Since the first approved hepatitis C virus (HCV) NS3 protease inhibitors in 2011, numerous direct acting antivirals (DAAs) have reached late stages of clinical trials. Today, several combination therapies, based on different DAAs, with or without the need of pegylated interferon-α injection, are available for chronic HCV infections. The chemical foundation of the approved and late-stage HCV NS3 protease inhibitors is markedly similar. This could partly explain the cross-resistance that have emerged under the pressure of NS3 protease inhibitors. The first-generation NS3 protease inhibitors were developed to efficiently inhibit genotype 1 of the virus and were less potent against other genotypes. The main focus in this thesis was to design and synthesize a new class of 2(1H)-pyrazinone based HCV NS3 protease inhibitors, structurally dissimilar to the inhibitors evaluated in clinical trials or approved, potentially with a unique resistance profile and with a broad genotypic coverage. Successive modifications were performed around the pyrazinone core structure to clarify the structure-activity relationship; a P3 urea capping group was found valuable for inhibitory potency, as were elongated R6 residues possibly directed towards the S2 pocket. Dissimilar to previously developed inhibitors, the P1’ aryl acyl sulfonamide was not essential for inhibition as shown by equally good inhibitory potency for P1’ truncated inhibitors. In vitro pharmacokinetic (PK) evaluations disclosed a marked influence from the R6 moiety on the overall drug-properties and biochemical evaluation of the inhibitors against drug resistant enzyme variants showed retained inhibitory potency as compared to the wild-type enzyme. Initial evaluation against genotype 3a displayed micro-molar potencies. Lead optimization, with respect to improved PK properties, were also performed on an advanced class of HCV NS3 protease inhibitors, containing a P2 quinazoline substituent in combination with a macro-cyclic proline urea scaffold with nano-molar cell based activities. Moreover, an efficient Pd-catalyzed C-N urea arylation protocol, enabling high yielding introductions of advanced urea substituents to the C3 position of the pyrazinone, and a Pd-catalyzed carbonylation procedure, to obtain acyl sulfinamides, were developed. These methods can be generally applicable in the synthesis of bioactive compounds containing peptidomimetic scaffolds and carboxylic acid bioisosteres.

This thesis investigates the design, synthesis and biological assay of cysteine protease inhibitors within the papain superfamily of cysteine proteases. This is achieved by examining the effect of inhibitor design, especially warheads, on IC₅₀ values and structureactivity relationships between cysteine protease inhibitors of the papain superfamily. The representative proteases used are m-calpain, μ-calpain, cathepsin B and papain. Chapter One is an introductory chapter; Chapters Two-Four describe the design and synthesis of cysteine protease inhibitors; Chapter Five discusses assay protocol; and Chapter Six contains the assay results and structure-activity relationships of the synthesised inhibitors. Chapter One introduces cysteine proteases of the papain family and examines the structure, physiology and role in disease of papain, cathepsin B, m-calpain and μ-calpain. The close structural homology that exists between these members of the papain superfamily is identified, as well characteristics unique to each protease. Covalent reversible, covalent irreversible and non-covalent warheads are defined. The generic inhibitor scaffold of address region, recognition and warhead, upon which the inhibitors synthesised in this thesis are based, is also introduced. Chapter Two introduces reversible cysteine protease inhibitors found in the literature and that little is known about the effect of inhibitor warhead on selectivity within the papain superfamily. Oxidation of the dipeptidyl alcohols 2.6, 2.26, 2.29, 2.30, 2.35 and 2.36 utilising the sulfur trioxide-pyridine complex gave the aldehydes 2.3, 2.27, 2.19, 2.2, 2.21 and 2.22. Semicarbazones 2.37-2.40 were synthesised by a condensation reaction between the alcohol 2.3 and four available semicarbazides. The amidoximes 2.48 and 2.49 separately underwent thermal intramolecular cyclodehydration to give the 3-methyl-1,2,4- oxadiazoles 2.41 and 2.50. The aldehydes 2.3 and 2.27 were reacted with potassium cyanide to give the cyanohydrins 2.51 and 2.52. The cyanohydrins 2.51 and 2.52 were separately reacted to give 1) the α-ketotetrazoles 2.43 and 2.55; 2) the α-ketooxazolines 2.42 and 2.58; 3) the esterified cyanohydrins 2.60 and 2.61. A two step SN2 displacement reaction of the alcohol 2.6 to give the azide 2.62, an example of a non-covalent cysteine protease inhibitor. Chapter Three introduces inhibitors with irreversible warheads. The well-known examples of epoxysuccinic acids 3.1 and 3.5 are discussed in detail, highlighting the lack of irreversible cysteine protease specific inhibitors. The aldehydes 2.3 and 2.27 were reacted under Wittig conditions to give the α,β-unsaturated carbonyls 3.14-3.18. Horner- Emmons-Wadsworth methodology was utilised for the synthesis of the vinyl sulfones 3.20- 3.23. The dipeptidyl acids 2.24 and 2.28 were separately reacted with diazomethane to give the diazoketones 3.25 and 3.26. The diazoketones 3.25 and 3.26 were separately reacted with hydrogen bromide in acetic acid (33%) to give the α-bromomethyl ketones 3.27 and 3.28, which were subsequently reduced to give the α-bromomethyl alcohols 3.29-3.32. Under basic conditions the α-bromomethyl alcohols 3.29-3.32 ring-closed to form the peptidyl epoxides 3.33-3.36. Chapter Four introduces the disadvantages of peptide-based inhibitors. A discussion is given on the benefits of constraining inhibitors into the extended bioactive conformation known as a β-strand. Ring closing metathesis is utilised in the synthesis of the macrocyclic aldehyde 4.4, macrocyclic semicarbazone 4.15, the macrocyclic cyanohydrin 4.16, the macrocyclic α-ketotetrazole 4.18 and the macrocyclic azide 4.19. Chapter Five introduces enzyme inhibition studies. The BODIPY-casein fluorogenic assay used for establishing inhibitor potency against m-calpain and μ-calpain is validated. Assay protocols are also established and validated for cathepsin B, papain, pepsin and α- chymotrypsin. A discussion of the effect of solvent on enzyme activity is also included as part of this study. Chapter Six presents the assay results for all the inhibitors synthesised throughout this thesis and an extensive structure-activity relationship study between inhibitors is included. The alcohols 2.26 and 2.30 are unprecedented examples of non-covalent, potent, cathepsin B inhibitors (IC₅₀ = 0.075 μM selectivity 80-fold and 1.1 μM, selectivity 18-fold). The macrocyclic semicarbazone 4.15 is an unprecedented example of a potent macrocyclic cysteine protease inhibitor (m-calpain: IC₅₀ = 0.16 μM, selectivity 8-fold). The cyanohydrin 2.51 contains an unprecedented cysteine protease warhead and is a potent and selective inhibitor of papain (IC₅₀ = 0.030 μM, selectivity 3-fold). The O-protected cyanohydrin 2.61 is a potent and selective inhibitor of pepsin (IC₅₀ = 1.6 μM, selectivity 1.5-fold). The top ten warheads for potent, selective cathepsin B inhibition are: carboxylic acid, methyl ester, diazoketone, esterified cyanohydrin, α-bromomethyl ketone, α,β- unsaturated aldehyde, vinyl sulfones, α-bromomethyl-C₃-S,R-alcohol, alcohol and α,β- unsaturated ethyl ester. The selectivity of these warheads was between 5- and 130-fold for cathepsin B. The best inhibitors for cathepsin B were the α-bromomethyl ketone 3.26 (IC₅₀ = 0.075 μM, selectivity 16-fold), the α,β-unsaturated aldehyde 3.18 (IC₅₀ = 0.13 μM, selectivity 13-fold) and the esterified cyanohydrin 3.59 (IC₅₀ = 0.35 μM, selectivity 22- fold). Chapter Seven outlines the experimental details and synthesis of the compounds prepared in this thesis.

Thesis (Ph. D.)--School of Pharmacy. University of Missouri--Kansas City, 2007. / "A dissertation in pharmaceutical science and pharmacology." Advisor: Ashim K. Mitra. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed July 16, 2008. Includes bibliographical references (leaves 231-248). Online version of the print edition.

Thesis (Ph.D. (Chemistry)) - Rhodes University, 2008.

Orientador: Sergio Roberto Peres Line / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-10T16:39:26Z (GMT). No. of bitstreams: 1 EspiritoSanto_AlexandreRibeirodo_D.pdf: 9422040 bytes, checksum: 9034465ff462c933a4d9d5ab9721b610 (MD5) Previous issue date: 2008 / Resumo: O esmalte envolve a porção coronária dos dentes e constitui a estrutura mais mineralizada do corpo vertebrado. Seu desenvolvimento tem início com secreção, processamento proteolítico e auto-agregação de uma complexa mistura de proteínas. O estabelecimento de uma matriz orgânica ordenada parece ser fundamental para a formação adequada da fase mineral do esmalte. Microscopia de luz polarizada mostra que a matriz orgânica do esmalte secretório (MOES) apresenta-se fortemente birrefringente em cortes não corados de 5 µm de espessura. Esta propriedade reflete alto grau de organização em nível molecular com possível relevância funcional. Alterações no brilho de birrefringência da MOES podem indicar desordens moleculares e estar associadas a alterações na formação da fase mineral. Atraso no processo de fixação da MOES pode levar a uma rápida perda de sua birrefringência, comprometendo o seu estudo por meio de microscopia de luz polarizada. No presente trabalho, analisaram-se os efeitos do nocauteamento dos genes Amelx e Mmp20 (experimento 1), dos bisfosfonatos (experimento 2) e de inibidores de serina proteinases e metaloproteinases (experimento 3) sobre a birrefringência da MOES. O experimento 1 mostrou quecamundongos fêmeas Amelx+/- apresentam redução significativa no brilho debirrefringência quando comparados aos animais Amelx+/+ do mesmo gênero (p=0,0029). A MOES dos camundongos fêmeas Amelx-/- não exibiu birrefringência. Os camundongos Mmp20-/- mostraram uma expressiva diminuição nos valores de retardo ótico em comparação aos camundongos Mmp20+/+ e Mmp20+/- (p=0,0000). Os animais Mmp20+/+ e Mmp20+/- apresentaram birrefringência semelhante (p=1,0000). O experimento 2 mostrou que ratos tratados com alendronato de sódio não apresentam alterações morfológicas na MOES, mas exibem diminuiçãoexpressiva no brilho de birrefringência quando comparados a ratos controles (p<0,01). Interessantemente, os ratos tratados com etidronato dissódico apresentaram alterações morfológicas severas na MOES, mas mostraram brilho de birrefringência na matriz secretada semelhante ao dos ratos controles (p>0,05). O experimento 3 mostrou que a fenantrolina (inibidora de metaloproteinases, como a Mmp20) e o fenilmetilsulfonil fluoreto (inibidor de serina proteinases, como a Klk- 4) preservam a birrefringência da MOES ex vivo. Os resultados aqui apresentados sugerem que: 1) a birrefringência da MOES depende da organização supramolecular das amelogeninas e é influenciada pela atividade proteolítica da Mmp20; 2) o alendronato de sódio pode induzir alterações quantitativas na organização supramolecular da MOES; 3) o etidronato dissódico não altera a ordem molecular da matriz orgânica do esmalte secretada e pode induzir defeitos no esmalte maduro através de interferência direta sobre a atividade secretora dos ameloblastos; 4) a rápida perda de birrefringência da MOES em amostras não imediatamente fixadas é resultante da atividade de proteinases do esmalte. Palavras-chave: Esmalte dentário, Birrefringência, Bisfosfonatos, Fenantrolina, Fenilmetilsulfonil fluoreto / Abstract: Enamel covers dental crown and is the most mineralized structure in the vertebrate body. Its development begins with the secretion, processing and selfassembly of a complex mixture of proteins. The establishment of an ordered organic matrix seems to be a crucial step for the proper formation of enamel mineral phase. Polarizing microscopy shows that the secretory-stage enamel organic matrix (SEOM) is strongly birefringent in non-stained 5 µm-thick sections. This property indicates high level of molecular organization, which may be physiologically important. Changes in SEOM birefringence brightness may reflect molecular disorders and may be associated with alterations in the forming enamel mineral phase. Delay in fixation of SEOM may lead to rapid loss of birefringence, impairing analysis of that tissue with polarized light microscopy. In the present work, we analyzed the effects of Amelx and Mmp20 knocking out (experiment 1), bisphosphonates (experiment 2) and metallo and serine proteinases¿ inhibitors (experiment 3) on SEOM birefringence. Experiment 1 showed that Amelx+/- female mice exhibit a significant reduction in the birefringence brightness when compared to Amelx+/+ female animals. (p=0.0029). The SEOM from Amelx-/- female mice did not show birefringence. Mmp20-/- mice presented an expressive reduction in the optical retardation values in comparison to Mmp20+/+ and Mmp20+/- animals (p=0.0000). Mmp20+/+ and Mmp20+/- mice presented similar birefringence (p=1.0000). Experiment 2 showed that rats treated with sodium alendronate do not present morphological alterations in the SEOM, but exhibit significant decrease in the birefringence brightness when compared to control rats (p<0.01). Interestingly, bisodic etidronate rats showed severe morphological alterations in the SEOM, but exhibited SEOM birefringence brightness similar to that observed in control rats (p>0.05). Experiment 3 evidenced that 1,10-phenanthroline (metalloproteinase inhibitor) and phenylmethylsulphonyl fluoride (serine proteinase inhibitor) preserve SEOM birefringence brightness ex vivo. The results presented here support the following conclusions: 1) SEOM birefringence results from amelogenin supramolecular organization and is influenced by proteolytic activity of Mmp20; 2) sodium alendronate can induce quantitative changes in the supramolecular organization of the SEOM; 3) bisodic etidronate does not disturb molecular order of the secreted enamel organic matrix and may induce changes in mature enamel by affecting directly secretory activity of ameloblasts; 4) rapid loss of birefringence in no immediately fixed SEOM is caused by the activity of enamel proteinases. Key Words: Dental enamel, Birefringence, Bisphosphonates, Phenanthroline, Phenylmethylsulphonyl Fluoride / Doutorado / Histologia e Embriologia / Doutor em Biologia Buco-Dental

This study has focused on the synthesis of truncated analogues of the hydroxyethylene dipeptide isosteres, such as Ritonavir®, currently in clinical use as HIV-1 protease inhibitors. The reactions of pyridine-2- and quinoline-2-carbaldehydes with methyl acrylate, in the presence of 1,4-diazabicyclo[2.2.2]octane (DABCO) or 3- hydroxyquinuclidine (3-HQ) as nucleophilic catalysts, have afforded a series of Baylis- Hillman adducts, acetylation and cyclisation of which have provided access to a series of indolizine-2-carboxylate esters. The carboxylic acids, obtained by base-catalyzed hydrolysis of these esters, have been coupled with various protected (and unprotected) amino compounds using the peptide coupling agent, 1,1’-carbonyldiimidazole (CDI), to afford a series of indolizine-2-carboxamides as indolizine-based truncated Ritonavir® analogues in quantitative yield. Aza-Michael reactions of pyridine-3-carbaldehydederived Baylis-Hillman adducts with various amino compounds have provided access to a range of pyridine-based products as mixtures of diastereomeric aza-Michael products. The assignment of the relative stereochemistry of the aza-Michael products has been established using 1-D and 2-NOESY experiments and computer modelling techniques. Computer modelling studies have also been conducted on selected aza-Michael products using ACCELRYS Cerius2 software, followed by interactive docking into the HIV-1 protease receptor site, using AUTODOCK 4.0. The docking studies have revealed hydrogen-bonding interactions between the enzyme and the synthetic ligands. Saturation Transfer Difference (STD) NMR experiments have also indicated binding of some of the aza-Michael products to the HIV-1 protease subtype C enzyme, thus indicating their binding and possible inhibitory potential.

Despite the current interventions to avert contagions and AIDS-related deaths, sub-Saharan Africa is still the region most severely affected by the HIV/AIDS pandemic, where clade C is the dominant circulating HIV-1 strain. The pol-encoded HIV-1 protease enzyme has been extensively exploited as a drug target. Protease inhibitors have been engineered within the framework of clade B, the commonest in America, Europe and Australia. Recent studies have attested the existence of sequence and catalytic disparities between clades B and C proteases that could upset drug susceptibilities. Emergence of drug-resistant associated mutations and combinatorial explosions due to recombination thwarts the attempt to stabilize the current highly active antiretroviral therapy (HAART) baseline. The project aimed at identifying the structural and molecular mechanisms hired by mutants to affect the efficacies of both FDA approved and Rhodes University (RU)-synthesized inhibitors, in order to define how current and or future drugs ought to be modified or synthesized with the intent of combating drug resistance. The rationale involved the generation of homology models of the HIV-1 sequences from the South African infants failing treatment with two protease inhibitors: lopinavir and ritonavir (as monitored by alterations in surrogate markers: CD4 cell count decline and viral load upsurge). Consistent with previous studies, we established nine polymorphisms: 12S, 15V, 19I, 36I, 41K, 63P, 69K, 89M, and 93L, linked to subtype C wild-type; some of which are associated with protease treatment in clade B. Even though we predicted two occurrence patterns of M46I, I54V and V82A mutations as V82A→I54V→M46I and I54V→V82A→M46V, other possibilities might exist. Mutations either caused a protracted or contracted active site cleft, which enforced differential drug responses. The in silico docking indicated susceptibility discordances between clades B and C in certain polymorphisms and non-polymorphisms. The RU-synthesized ligands displayed varied efficacies that were below those of the FDA approved protease inhibitors. The flaps underwent a wide range of structural motions to accommodate and stabilize the ligands. Computational analyses unravelled the need for these potential drugs to be restructured by (de novo) drug engineers to improve their binding fits, affinities, energies and interactions with multiple key protease residues in order to target resilient HIV-1 assemblages. Accumulating evidences on contrasting drug-choice interpretations from the Stanford HIVdb should act as an impetus for the customization of a HIVdb for the sub-Saharan subcontinent.

A series of chromone-3-carbaldehydes have been prepared using Vilsmeier-Haack methodology while a corresponding series of chromone-2-carbaldeydes have been synthesized via the Kostanecki-Robinson reaction. Baylis-Hillman reactions have been conducted on both series of chromone carbaldehydes using three different catalysts, viz., 1,4-diazabicyclo(2.2.2]octane (DABCO), 1,8-diazabicyclo[5.4.0]undec- 7-ene (DBU) and 3-hydroxyquinuclidine (3HQ), and acrylonitrile, methyl acrylate and methyl vinyl ketone as the activated alkenes. These reactions have typically (but not always!) afforded both normal Baylis-Hillman and dimeric products. Attention has also been given to the use of 1-methyl-2-pyrrolidine (1-NMP), an ionic liquid, to replace normal organic solvents, and it has been found that, in the presence of DABCO, chromone-3-carbaldehydes afford the dimeric products alone. Reactions of chromone-3-carbaldehydes with methyl vinyl ketone have yielded unexpected, novel adducts, which appear to arise from preferential attack at C(2) in the chromone nucleus. Research on chromone-2-carbaldeydes under Baylis-Hillman conditions has also resulted in the formation of some interesting products instead of the expected Baylis-Hillman adducts. The Baylis-Hillman products have been explored as substrates for aza-Michael reactions using various amino derivatives including protected amino acids in the presence of the tetrabutylammonium bromide (TBAB) and the ionic liquid, 3-butyl-1- methylimidazoleboranetetrafluoride (BmimBF₄), as catalysts. The aza-Michael products have been targeted as truncated ritonavir analogues for investigation as potential HIV -1 protease inhibitors, and representative compounds have been subjected to enzyme inhibition assays to explore the extent and type of inhibition. Lineweaver-Burk and Dixon plots have indicated competitive inhibition in one case as well as non-competitive inhibition in another, and the inhibition constants (Ki) have been compared with that of the ritonavir. Computer modelling studies have also been conducted on selected chromonecontaining derivatives, using the ACCELRYS Cerius² platform. Interactive docking of the chromone-containing ligands into the HIV -1 protease receptor site, using the Ligandfit module, has indicated the importance of hydrogen-bonding interactions mediated by bridging water molecules situated in the receptor cavity. NMR spectroscopy has been used to elucidate complex and competing mechanistic pathways involved in the Baylis-Hillman reactions of selected 2-nitrobenzaldehydes with MVK in the presence of DABCO - reactions which afford the normal BaylisHillman product, the MVK dimer and syn- and anti-Baylis-Hillman type diadducts. The kinetic data confirm the concomitant operation of two pathways and reveal that, in the initial stage of the reaction, the product distribution is kinetically controlled, whereas in the latter stage, thermodynamic control results in the consumption of the normal Baylis-Hillman product and predominance of the anti-diadduct.

This thesis describes the design and synthesis of compounds that are intended to inhibit serine and aspartic proteases. The first part of the text deals with preparation of inhibitors of the hepatitis C virus (HCV) NS3 serine protease. Hepatitis C is predominantly a chronic disease that afflicts about 170 million people worldwide. The NS3 protease, encoded by HCV, is essential for replication of the virus and has become one of the main targets when developing drugs to fight HCV. The inhibitors discussed here constitute surrogates for the widely used N-acyl-hydroxyproline isostere designated 4-hydroxy-cyclopentene. The stereochemistry of the 4-hydroxy-cyclopentene scaffold was determined by nuclear overhauser effect spectroscopy (NOESY) and the regiochemistry by heteronuclear multiple bond correlation (HMBC). The scaffold was decorated with different substituents to obtain both linear and macrocyclic HCV NS3 protease inhibitors that display low nanomolar activity. The second part of the thesis describes the design and synthesis of potential aspartic protease inhibitors. The hydroxyethylene motif was used as a noncleavable transition state isostere. The synthetic route yielded a pivotal intermediate with excellent stereochemical control, which was corroborated by NOESY experiments. This intermediate can be diversified with different substituents to furnish novel aspartic protease inhibitors. / <p>Report code: LIU-TEK-LIC-2006:45</p>

Les patients infectés par le VIH (Virus de l'Immunodéficience Humaine) traités par les antirétroviraux (ARV) ont aujourd'hui une espérance de vie quasi normale. Cependant, ils présentent une augmentation de la prévalence de pathologies classiquement associées au vieillissement, dont l'ostéoporose, suggérant un vieillissement prématuré ou accentué. Les facteurs impliqués sont, entre autres, l'infection par le VIH, les ARV et un état d'inflammation chronique. L'ostéoporose correspond à une déminéralisation, suite à un déséquilibre entre formation (ostéoblastes) et résorption osseuse (ostéoclastes). L'infection par le VIH et les ARV, en particulier les inhibiteurs de protéase (PI), augmentent la prévalence de l'ostéoporose. Dans ce contexte, je me suis intéressée à l'effet de certaines protéines du VIH et PI sur les précurseurs ostéoblastiques, les cellules souches mésenchymateuses (MSC). Nous montrons que deux protéines du VIH, Tat et Nef, induisent une sénescence prématurée des MSC, associée à un stress oxydant et in fine à un défaut de différenciation en ostéoblastes. Les effets de Tat sont médiés par le facteur pro-inflammatoire et pro-sénescent NF-?B, et ceux de Nef sont liés à une inhibition de l'autophagie. Nous montrons également que les PI atazanavir et lopinavir associés au ritonavir induisent une sénescence et un stress oxydant du fait de l'accumulation de prélamine A farnésylée toxique conduisant à un déficit de la différentiation ostéoblastique. Ces travaux montrent que le VIH et certains PI peuvent jouer un rôle délétère sur les MSC, et mettent en lumière certains des mécanismes impliqués dans le vieillissement des patients infectés par le VIH et traités. / The efficacy of highly active antiretroviral treatment (ARV) has resulted in a considerable improvement in the life expectancy of HIV (Human Immunodeficiency Virus)-infected patients. However, many patients encounter the early occurrence of several common age-related comorbidities, such as osteoporosis, stressing for a premature or accentuated aging process. Proposed pathogenic mechanisms include HIV infection, ARV treatment and chronic inflammation. Osteoporosis is defined by a decrease in bone mineral density, resulting from the alteration of the balance between bone formation (osteoblasts) and resorption (osteoclasts). HIV infection, through the bystander effect of HIV secreted proteins, and ARV, particularly protease inhibitors (PI) increase the prevalence of osteoporosis.Our studies focused on the capacity of some HIV proteins, and of some PI to alter osteoblast precursors, namely mesenchymal stem cells (MSC). We showed that two HIV proteins, Tat and Nef, induced premature senescence of MSC, associated with an oxidative stress and a decreased osteoblastic differentiation potential. Tat triggered senescence via NF-κB activation, whereas the effect of Nef was linked to the inhibition of autophagy. We also showed that the PI, atazanavir and lopinavir boosted with ritonavir, induced senescence and oxidative stress through the accumulation of toxic farnesylated prelamin A, thus leading to a decreased osteoblastic differentiation.Overall, these data show that some HIV proteins and some PI can exert deleterious effects on MSC, resulting in senescence, and highlight several mechanisms which could be involved in the aging process of ART-controlled HIV infected patients.