Evolutionarily conserved sequence motif analysis guides development of chemically defined hydrogels for therapeutic vascularization.

Biologically active ligands (e.g., RGDS from fibronectin) play critical roles in the development of chemically defined biomaterials. However, recent decades have shown only limited progress in discovering novel extracellular matrix-protein-derived ligands for translational applications. Through motif analysis of evolutionarily conserved RGD-containing regions in laminin (LM) and peptide-functionalized hydrogel microarray screening, we identified a peptide (a1) that showed superior supports for endothelial cell (EC) functions. Mechanistic studies attributed the results to the capacity of a1 engaging both LM- and Fn-binding integrins. RNA sequencing of ECs in a1-functionalized hydrogels showed ~60% similarities with Matrigel in "vasculature development" gene ontology terms. Vasculogenesis assays revealed the capacity of a1-formulated hydrogels to improve EC network formation. Injectable alginates functionalized with a1 and MMPQK (a vascular endothelial growth factor-mimetic peptide with a matrix metalloproteinase-degradable linker) increased blood perfusion and functional recovery over decellularized extracellular matrix and (RGDS + MMPQK)-functionalized hydrogels in an ischemic hindlimb model, illustrating the power of this approach.

HDAC1 localizes to the mitochondria of cardiac myocytes and contributes to early cardiac reperfusion injury.

RATIONALE: Recent evidence indicates that histone deacetylase enzymes (HDACs) contribute to ischemia reperfusion (I/R) injury, and pan-HDAC inhibitors have been shown to be cardioprotective when administered either before an ischemic insult or during reperfusion. We have shown previously that selective inhibition of class I HDACs provides superior cardioprotection when compared to pan-HDAC inhibition in a pretreatment model, but selective class I HDAC inhibition has not been tested during reperfusion, and specific targets of class I HDACs in I/R injury have not been identified. OBJECTIVE: We hypothesized that selective inhibition of class I HDACs with the drug MS-275 (entinostat) during reperfusion would improve recovery from I/R injury in the first hour of reperfusion. METHODS AND RESULTS: Hearts from male Sprague-Dawley rats were subjected to ex vivo I/R injury±MS-275 class I HDAC inhibition during reperfusion alone. MS-275 significantly attenuated I/R injury, as indicated by improved LV function and tissue viability at the end of reperfusion. Unexpectedly, we observed that HDAC1 is present in the mitochondria of cardiac myocytes, but not fibroblasts or endothelial cells. We then designed mitochondria-restricted and mitochondria-excluded HDAC inhibitors, and tested both in our ex vivo I/R model. The selective inhibition of mitochondrial HDAC1 attenuated I/R injury to the same extent as MS-275, whereas the mitochondrial-excluded inhibitor did not. Further assays demonstrated that these effects are attributable to a decrease in SDHA activity and subsequent metabolic ROS production in reperfusion. CONCLUSIONS: We demonstrate for the first time that HDAC1 is present within the mitochondria of cardiac myocytes, and mitochondrial HDAC1 contributes significantly to I/R injury within the first hour of reperfusion.

HDACs Regulate miR-133a Expression in Pressure Overload-Induced Cardiac Fibrosis.

BACKGROUND: MicroRNAs (miRNAs) and histone deacetylases (HDACs) serve a significant role in the pathogenesis of a variety of cardiovascular diseases. The transcriptional regulation of miRNAs is poorly understood in cardiac hypertrophy. We investigated whether the expression of miR-133a is epigenetically regulated by class I and IIb HDACs during hypertrophic remodeling. METHODS AND RESULTS: Transverse aortic constriction (TAC) was performed in CD1 mice to induce pressure overload hypertrophy. Mice were treated with class I and IIb HDAC inhibitor (HDACi) via drinking water for 2 and 4 weeks post TAC. miRNA expression was determined by real-time polymerase chain reaction. Echocardiography was performed at baseline and post TAC end points for structural and functional assessment. Chromatin immunoprecipitation was used to identify HDACs and transcription factors associated with miR-133a promoter. miR-133a expression was downregulated by 0.7- and 0.5-fold at 2 and 4 weeks post TAC, respectively, when compared with vehicle control (P<0.05). HDAC inhibition prevented this significant decrease 2 weeks post TAC and maintained miR-133a expression near vehicle control levels, which coincided with (1) a decrease in connective tissue growth factor expression, (2) a reduction in cardiac fibrosis and left atrium diameter (marker of end-diastolic pressure), suggesting an improvement in diastolic function. Chromatin immunoprecipitation analysis revealed that HDAC1 and HDAC2 are present on the miR-133a enhancer regions. CONCLUSIONS: The results reveal that HDACs play a role in the regulation of pressure overload-induced miR-133a downregulation. This work is the first to provide insight into an epigenetic-miRNA regulatory pathway in pressure overload-induced cardiac fibrosis.

Inhibition of class I histone deacetylase activity represses matrix metalloproteinase-2 and -9 expression and preserves LV function postmyocardial infarction.

Left ventricular (LV) remodeling, after myocardial infarction (MI), can result in LV dilation and LV pump dysfunction. Post-MI induction of matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, have been implicated as causing deleterious effects on LV and extracellular matrix remodeling in the MI region and within the initially unaffected remote zone. Histone deacetylases (HDACs) are a class of enzymes that affect the transcriptional regulation of genes during pathological conditions. We assessed the efficacy of both class I/IIb- and class I-selective HDAC inhibitors on MMP-2 and MMP-9 abundance and determined if treatment resulted in the attenuation of adverse LV and extracellular matrix remodeling and improved LV pump function post-MI. MI was surgically induced in MMP-9 promoter reporter mice and randomized for treatment with a class I/IIb HDAC inhibitor for 7 days post-MI. After MI, LV dilation, LV pump dysfunction, and activation of the MMP-9 gene promoter were significantly attenuated in mice treated with either the class I/IIb HDAC inhibitor tichostatin A or suberanilohydroxamic acid (voronistat) compared with MI-only mice. Immunohistological staining and zymographic levels of MMP-2 and MMP-9 were reduced with either tichostatin A or suberanilohydroxamic acid treatment. Class I HDAC activity was dramatically increased post-MI. Treatment with the selective class I HDAC inhibitor PD-106 reduced post-MI levels of both MMP-2 and MMP-9 and attenuated LV dilation and LV pump dysfunction post-MI, similar to class I/IIb HDAC inhibition. Taken together, these unique findings demonstrate that selective inhibition of class I HDACs may provide a novel therapeutic means to attenuate adverse LV remodeling post-MI.

Potent activity against K562 cells by polyamide-seco-CBI conjugates targeting histone H4 genes.

We designed and synthesized conjugates between pyrrole-imidazole polyamides and seco-CBI that alkylate within the coding regions of the histone H4 genes. DNA alkylating activity on the histone H4 fragment and cellular effects against K562 chronic myelogenous leukemia cells were investigated. One of the conjugates, 5-CBI, showed strong DNA alkylation activity and good sequence specificity on a histone H4 gene fragment. K562 cells treated with 5-CBI down-regulated the histone H4 gene and induced apoptosis efficiently. Global gene expression data revealed that a number of histone H4 genes were down-regulated by 5-CBI treatment. These results suggest that sequence-specific DNA alkylating agents may have the potential of targeting specific genes for cancer chemotherapy.

Maintenance treatment of bipolar disorder: Applying research to clinical practice.

The authors review available controlled trials of bipolar maintenance treatment and discuss the strengths and weaknesses of various study designs. Bipolar maintenance trials are organized according to the features of their designs, such as use of responder-enriched samples; inclusion following an index manic versus an index depressive episode; outcome defined as relapse into mania, depression, or either; and use of survival analysis. Pivotal studies of lithium, divalproex, lamotrigine, olanzapine, aripiprazole, and other medications are reviewed. The directional efficacy of the different medications as maintenance treatment is discussed, with treatments differentiated in terms of whether they primarily prolong time to mania or to depression or have bidirectional effects. Also discussed are findings concerning the continuation of acute treatments, including antidepressants, into the maintenance phase; dosage adjustments for maintenance treatment; the rationale for combination treatments; and implications of comorbid substance abuse and strategies for its management. Directions for future research are suggested.

Randomized, placebo-controlled trial of olanzapine as maintenance therapy in patients with bipolar I disorder responding to acute treatment with olanzapine.

OBJECTIVE: In a placebo-controlled, double-blind study, the authors investigated the efficacy and safety of olanzapine as monotherapy in relapse prevention in bipolar I disorder. METHOD: Patients achieving symptomatic remission from a manic or mixed episode of bipolar I disorder (Young Mania Rating Scale [YMRS] total score < or =12 and 21-item Hamilton Depression Rating Scale [HAM-D] score or =15, HAM-D score > or =15, or hospitalization). RESULTS: Time to symptomatic relapse into any mood episode was significantly longer among patients receiving olanzapine (a median of 174 days, compared with a median of 22 days in patients receiving placebo). Times to symptomatic relapse into manic, depressive, and mixed episodes were all significantly longer among patients receiving olanzapine than among patients receiving placebo. The relapse rate was significantly lower in the olanzapine group (46.7%) than in the placebo group (80.1%). During olanzapine treatment, the most common emergent event was weight gain; during the open-label phase, patients who received olanzapine gained a mean of 3.1 kg (SD=3.4). In double-blind treatment, placebo patients lost a mean of 2.0 kg (SD=4.4) and patients who continued to take olanzapine gained an additional 1.0 kg (SD=5.2). CONCLUSIONS: Compared to placebo, olanzapine delays relapse into subsequent mood episodes in bipolar I disorder patients who responded to open-label acute treatment with olanzapine for a manic or mixed episode.

Cocaine craving and attentional bias in cocaine-dependent schizophrenic patients.

Cocaine craving has been implicated as a major factor underlying addiction and drug relapse. From a cognitive viewpoint, craving may reflect, in part, attentional processing biased in favor of drug-related cues and stimuli. Schizophrenic individuals (SZ), however, abuse cocaine in high numbers but typically manifest baseline cognitive deficits that impair their ability to selectively allocate their attentional resources. In this study, we examined the relationship between attentional bias and craving in patients with cocaine dependence (COC; n=20), schizophrenic patients comorbid for cocaine dependence (COC+SZ; n=23), as well as two other comparison groups using a modified version of the Stroop test to include cocaine-relevant words. Results revealed that only the COC patients demonstrated Stroop interference on the cocaine-related words. Moreover, COC patients' attentional processing biases were significantly associated with their cocaine craving severity ratings. COC+SZ patients, in contrast, did not demonstrate Stroop interference and manifested significantly fewer craving symptoms than their COC counterparts. These results suggest that COC+SZ patients' inability to selectively encode their drug-use experience may limit and shape their subjective experience of craving cocaine and motivation for cocaine use.

Acute treatment of psychotic agitation: a randomized comparison of oral treatment with risperidone and lorazepam versus intramuscular treatment with haloperidol and lorazepam.

BACKGROUND: Standard treatment for acute psychotic agitation often involves intramuscular administration of the benzodiazepine lorazepam and the antipsychotic haloperidol. This study compared the efficacy and safety of oral treatment with the atypical antipsychotic risperidone plus lorazepam with those of standard intramuscular treatment. We hypothesized that the efficacy and speed of action of both treatments would be similar. METHOD: In a prospective, parallel-group, randomized, rater-blinded noninferiority study conducted at 24 sites in the United States, 162 patients exhibiting agitation associated with active psychosis were randomly assigned to receive either oral treatment with 2 mg of risperidone plus 2 mg of lorazepam (N = 83) or intramuscular treatment with 5 mg of haloperidol plus 2 mg of lorazepam (N = 79). The change scores on a 5-item acute-agitation cluster from the Positive and Negative Syndrome Scale (hallucinatory behavior, excitement, hostility, uncooperativeness, and poor impulse control) were the main outcome measure. The study was conducted from January 8 to August 8, 2001. RESULTS: Mean acute-agitation cluster scores were similar in the 2 groups at baseline. Mean score improvements at 30, 60, and 120 minutes after dosing were significant at each timepoint in both groups (p <.0001) and were similar in both groups (p >.05). Both treatments were well tolerated. CONCLUSION: A single oral dose of risperidone plus lorazepam was as effective as parenterally administered haloperidol plus lorazepam for the rapid control of agitation and psychosis. These findings suggest that this oral regimen is an acceptable alternative to the current intramuscular treatment for acute psychotic agitation.

The InterSePT scale for suicidal thinking reliability and validity.

BACKGROUND: The InterSePT Scale for Suicidal Thinking (ISST) is a 12-item instrument for the assessment of current suicidal ideation in patients with schizophrenia and schizoaffective disorders. We report the psychometric characteristics of this new scale based on two studies. METHOD: In Study 1, 22 inpatients with schizophrenia and schizoaffective disorders, who had recently attempted suicide or engaged in suicidal ideation, were rated by three trained independent raters to examine interrater reliability. In Study 2, a total of 980 patients with schizophrenia or schizoaffective disorder with a history of suicidal ideation in the past 36 months were enrolled in a 2-year industry-sponsored suicide prevention study. At baseline, these patients were administered the ISST and the Clinical Global Impression Scale for Severity of Suicidality (CGI-SS) by the Principal Investigator (PI) and by a blinded rater (BR), who also administered the Positive and Negative Symptom Scale (PANSS), the Calgary Depression Scale (CDS), and the Scale of Functioning (SOF). Indices of internal reliability, construct and discriminant validity were examined. RESULTS: The intraclass correlation coefficient (ICC) for the total ISST score for the 22 subjects in Study 1 was 0.90 and mean weighted item kappa coefficients ranged from 0.66 to 0.92. In Study 2, internal reliability (Cronbach alpha) was high, ranging from 0.86 to 0.89 for the individual items, and the overall Cronbach alpha coefficient for all items was 0.88. The ISST (PI) total score was highly correlated with the CGI-SS by the blind rater (r = 0.61, p < 0.0001). ISST total scores significantly differentiated the different levels of CGI-SS (F = 519.2; p < 0.0001). Results of construct and discriminant validity analyses are also presented. CONCLUSION: The ISST is a reliable and valid instrument for the assessment of current suicidal thinking in patients with schizophrenia and schizoaffective disorder by both clinicians and researchers.

Maintenance efficacy of divalproex in the prevention of bipolar depression.

Breakthrough depression is a common problem in the treatment of bipolar disorder. Only one, recently published, double-blind, placebo-controlled trial has examined the efficacy of divalproex in the prevention of depressive episodes in bipolar patients. This report describes, in further detail, the findings from that trial of the effect of divalproex on multiple dimensions of depressive morbidity in bipolar disorder. A randomized, double-blind, parallel-group, multicenter study was conducted over a 52-week maintenance period. Bipolar I patients, who may have been treated with open-label lithium or divalproex and who met recovery criteria within 3 months of onset of an index manic episode, were randomized to maintenance treatment with divalproex, lithium, or placebo in a 2 : 1 : 1 ratio. Adjunctive paroxetine or sertraline for breakthrough depression was allowed in maintenance phase. Outcome measures were the rate of early discontinuation for depression, time to depressive relapse, proportion of patients with depressive relapse, mean change in Depressive Syndrome Scale score, proportion of patients receiving antidepressants, and time in the study. Among patients taking an antidepressant, a higher percentage of patients on placebo than divalproex discontinued early for depression. Patients who were previously hospitalized for affective episodes or took divalproex in the open period relapsed later on divalproex than on lithium during the maintenance period. Divalproex-treated patients had less worsening of depressive symptoms than lithium-treated patients during maintenance. Indices of severity of prestudy illness course predicted worse outcome in all treatment groups. Divalproex improved several dimensions of depressive morbidity and reduced the probability of depressive relapse in bipolar disorder, particularly in patients who had responded to divalproex when manic, and among patients with a more severe course of illness.