protective effects on atherosclerosis. Our aim was to determine the effects and its mechanisms of DPP-4 inhibitors on cultured endothelial cells. Human umbilical vein endothelial cells (HUVECs) were cultured in hypoxic condition. To evaluate the protective effects of DPP-4 inhibitor on HUVECs, DPP-4 inhibitor was added in the cell culture medium and the cell viability was assessed by TUNEL assay. And we examined the intracellular signaling pathways in relation to the effects of DPP-4 inhibitor. DPP-4 inhibition had beneficial effects by inhibiting the apoptosis under hypoxic conditions in HUVECs. The antiapoptotic effects of DPP-4 inhibitor were abolished by the pretreatment with a CXCR4 antagonist or a Stat3 inhibitor. DPP-4 inhibition has beneficial effects on HUVECs by inhibiting the apoptosis under hypoxic conditions. SDF-1α/CXCR4/Stat3 pathways might be involved in the mechanisms of the cytoprotective effects of DPP-4 inhibitor. These results suggested that DPP-4 inhibitor has a potential for protecting vessels.

DPP-4 inhibition has beneficial effects on the heart after myocardial infarction.

AIMS: Dipeptidyl peptidase-4 (DPP-4) inhibitors are reported to have protective effects on various cells but it is unclear how DPP-4 inhibitors have cardioprotective effects. Our aim was to study the mechanisms of cardioprotective effects by DPP-4 inhibition. METHODS AND RESULTS: C57BL/6 mice and DPP-4 knockout (DPP-4KO) mice were subjected to left coronary artery ligation to produce acute myocardial infarction (MI). C57BL/6 mice were then treated with vehicle or DPP-4 inhibitor. Left ventricular function, infarct size, the number of vessels, and myocardial ischemia were assessed at 5days after MI. The treatment with DPP-4 inhibitor significantly improved cardiac function and decreased the infarct size. DPP-4 inhibitor increased the ratio of endothelial cell numbers to a cardiomyocyte. The extent of myocardial ischemia and the number of TUNEL-positive cells in the border area were significantly decreased by DPP-4 inhibitor. Stromal cell-derived factor-1α (SDF-1α) level in myocardium was significantly increased by DPP-4 inhibitor. Those cardioprotective effects after MI were also recognized in DPP-4KO mice. DPP-4 protein was expressed on rat neonatal cardiomyocytes and DPP-4 inhibitor significantly reduced hypoxia-induced apoptosis in the cardiomyocytes. However, this effect was abolished by the pretreatment with a CXCR4 antagonist or a signal transducer and activator of transcription 3 (STAT3) inhibitor. The beneficial effects of DPP-4 inhibitor on heart failure after MI were abolished by cardiomyocyte-specific deletion of STAT3. CONCLUSIONS: DPP-4 inhibition may have direct protective effects on the post-MI heart by inducing an antiapoptotic effect and inhibiting a decrease in vessel number through the SDF-1α/CXCR4-mediated STAT3 signaling pathway.

Deletion of CD28 Co-stimulatory Signals Exacerbates Left Ventricular Remodeling and Increases Cardiac Rupture After Myocardial Infarction.

BACKGROUND: Inflammatory responses, especially by CD4(+)T cells activated by dendritic cells, are known to be important in the pathophysiology of cardiac repair after myocardial infarction (MI). Although co-stimulatory signals through B7 (CD80/86) and CD28 are necessary for CD4(+)T cell activation and survival, the roles of these signals in cardiac repair after MI are still unclear. METHODS AND RESULTS: C57BL/6 (Control) mice and CD28 knockout (CD28KO) mice were subjected to left coronary artery permanent ligation. The ratio of death by cardiac rupture within 5 days after MI was significantly higher in CD28KO mice compared with Control mice. Although there were no significant differences in the infarct size between the 2 groups, left ventricular end-diastolic and end-systolic diameters were significantly increased, and fractional shortening was significantly decreased in CD28KO mice compared with Control mice. Electron microscopic observation revealed that the extent of extracellular collagen fiber was significantly decreased in CD28KO mice compared with Control mice. The number of α-smooth muscle actin-positive myofibroblasts was significantly decreased, and matrix metalloproteinase-9 activity and the mRNA expression of interleukin-1ß were significantly increased in CD28KO mice compared with Control mice. CONCLUSIONS: Deletion of CD28 co-stimulatory signals exacerbates left ventricular remodeling and increases cardiac rupture after MI through prolongation of the inflammatory period and reduction of collagen fiber in the infarct scars. (Circ J 2016; 80: 1971-1979).

Mitochondrial protein C15ORF48 is a stress-independent inducer of autophagy that regulates oxidative stress and autoimmunity.

Autophagy is primarily activated by cellular stress, such as starvation or mitochondrial damage. However, stress-independent autophagy is activated by unclear mechanisms in several cell types, such as thymic epithelial cells (TECs). Here we report that the mitochondrial protein, C15ORF48, is a critical inducer of stress-independent autophagy. Mechanistically, C15ORF48 reduces the mitochondrial membrane potential and lowers intracellular ATP levels, thereby activating AMP-activated protein kinase and its downstream Unc-51-like kinase 1. Interestingly, C15ORF48-dependent induction of autophagy upregulates intracellular glutathione levels, promoting cell survival by reducing oxidative stress. Mice deficient in C15orf48 show a reduction in stress-independent autophagy in TECs, but not in typical starvation-induced autophagy in skeletal muscles. Moreover, C15orf48-/- mice develop autoimmunity, which is consistent with the fact that the stress-independent autophagy in TECs is crucial for the thymic self-tolerance. These results suggest that C15ORF48 induces stress-independent autophagy, thereby regulating oxidative stress and self-tolerance.

Effects of pitavastatin in Japanese patients with chronic heart failure: the Pitavastatin Heart Failure Study (PEARL Study).

BACKGROUND: Recent clinical trials using rosuvastatin, a hydrophilic statin, did not show beneficial effects on cardiovascular events in patients with heart failure. We examined the cardioprotective effects of pitavastatin, a lipophilic statin, on Japanese patients with chronic heart failure (CHF). METHODS AND RESULTS: A total of 574 Japanese patients with CHF were randomly assigned to the pitavastatin group (n=288) or the control group (n=286). There was no significant difference between the 2 groups for the primary outcome, which was a composite of cardiac death and hospitalization for worsening HF (adjusted hazard ratio (aHR): 0.922, 95% confidence interval (CI): 0.632-1.345, P=0.672). A strongly significant statistical interaction between the effect of pitavastatin and left ventricular ejection fraction (LVEF) was found (P=0.004). In patients with LVEF ≥30%, a significant reduction in the primary outcome (aHR: 0.525, 95% CI: 0.308-0.896, P=0.018) was observed in the pitavastatin group. Pitavastatin did not show any effects on the primary outcome (aHR: 1.582, 95% CI: 0.890-2.813, P=0.118) in the subgroup of patients with LVEF <30%. CONCLUSIONS: Pitavastatin did not reduce cardiac death or hospitalization for worsening HF in Japanese patients with CHF. (UMIN-ID: UMINC000000428).

Role of regulatory T cells in atheroprotective effects of granulocyte colony-stimulating factor.

We and others have previously reported that granulocyte colony-stimulating factor (G-CSF) prevents left ventricular remodeling and dysfunction after myocardial infarction in animal models and human. We have also reported that G-CSF inhibits the progression of atherosclerosis in animal models, but its precise mechanism is still elusive. So, we examined the effects of G-CSF on atherosclerosis in apolipoprotein E-deficient (ApoE(-/-)) mice. Twelve-week-old male ApoE(-/-) mice were subcutaneously administrated with 200 µg/kg of G-CSF or saline once a day for 5 consecutive days per a week for 4 weeks. Atherosclerotic lesion of aortic sinus was significantly reduced in the G-CSF-treated mice compared with the saline-treated mice (35% reduction, P<0.05). G-CSF significantly reduced the expression level of interferon-γ by 31% and increased the expression level of interleukin-10 by 20% in atherosclerotic lesions of aortic sinus. G-CSF increased the number of CD4(+)CD25(+) regulatory T cells in lymph nodes and spleen, and enhanced the suppressive function of regulatory T cells in vitro. G-CSF markedly increased the number of Foxp3-positive regulatory T cells in atherosclerotic lesions of aortic sinus. Administration of anti-CD25 antibody (PC61) that depletes regulatory T cells abrogated these atheroprotective effects of G-CSF. Moreover, in ApoE(-/-)/CD28(-/-) mice, that lack regulatory T cells, the protective effects of G-CSF on atherosclerosis were not recognized. These findings suggest that regulatory T cells play an important role in the atheroprotective effects of G-CSF.

Effects of pitavastatin on pressure overload-induced heart failure in mice.

BACKGROUND: 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins), which are widely used to lower plasma cholesterol levels, have been reported to have various pleiotropic effects such as protective effect of endothelial cells, angiogenic effect, antioxidant effect and anti-inflammatory effect. It is unclear, however, whether statins have any effects on the progression from left ventricular (LV) hypertrophy to heart failure in the established hypertrophied heart. METHODS AND RESULTS: C57BL/6 mice were treated with pitavastatin (pitava) or vehicle (control) from 2 weeks (established hypertrophy stage) after transverse aortic constriction (TAC) and the treatment was continued for 4 weeks. Pitavastatin significantly inhibited the progression from LV hypertrophy to heart failure as assessed on echocardiography. The cardiomyocyte cross-sectional area was significantly increased in the control group compared to the sham-operated mice (sham group), but it was not significantly different between the control group and the pitava group at 6 weeks after TAC. Moreover, pitavastatin induced myocardial angiogenesis (ratio of number of endothelial cells to cardiomyocytes) and decreased the myocardial fibrosis and oxidative stress. The expression of angiopoietin-1 in the heart was significantly increased by pitavastatin at 6 weeks after TAC. CONCLUSIONS: Pitavastatin has preventive effects on the progression of heart failure even in the hypertrophied heart.

G-CSF prevents cardiac remodeling after myocardial infarction by activating the Jak-Stat pathway in cardiomyocytes.

Granulocyte colony-stimulating factor (G-CSF) was reported to induce myocardial regeneration by promoting mobilization of bone marrow stem cells to the injured heart after myocardial infarction, but the precise mechanisms of the beneficial effects of G-CSF are not fully understood. Here we show that G-CSF acts directly on cardiomyocytes and promotes their survival after myocardial infarction. G-CSF receptor was expressed on cardiomyocytes and G-CSF activated the Jak/Stat pathway in cardiomyocytes. The G-CSF treatment did not affect initial infarct size at 3 d but improved cardiac function as early as 1 week after myocardial infarction. Moreover, the beneficial effects of G-CSF on cardiac function were reduced by delayed start of the treatment. G-CSF induced antiapoptotic proteins and inhibited apoptotic death of cardiomyocytes in the infarcted hearts. G-CSF also reduced apoptosis of endothelial cells and increased vascularization in the infarcted hearts, further protecting against ischemic injury. All these effects of G-CSF on infarcted hearts were abolished by overexpression of a dominant-negative mutant Stat3 protein in cardiomyocytes. These results suggest that G-CSF promotes survival of cardiac myocytes and prevents left ventricular remodeling after myocardial infarction through the functional communication between cardiomyocytes and noncardiomyocytes.

Effect of switching from telmisartan, valsartan, olmesartan, or losartan to candesartan on morning hypertension.

The Candesartan Cooperative Research of Therapy Design for Early Morning Hypertension in CHIBA was designed to investigate whether switching from angiotensin II receptor blockers (ARBs) except candesartan to candesartan might be effective in Japanese patients with morning hypertension. Seventy-eight mild to moderate hypertensive patients, who were treated with the standard doses of ARBs except candesartan (losartan, 50 mg; valsartan, 80 mg; telmisartan, 40 mg; or olmesartan, 20 mg), were entered into 12-week treatment period with candesartan 8 mg according to a multicenter, open-label design. Morning and office blood pressures (BPs) were significantly reduced (morning, -10.1 ± 10.5/-4.5 ± 8.4 mm Hg; office, -13.1 ± 17.3/-6.2 ± 11.3 mm Hg) after medication change. Target BPs (morning BPs ≤ 135/85 mm Hg and office BPs ≤ 140/90 mm Hg) achievement rates were 42.9% in the morning and 64.3% at office. No adverse events were recognized in all patients. Candesartan treatment significantly reduced the morning and office BPs compared with other ARBs in Japanese patients with morning hypertension.

Ecological risk assessment of on-site soil washing with iron(III) chloride in cadmium-contaminated paddy field.

On-site soil washing with iron(III) chloride reduces Cd levels in soil, and thus the human health risks caused by Cd in food. However, it may threaten aquatic organisms when soil washing effluent is discharged to open aquatic systems. Therefore, we conducted trial-scale on-site soil washing and ecological risk assessment in Nagano and Niigata prefectures, Japan. The ecological effect of effluent water was investigated by two methods. The first was bioassay using standard aquatic test organisms. Twice-diluted effluent water from the Nagano site and the original effluent water from the Niigata site had no significant effects on green algae, water flea, caddisfly, and fish. The safe dilution rates were estimated as 20 times and 10 times for the Nagano and Niigata sites, respectively, considering an assessment factor of 10. The second method was probabilistic effect analysis using chemical analysis and the species sensitivity distribution concept. The mixture effects of CaCl(2), Al, Zn, and Mn were considered by applying a response additive model. The safe dilution rates, assessed for a potentially affected fraction of species of 5%, were 7.1 times and 23.6 times for the Nagano and Niigata sites, respectively. The actual dilution rates of effluent water by river water at the Nagano and Niigata sites were 2200-67,000 times and 1300-110,000 times, respectively. These are much larger than the safe dilution rates derived from the two approaches. Consequently, the ecological risk to aquatic organisms of soil washing is evaluated as being below the concern level.

Heat shock transcription factor 1 protects heart after pressure overload through promoting myocardial angiogenesis in male mice.

Heat shock transcription factor 1 (HSF1) plays an important role not only in excise-induced cardiac hypertrophy but also in protection against pressure overload-induced cardiac dysfunction. However, the mechanism is not completely understood. We here elucidate the potential mechanisms by which HSF1 protects against pressure overload-induced cardiac remodeling and dysfunction. A sustained constriction of transverse aorta (TAC) was imposed to HSF1 transgenic (TG), knockout (KO) and their littermate wild type (WT) male mice. Four weeks later, adaptive responses to TAC, such as cardiac hypertrophy, contractility and angiogenesis evaluated by echocardiography, catheterization, coronary perfusion pressure and immunohistochemistry were well preserved in TG but not in KO compared with WT mice. An angiogenesis inhibitor TNP-470 abrogated all these adaptive responses in TG mice, while cardiac transfection of VEGF with angiopoietin-1 rescued the broken heart in KO mice. In response to TAC, p53 was downregulated and hypoxia-inducing transcription factor-1 (HIF-1) was upregulated not only in the heart but also in the cultured cardiac endothelial cells (EC) of TG mice as compared to WT mice whereas these changes became opposite in KO mice. A small interfering RNA (siRNA) of HIF-1 but not a p53 gene impaired the adaptive responses of the heart and EC in TG mice, and a siRNA of p53 but not a HIF-1 gene significantly reversed the heart and EC disorders in KO mice after TAC. We conclude that HSF1 promotes cardiac angiogenesis through suppression of p53 and subsequent upregulation of HIF-1 in endothelial cells during chronic pressure overload, leading to the maintenance of cardiac adaptation.