Elucidating the importance and regulation of key enhancers for human MEIS1 expression.

Myeloid ecotropic virus insertion site 1 (MEIS1) is essential for normal hematopoiesis and is a critical factor in the pathogenesis of a large subset of acute myeloid leukemia (AML). Despite the clinical relevance of MEIS1, its regulation is largely unknown. To understand the transcriptional regulatory mechanisms contributing to human MEIS1 expression, we created a knock-in green florescent protein (GFP) reporter system at the endogenous MEIS1 locus in a human AML cell line. Using this model, we have delineated and dissected a critical enhancer region of the MEIS1 locus for transcription factor (TF) binding through in silico prediction in combination with oligo pull-down, mass-spectrometry and knockout analysis leading to the identification of FLI1, an E-twenty-six (ETS) transcription factor, as an important regulator of MEIS1 transcription. We further show direct binding of FLI1 to the MEIS1 locus in human AML cell lines as well as enrichment of histone acetylation in MEIS1-high healthy and leukemic cells. We also observe a positive correlation between high FLI1 transcript levels and worse overall survival in AML patients. Our study expands the role of ETS factors in AML and our model constitutes a feasible tool for a more detailed understanding of transcriptional regulatory elements and their interactome.

A New CYP2E1 Inhibitor, 12-Imidazolyl-1-dodecanol, Represents a Potential Treatment for Hepatocellular Carcinoma.

Cytochrome P450 2E1 (CYP2E1) is a key target protein in the development of alcoholic and nonalcoholic fatty liver disease (FLD). The pathophysiological correlate is the massive production of reactive oxygen species. The role of CYP2E1 in the development of hepatocellular carcinoma (HCC), the final complication of FLD, remains controversial. Specifically, CYP2E1 has not yet been defined as a molecular target for HCC therapy. In addition, a CYP2E1-specific drug has not been developed. We have already shown that our newly developed CYP2E1 inhibitor 12-imidazolyl-1-dodecanol (I-ol) was therapeutically effective against alcoholic and nonalcoholic steatohepatitis. In this study, we investigated the effect of I-ol on HCC tumorigenesis and whether I-ol could serve as a possible treatment option for terminal-stage FLD. I-ol exerted a very highly significant antitumour effect against hepatocellular HepG2 cells. Cell viability was reduced in a dose-dependent manner, with only the highest doses causing a cytotoxic effect associated with caspase 3/7 activation. Comparable results were obtained for the model colorectal adenocarcinoma cell line, DLD-1, whose tumorigenesis is also associated with CYP2E1. Transcriptome analyses showed a clear effect of I-ol on apoptosis and cell-cycle regulation, with the increased expression of p27Kip1 being particularly noticeable. These observations were confirmed at the protein level for HepG2 and DLD-1 cells grafted on a chorioallantoic membrane. Cell-cycle analysis showed a complete loss of proliferating cells with a simultaneous increase in S-phase arrest beginning at a threshold dose of 30 µM. I-ol also reduced xenograft tumour growth in nude mice. This antitumour effect was not associated with tumour cachexia. I-ol was not toxic to healthy tissues or organs. This study demonstrates for the first time the therapeutic effect of the specific CYP2E1 inhibitor I-ol on the tumorigenesis of HCC. Our findings imply that I-ol can potentially be applied therapeutically on patients at the final stage of FLD.

Drug targeting CYP2E1 for the treatment of early-stage alcoholic steatohepatitis.

BACKGROUND AND AIMS: Alcoholic steatohepatitis (ASH)-the inflammation of fatty liver-is caused by chronic alcohol consumption and represents one of the leading chronic liver diseases in Western Countries. ASH can lead to organ dysfunction or progress to hepatocellular carcinoma (HCC). Long-term alcohol abstinence reduces this probability and is the prerequisite for liver transplantation-the only effective therapy option at present. Elevated enzymatic activity of cytochrome P450 2E1 (CYP2E1) is known to be critically responsible for the development of ASH due to excessively high levels of reactive oxygen species (ROS) during metabolization of ethanol. Up to now, no rational drug discovery process was successfully initiated to target CYP2E1 for the treatment of ASH. METHODS: In this study, we applied a rational drug design concept to develop drug candidates (NCE) including preclinical studies. RESULTS: A new class of drug candidates was generated successfully. Two of the most promising small compounds named 12-Imidazolyl-1-dodecanol (abbr.: I-ol) and 1-Imidazolyldodecane (abbr.: I-an) were selected at the end of this process of drug discovery and developability. These new ω-imidazolyl-alkyl derivatives act as strong chimeric CYP2E1 inhibitors at a nanomolar range. They restore redox balance, reduce inflammation process as well as the fat content in the liver and rescue the physiological liver architecture of rats consuming continuously a high amount of alcohol. CONCLUSIONS: Due to its oral application and therapeutic superiority over an off-label use of the hepatoprotector ursodeoxycholic acid (UDCA), this new class of inhibitors marks the first rational, pharmaceutical concept in long-term treatment of ASH.

MicroRNA-708 is a novel regulator of the Hoxa9 program in myeloid cells.

MicroRNAs (miRNAs) are commonly deregulated in acute myeloid leukemia (AML), affecting critical genes not only through direct targeting, but also through modulation of downstream effectors. Homeobox (Hox) genes balance self-renewal, proliferation, cell death, and differentiation in many tissues and aberrant Hox gene expression can create a predisposition to leukemogenesis in hematopoietic cells. However, possible linkages between the regulatory pathways of Hox genes and miRNAs are not yet fully resolved. We identified miR-708 to be upregulated in Hoxa9/Meis1 AML inducing cell lines as well as in AML patients. We further showed Meis1 directly targeting miR-708 and modulating its expression through epigenetic transcriptional regulation. CRISPR/Cas9 mediated knockout of miR-708 in Hoxa9/Meis1 cells delayed disease onset in vivo, demonstrating for the first time a pro-leukemic contribution of miR-708 in this context. Overexpression of miR-708 however strongly impeded Hoxa9 mediated transformation and homing capacity in vivo through modulation of adhesion factors and induction of myeloid differentiation. Taken together, we reveal miR-708, a putative tumor suppressor miRNA and direct target of Meis1, as a potent antagonist of the Hoxa9 phenotype but an effector of transformation in Hoxa9/Meis1. This unexpected finding highlights the yet unexplored role of miRNAs as indirect regulators of the Hox program during normal and aberrant hematopoiesis.

Micro-ribonucleic acid-155 is a direct target of Meis1, but not a driver in acute myeloid leukemia.

Micro-ribonucleic acid-155 (miR-155) is one of the first described oncogenic miRNAs. Although multiple direct targets of miR-155 have been identified, it is not clear how it contributes to the pathogenesis of acute myeloid leukemia. We found miR-155 to be a direct target of Meis1 in murine Hoxa9/Meis1 induced acute myeloid leukemia. The additional overexpression of miR-155 accelerated the formation of acute myeloid leukemia in Hoxa9 as well as in Hoxa9/Meis1 cells in vivo However, in the absence or following the removal of miR-155, leukemia onset and progression were unaffected. Although miR-155 accelerated growth and homing in addition to impairing differentiation, our data underscore the pathophysiological relevance of miR-155 as an accelerator rather than a driver of leukemogenesis. This further highlights the complexity of the oncogenic program of Meis1 to compensate for the loss of a potent oncogene such as miR-155. These findings are highly relevant to current and developing approaches for targeting miR-155 in acute myeloid leukemia.

Protein phosphatase 4 regulatory subunit 2 (PPP4R2) is recurrently deleted in acute myeloid leukemia and required for efficient DNA double strand break repair.

We have previously identified a recurrent deletion at chromosomal band 3p14.1-p13 in patients with acute myeloid leukemia (AML). Among eight protein-coding genes, this microdeletion affects the protein phosphatase 4 regulatory subunit 2 (PPP4R2), which plays an important role in DNA damage response (DDR). Investigation of mRNA expression during murine myelopoiesis determined that Ppp4r2 is higher expressed in more primitive hematopoietic cells. PPP4R2 expression in primary AML samples compared to healthy bone marrow was significantly lower, particularly in patients with 3p microdeletion or complex karyotype. To identify a functional role of PPP4R2 in hematopoiesis and leukemia, we genetically inactivated Ppp4r2 by RNAi in murine hematopoietic stem and progenitor cells and murine myeloid leukemia. Furthermore, we ectopically expressed PPP4R2 in a deficient human myeloid leukemic cell line. While PPP4R2 is involved in DDR of both hematopoietic and leukemic cells, our findings indicate that PPP4R2 deficiency impairs de-phosphorylation of phosphorylated key DDR proteins KRAB-domain associated protein 1 (pKAP1), histone variant H2AX (γH2AX), tumor protein P53 (pP53), and replication protein A2 (pRPA2). Potential impact of affected DNA repair processes in primary AML cases with regard to differential PPP4R2 expression or 3p microdeletion is also supported by our results obtained by gene expression profiling and whole exome sequencing. Impaired DDR and increased DNA damage by PPP4R2 suppression is one possible mechanism by which the 3p microdeletion may contribute to the pathogenesis of AML. Further studies are warranted to determine the potential benefit of inefficient DNA repair upon PPP4R2 deletion to the development of therapeutic agents.

A knock-in mouse strain facilitates dynamic tracking and enrichment of MEIS1.

Myeloid ecotropic viral integration site 1 (MEIS1), a HOX transcription cofactor, is a critical regulator of normal hematopoiesis, and its overexpression is implicated in a wide range of leukemias. Using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 (Cas9) gene-editing system, we generated a knock-in transgenic mouse line in which a green fluorescent protein (GFP) reporter and a hemagglutinin (HA) epitope tag are inserted near the translational start site of endogenous Meis1. This novel reporter strain readily enables tracking of MEIS1 expression at single-cell-level resolution via the fluorescence reporter GFP, and facilitates MEIS1 detection and purification via the HA epitope tag. This new Meis1 reporter mouse line provides powerful new approaches to track Meis1-expressing hematopoietic cells and to explore Meis1 function and regulation during normal and leukemic hematopoiesis.

MicroRNA-155 is upregulated in MLL-rearranged AML but its absence does not affect leukemia development.

MicroRNA-155 (miR-155) is an oncogenic miRNA upregulated in various tumor types and leukemias and has been suggested as a potential drug target. Based on our previous work detecting high miR-155 levels in response to Meis1 overexpression in a murine Hox leukemia model, we show here the relationship among HOXA9, MEIS1, and miR-155 levels in MLL-translocated acute myeloid leukemia (AML) patients. Using mouse bone marrow cells transformed by MLL-fusion genes expressing graduated levels of Meis1, we show a positive correlation between miR-155 and Meis1. However, using a miR-155-knockout mouse model, we show that the absence and the depletion of miR-155 have no effect on leukemia formation or progression. We also show for the first time that miR-155 levels are correlated with MLL translocations, but that miR-155 expression is dispensable for the formation of AML and has no effect on leukemia progression.

Impact of comorbidities on pharmacotherapy of painful diabetic neuropathy in clinical practice.

AIMS: We evaluated the impact of baseline comorbidities on the effectiveness of duloxetine and anticonvulsants (pregabalin/gabapentin) in patients with painful diabetic neuropathy in clinical care. METHODS: Outcomes from a 6-month, observational study with 2575 patients initiating/switching DPNP treatment were analyzed post-hoc. Propensity scoring was used to adjust for baseline factors influencing treatment choice in 1523 patients receiving duloxetine or anticonvulsants. Analysis of covariance models with fixed effects for baseline pain, treatment, propensity score, baseline characteristics or comorbidities, and their interaction with treatment were used to estimate LSmean effects on Brief Pain Inventory (BPI) average pain and interference scores. RESULTS: 89.5% of patients reported comorbidities, including hypertension (70.5%), hyperlipidemia (39.2%), and depression (24.8%). Macrovascular complications (37.0%) and 'other chronic pain' (41.5%), particularly joint pain had an impact on both pain treatments, i.e. less improvement of average pain and interference of pain. Better treatment responses with duloxetine vs. anticonvulsants were observed in patients with depression, those with high baseline BPI total interference score, especially general activity, and in patients with joint pain. CONCLUSIONS: Comorbidities such as macroangiopathy and depression as well as pain characteristics should be considered in the treatment of DPNP as they may predict the effectiveness of duloxetine and anticonvulsants.

Patient expectations in the treatment of painful diabetic polyneuropathy: results from a non-interventional study.

OBJECTIVE: Pain control is the main objective when treating patients with painful diabetic peripheral neuropathic pain (DPNP). However, DPNP is associated with further substantial patient burden that often is not appropriately addressed. Our study identified patients' needs and asked patients what they expected from DPNP treatment. METHODS: Baseline data were collected in a German prospective, non-interventional study in patients with DPNP starting or switching pain medication at the discretion of the investigator. DPNP severity was evaluated using Brief Pain Inventory (BPI) and Clinician/Patient Global Impression-Severity (CGI-S/PGI-S). Primary objective of this study was to evaluate for which interference item of the BPI DPNP patients expected most to improve due to DPNP therapy. RESULTS: We enrolled 2,576 patients with DPNP from 307 outpatient centers (mean [standard deviation {SD}] age: 65.8 years [11.5], 51.2% female). Mean (SD) CGI-S and PGI-S at baseline were 4.4 (0.91) and 4.5 (1.05), respectively. BPI average pain score was 5.1 (2.04). The BPI interference score was 4.8 (2.18); items most impaired at baseline were walking ability 5.5 (2.60) and general activity 5.4 (2.37). The most frequently chosen BPI interference items expected to improve as a result of the pain treatment were: General activity (29.3%; 95% confidence interval [CI] 27.5-31.0%) and walking ability (24.4%; 95% CI 22.8-26.1%), followed by sleep (14.7%), enjoyment of life (13.6%), mood (8.3%), normal work (7.7%), and relations with other people (1.9%). CONCLUSIONS: The majority of patients identified "general activity" and "walking ability" as most relevant BPI interference items for which they expect improvement from DPNP treatment.

Effectiveness of duloxetine compared with pregabalin and gabapentin in diabetic peripheral neuropathic pain: results from a German observational study.

OBJECTIVES: This study aimed to compare the effectiveness of duloxetine (DLX) and the anticonvulsants pregabalin (PGB) and gabapentin (GBP) for the treatment of diabetic peripheral neuropathic pain (DPNP) in routine clinical care. MATERIALS AND METHODS: Data from a 6-month, noninterventional study involving 2575 patients in whom treatment of DPNP was initiated with or changed to DLX, PGB, or GBP (n=1523) were analyzed post hoc; patients treated with other medications or combinations were excluded from this analysis. Propensity scoring was used to compare patient groups, assessing Brief Pain Inventory (BPI), Clinical and Patient Global Impression (CGI/PGI), the Hospital Anxiety and Depression Scale (HADS), the Sheehan Disability Scale (SDS), and the Short Form Health Survey (SF 12). RESULTS: Mean median daily dosage over 6 months was 53.9 mg for DLX (N=931), 173.5 mg for PGB (N=248), and 727.8 mg for GBP (N=351). BPI average pain severity (last observation carried forward, mean [SD]) decreased by 2.3 [2.30] points for DLX patients, and by 1.9 [2.22] in PGB, and 1.1 [2.15] in GBP patients. This difference remained statistically significant (DLX vs. PGB: P=0.029; DLX vs. GBP: P<0.001) after adjustment by propensity scores. Similar findings were also seen for the BPI interference score, CGI and PGI, the HADS anxiety score, the HADS depression score. DISCUSSION: When compared with DLX, the low doses of PGB and GBP used in this noninterventional study might have contributed to the lower effectiveness found for both anticonvulsants in the treatment of patients with DPNP.

Patient preferences for outcomes of depression treatment in Germany: a choice-based conjoint analysis study.

BACKGROUND: In general, treatment efficacy in depressed patients is evaluated mainly based on the core symptoms of depression. However, patients might consider different outcomes. This study used choice-based conjoint analysis (CBC) to evaluate patient preferences for depression treatment outcomes. METHODS: Adult subjects from Germany, currently or previously on antidepressant treatment, were presented with 18 pairs of hypothetical treatment outcome scenarios, differing in eight attributes (2-3 factor levels each): depressed mood, loss of interest and enjoyment, loss of energy/fatigue, sleep disturbance, feelings of guilt, depression-related pain, treatment duration, side effects after 2 weeks. Attributes and factor levels were defined by literature review, expert consultations, and in-depth subject interviews. Data were analyzed using multinomial logit modeling; individual part-worth utilities were estimated using hierarchical Bayes routines. RESULTS: Two hundred twenty-seven subjects (89.4% currently treated with antidepressants, 30.0% with depression-related pain) completed the survey. They valued the relative importance of outcomes as follows: loss of energy/fatigue 18.5%, side effects after 2 weeks 14.2%, loss of interest and enjoyment 13.5%, depression-related pain 12.0%, sleep disturbance 12.0%, feelings of guilt 11.5%, treatment duration 9.9%, depressed mood 8.5%. LIMITATIONS: Participants were not required to meet ICD-10 or DSM-IV criteria for depression and had heterogeneous disease severity. CONCLUSIONS: CBC analysis was able to reveal patient preferences for outcomes of depression treatment. Subjects valued the ability to cope with activities of everyday living highest. They considered being free of depression-related pain and side effects more important than being free of depressed mood. These findings should be considered when making treatment decisions.

Depression treatment with duloxetine and reduction of inability to work.

Data on inability to work from an observational study in patients treated with duloxetine for major depressive disorder in clinical practice in Germany were collected. Ability to work was compared between baseline and up to 6 months after initiation of duloxetine. All patients with a working status at baseline other than retired or retired early were included. 2,825 patients were analyzed, 54.8% were able to work at baseline increasing to 83.8% at 6 months. Of those patients unable to work at baseline, 72.7% were able to work after 6 months. A relevant reduction of inability to work was also found for patient subgroups with moderate to severe pain at baseline and those with and without MDD pretreatment. As inability to work is one of the main cost drivers for depressive patients in Germany, the reduction of inability to work could potentially result in considerable cost savings for health insurance companies and society.

Tolerability aspects in duloxetine-treated patients with depression: Should one use a lower starting dose in clinical practice?

OBJECTIVE: This study questions whether a lower starting dose of duloxetine (DLX) could be beneficial for patients with depression, in terms of tolerability and safety in routine clinical care. RESEARCH DESIGN AND METHODS: Post-hoc analyses of a multicenter, prospective, non-interventional, 6-month study in adult outpatients with a depressive episode was undertaken. MAIN OUTCOME MEASURES: Treatment-emergent adverse events (TEAEs), serious adverse events (SAEs), discontinuations due to TEAEs and hospitalizations due to depression, were all documented at 2 weeks, 4 weeks, 3 months and 6 months after treatment initiation/switch to DLX. RESULTS: Of 4517 patients enrolled, 4313 were included for TEAE evaluation. TEAEs occurred in 17.2% of patients, and SAEs occurred in 0.79% of patients, including one case of suicidal ideation. 1404 patients discontinued within 6 months (TEAEs: n = 119). Starting treatment with 30 mg/day DLX (72.7%) was favored in females, or after inadequate efficacy of previous antidepressant treatment; 60 mg/day DLX was favored in more severe depression and patients receiving concomitant pain medication. CONCLUSION: Initiating treatment with 60 mg/day DLX was not associated with poorer tolerability in this study. Physicians may be guided by their clinical experience to carefully consider the individual benefit/risk ratio and TEAE susceptibility when deciding to start treatment with a higher or a lower dose of DLX.

Early reduction in painful physical symptoms is associated with improvements in long-term depression outcomes in patients treated with duloxetine.

BACKGROUND: To investigate the association of the change of painful physical symptoms (PPS) after 4 weeks, with the 6-month treatment outcomes of depressive symptoms in patients treated with duloxetine in clinical practice. METHODS: Multicenter, prospective, 6-month, non-interventional study in adult outpatients with a depressive episode and starting treatment with duloxetine. Depression severity was assessed by the clinician (Inventory for Depressive Symptomatology [IDS-C]) and patient (Kurz-Skala Stimmung/Aktivierung [KUSTA]). Somatic symptoms and PPS were assessed using the patient-rated Somatic Symptom Inventory (SSI) and visual analog scales (VAS) for pain items. Association of change in PPS with outcomes of depressive symptoms was analyzed based on mean KUSTA scores (mean of items mood, activity, tension/relaxation, sleep) and achievement of a 50% reduction in the total IDS-C score after 6 months using linear and logistic regression models, respectively. RESULTS: Of the 4,517 patients enrolled (mean age: 52.2 years, 71.8% female), 3,320 patients (73.5%) completed the study. 80% of the patients had moderate to severe overall pain (VAS > 30 mm) at baseline. A 50% VAS overall pain reduction after 4 weeks was associated with a 13.32 points higher mean KUSTA score after 6 months, and a 50% pain reduction after 2 weeks with a 6.33 points improvement. No unexpected safety signals were detected in this naturalistic study. CONCLUSION: Pain reduction after 2 and 4 weeks can be used to estimate outcomes of long-term treatment with duloxetine. PPS associated with depression have a potential role in predicting remission of depressive symptoms in clinical practice.

Quality of life and subjective well-being during treatment with antipsychotics in out-patients with schizophrenia.

OBJECTIVE: To assess the Quality of Life (QOL) in outpatients with schizophrenia under antipsychotics from two perspectives: a "subjective" perspective as rated by the patient and an "objective" perspective as rated by the physician. METHOD: EASE (External Assessment of Quality of Life in Out-patients with Schizophrenia) is a 12-month, prospective, naturalistic study of the QOL in patients on antipsychotic treatment for schizophrenia in an out-patient setting in Germany. The study included 1462 patients who were initiated on a new antipsychotic or switched to another antipsychotic. The Subjective Well-being under Neuroleptics scale (SWN) and the Quality of Life Scale (QLS) were used to assess the QOL in these patients. The Clinical Global Impression (CGI) scale was used to assess overall symptom severity. Four cohorts were identified and evaluated: (a) patients treated with olanzapine monotherapy (N=1007), (b) another atypical antipsychotic as monotherapy (N=335), (c) a typical antipsychotic as monotherapy (N=32) and (d) combination therapy with more than one antipsychotic (N=88). RESULTS: QOL as assessed by both SWN and QLS improved in all treatment cohorts. SWN responses in the respective cohorts were (a) 52.3%, (b) 38.8%, (c) 31.3% and (d) 44.3%, whilst the QLS responses were (a) 58.2%, (b) 45.1%, (c) 59.4% and (c) 40.9%. Symptom severity as assessed by the CGI also improved over time regardless of the type of antipsychotic. An increase of one point on the CGI corresponded to a change in SWN total score of -9.67 points and a change in QLS total score of -13.36 points. CONCLUSIONS: Both QOL and symptom severity improved over the 12-month study period, regardless of the type of antipsychotic taken. QOL improvement as perceived both from a "subjective" and an "objective" perspective was greatest in the cohort on olanzapine monotherapy.

Duloxetine: a new selective and dual-acting antidepressant.

Antidepressants that inhibit the re-uptake of serotonin and noradrenaline might offer a chance to reduce the multiple symptoms of depression, as both serotonin and noradrenaline seem to be responsible for the emotional and physical symptoms of depression. The potential superiority of a dual mechanism of action has already been demonstrated in a number of clinical trials. Duloxetine, a novel dual acting, selective serotonin and noradrenaline-re-uptake inhibitor, has demonstrated high remission rates and good efficacy on physical symptoms, especially painful physical symptoms of depression. The results from studies in diabetic neuropathic pain provide further evidence of the effect of duloxetine on pain, independent of its effect on depression. Therefore, duloxetine provides an alternative to current therapeutic options in the treatment of the different symptoms of depression.

Homer-1a/Vesl-1S enhances hippocampal synaptic transmission.

Homer/Vesl proteins are involved in regulating metabotropic glutamate receptors, synaptogenesis, dendritic spine development and axonal pathfinding. We investigated the potential modulation of glutamatergic synaptic transmission by the immediate early gene product Homer-1a/Vesl-1S and by the constitutively expressed long-form Homer-1c/Vesl-1L in CA1 pyramidal cells from cultured rat hippocampal slices. Semliki Forest virus vector-mediated overexpression of Homer-1a enhanced alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor function, but did not detectably affect N-methyl-d-aspartate (NMDA) receptor function and presynaptic glutamate release. Overexpression of Homer-1c, by contrast, did not alter synaptic transmission. To corroborate our electrophysiological results obtained in slice cultures, we performed quantitative immunocytochemistry in cultures of dissociated hippocampal neurons. Homer-1a also increased synaptic clustering of AMPA but not NMDA receptors, whereas Homer-1c had no detectable effect. Our results show that Homer-1a potentiates synaptic AMPA receptor function, supporting a critical role for Homer-1a in hippocampal synaptic plasticity.

Novel formulations of cetrorelix acetate in healthy men: pharmacodynamic effects and noncompartmental pharmacokinetics.

The objective of this study was to investigate the effects on the pharmacodynamics and noncompartmental pharmacokinetics after weekly subcutaneous administration of novel formulations of cetrorelix acetate in healthy men. In a randomized parallel-group study, single subcutaneous doses of cetrorelix acetate (concentration: 2.5 mg peptide base/ml) dissolved in aqueous gluconic acid (CET/glu, dose: 5 or 10 mg peptide base) or in water (CET/wat, dose: 10 mg peptide base) were given to 36 subjects once weekly in the morning for 4 weeks. Cetrorelix plasma, serum testosterone, luteinizing hormone, andfollicle-stimulating hormone concentrations were monitored after each administration for 1 week, with extensive profiling after the first and fourth administration. Cetrorelix plasma concentrations were analyzed by radioimmunoassay and serum hormone concentrations by enzyme immunoassays. At least half-maximum testosterone suppression started with all treatments within less than 1 day. Deepest and longest testosterone suppression was achieved by 10 mg CET/glu. Duration of atleasthalf-maximum suppression was after the first dose median of 82 hours and after the fourth dose median of 122 hours, respectively. Substantial suppression was also evidentfor luteinizing hormone (LH) and, to a lesser extent, forfollicle-stimulating hormone (FSH). On average, Cmax was nearly doubled after single and multiple doses, and AUC(tau) was increased by about 50% after single doses and about 30% after multiple doses of 10 mg CET/glu as compared to 10 mg CET/wat. For tmax and t1/2, no significant differences were found between formulations. It was concluded that testosterone suppression increased with weekly subcutaneous administrations of 10 mg CET/glu. Compared to CET/wat, bioavailability and duration of suppression were increased with CET/glu.