Ursolic acid alleviates steroid-induced avascular necrosis of the femoral head in mouse by inhibiting apoptosis and rescuing osteogenic differentiation.

Steroid-induced avascular necrosis of femoral head (SANFH) is a common disorder worldwide with high disability. Overdose of glucocorticoid (GC) is the most common non-traumatic cause of SANFH. Up until now, there are limited therapeutic strategies for curing SANFH, and the mechanisms underlying SANFH progression remain unclear. Nevertheless, Osteogenic dysfunction is considered to be one of the crucial pathobiological mechanisms in the development of SANFH, which involves mouse bone marrow mesenchymal stem cells (BMSCs) apoptosis and osteogenic differentiation disorder. Ursolic acid (UA), an important component of the Chinese medicine formula Yougui Yin, has a wide range of pharmacological properties such as anti-tumor, anti-inflammatory and bone remodeling. Due to the positive effect of Yougui Yin on bone remodeling, the purpose of this study was to investigate the effects of UA on dexamethasone (DEX)-induced SANFH in vitro and vivo. In vitro, we demonstrated that UA can promote mouse BMSCs proliferation and resist DEX-induced apoptosis by CCK8, Western blotting, TUNEL and so on. In addition, vitro experiments such as ALP and Alizarin red staining assay showed that UA had a beneficial effect on the osteogenic differentiation of mouse BMSCs. In vivo, the results of H&E staining, immunohistochemistry staining, Elisa and micro-CT analysis showed that UA had a bone repair-promoting effect in SANFH model. Moreover, the results of Western blot and TUNEL experiments showed that UA could delay the disease progression of SANFH in mice by inhibiting apoptosis. Overall, our study suggests that UA is a potential compound for the treatment of SANFH.

PSME4 determines mesenchymal stem cell fate towards cardiac commitment through YAP1 degradation.

The regeneration of myocardium following acute circulatory events remains a challenge, despite numerous efforts. Mesenchymal stem cells (MSCs) present a promising cell therapy option, but their differentiation into cardiomyocytes is a time-consuming process. Although it has been demonstrated that PSME4 degrades acetyl-YAP1, the role of PSME4 in the cardiac commitment of MSCs has not been fully elucidated. Here we reported the novel role of PSME4 in MSCs cardiac commitment. It was found that overnight treatment with apicidin in primary-cultured mouse MSCs led to rapid cardiac commitment, while MSCs from PSME4 knock-out mice did not undergo this process. Cardiac commitment was also observed using lentivirus-mediated PSME4 knockdown in immortalized human MSCs. Immunofluorescence and Western blot experiments revealed that YAP1 persisted in the nucleus of PSME4 knockdown cells even after apicidin treatment. To investigate the importance of YAP1 removal, MSCs were treated with shYAP1 and apicidin simultaneously. This combined treatment resulted in rapid YAP1 elimination and accelerated cardiac commitment. However, overexpression of acetylation-resistant YAP1 in apicidin-treated MSCs impeded cardiac commitment. In addition to apicidin, the universal effect of histone deacetylase (HDAC) inhibition on cardiac commitment was confirmed using tubastatin A and HDAC6 siRNA. Collectively, this study demonstrates that PSME4 is crucial for promoting the cardiac commitment of MSCs. HDAC inhibition acetylates YAP1 and facilitates its translocation to the nucleus, where it is removed by PSME4, promoting cardiac commitment. The failure of YAP1 to translocate or be eliminated from the nucleus results in the MSCs' inability to undergo cardiac commitment.

S-Nitrosylation of Histone Deacetylase 2 by Neuronal Nitric Oxide Synthase as a Mechanism of Diastolic Dysfunction.

BACKGROUND: Although the clinical importance of heart failure with preserved ejection fraction has been extensively explored, most therapeutic regimens, including nitric oxide (NO) donors, lack therapeutic benefit. Although the clinical characteristics of heart failure with preserved ejection fraction are somewhat heterogeneous, diastolic dysfunction (DD) is one of the most important features. Here we report that neuronal NO synthase (nNOS) induces DD by S-nitrosylation of HDAC2 (histone deacetylase 2). METHODS: Two animal models of DD-SAUNA (SAlty drinking water/Unilateral Nephrectomy/Aldosterone) and mild transverse aortic constriction mice-as well as human heart samples from patients with left ventricular hypertrophy were used. Genetically modified mice that were either nNOS-ablated or HDAC2 S-nitrosylation-resistant were also challenged. N(ω)-propyl-L-arginine, an nNOS selective inhibitor, and dimethyl fumarate, an NRF2 (nuclear factor erythroid 2-related factor 2) inducer, were used. Molecular events were further checked in human left ventricle specimens. RESULTS: SAUNA or mild transverse aortic constriction stress impaired diastolic function and exercise tolerance without overt systolic failure. Among the posttranslational modifications tested, S-nitrosylation was most dramatically increased in both models. Utilizing heart samples from both mice and humans, we observed increases in nNOS expression and NO production. N(ω)-propyl-L-arginine alleviated the development of DD in vivo. Similarly, nNOS knockout mice were resistant to SAUNA stress. nNOS-induced S-nitrosylation of HDAC2 was relayed by transnitrosylation of GAPDH. HDAC2 S-nitrosylation was confirmed in both DD mouse and human left ventricular hypertrophy. S-nitrosylation of HDAC2 took place at C262 and C274. When DD was induced, HDAC2 S-nitrosylation was detected in wild-type mouse, but not in HDAC2 knock-in mouse heart that expressed HDAC2 C262A/C274A. In addition, HDAC2 C262A/C274A mice maintained normal diastolic function under DD stimuli. Gene delivery with adenovirus-associated virus 9 (AAV9)-NRF2, a putative denitrosylase of HDAC2, or pharmacological intervention by dimethyl fumarate successfully induced HDAC2 denitrosylation and mitigated DD in vivo. CONCLUSIONS: Our observations are the first to demonstrate a new mechanism underlying DD pathophysiology. Our results provide theoretical and experimental evidence to explain the ineffectiveness of conventional NO enhancement trials for improving DD with heart failure symptoms. More important, our results suggest that reduction of NO or denitrosylation of HDAC2 may provide a new therapeutic platform for the treatment of refractory heart failure with preserved ejection fraction.

Nitrosative Stress and Human Disease: Therapeutic Potential of Denitrosylation.

Proteins dynamically contribute towards maintaining cellular homeostasis. Posttranslational modification regulates the function of target proteins through their immediate activation, sudden inhibition, or permanent degradation. Among numerous protein modifications, protein nitrosation and its functional relevance have emerged. Nitrosation generally initiates nitric oxide (NO) production in association with NO synthase. NO is conjugated to free thiol in the cysteine side chain (S-nitrosylation) and is propagated via the transnitrosylation mechanism. S-nitrosylation is a signaling pathway frequently involved in physiologic regulation. NO forms peroxynitrite in excessive oxidation conditions and induces tyrosine nitration, which is quite stable and is considered irreversible. Two main reducing systems are attributed to denitrosylation: glutathione and thioredoxin (TRX). Glutathione captures NO from S-nitrosylated protein and forms S-nitrosoglutathione (GSNO). The intracellular reducing system catalyzes GSNO into GSH again. TRX can remove NO-like glutathione and break down the disulfide bridge. Although NO is usually beneficial in the basal context, cumulative stress from chronic inflammation or oxidative insult produces a large amount of NO, which induces atypical protein nitrosation. Herein, we (1) provide a brief introduction to the nitrosation and denitrosylation processes, (2) discuss nitrosation-associated human diseases, and (3) discuss a possible denitrosylation strategy and its therapeutic applications.

HDAC Inhibitors: Therapeutic Potential in Fibrosis-Associated Human Diseases.

Fibrosis is characterized by excessive deposition of the extracellular matrix and develops because of fibroblast differentiation during the process of inflammation. Various cytokines stimulate resident fibroblasts, which differentiate into myofibroblasts. Myofibroblasts actively synthesize an excessive amount of extracellular matrix, which indicates pathologic fibrosis. Although initial fibrosis is a physiologic response, the accumulated fibrous material causes failure of normal organ function. Cardiac fibrosis interferes with proper diastole, whereas pulmonary fibrosis results in chronic hypoxia; liver cirrhosis induces portal hypertension, and overgrowth of fibroblasts in the conjunctiva is a major cause of glaucoma surgical failure. Recently, several reports have clearly demonstrated the functional relevance of certain types of histone deacetylases (HDACs) in various kinds of fibrosis and the successful alleviation of the condition in animal models using HDAC inhibitors. In this review, we discuss the therapeutic potential of HDAC inhibitors in fibrosis-associated human diseases using results obtained from animal models.

Novel NTRK1 mutations associated with congenital insensitivity to pain with anhidrosis verified by functional studies.

Congenital insensitivity to pain with anhidrosis (CIPA), also known as hereditary sensory and autonomic neuropathy type IV, features loss of pain sensation, decreased or absent sweating (anhidrosis), recurrent episodes of unexplained fever, self-mutilating behavior, and variable mental retardation. Mutations in neurotrophic receptor tyrosine kinase 1 (NTRK1) have been reported to be associated with CIPA. We identified four novel NTRK1 mutations in six Korean patients from four unrelated families. Of the four mutations, we demonstrated using a splicing assay that IVS14+3A>T causes aberrant splicing of NTRK1 mRNA, leading to introduction of a premature termination codon. An NTRK1 autophosphorylation assay showed that c.1786G>A (p.Asp596Asn) abolished autophosphorylation of NTRK1. In addition, Western blotting showed that c.704C>G (p.Ser235*) and c.2350_2363del (p.Leu784Serfs*79) blunted NTRK1 expression to undetectable levels. The four novel NTRK1 mutations we report here will expand the repertoire of NTRK1 mutations in CIPA patients, and further our understanding of CIPA pathogenesis.

Glycoprotein 90K Promotes E-Cadherin Degradation in a Cell Density-Dependent Manner via Dissociation of E-Cadherin-p120-Catenin Complex.

Glycoprotein 90K (also known as LGALS3BP or Mac-2BP) is a tumor-associated protein, and high 90K levels are associated with poor prognosis in some cancers. To clarify the role of 90K as an indicator for poor prognosis and metastasis in epithelial cancers, the present study investigated the effect of 90K on an adherens junctional protein, E-cadherin, which is frequently absent or downregulated in human epithelial cancers. Treatment of certain cancer cells with 90K significantly reduced E-cadherin levels in a cell-population-dependent manner, and these cells showed decreases in cell adhesion and increases in invasive cell motility. Mechanistically, 90K-induced E-cadherin downregulation occurred via ubiquitination-mediated proteasomal degradation. 90K interacted with the E-cadherin-p120-catenin complex and induced its dissociation, altering the phosphorylation status of p120-catenin, whereas it did not associate with ß-catenin. In subconfluent cells, 90K decreased membrane-localized p120-catenin and the membrane fraction of the p120-catenin. Particularly, 90K-induced E-cadherin downregulation was diminished in p120-catenin knocked-down cells. Taken together, 90K upregulation promotes the dissociation of the E-cadherin-p120-catenin complex, leading to E-cadherin proteasomal degradation, and thereby destabilizing adherens junctions in less confluent tumor cells. Our results provide a potential mechanism to explain the poor prognosis of cancer patients with high serum 90K levels.

KITENIN-targeting microRNA-124 suppresses colorectal cancer cell motility and tumorigenesis.

MicroRNAs are increasingly implicated in the modulation of the progression of various cancers. We previously observed that KAI1 C-terminal interacting tetraspanin (KITENIN) is highly expressed in sporadic human colorectal cancer (CRC) tissues and hence the functional KITENIN complex acts to promote progression of CRC. However, it remains unknown that microRNAs target KITENIN and whether KITENIN-targeting microRNAs modulate CRC cell motility and colorectal tumorigenesis. Here, through bioinformatic analyses and functional studies, we showed that miR-124, miR-27a, and miR-30b negatively regulate KITENIN expression and suppress the migration and invasion of several CRC cell lines via modulation of KITENIN expression. Through in vitro and in vivo induction of mature microRNAs using a tetracycline-inducible system, miR-124 was found to effectively inhibit the invasion of CT-26 colon adenocarcinoma cells and tumor growth in a syngeneic mouse xenograft model. Constitutive overexpression of precursor miR-124 in CT-26 cells suppressed in vivo tumorigenicity and resulted in decreased expression of KITENIN as well as that of MYH9 and SOX9, which are targets of miR-124. Thus, our findings identify that KITENIN-targeting miR-124, miR-27a, and miR-30b function as endogenous inhibitors of CRC cell motility and demonstrate that miR-124 among KITENIN-targeting microRNAs plays a suppressor role in colorectal tumorigenesis.

PSME4 Degrades Acetylated YAP1 in the Nucleus of Mesenchymal Stem Cells.

Intensive research has focused on minimizing the infarct area and stimulating endogenous regeneration after myocardial infarction. Our group previously elucidated that apicidin, a histone deacetylase (HDAC) inhibitor, robustly accelerates the cardiac commitment of naïve mesenchymal stem cells (MSCs) through acute loss of YAP1. Here, we propose the novel regulation of YAP1 in MSCs. We found that acute loss of YAP1 after apicidin treatment resulted in the mixed effects of transcriptional arrest and proteasomal degradation. Subcellular fractionation revealed that YAP1 was primarily localized in the cytoplasm. YAP1 was acutely relocalized into the nucleus and underwent proteasomal degradation. Interestingly, phosphor-S127 YAP1 was shuttled into the nucleus, suggesting that a mechanism other than phosphorylation governed the subcellular localization of YAP1. Apicidin successfully induced acetylation and subsequent dissociation of YAP1 from 14-3-3, an essential molecule for cytoplasmic restriction. HDAC6 regulated both acetylation and subcellular localization of YAP1. An acetylation-dead mutant of YAP1 retarded nuclear redistribution upon apicidin treatment. We failed to acquire convincing evidence for polyubiquitination-dependent degradation of YAP1, suggesting that a polyubiquitination-independent regulator determined YAP1 fate. Nuclear PSME4, a subunit of the 26 S proteasome, recognized and degraded acetyl YAP1 in the nucleus. MSCs from PSME4-null mice were injected into infarcted heart, and aberrant sudden death was observed. Injection of immortalized human MSCs after knocking down PSME4 failed to improve either cardiac function or the fibrotic scar area. Our data suggest that acetylation-dependent proteasome subunit PSME4 clears acetyl-YAP1 in response to apicidin treatment in the nucleus of MSCs.

Overexpression of Heat Shock Protein 70 Improves Cardiac Remodeling and Survival in Protein Phosphatase 2A-Expressing Transgenic Mice with Chronic Heart Failure.

Heat shock protein (HSP) 70 is a molecular chaperone that regulates protein structure in response to thermal stress. In addition, HSP70 is involved in post-translational modification and is related to the severity of some diseases. Here, we tested the functional relevance of long-lasting HSP70 expression in a model of nonischemic heart failure using protein phosphatase 2 catalytic subunit A (PP2CA)-expressing transgenic mice. These transgenic mice, with cardiac-specific overexpression of PP2CA, abruptly died after 12 weeks of postnatal life. Serial echocardiograms to assess cardiac function revealed that the ejection fraction (EF) was gradually decreased in transgenic PP2CA (TgPP2CA) mice. In addition, PP2CA expression exacerbated systolic dysfunction and LV dilatation, with free wall thinning, which are indicators of fatal dilated cardiomyopathy. Interestingly, simultaneous expression of HSP70 in double transgenic mice (dTg) significantly improved the dilated cardiomyopathy phenotype of TgPP2CA mice. We observed better survival, preserved EF, reduced chamber enlargement, and suppression of free wall thinning. In the proposed molecular mechanism, HSP70 preferentially regulates the phosphorylation of AKT. Phosphorylation of AKT was significantly reduced in TgPP2CA mice but was not significantly lower in dTg mice. Signal crosstalk between AKT and its substrates, in association with HSP70, might be a useful intervention for patients with nonischemic heart failure to suppress cardiac remodeling and improve survival.

Serum Ferritin as a Diagnostic Biomarker for Kawasaki Disease.

Diagnosis of Kawasaki disease (KD) is occasionally delayed because it is solely based on clinical symptoms. Previous studies have attempted to identify diagnostic biomarkers for KD. Recently, patients with KD were reported to have elevated serum ferritin levels. We investigated the usefulness of the serum ferritin level as a diagnostic biomarker for distinguishing KD from other acute febrile illnesses. Blood samples were obtained from pediatric patients with KD (N=77) and those with other acute febrile illnesses (N=32) between December 2007 and June 2011 for measuring various laboratory parameters, including serum ferritin levels. In patients with KD, laboratory tests were performed at diagnosis and repeated at 2, 14, and 56 days after intravenous immunoglobulin treatment. At the time of diagnosis, serum ferritin levels in patients with KD (188.8 µg/L) were significantly higher than those in patients with other acute febrile illnesses (106.8 µg/L, P=0.003). The serum ferritin cut-off value of 120.8 µg/L effectively distinguished patients with KD from those with other acute febrile illnesses, with a sensitivity and specificity of 74.5% and 83.3%, respectively. Serum ferritin may be a useful biomarker to distinguish KD from other acute febrile illnesses.

Chimeric Antigen Receptor T Cell Therapy: A Novel Modality for Immune Modulation.

Cancer remains a leading cause of death, despite multimodal treatment approaches. Even in patients with a healthy immune response, cancer cells can escape the immune system during tumorigenesis. Cancer cells incapacitate the normal cell-mediated immune system by expressing immune modulation ligands such as programmed death (PD) ligand 1, the B7 molecule, or secreting activators of immune modulators. Chimeric antigen receptor (CAR) T cells were originally designed to target cancer cells. Engineered approaches allow CAR T cells, which possess a simplified yet specific receptor, to be easily activated in limited situations. CAR T cell treatment is a derivative of the antigen-antibody reaction and can be applied to various diseases. In this review, the current successes of CAR T cells in cancer treatment and the therapeutic potential of CAR T cells are discussed.

Heart failure with preserved ejection fraction: present status and future directions.

The clinical importance of heart failure with preserved ejection fraction (HFpEF) has recently become apparent. HFpEF refers to heart failure (HF) symptoms with normal or near-normal cardiac function on echocardiography. Common clinical features of HFpEF include diastolic dysfunction, reduced compliance, and ventricular hypokinesia. HFpEF differs from the better-known HF with reduced ejection fraction (HFrEF). Despite having a "preserved ejection fraction," patients with HFpEF have symptoms such as shortness of breath, excessive tiredness, and limited exercise capability. Furthermore, the mortality rate and cumulative survival rate are as severe in HFpEF as they are in HFrEF. While beta-blockers and renin-angiotensin-aldosterone system modulators can improve the survival rate in HFrEF, no known therapeutic agents show similar effectiveness in HFpEF. Researchers have examined molecular events in the development of HFpEF using small and middle-sized animal models. This review discusses HFpEF with regard to etiology and clinical features and introduces the use of mouse and other animal models of human HFpEF.

Author Correction: PP2A negatively regulates the hypertrophic response by dephosphorylating HDAC2 S394 in the heart.

After the publication of this article, the authors noticed an error in one of the grant numbers (2015R1A2A1A05001708) in the Acknowledgements section.

Inhibition of heat shock protein 70 blocks the development of cardiac hypertrophy by modulating the phosphorylation of histone deacetylase 2.

AIMS: Previously, we reported that phosphorylation of histone deacetylase 2 (HDAC2) and the resulting activation causes cardiac hypertrophy. Through further study of the specific binding partners of phosphorylated HDAC2 and their mechanism of regulation, we can better understand how cardiac hypertrophy develops. Thus, in the present study, we aimed to elucidate the function of one such binding partner, heat shock protein 70 (HSP70). METHODS AND RESULTS: Primary cultures of rat neonatal ventricular cardiomyocytes and H9c2 cardiomyoblasts were used for in vitro cellular experiments. HSP70 knockout (KO) mice and transgenic (Tg) mice that overexpress HSP70 in the heart were used for in vivo analysis. Peptide-precipitation and immunoprecipitation assay revealed that HSP70 preferentially binds to phosphorylated HDAC2 S394. Forced expression of HSP70 increased phosphorylation of HDAC2 S394 and its activation, but not that of S422/424, whereas knocking down of HSP70 reduced it. However, HSP70 failed to phosphorylate HDAC2 in the cell-free condition. Phosphorylation of HDAC2 S394 by casein kinase 2α1 enhanced the binding of HSP70 to HDAC2, whereas dephosphorylation induced by the catalytic subunit of protein phosphatase 2A (PP2CA) had the opposite effect. HSP70 prevented HDAC2 dephosphorylation by reducing the binding of HDAC2 to PP2CA. HSP70 KO mouse hearts failed to phosphorylate S394 HDAC2 in response to isoproterenol infusion, whereas Tg overexpression of HSP70 increased the phosphorylation and activation of HDAC2. 2-Phenylethynesulfonamide (PES), an HSP70 inhibitor, attenuated cardiac hypertrophy induced either by phenylephrine in neonatal ventricular cardiomyocytes or by aortic banding in mice. PES reduced HDAC2 S394 phosphorylation and its activation by interfering with the binding of HSP70 to HDAC2. CONCLUSION: These results demonstrate that HSP70 specifically binds to S394-phosphorylated HDAC2 and maintains its phosphorylation status, which results in HDAC2 activation and the development of cardiac hypertrophy. Inhibition of HSP70 has possible application as a therapeutic.

Serial evaluation of myocardial function using the myocardial performance index in Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is known as systemic vasculitis, and more than half of the patients with KD have myocarditis, which can induce ventricular dysfunction. In this study, we evaluate left ventricular (LV) dysfunction in patients with KD based on the myocardial performance index (MPI) using pulse Doppler (PD) and tissue Doppler imaging (TDI), from the acute to convalescent phases. METHODS: We retrospectively studied 89 children diagnosed with KD from January 2010 to August 2012. We assessed the presence of coronary artery lesions (CALs) and the LV ejection fraction, PD-MPI, and TDI-MPI at diagnosis, and 2, 14, and 56 days after intravenous immunoglobulin (IVIG) treatment. We enrolled 70 healthy children as a control group. RESULTS: The ejection fraction in patients with KD at diagnosis (67.3 ± 0.9%) was lower than that in the control group (69.8 ± 0.8%, P = 0.035), and the LV TDI-MPIs for patients with KD at diagnosis (0.49 ± 0.01) and 2 days after IVIG treatment (0.48 ± 0.01) were higher than those in the control group (0.45 ± 0.01, P = 0.002, P = 0.033, respectively). No significant differences were found in the LV dysfunction between the patients with complete and incomplete KD. Septal TDI-MPIs in patients with KD with CAL at diagnosis (0.52 ± 0.02) were higher than those in patients with KD without CAL (0.47 ± 0.01, P = 0.019). CONCLUSIONS: Transient LV dysfunction occurred in patients with complete and incomplete KD in the acute stage. In patients with KD with CAL at diagnosis, the LV dysfunction was more prominent. The PD-MPI and TDI-MPI are useful parameters for assessing LV function in patients with KD.

PP2A negatively regulates the hypertrophic response by dephosphorylating HDAC2 S394 in the heart.

Cardiac hypertrophy occurs in response to increased hemodynamic demand and can progress to heart failure. Identifying the key regulators of this process is clinically important. Though it is thought that the phosphorylation of histone deacetylase (HDAC) 2 plays a crucial role in the development of pathological cardiac hypertrophy, the detailed mechanism by which this occurs remains unclear. Here, we performed immunoprecipitation and peptide pull-down assays to characterize the functional complex of HDAC2. Protein phosphatase (PP) 2 A was confirmed as a binding partner of HDAC2. PPP2CA, the catalytic subunit of PP2A, bound to HDAC2 and prevented its phosphorylation. Transient overexpression of PPP2CA specifically regulated both the phosphorylation of HDAC2 S394 and hypertrophy-associated HDAC2 activation. HDAC2 S394 phosphorylation was increased in a dose-dependent manner by PP2A inhibitors. Hypertrophic stresses, such as phenylephrine in vitro or pressure overload in vivo, caused PPP2CA to dissociate from HDAC2. Forced expression of PPP2CA negatively regulated the hypertrophic response, but PP2A inhibitors provoked hypertrophy. Adenoviral delivery of a phosphomimic HDAC2 mutant, adenovirus HDAC2 S394E, successfully blocked the anti-hypertrophic effect of adenovirus-PPP2CA, implicating HDAC2 S394 phosphorylation as a critical event for the anti-hypertrophic response. PPP2CA transgenic mice were protected against isoproterenol-induced cardiac hypertrophy and subsequent cardiac fibrosis, whereas simultaneous expression of HDAC2 S394E in the heart did induce hypertrophy. Taken together, our results suggest that PP2A is a critical regulator of HDAC2 activity and pathological cardiac hypertrophy and is a promising target for future therapeutic interventions.

Usefulness of Age-Stratified N-Terminal Prohormone of Brain Natriuretic Peptide for Diagnosing Kawasaki Disease.

N-terminal prohormone of brain natriuretic peptide (NT-proBNP) was recently reported as a biomarker for diagnosing Kawasaki disease (KD). The basal NT-proBNP level, however, gradually decreases with age. We investigated the usefulness of an age-stratified cutoff value of NT-proBNP for diagnosing KD. All the patients enrolled in this study visited Chonnam National University Hospital between December 2007 and March 2016. The KD groups consisted of 214 patients with complete KD and 129 patients with incomplete KD. The control group included 62 children with simple febrile illness but without heart disease. Laboratory data including NT-proBNP level were evaluated. Each group was divided into subgroups according to patient age (<6 months, 6-12 months, 12-24 months, and >24 months), and different cutoff values of NT-proBNP were calculated. The cutoff values of NT-proBNP used to diagnose total KD and incomplete KD were 762 and 762 pg/mL (<6 months), 310 and 310 pg/mL (6-12 months), 326 and 326 pg/mL (12-24 months), and 208 and 137 pg/mL (>24 months), respectively. In conclusion, age-stratified NT-proBNP is a useful biomarker for the differential diagnosis of KD in patients with a simple febrile illness.

HDAC and HDAC Inhibitor: From Cancer to Cardiovascular Diseases.

Histone deacetylases (HDACs) are epigenetic regulators that regulate the histone tail, chromatin conformation, protein-DNA interaction, and even transcription. HDACs are also post-transcriptional modifiers that regulate the protein acetylation implicated in several pathophysiologic states. HDAC inhibitors have been highlighted as a novel category of anti-cancer drugs. To date, four HDAC inhibitors, Vorinostat, Romidepsin, Panobinostat, and Belinostat, have been approved by the United States Food and Drug Administration. Principally, these HDAC inhibitors are used for hematologic cancers in clinic with less severe side effects. Clinical trials are continuously expanding to address other types of cancer and also nonmalignant diseases. HDAC inhibition also results in beneficial outcomes in various types of neurodegenerative diseases, inflammation disorders, and cardiovascular diseases. In this review, we will briefly discuss 1) the roles of HDACs in the acquisition of a cancer's phenotype and the general outcome of the HDAC inhibitors in cancer, 2) the functional relevance of HDACs in cardiovascular diseases and the possible therapeutic implications of HDAC inhibitors in cardiovascular disease.

90K Glycoprotein Promotes Degradation of Mutant ß-Catenin Lacking the ISGylation or Phosphorylation Sites in the N-terminus.

ß-Catenin is a major transducer of the Wnt signaling pathway, which is aberrantly expressed in colorectal and other cancers. Previously, we showed that ß-catenin is downregulated by the 90K glycoprotein via ISGylation-dependent degradation. However, the further mechanisms of ß-catenin degradation by 90K-mediated ISGylation pathway were not investigated. This study aimed to identify the ß-catenin domain responsible for the action of 90K and to compare the mechanism of 90K on ß-catenin degradation with phosphorylation-dependent ubiquitinational degradation of ß-catenin. The deletion mutants of ß-catenin lacking N- or C-terminal domain or mutating the N-terminal lysine or nonlysine residue were employed to delineate the characteristics of ß-catenin degradation by 90K-mediated ISGylation pathway. 90K induced Herc5 and ISG15 expression and reduced ß-catenin levels in HeLa and CSC221 cells. The N-terminus of ß-catenin is required for 90K-induced ß-catenin degradation, but the N-terminus of ß-catenin is not essential for interaction with Herc5. However, substituting lysine residues in the N-terminus of ß-catenin with arginine or deleting serine or threonine residue containing domains from the N-terminus does not affect 90K-induced ß-catenin degradation, indicating that the N-terminal 86 amino acids of ß-catenin are crucial for 90K-mediated ISGylation/degradation of ß-catenin in which the responsible lysine or nonlysine residues were not identified. Our present results highlight the action of 90K on promoting degradation of mutant ß-catenin lacking the phosphorylation sites in the N-terminus. It provides further insights into the discrete pathway downregulating the stabilized ß-catenin via acquiring mutations at the serine/threonine residues in the N-terminus.