<p dir="ltr">Immunotherapy has revolutionized the field of oncology. While a lot of antibodies and small molecule inhibitors have been developed for this, a lot of targets remain undruggable in humans.</p><p dir="ltr">Targeted protein degradation has opened a new horizon in drug discovery where we can target these undruggable proteins. Proteolysis targeting chimeras using the ubiquitin-proteasomal system is one of the most popular TPD strategies that complement lysosomal degradation strategies to degrade intracellular proteins, typically using bifunctional small molecule degraders. Recently, large biomolecular and antibody conjugates have been developed for degrading membrane and extracellular proteins in cells, such as lysosomal targeting chimeras (LYTACs) and genetically encoded LYTACS, among several others. However, larger molecules have limitations in penetrating solid tumors. This dissertation work focused on the development of bifunctional small molecule degraders for programmed death-ligand 1 (PD-L1), a transmembrane protein ligand for the immune checkpoint programmed cell death 1 (PD-1). PD-L1 is highly expressed on several tumors, such as triple-negative breast cancer (TNBC), non-small cell lung carcinoma, and renal cancer, and is known to suppress cancer-killing immune cells via interaction with PD-1 on T-cells. In addition, PD-L1 is also present on macrophages in the tumor microenvironments leading to further immune suppression and acquired resistance to anti-PD-1 therapy is associated with the upregulation of alternative immune checkpoints, thereby reducing anti-tumor efficacy. We have designed and synthesized bifunctional small molecules as PD-L1 degraders with different recruiters and linkers guided by computational studies with known PD-1/PD-L1 structures to show both cell surface and total protein degradation in human TNBC cells. In a separate project, we also developed small molecule conjugates to degrade an intracellular integral membrane protein of the endoplasmic reticulum with an unknown 3D structure, namely Diglyceride acyltransferase 2 (DGAT2). Recently, our lab identified DGAT2 as a new target for combating Alzheimer’s disease. Specifically, DGAT2 catalyzes triacylglycerol (TAG) synthesis using diacylglycerol and fatty acyl CoA as substrates. The accumulation of TAGs, mechanistically linked to DGAT2, results in “fat” or lipid droplets (LDs) inside the cells. Our lab showed that microglial cells (resident immune cells in the brain) accumulate LDs in the postmortem brains of human patients and mouse models (5xFAD) of Alzheimer’s disease and that the LD accumulation is driven by amyloid-beta (Ab) – a hallmark of Alzheimer’s disease – via DGAT2 pathway. Further, these LD-laden microglia have phagocytic defects and are spared Aβ thereby affecting plaque accumulation and clearance. Inhibiting DGAT2 reduces the amount of TAG in the brain, which in turn reduces LDs and restores microglial ability to phagocytose Ab. However, commercially available DGAT2 inhibitors were unable to reduce LD load in older 5xFAD mice. Using AlphaFold’s models of DGAT2, we designed and identified sites to synthesize bifunctional DGAT2 degraders that resulted in reduced LDs in mouse primary microglial cells and enhanced phagocytosis of Aβ plaques in vivo in aged 5xFAD mice. Our approach shows a framework to develop bifunctional small molecule degraders for membrane proteins to potentially combat immune dysregulation in chronic diseases.</p>

Anticancer active metal complexes such as cisplatin are routinely used for treating various cancers since 1978. However, the side effects of cisplatin overwhelm its therapeutic potential, especially in the latter stages of treatment. The nonspecific cytotoxicity of drugs could be avoided if targeted delivery to cancer cells is achieved using two different methodologies namely, enhanced permeability and retention in solid tumors (EPR) and receptor mediated endocytosis using a homing agent (RME). Ru(II)-arene complexes which are delivered specifically into cancer cells by the transferrin enzyme are less toxic compared to other metal complexes. The thesis describes the synthesis and use of Ru(II)-η6cymene complexes with different ancillary ligands which modulates the anticancer activity and the utility of two macromolecular vehicles in directed drug delivery. Ru(II)-η6cymene complexes with different heterocyclic ancillary ligands are synthesized and their anticancer activity tested against various cancer cell lines. Ruthenium complexes with mercaptobenzothiazoles are found to be quite active against the H460 cell lines that overexpress transferrin receptors and non-cytotoxic to the normal cell line, HEL299. Biophysical studies show that complexes (H1 and H8) can unwind the pBR322 DNA and inhibit the Topo IIα enzyme. A unique biphasic melting curve of CT DNA is observed in the presence of H1 which is attributed to formation of a dinuclear species (H20). Half-sandwich complexes of 6-thioguanine (6-TG) have also been prepared to improve the delivery and efficacy of 6-TG which is used in spite of a deleterious photoreaction. The Ru complexes cytotoxic to several leukemia cell lines. As they are photostable and anticancer active, they are better than 6-TG. Anticancer activity exhibiting piazselenols are used as ancillary ligands to make Ru(II)-arene complexes. Unfortunately, 1H NMR spectra suggests that piazselenol complexes dissociate in solution. However, the nitro substituted piazselenol and its Ru complex show the greatest cytotoxicity (<0.1 µM) against the A2780 cell line. The utility of PAMAM dendrimers and hyper branched polymers (hybramers) conjugated with a homing agent to target cancer cells by EPR and RME is probed. A cytotoxic copper complex (CuATSM) is covalently attached to the macromolecules through a disulfide linker, cleaved in the presence of GSH. Targeting efficacy of the folic acid-dendrimer conjugates is checked against two glioma cell lines. The folic acid-dendrimer conjugate is more active compared to dendrimer conjugate without folic acid against folate-receptor-overexpressing LN18 cell line. Biotin conjugated dendrimer shows better accumulation in HeLa cells, which require high amounts of biotin for growth. In vivo studies demonstrate that the conjugate can cross the blood-brain barrier. These studies suggest that PAMAM dendrimer can be used as a targeted delivery vehicle for cytotoxic metal complexes. Hyperbranched polymers decorated with propargyl groups and hydrophilic OH terminated TEG groups are attached to biotin and a cytotoxic Cu complex. (CuATSM-SS-CONH-N3) through ‘click’ reactions and tested against the HeLa cell line. On the basis of the studies conducted, it is concluded that targeted delivery of cytotoxic metal complexes are possible in the case of Ru(II) half-sandwich complexes and macromolecular vehicles like dendrimers are suitable for specifically delivering copper complexes into cancer cells.

A range of microgels with two different functionalities were synthesized, and their utility in novel bioapplications was examined. Cationic microgels with varying properties were developed by tuning synthesis conditions. Their size and primary amine content was analyzed, and one microgel system was selected as a model construct. Its primary amine groups were conjugated to two dyes with properties favorable for utilization as contrast agents in photoacoustic imaging. The concentration of contrast agent in single particles was determined. The implications of a high local dye concentration in the generation of high intensity photoacoustic signals, are discussed. The second bioapplication involved the targeted delivery of fibrinolytics to fibrin clots, in order to bring about dissolution of abnormal thrombi. For this purpose, core/shell microgels with carboxylic acid groups in their shells were synthesized in three size ranges. Following this, their dimension based differential localization in and around porous fibrin clots was examined. Fibrin-specific peptides were then conjugated onto the shells of these particles and the conjugates were shown to demonstrate strong interactions with the fibrin clots. The microgels conjugated to the peptide with the highest binding affinity to fibrin, were observed to bring about disruption of fibrin clots, merely through interference in the dynamic interactions among clot fibers, due to the equilibrium nature of the fibrin polymer. The implications of these novel results and future studies required to facilitate a better understanding of the phenomena involved, are discussed.

Thesis (MScMedSc (Biomedical Sciences. Medical Biochemistry))--University of Stellenbosch, 2010. / Bibliography / ENGLISH ABSTRACT: The genome of the pathogen Mycobacterium tuberculosis contains five copies of the ESAT-6 (ESX) gene cluster region, which encodes for a novel type VII secretion system. These gene cluster regions, which are directly involved in pathogenicity and phagosomal escape, contain genes encoding exported T-cell antigens ESAT-6 and CFP-10. The mechanism of action of the ESX secretion system however, remains largely unknown. This study focused on ESX gene cluster region 4 (ESX-4), which has been shown to be the most ancestral region and is also present in other species of Mycobacteria and even in other high G+C Gram-positive bacteria, such as Corynebacterium diptheriae and Streptomyces coelicolor. This project aimed to investigate the protein-protein interactions of ESX-4 of M. tuberculosis in the model organism Mycobacterium smegmatis by means of Mycobacterial Protein Fragment Complementation (M-PFC). M-PFC is a two-hybrid technique which employs two cloning vectors, pUAB300 (conferring resistance to hygromycin B) and pUAB400 (conferring resistance to kanamycin). Genes of interest are cloned into these vectors and co-transformed into the model organism M. smegmatis after which it is expressed as fusion proteins. Interaction of the proteins allows selective growth on a medium containing the antibiotic trimethoprim. Various interactions were identified throughout this region, including selfinteractions as well as the expected interaction between the ESAT-6 and CFP-10 protein family members esxT and esxU. Since this region is ancestral, ESX-4 provides the basic model of the mechanism of secretion of the type VII secretion system. Many similarities were apparent when the interactions identified for ESX-4 were compared to the interactions previously identified in ESX-3. Interactions identified by means of M-PFC provide a basis for the further study of the structure of this secretion system, and should be confirmed by means of other techniques, such as co-immunoprecipitation. Despite the ability of M-PFC to identify protein-protein interactions in a mycobacterial system, and thus overcoming some of the limitations of the classical yeast two-hybrid model, it must still be regarded as a fishing experiment for potential interactions. A further aim of the project was to construct a knock-out of ESX-4 in the model organism M. smegmatis, which contains three ESX regions, namely ESX-1, -3 and -4. Homologous recombination proved to be an effective technique for the construction of the knock-out, also indicating that ESX-4 is not essential for in vitro growth of M. smegmatis. The knock-out strain showed no morphological differences to the wild type strain of M. smegmatis. The knock-out strain will in future be compared to the wild type strain in various functional studies in order to determine the function of the ancestral ESX region. / AFRIKAANSE OPSOMMING: Die genoom van die patogeen Mycobacterium tuberculosis bavat vyf kopieë van die ESAT-6 geen groep gebiede wat kodeer vir ‘n unieke tipe VII sekresie sisteem. Die geen groep gebiede, wat direk betrokke is by patogenisiteit en fagosomale ontsnapping, bevat gene wat kodeer vir die gesekreteerde T-sel antigene ESAT-6 en CFP-10. Die meganisme van die ESX sekresie sisteem is egter steeds tot ‘n groot mate onbekend. Hierdie studie het gefokus op die ESX geen groep gebied 4 (ESX-4), wat voorheen bepaal is om die vroegste kopie van die gebied te wees en wat ook in ander species van Mikobakterieë en hoë G+C Gram-positiewe bakterieë, soos Corynebacterium diptheriae en Streptomyces coelicolor, voorkom. Hierdie projek was daarop gemik om die proteïen-proteïen interaksies van ESX-4 van M. tuberculosis in die model organisme Mycobacterium smegmatis te ondersoek deur middel van Mikobakteriële Proteïen Fragment Komplementasie (M-PFK). M-PFK is ‘n twee-hibried tegniek wat van twee kloningsvektore, naamlik pUAB300 (wat weerstand teen hygromycin B bied) en pUAB400 (wat weerstand teen kanamycin bied) gebruik maak. Gene van belang word in die vektore ingekloneer en in die model organisme, M. smegmatis geko-transformeer, waarna dit as fusieproteïene uitgedruk word. Indien ‘n interaksie tussen die proteïene plaasvind, sal selektiewe groei op ‘n medium wat die antibiotikum trimethoprim bevat, waargeneem word. Verskeie interaksies is in hierdie gebied geïdentifiseer, insluitende self-interaksies, sowel as die verwagte interaksie tussen die ESAT-6 en CFP-10 proteïen familielede esxT en esxU. Aangesien hierdie gebied die vroegste kopie is, bied ESX-4 die basiese model vir die meganisme van sekresie van die tipe VII sekresie sisteem. Wanneer interaksies wat vir ESX-4 geïdentifiseer is met die wat voorheen vir ESX-3 geïdentifiseer is vergelyk word is daar heelwat ooreenkomste. Interaksies wat deur middel van M-PFK geïdentifiseer is, verskaf ‘n basis vir die vêrdere studie van interaksies van hierdie gebied, en sal bevestig moet word deur gebruik te maak van aanvullende tegnieke, soos ko-immunopresipitasie. Ten spyte van die vermoë van M-PFK om proteïen-proteïen interaksies in ‘n mikobakteriële sisteem, wat dus sommige van die beperkings van die klassieke gis twee-hibriedmodel oorkom, te bestudeer, behoort dit steeds as ‘n voorlopige metode van identifikasie beskou te word. ‘n Vêrdere doel van die projek was om ‘n uitslaanmutant van ESX-4 in die model organisme M. smegmatis, wat drie van die ESX gebiede, naamlik ESX-1, -3 en -4 bevat, te skep. Homoloë rekombinasie is bewys om ‘n effektiewe tegniek te wees vir die skep van ‘n uitslaanmuntant en het daarop gedui dat ESX-4 nie essensieel is vir die in vitro groei van M. smegmatis nie. Die uitslaanstam het ook geen morfologiese verskille getoon teenoor die oorspronklike stam nie. Die uitslaanmutant sal in die toekoms gebruik word in ‘n verskeidenheid funksionele studies waar dit vergelyk sal word met die oorspronklike stam, ten einde die funksie van die vroegste ESX-gebied te bepaal. / Medical Research Council of South Africa / National Research Foundation of South Africa / Ernst and Ethel Eriksen Trust

This paper assesses U.S. national security policies in surveillance, detention, interrogation and torture, and targeted killing to determine whether they comport with international human rights law and international humanitarian law. The U.S. is responsible for adhering to the Universal Declaration of Human Rights, the International Covenant on Civil and Political Rights, and the Geneva Conventions. These human rights law documents can be understood through court decisions, congressional statutes, and widely accepted interpretations from organizations such as the International Committee of the Red Cross, and the UN Human Rights Council. Further, this paper offers prescriptions on how international human rights law and international humanitarian law can be updated to better deal with the current war on terror. / text

<p>Developing radiation delivery systems for optimisation of absorbed dose to the target without normal tissue toxicity requires advanced calculations for transport of radiation. In this thesis absorbed dose and fluence in different radiotherapy applications were calculated by using Monte Carlo (MC) simulations.</p><p>In paper I-III external neutron activation of gadolinium (Gd) for intravascular brachytherapy (GdNCB) and tumour therapy (GdNCT) was investigated. MC codes MCNP and GEANT4 were compared. MCNP was chosen for neutron capture reaction calculations. Gd neutron capture reaction includes both very short range (Auger electrons) and long range (IC electrons and gamma) products. In GdNCB the high-energetic gamma gives an almost flat absorbed dose delivery pattern, up to 4 mm around the stent. Dose distribution at the edges and inside the stent may prevent stent edge and in-stent restenosis. For GdNCT the absorbed dose from prompt gamma will dominate over the dose from IC and Auger electrons in an in vivo situation. The absorbed dose from IC electrons will enhance the total absorbed dose in the tumours and contribute to the cell killing.</p><p>In paper IV a model for calculation of inter-cluster cross-fire radiation dose from β-emitting radionuclides in a breast cancer model was developed. GEANT4 was used for obtaining absorbed dose. The dose internally in cells binding the isotope (self-dose) increased with decreasing β-energy except for the radionuclides with substantial amounts of conversion electrons and Auger electrons. An effective therapy approach may be a combination of radionuclides where the high self-dose from nuclides with low β-energy should be combined with the inter-cell cluster cross-fire dose from high energy β-particles.</p><p>In paper V MC simulations using correlated sampling together with importance sampling were used to calculate spectra perturbations in detector volumes caused by the detector silicon chip and its encapsulation. Penelope and EGSnrc were used and yielded similar results. The low energy part of the electron spectrum increased but to a less extent if the silicon detector was encapsulated in low z-materials.</p>

Prostate cancer (PCa) is the most common non-skin malignancy of men in developed countries. In spite of treatment with curative intent up to 30-40% of patients have disease recurrence after treatment, resulting from any combination of lymphatic, hematogenous, or contiguous local spread. The concept of early detection of PCa offer benefits in terms of reduced mortality, but at the cost of over-diagnosis and overtreatment of indolent disease. This is largely due to the random nature of conventional biopsies, with a risk of missing significant cancer and randomly hitting indolent disease. In the present thesis, diagnostic performance of MRI DWI and 11C Acetate PET/CT lymph node staging of intermediate and high risk PCa, was investigated, and additionally, predictive factors of regional lymph node metastases were evaluated. Further, additional value of targeted biopsies to conventional biopsies, for detection of clinically significant PCa, was investigated. In paper one and two, 53 and 40 patients with predominantly high risk PCa underwent 11C Acetate PET/CT and 3T MRI DWI, respectively, for lymph node staging, before extended pelvic lymph node dissection (ePLND). The sensitivity and specificity for PET/CT was 38% and 96% respectively. The sensitivity and specificity for MRI DWI was 55% and 90% respectively. In paper three, 53 patients with newly diagnosed PCa were included. All patients underwent multi-parametric MRI, followed by two cognitive targeted biopsies. Five more clinically significant cancers were detected by adding targeted biopsies to conventional biopsies. In paper four the value of quantitative and qualitative MRI DWI and 11C Acetate PET/CT parameters, alone and in combination, in predicting regional lymph node metastases were examined. ADCmean in lymph nodes and T-stage on MRI were independent predictors of lymph node metastases in multiple logistic regression analysis. In conclusion the specificity of diffusion weighted MRI and 11C Acetate PET/CT for lymph node staging was high, although the sensitivity was low. Predictive factors of regional lymph node metastases could be retrieved from diffusion weighted MRI and 11C Acetate PET/CT. By combining targeted biopsies with conventional biopsies the detection rate of clinically significant PCa could be increased.

"Mémoire présenté à la faculté des études supérieures en vue de l'obtention du grade de Maîtrise en droit (LL.M.)". Ce mémoire a été accepté à l'unanimité et classé parmi les 10% des mémoires de la discipline. / À la suite d'attaques terroristes massives est apparue une motivation féroce qui risque d'être manipulée pour justifier des excès de force. Voulant prévenir des attaques armées contre leurs intérêts, certains États ont adopté des politiques de « tuerie ciblée » pour éliminer de façon permanente des terroristes en sol étranger qui menacent leur sécurité. II est pourtant illégal de tuer des individus en l'absence de conflits armes sans égard au droit à la vie. La présente recherche tient à déterminer si, en vertu du droit international, des États peuvent neutraliser par force des individus dangereux ou bien venir au secours d' otages en sol etranger. En étudiant l'article 51 de la Charte des Nations Unies, un certain nombre de conclusions sont apparues, notamment que des opérations pour « arrêter ou neutraliser » ne peuvent avoir lieu que dans des États qui supportent des terroristes ou qui restent indifférents face à leur présence, et que I'expression « guerre contre Ie terrorisme » ne peut permettre des «tueries ciblées » sans avoir à considérer les droits à la vie et à la légitime défense. Puisque toute division entre les membres de la communauté internationale peut venir limiter la prévention d'attaques, le fait que la coopération entre les États ayant abolis la peine de mort et ceux ayant recours aux « tueries ciblées » puissent en souffiir fait l'objet de cet ouvrage. Ladite recherche conclue que l'utilisation de « tueries ciblées » en dehors du contexte de conflits armés ne peut être permis qu'en dernière mesure lorsque réellement nécessaire pour prévenir des attaques armées et protéger la vie. / From the ashes of devastating acts of terrorism has arIsen a resolve so powerful that measures of counterterrorism risk being manipulated by states to justify excess. In an attempt to prevent armed attacks against their interests, a number of states have adopted policies of targeted killing to permanently incapacitate terrorists on foreign soil. The intentional killing of suspected offenders, however, cannot be lawfully carried-out by states in the absence of armed conflict without regard for the right to life. The following research attempts to determine whether it is permissible for nations to use force on foreign soil to . incapacitate dangerous individuals or rescue hostages under international law. By studying article 51 selfdefense of the United Nations charter, a number of conclusions are asserted, namely that operations to "arrest or neutralise" can only be carried-out in states that support terrorists or are complacent to their presence, and that declaring "war on terrorism" cannot allow governments to kill suspected terrorists in countries where there is no war, except in a manner that is reconcilable with the rights to life and selfdefense. Since division among members of the international community may ultimately diminish their ability to collectively suppress international terrorism, the potential for hindered cooperation between abolitionist states and those that carry-out targeted killings is also addressed. The current research concludes that targeted killings can only be justified outside the context of armed conflict when they are truly necessary as a last resort to prevent armed attacks and save lives.

Background: Cancer is the second leading cause of death in economically developed countries. The use and availability of oral treatment for cancer has increased dramatically in the past 10 years. Few studies have described the use of oral chemotherapy in non-traditional ambulatory settings by health care professionals across different specialties. Objective: The purpose of this study is to describe the usage of oral chemotherapeutic medications in ambulatory settings. Methods: Cross sectional study of 2007 NAMCS Survey analysis involving 21,761 subjects aged 18 years and above with cancer who participated in the 2007 National Ambulatory Medical Survey (NAMCS). Main Outcome Measure: Physician-reported use of oral chemotherapeutic medications (includes all major drug classes) as indicated on questionnaire for 2007 NAMCS survey. Results: Health care providers in non-traditional settings are less likely to prescribe oral chemotherapy than in traditional ambulatory settings (Adjusted odds ratio (AOR)=0.65{95% confidence interval: 0.61-0.69}). The study results suggest that oncologists are prescribing oral anti-cancer drugs the most as compared to other physician specialties. Conclusion: Health care providers in non-traditional settings are less likely to prescribe oral chemotherapy than in traditional ambulatory settings. Primary care physicians may have limited experience in monitoring and prescribing these potentially toxic medications. Clear guidelines are required for the use of oral chemotherapy medications, considering the potential for their use in non-traditional ambulatory settings and by non-oncologists.

La documentation scientifique fait état de la présence, chez l’adulte, de cellules souches et progénitrices neurales (CSPN) endogènes dans les zones sous-ventriculaire et sous-granulaire du cerveau ainsi que dans le gyrus denté de l’hippocampe. De plus, un postulat selon lequel il serait également possible de retrouver ce type de cellules dans la moelle épinière et le néocortex des mammifères adultes a été énoncé. L’encéphalopathie de Wernicke, un trouble neurologique grave toutefois réversible qui entraîne un dysfonctionnement, voire une défaillance du cerveau, est causée principalement par une carence importante en thiamine (CT). Des observations récentes laissent envisager que les facteurs en cause dans la prolifération et la différenciation des CSPN pourraient également jouer un rôle important lors d’un épisode de CT. L’hypothèse, selon laquelle l’identification de nouveaux métabolites entrant dans le mécanisme ou la séquence de réactions se soldant en une CT pourraient en faciliter la compréhension, a été émise au moyen d'une démarche en cours permettant d’établir le profil des modifications métaboliques qui surviennent en de telles situations. Cette approche a été utilisée pour constater les changements métaboliques survenus au niveau du foyer cérébral dans un modèle de rats déficients en thiamine (rats DT), particulièrement au niveau du thalamus et du colliculus inférieur (CI). La greffe de CSPN a quant à elle été envisagée afin d’apporter de nouvelles informations sur la participation des CSPN lors d’un épisode de CT et de déterminer les bénéfices thérapeutiques potentiels offerts par cette intervention. Les sujets de l’étude étaient répartis en quatre groupes expérimentaux : un premier groupe constitué de rats dont la CT était induite par la pyrithiamine (rats DTiP), un deuxième groupe constitué de rats-contrôles nourris ensemble (« pair-fed control rats » ou rats PFC) ainsi que deux groupes de rats ayant subi une greffe de CSPN, soit un groupe de rats DTiP greffés et un dernier groupe constitué de rats-contrôles (rats PFC) greffés. Les échantillons de foyers cérébraux (thalamus et CI) des quatre groupes de rats ont été prélevés et soumis à des analyses métabolomiques non ciblées ainsi qu’à une analyse visuelle par microscopie à balayage électronique (SEM). Une variété de métabolites-clés a été observée chez les groupes de rats déficients en thiamine (rats DTiP) en plus de plusieurs métabolites dont la documentation ne faisait pas mention. On a notamment constaté la présence d’acides biliaires, d’acide cynurénique et d’acide 1,9— diméthylurique dans le thalamus, alors que la présence de taurine et de carnosine a été observée dans le colliculus inférieur. L’étude a de plus démontré une possible implication des CSPN endogènes dans les foyers cérébraux du thalamus et du colliculus inférieur en identifiant les métabolites-clés ciblant les CSPN. Enfin, les analyses par SEM ont montré une amélioration notable des tissus à la suite de la greffe de CSPN. Ces constatations suggèrent que l’utilisation de CSPN pourrait s’avérer une avenue thérapeutique intéressante pour soulager la dégénérescence symptomatique liée à une grave carence en thiamine chez l’humain. / Endogenous neural-stem progenitor cells (NSPC) have been documented to be found in the subventricular and subgranular zones, the dentate gyrus, and suggestions of the possibility of these cells being found in the spinal cord and neocortex in adult mammalian brain have been postulated. Thiamine deficiency (TD) is the major cause of Wernicke's Encephalopathy, a reversible neurological disorder that results in cerebral dysfunction and impairment. Recent evidence suggests factors involved in neural NSPC proliferation and differentiation are involved during TD. By means of a current approach for profiling metabolic changes occurring in focal areas of the TD rat brain, specifically the thalamus and the inferior colliculus (IC), it was hypothesized that new metabolites that might offer a better understanding into the sequel and/or mechanism of TD could be identified. It was also considered that the use of NSPC transplantation could offer new information into the involvement of NSPC and potential therapeutic benefit in TD. Non-targeted metabolomics analysis, fluorescences microscopy, and scanning election microscopy (SEM) analysis visualization was performed on samples of the focal areas (thalamus and IC) of pyrithiamine induced TD rats (PTD), pair-fed controls (PFC) rats, and NSPC transplanted TD and PFC rats. Various key metabolites were identified in rats with TD, including previous undocumented metabolites such as bile acids, kynurenic acid, and 1,9-dimethyluric acid in the thalamus and taurine and carnosine in the IC. The study also demonstrated a possible involvement of endogenous NSPC in focal areas of the thalamus and IC identifying key metabolites targeting NSPC and showed tissue amelioration (observed through SEM) following NSPC transplantation. The findings suggested that NSPC could offer a therapeutic alternative to alleviate some of symptomatic degeneration of TD.