Abstract The purpose of this study was to elucidate the background of valproate-related weight gain and hyperinsulinaemia both in men and women by studying markers of insulin resistance and metabolic syndrome. In addition, the role of leptin, a messenger between adipose tissue and the central nervous system was studied. Valproate has a broad spectrum of antiepileptic activity and is widely used for the treatment of epilepsy. It has been the drug of choice for generalised epilepsy, such as juvenile myoclonic epilepsy, and it is also effective for treatment of partial seizures. In addition, valproate is used to treat other diseases, such as bipolar psychiatric disorders and migraine. The results show that valproate-treated patients have higher serum insulin levels in relation to body mass index than control subjects. This indicates that the high serum insulin levels are not a consequence of increased body mass, especially, as the body mass index did not differ between the VPA treated patients and the control groups. Valproate therapy started at a young age may more often result in elevated serum insulin levels and associated other untoward metabolic changes. Furthermore, according to the present data, high serum insulin levels are a consequence of compromised metabolism of insulin in the liver, rather than reflecting reduced insulin sensitivity. However, the valproate-treated patients cluster risk factors for cardiovascular diseases, although the occurrence of metabolic syndrome is not more common in valproate-treated patients than in control subjects. Leptin does not play an independent role in valproate-related weight gain.

No description available.

Valproic acid (Depakote) is an antiepileptic drug approved for the treatment of bipolar disorder, migraine prophylaxis, and seizure disorders. While the exact mechanism is still unknown, thrombocytopenia, defined as platelet counts < 150,000/uL, has been reported secondary to Depakote treatment. The frequency of Depakote-induced thrombocytopenia varies greatly, with reported rates ranging from 5 to 54%. This adverse effect is dose-dependent and possible risk factors include lower baseline platelet counts, female gender, and high VPA serum concentrations.Our team came across two patient cases where thrombocytopenia during Depakote therapy was observed. Patient information was gathered through electronic medical records. The first patient was a 65-year-old male who was started on 500 mg Depakote ER three tablets at night for bipolar affective disorder. After several months on this dose, the patient’s platelets decreased to 59 X 103per microliter. One month after the drug was discontinued, the platelets recovered to 160 X 103per microliter. The second patient was a 57-year-old woman who had two occurrences of thrombocytopenia while on Depakote. The patient was started on Depakote for a seizure disorder. She was later admitted for symptomatic bradycardia, hypotension, and concern for thrombocytopenia. Her Depakote dose was decreased from 500 mg three times a day to twice a day. Approximately 5 weeks later, she presented to the emergency room for decreased arousal and hypotension. She was again found to have thrombocytopenia with a platelet count of 28 X 103per microliter with a Depakote level of 101 mcg/mL. The team discovered she had been receiving Depakote 500 mg three times a day following discharge from her last admission, not the reduced dose prescribed. On day four of admission, her platelets had not improved and the Depakote dose was decreased further to 250 mg twice daily. After Depakote was discontinued her platelets gradually improved and returned to normal after four days, the eighth day of admission. Utilizing the Naranjo adverse drug reaction probability scale, the first patient case had a probable reliability that this adverse reaction was due to Depakote, while the second patient case had a definite reliability.These cases illustrate the potential for thrombocytopenia secondary to Valproic acid use. Although this adverse event isn’t well understood, these cases add to the evidence that it can occur. Recognition of this reaction is important and clinicians should monitor hematologic labs, including platelets, for patients receiving Valproic acid.

Cancer is one of the most challenging problems the modern medicine is facing today. An increasing incidence and a great variability of tumor cells are the main reasons those drive the research to develop better diagnostics and therapeutic protocols. Histone deacetylase inhibitors, a group of epigenetic chemotherapeutics, are able to improve the performance of currently used anticancer agents. Vaplroic acid that is commonly used as antiepileptic drug exhibits a remarkable anticancer activity by itself as well as it is capable of therapy potentiation based on other therapeutic agents. Its effect to inhibit growth of tumor cells and induce apoptotic cell death seems to be even greater under hypoxic conditions (<1% O2). This study is focused on effect of valproic acid on neuroblastoma cell lines in vitro under normoxic and hypoxic conditions. We observed significantly greater efficacy of valproic acid in hypoxia compared to normoxia. The mechanism of induction of apoptotic cell death is based on disruption of the balance between pro- and antiapoptoic proteins. Intrinsic apoptotic pathway is probably initiated by the action of 19 kDa variant of proapoptotic protein Bax on mitochondrial membrane. Moreover, we examined the efficiency of a combined treatment of neuroblastoma cells with valproic acid and...

Valproic acid (VPA), a widely prescribed drug for seizures and bipolar disorder, induces apoptosis in microglia, but the underlying mechanism by which microglia apoptosis in response to VPA is not yet known. In this study, we found that the mitochondrial pathway played an important role in VPA-induced apoptosis in both BV-2 microglia and mouse primary microglial cells. In addition, VPA increased the level of phospho-p38 mitogen-activated protein kinase (MAPK), but had no effects on phospho-ERK and phospho-JNK MAPKs. Moreover, p38 inhibitor SB203580 strongly inhibited VPA-induced apoptosis and caspase-3 activation. Taken together, our results clearly demonstrated that VPA could induce apoptosis of microglia via p38 MAPK and mitochondrial apoptosis pathway.

Bipolar disorder (BD) is a chronic mood disorder affecting ~1-2% of the global population, characterized by cycling moods of mania and depression. The exact pathogenesis of BD is unknown; however, it has been established that endoplasmic reticulum (ER) stress plays an important role. It is known that BD patients have abnormal activity and expression of ER stress proteins in several brain regions. There exists a need for a definitive diagnostic test for the early detection of BD as it is often misdiagnosed for other conditions including unipolar depression and schizophrenia. Understanding the underlying mechanisms and therapeutic targets being used by BD treatments will be helpful in establishing a diagnostic test. The current gold standard for BD treatment includes Lithium (LiCl) prescription, along with other mood stabilizers such as Valproic acid (VPA) and antipsychotics such as Olanzapine. Current therapies only relieve symptoms and are unable to stop disease progression. Neurotrophic factors (NTFs) are naturally occurring proteins that are responsible for the maintenance, differentiation, and survival of neurons. Cerebral dopamine NTF (CDNF) and Mesencephalic astrocyte-derived NTF (MANF) belong to a novel class of NTFs specific to dopaminergic neurons. This study investigated the role of CDNF and MANF as therapeutic targets for bipolar disorder in SH-SY5Y cells and Sprague Dawley rats, as well as determining the endogenous mRNA levels of CDNF and MANF in BD patients. We demonstrated that common BD mood stabilizers – LiCl and VPA – significantly increased the mRNA expression of MANF and CDNF in vitro. Additionally, we also established that these mood stabilizers alter the NTFs expression in different rat brain regions including pre-frontal cortex (PFC) and cortex. These findings suggest that BD drug treatments potentially act via NTFs in order to relieve symptoms. Thus it highlights the importance of further investigating the interaction between neurotrophic factors and bipolar disorder. / Thesis / Master of Science (MSc)

Nicotinamide delivered in drinking water at about 2 g/kg/day significantly prolonged survival and showed a suggestive improvement on memory in the Npc1 (nih) / Npc1 (nih) mouse model of infantile NPC1 disease. It is likely that this role is due to its function as a histone deacetylase (HDAC) inhibitor although another HDAC inhibitor, valproic acid, was without effect. Nicotinamide could also work by preventing/reversing oxidative stress.

Nous avons mis en place au cours de ce travail de thèse différentes stratégies permettant d’améliorer l’efficacité thérapeutique des adénovirus (Ad) oncolytiques contre différents types de tumeurs. Une première stratégie a été de combiner un inhibiteur d’histone-désacétylase, l’acide valproique (VPA) avec un Ad oncolytique à capside sauvage E1Δ24 (CRAd) dans le traitement de carcinomes côliques. Nous avons dans un premier temps démontré que la combinaison du CRAd et du VPA permettait une diminution plus importante de la survie des cellules cancéreuses côliques comparé au simple traitement basé sur le CRAd ou le VPA in vitro mais aussi in vivo.De plus, nous avons observé que cet effet n’était pas lié à une meilleure réplication du CRAd par le VPA. En effet, le VPA provoquait un ralentissement de la réplication virale à des temps précoces mais ne modifiait pas la production virale. Nous avons également découvert que le co-traitement CRAd+VPA conduisait à une forte inhibition de la croissance cellulaire mais aussi à une mort cellulaire non apoptotique. Par ailleurs, nous avons mis en évidence que les cellules co-traitées par le CRAd et le VPA affichaient une forte polyploïdie accompagnée d’une augmentation de la phosphorylation de l’histone H2AX, un marqueur de dommages à l’ADN. Une deuxième stratégie a été de fournir aux Ad oncolytiques de nouvelles voies d’entrée afin d’infecter et de détruire plus efficacement des cellules de carcinomes rénaux réfractaires à l’infection adénovirale. Nous avons démontré que les CRAd à hexon modifié porteurs d’un ligand CKS-17 (Ad-HCKS-17-E1Δ24) ou à fibre modifiée de sérotype 3 (AdF3-E1Δ24) étaient capables d’infecter et de tuer plus efficacement ces cellules qu’un CRAd à capside sauvage in vitro. Malheureusement in vivo, les modifications de capside n’ont permis ni d’améliorer l’entrée des CRAd dans les tumeurs rénales, ni d’améliorer leur efficacité anti-tumorale. Cependant, nous avons observé qu’après administration intra-tumorale, les Ad à capside modifiée présentaient un plus faible tropisme hépatique comparé à un Ad à capside sauvage. / During this thesis, we investigated different strategies to increase the therapeutic effects of oncolytic adenovirus (CRAd) to fight several kinds of tumors.The first strategy seeks to evaluate in human colon carcinomas the association of a CRAd bearing Δ24 deletion in E1A with valproic acid (VPA), a histone deacetylase inhibitor. Interestingly, this combination led to a dramatic reduction of cell survival both in vitro and in vivo compared to single treatment with CRAd or VPA. This effect did not stem from a better CRAd replication and production in the presence of VPA. Inhibition of cell proliferation and a non-apoptotic cell death were shown to be two mechanisms mediating the effects of the combined treatment. Interestingly, whereas cells treated only with CRAd displayed a > 4N population and polyploidy, this phenotype was strongly increased in cells treated with both CRAd and VPA. In addition, the increase in polyploidy triggered by a combined treatment with CRAd and VPA was associated with the enhancement of H2AX phosphorylation (γH2AX), a hallmark of DNA damage. The second strategy developed aimed to find new entry pathways allowing CRAd to better infect and kill renal tumor cells, known to be refractory of Ad infection. We demonstrated that CRAd with capsid modified (Ad-HCKS-17-E1Δ24 and AdF3-E1Δ24), containing respectively a ligand CKS-17 in hexon or a fiber of serotype 3, were more efficient to infect different renal cell carcinomas in vitro compared to a CRAd with a wild type capsid. However, these capsid-modified oncolytic adenovirus provoked, neither increase of the infection level, nor a better efficacy of growth inhibition in renal tumor xenografts bearing by nude mice. Nevertheless, both types of modifications reduce Ad ability to transduce hepatocytes after intratumoral injection.

Background. Clinicians are divided on dosing recommendations when a dose is delayed or missed. For a neuropsychiatric agent like valproic acid (VPA), rational dosing recommendations are of particular importance. VPA is subject to therapeutic monitoring using total concentrations. Due to non-linear binding of VPA to plasma proteins, current dose titration schemes for VPA are empirical. The objectives of this research were to 1- study the effect of missed/delayed doses on steady state concentrations of VPA and 2-design a nomogram that can be used for dose titration based on total VPA concentrations. Methods. 1- A simulation study was conducted to test for different poor compliance scenarios. The effect of missed doses was quantified and used to derive dosing recommendations. 2- A clinical study was carried out in healthy volunteers. Nine volunteers were administered 500, 750 and 1000 mg VPA in a dose escalation study. A nomogram was developed using in vitro plasma protein binding data in all volunteers and tested using dose escalation data. Several delayed/missed doses scenarios were tested in order to validate the simulation model. 3- A revised simulation model was developed using combined information from plasma protein binding and pharmacokinetic analysis of clinical study data. Results and Discussion. Simulation study: Dosing recommendations in the case of a missed or delayed dose are both formulation and dose dependent. Results from the clinical study validated the simulation model and the revised simulation model properly incorporated intra and inter individual variabilities. VPA nomogram: A one-site saturable binding model provided an adequate description of the binding of VPA to albumin. A dosing nomogram for VPA was constructed. To avoid the risk of achieving toxic concentrations, the dose should not be increased by more than 2 fold at a time. The nomogram should be used in conjunction with patient history and clinical response. Conclusions. This research provides dosing recommendations to the clinicians to counsel patients taking preparations of VPA in the event of a missed dose. The use and validation of VPA nomogram will foster the rational use of VPA for the treatment of epilepsy and its role in other neuropsychiatric disorders.

Acute myeloid leukemia (AML) is a genetic disease whereby sequential genetic aberrations alter essential white blood cell development leading to differentiation arrest and hyperproliferation. Pertinent animal models serve as essential intermediaries between in vitro molecular studies and the use of new agents in clinical trials. We previously generated a transgenic zebrafish model expressing human NUP98-HOXA9 (NHA9), a fusion oncogene found in high-risk AML. This expression yields a pre-leukemic state in both embryos and adults. Using this model, we have identified the overexpression of dnmt1 and the Wnt/β-catenin pathway as downstream contributors to the myeloproliferative phenotype. Targeted dnmt1 morpholino knockdown and pharmacological inhibition with methyltransferase inhibitors rescues NHA9 embryos. Similarly, inhibition of β-catenin with COX inhibitors partially restores normal hematopoiesis. Interestingly, concurrent treatment with a histone deacetylase inhibitor and either a methyltransferase inhibitor or a COX inhibitor, synergistically inhibits the effects of NHA9 on embryonic hematopoiesis. Thus, we have identified potential pharmacological targets in NHA9-induced myeloid disease that may offer a highly efficient therapy with limited toxicity – addressing a major long-term goal of AML research.