The Secreted Aminopeptidase of Pseudomonas aeruginosa (PaAP).

Pseudomonas aeruginosa is an opportunistic pathogen that causes severe infections in compromised hosts. P. aeruginosa infections are difficult to treat because of the inherent ability of the bacteria to develop antibiotic resistance, secrete a variety of virulence factors, and form biofilms. The secreted aminopeptidase (PaAP) is an emerging virulence factor, key in providing essential low molecular weight nutrients and a cardinal modulator of biofilm development. PaAP is therefore a new potential target for therapy of P. aeruginosa infections. The present review summarizes the current knowledge of PaAP, with special emphasis on its biochemical and enzymatic properties, activation mechanism, biological roles, regulation, and structure. Recently developed specific inhibitors and their potential as adjuncts in the treatment of P. aeruginosa infections are also described.

Inhibitors of Rickettsia prowazekii methionine aminopeptidase 1 identified from the Pandemic Response Box.

Methionine aminopeptidase (MetAp) enzymes catalyze the post-translational removal of the initiator methionine residue in newly synthesized proteins, a process that is often essential in the maturation of proteins. Consequently, these enzymes serve as important targets for drug development. Rickettsia prowazekii (Rp) is an obligate coccobacillus and the causative agent of the louse-borne epidemic typhus and despite adequate treatment causes a latent infection. This research aimed to identify potential anti-rickettsial agents by screening 400 compounds from the MMV Pandemic Response Box against RpMetAp1. Overall, 19 compounds were identified that possessed IC50 values from 10 µM to 340 nM. The most potent inhibitor was MMV 1580488 (17), which was observed to have an IC50 of 340 nM. The selected hits serve as chemical leads that can be used for the development of potent inhibitors of the RpMetAp1 enzyme.

The effect of rs2910686 on ERAP2 expression in IBD and epithelial inflammatory response.

BACKGROUND: ERAP2 is an aminopeptidase involved in antigen processing and presentation, and harbor genetic variants linked to several inflammatory diseases such as Inflammatory Bowel Disease (IBD). The lack of an ERAP2 gene homologue in mice has hampered functional studies, and most human studies have focused on cells of hematopoietic origin. Using an IBD biobank as vantage point, this study explores how genetic variation in ERAP2 affects gene expression in human-derived epithelial organoids upon proinflammatory stimulation. METHODS: An IBD patient cohort was genotyped with regards to two single nucleotide polymorphisms (SNP) (rs2910686/rs2248374) associated with ERAP2 expression levels, and we examined the correlation between colon gene expression and genotype, specifically aiming to establish a relationship with ERAP2 expression proficiency. Human-derived colon organoids (colonoids) with known ERAP2 genotype were established and used to explore differences in whole genome gene expression between ERAP2-deficient (n = 4) and -proficient (n = 4) donors upon pro-inflammatory encounter. RESULTS: When taking rs2910686 genotype into account, ERAP2 gene expression is upregulated in the inflamed colon of IBD patients. Colonoids upregulate ERAP2 upon IFNÉ£ stimulation, and ERAP2 expression proficiency is dependent on rs2910686 genotype. Colonoid genotyping confirms that mechanisms independent of the frequently studied SNP rs2248374 can cause ERAP2-deficiency. A total of 586 genes involved in various molecular mechanisms are differentially expressed between ERAP2 proficient- and deficient colonoids upon proinflammatory stimulation, including genes encoding proteins with the following molecular function: catalytic activity (AOC1, CPE, ANPEP and MEP1A), regulator activity (TNFSF9, MDK, GDF15, ILR6A, LGALS3 and FLNA), transmembrane transporter activity (SLC40A1 and SLC5A1), and extracellular matrix structural constituents (FGL2, HMCN2, and MUC17). CONCLUSIONS: ERAP2 is upregulated in the inflamed IBD colon mucosa, and expression proficiency is highly correlated with genotype of rs2910686. While the SNP rs2248374 is commonly used to determine ERAP2 expressional proficiency, our data confirms that mechanisms independent of this SNP can lead to ERAP2 deficiency. Our data demonstrates that epithelial ERAP2 presence affects the inflammatory response in colonoids, suggesting a pleiotropic role of ERAP2 beyond MHC class I antigen processing.

Carnosic Acid: A Novel Selective Inhibitor of ERAP1 by Direct Binding and Its Modulation of Antigen Processing and Presentation.

ERAP1 is an emerging target for a large subclass of severe autoimmune diseases known as "MHC-I-opathy", together with tumor immunity. Nevertheless, effective inhibitors targeting ERAP1 remain a challenge. In this study, a novel food-derived natural product ERAP1-targeting inhibitor, carnosic acid, was identified, and to our knowledge, it is one of the best active compounds among the highly selective inhibitors targeting the orthosteric site of ERAP1. The results reveal that carnosic acid could bind strongly, like a key to the ERAP1 active site in the biased S1' pocket, which is different from the binding mode of the existing orthosteric site inhibitors. HLA-B27-mediated cell modeling validated that carnosic acid has the activity to reverse the AS-associated cellular phenotype brought on by ERAP1 through inhibition. Our findings provide insights into the design of potent inhibitors against the ERAP1 orthosteric site and the discovery of a key direct target of carnosic acid.

Biology of HLA class I associated inflammatory diseases.

Human leukocyte antigen (HLA) class I association is a well-established feature of common and uncommon inflammatory diseases, but it is unknown whether it impacts the pathogenesis of these disorders. The "arthritogenic peptide" hypothesis proposed initially for HLA-B27-associated ankylosing spondylitis (AS) seems the most intuitive to serve as a model for other HLA class I-associated diseases, but evidence supporting it has been scarce. Recent technological advances and the discovery of epistatic relationships between disease-associated HLA class I and endoplasmic reticulum aminopeptidase (ERAP) coding variants have led to the generation of new data and conceptual approaches to the problem requiring its re-examination. Continued success in these endeavors holds promise to resolve a Gordian Knot in human immunobiology. It may ultimately benefit patients by enabling the development of new therapies and precision tools for assessing disease risk and predicting treatment responses.

Association of Endoplasmic Reticulum Aminopeptidase 1 Gene Polymorphism with Susceptibility and Severity of Axial Spondyloarthritis in Egyptian Population: A Single-center Case-Control Study.

BACKGROUND: Axial spondyloarthritis (axSpA) is a systemic, progressive, autoimmune disease. Complex interactions between environmental factors and host immune responses are the origin of axSpA. Together with human leukocyte antigen (HLA-B27), endoplasmic reticulum aminopeptidase 1 (ERAP1) gene is a potential non-HLA contributor to axSpA susceptibility. AIM: This study aimed to identify the role of ERAP1 single-nucleotide polymorphisms (SNPs) (rs30187, rs27044, and rs27037) in susceptibility to and severity of axSpA in Egyptian patients. METHODS: In this case-control study, we enrolled 120 patients with axSpA and 120 healthy individuals as controls. Real-time polymerase chain reaction was used to identify ERAP1 polymorphisms. RESULTS: The present study revealed no significant association between ERAP1 SNPs (rs30187, rs27044, and rs27037) and axSpA susceptibility in Egyptian patients. A significant relationship was found only between the ERAP1 SNP rs27037 "GT" genotype and axSpA HLA-B27-positive cases, demonstrating a functional interaction between ERAP1 and HLA-B27-positive cases. Our analysis revealed a significant association between the ERAP1 SNP rs27037 "GT and TT" genotypes and Bath Ankylosing Spondylitis Disease Activity Index, in addition to an association between the ERAP1 SNP rs27037 "TT" genotype and active enthesitis. The ERAP1 SNP rs27044 "GG" genotype was significantly associated with active enthesitis, but not with clinical axial involvement. Finally, we did not observe a significant relationship between HLA-B27 positivity and disease severity in the studied cases. CONCLUSION: Three SNPs (rs30187, rs27044, and rs27037) in ERAP1 do not confer susceptibility to axSpA in Egyptian patients. This association existed exclusively between the ERAP1 SNP (rs27037) "GT" genotype and axSpA HLA-B27-positive cases.

Résumé Contexte:la spondyloarthrite axiale (SpAx) est une maladie auto-immune systémique et progressive. Les interactions complexes entre les facteurs environnementaux et les réponses immunitaires de l'hôte sont à l'origine de la SpAx. En plus de l'antigène leucocytaire humain (HLAB27), le gène de l'aminopeptidase du réticulum endoplasmique 1 (ERAP1) est un contributeur potentiel non-HLA à la susceptibilité à la SpAx.Objectif:cette étude visait à identifier le rôle des polymorphismes mononucléotidiques (SNP) de l'ERAP1 (rs30187, rs27044 et rs27037) dans la susceptibilité et la gravité de la SpAx chez les patients égyptiens.Méthodes:dans cette étude cas-témoins, nous avons inclus 120 patients atteints de SpAx et 120 individus en bonne santé comme témoins. La réaction en chaîne de la polymérase en temps réel a été utilisée pour identifier les polymorphismes de l'ERAP1.Résultats:cette étude a révélé qu'il n'y avait pas d'association significative entre les SNP de l'ERAP1 (rs30187, rs27044 et rs27037) et la susceptibilité à la SpAx chez les patients égyptiens. Une relation significative a été trouvée uniquement entre le génotype "GT" du SNP rs27037 de l'ERAP1 et les cas de SpAx positifs pour le HLA-B27, démontrant une interaction fonctionnelle entre l'ERAP1 et les cas positifs pour le HLA-B27. Notre analyse a révélé une association significative entre les génotypes "GT et TT" du SNP rs27037 de l'ERAP1 et l'indice d'activité de la maladie de spondylarthrite ankylosante de Bath, ainsi qu'une association entre le génotype "TT" du SNP rs27037 de l'ERAP1 et l'enthésite active. Le génotype "GG" du SNP rs27044 de l'ERAP1 était significativement associé à l'enthésite active, mais non à l'atteinte axiale clinique. Enfin, nous n'avons pas observé de relation significative entre la positivité du HLA-B27 et la gravité de la maladie dans les cas étudiés.Conclusion:trois SNP (rs30187, rs27044 et rs27037) dans l'ERAP1 ne confèrent pas de susceptibilité à la SpAx chez les patients égyptiens. Cette association existait exclusivement entre le génotype "GT" du SNP rs27037 de l'ERAP1 et les cas de SpAx positifs pour le HLA-B27.

Substrate Characterization for Hydrolysis of Multiple Types of Aromatic Esters by Promiscuous Aminopeptidases.

Synthetic aromatic esters, widely employed in agriculture, food, and chemical industries, have become emerging environmental pollutants due to their strong hydrophobicity and poor bioavailability. This study attempted to address this issue by extracellularly expressing the promiscuous aminopeptidase (Aps) from Pseudomonas aeruginosa GF31 in B. subtilis, achieving an impressive enzyme activity of 13.7 U/mg. Notably, we have demonstrated, for the first time, the Aps-mediated degradation of diverse aromatic esters, including but not limited to pyrethroids, phthalates, and parabens. A biochemical characterization of Aps reveals its esterase properties and a broader spectrum of substrate profiles. The degradation rates of p-nitrobenzene esters (p-NB) with different side chain structures vary under the action of Aps, showing a preference for substrates with relatively longer alkyl side chains. The structure-dependent degradability aligns well with the binding energies between Aps and p-NB. Molecular docking and enzyme-substrate interaction elucidate that hydrogen bonding, hydrophobic interactions, and π-π stacking collectively stabilize the enzyme-substrate conformation, promoting substrate hydrolysis. These findings provide new insights into the enzymatic degradation of aromatic ester pollutants, laying a foundation for the further development and modification of promiscuous enzymes.

Chemoproteomics validates selective targeting of Plasmodium M1 alanyl aminopeptidase as an antimalarial strategy.

New antimalarial drug candidates that act via novel mechanisms are urgently needed to combat malaria drug resistance. Here, we describe the multi-omic chemical validation of Plasmodium M1 alanyl metalloaminopeptidase as an attractive drug target using the selective inhibitor, MIPS2673. MIPS2673 demonstrated potent inhibition of recombinant Plasmodium falciparum (PfA-M1) and Plasmodium vivax (PvA-M1) M1 metalloaminopeptidases, with selectivity over other Plasmodium and human aminopeptidases, and displayed excellent in vitro antimalarial activity with no significant host cytotoxicity. Orthogonal label-free chemoproteomic methods based on thermal stability and limited proteolysis of whole parasite lysates revealed that MIPS2673 solely targets PfA-M1 in parasites, with limited proteolysis also enabling estimation of the binding site on PfA-M1 to within ~5 Å of that determined by X-ray crystallography. Finally, functional investigation by untargeted metabolomics demonstrated that MIPS2673 inhibits the key role of PfA-M1 in haemoglobin digestion. Combined, our unbiased multi-omic target deconvolution methods confirmed the on-target activity of MIPS2673, and validated selective inhibition of M1 alanyl metalloaminopeptidase as a promising antimalarial strategy.

The association between endoplasmic reticulum aminopeptidase 2 gene single nucleotide polymorphisms and the risk of psoriasis and psoriatic arthritis in Egyptians.

BACKGROUND: Psoriasis (Ps) is a disorder attributed to the immune system that involves inflammation of the skin and joints. Psoriasis is a multifactorial disorder in which genetic factors represent about 70% of the disease risk. This study aims to establish the correlation between the ERAP2 gene's single nucleotide polymorphisms (SNPs) rs2910686 and rs2248374 with the susceptibility to Ps and/or psoriatic arthritis (PsA) among the Egyptian population. METHODS AND RESULTS: Genotyping of ERAP2 gene SNPs (rs2910686 and rs2248374) in 120 psoriatic patients with and without arthritis and 100 controls was done using real-time PCR. The genotype frequency and distribution of the ERAP2 SNP (rs2910686 and rs2248374) were in Hardy-Weinberg equilibrium (HWE). For rs2910686, the TC and CC genotypes and C allele frequency were significant risk factors for PsA compared to the controls (OR = 5.708, OR = 10.165, and OR = 4.282, respectively). They also were significant risk factors for Ps compared to the controls (OR = 5.165, OR = 5.040, and OR = 3.258, respectively). For rs2248374, the AG genotype significantly increased the risk of PsA (OR = 2.605) and Ps (OR = 3.768) compared to controls. The AG genotype was significantly related to the risk of Ps (OR = 3.369) G allele with PsA (OR = 1.608) and Ps (OR = 1.965) compared to controls. CONCLUSION: In Egyptian individuals, the ERAP2 gene polymorphisms (rs2248374 and rs2910686) may contribute genetically to the pathophysiology of psoriasis and PsA.

Epistatic interaction between ERAP2 and HLA modulates HIV-1 adaptation and disease outcome in an Australian population.

A strong genetic predictor of outcome following untreated HIV-1 infection is the carriage of specific alleles of human leukocyte antigens (HLAs) that present viral epitopes to T cells. Residual variation in outcome measures may be attributed, in part, to viral adaptation to HLA-restricted T cell responses. Variants of the endoplasmic reticulum aminopeptidases (ERAPs) influence the repertoire of T cell epitopes presented by HLA alleles as they trim pathogen-derived peptide precursors to optimal lengths for antigen presentation, along with other functions unrelated to antigen presentation. We investigated whether ERAP variants influence HLA-associated HIV-1 adaptation with demonstrable effects on overall HIV-1 disease outcome. Utilizing host and viral data of 249 West Australian individuals with HIV-1 subtype B infection, we identified a novel association between two linked ERAP2 single nucleotide polymorphisms (SNPs; rs2248374 and rs2549782) with plasma HIV RNA concentration (viral load) (P adjusted = 0.0024 for both SNPs). Greater HLA-associated HIV-1 adaptation in the HIV-1 Gag gene correlated significantly with higher viral load, lower CD4+ T cell count and proportion; P = 0.0103, P = 0.0061, P = 0.0061, respectively). When considered together, there was a significant interaction between the two ERAP2 SNPs and HLA-associated HIV-1 adaptation on viral load (P = 0.0111). In a comprehensive multivariate model, addition of ERAP2 haplotypes and HLA associated adaptation as an interaction term to known HLA and CCR5 determinants and demographic factors, increased the explanatory variance of population viral load from 17.67% to 45.1% in this dataset. These effects were not replicated in publicly available datasets with comparably sized cohorts, suggesting that any true global epistasis may be dependent on specific HLA-ERAP allelic combinations. Our data raises the possibility that ERAP2 variants may shape peptide repertoires presented to HLA class I-restricted T cells to modulate the degree of viral adaptation within individuals, in turn contributing to disease variability at the population level. Analyses of other populations and experimental studies, ideally with locally derived ERAP genotyping and HLA-specific viral adaptations are needed to elucidate this further.

[Relationship between maternal and fetal ERAP-1 gene polymorphism and pre-eclampsia].

Objective: To investigate the relationship between the polymorphism of endoplasmic reticulum aminopeptidase 1 (ERAP-1) gene and the occurrence of pre-eclampsia (PE). Methods: A case-control study was conducted in Beijing Obstetrics and Gynecology Hospital from October 2018 to October 2021. A total of 51 PE pregnant women with onset gestational age<34 weeks were selected as the PE group, and 48 normal pregnant women during the same period were selected as the control group. Venous blood samples were collected from the pregnant women before delivery and umbilical cord within 5 minutes after delivery. Single nucleotide polymorphisms (SNP) of ERAP-1 gene in the pregnant women and their fetus were detected by next-generation sequencing. Univariate analysis and multivariate logistic regression analysis were used to analyze all the SNP loci and alleles detected in the two groups, and the significant SNP were screened. Results: (1) A total of 13 target SNP loci of maternal ERAP-1 gene were selected by univariate analysis. Among them, the frequency distribution of genotypes at 96096828, 96121524, 96121715, 96122260 and 96122281 showed statistically significant differences between PE group and control group (all P<0.05). Multivariate logistic regression analysis showed that the risk of PE in pregnant women with TC genotype at locus 96121524 was 2.002 times higher than those with TT genotype (95%CI: 0.687-5.831, P=0.020). (2) A total of 4 target SNP loci of ERAP-1 gene in fetal were selected by univariate analysis, and there was no statistical significance in gene polymorphism of the 4 loci between PE group and control group (all P>0.05). Multivariate logistic regression analysis showed that the risk of PE in fetus with genotype AA at locus 96121406 was 0.236 times that of fetus with genotype GG (95%CI: 0.055-1.025, P=0.016). Conclusion: ERAP-1 gene with TC genotype at 96121524 in the mother and GG genotype at 96121406 in the fetus might be related to the incidence of PE.

ERAP Inhibitors in Autoimmunity and Immuno-Oncology: Medicinal Chemistry Insights.

Endoplasmic reticulum aminopeptidases ERAP1 and 2 are intracellular aminopeptidases that trim antigenic precursors and generate antigens presented by major histocompatibility complex class I (MHC-I) molecules. They thus modulate the antigenic repertoire and drive the adaptive immune response. ERAPs are considered as emerging targets for precision immuno-oncology or for the treatment of autoimmune diseases, in particular MHC-I-opathies. This perspective covers the structural and biological characterization of ERAP, their relevance to these diseases and the ongoing research on small-molecule inhibitors. We describe the chemical and pharmacological space explored by medicinal chemists to exploit the potential of these targets given their localization, biological functions, and family depth. Specific emphasis is put on the binding mode, potency, selectivity, and physchem properties of inhibitors featuring diverse scaffolds. The discussion provides valuable insights for the future development of ERAP inhibitors and analysis of persisting challenges for the translation for clinical applications.

ERAMER: A novel in silico tool for prediction of ERAP1 enzyme trimming.

MHC class I pathway consists of four main steps: proteasomal cleavage in the cytosol in which precursor proteins are cleaved into smaller peptides, which are then transported into the endoplasmic reticulum by the transporter associated with antigen processing, TAP, for further processing (trimming) from the N-terminal region by an ER resident aminopeptidases 1 (ERAP1) enzyme, to generate optimal peptides (8-10 amino acids in length) to produce a stable MHCI-peptide complex, that get transited via the Golgi apparatus to the cell surface for presentation to the cellular immune system. Several studies reported specificities related to the ERAP1 trimming process, yet there is no in silico tool for the prediction of the trimming process of the ERAP1 enzyme. In this paper, we provide and implement a prediction model for the trimming process of the ERAP1 enzyme.

Modulation of endogenous opioid signaling by inhibitors of puromycin-sensitive aminopeptidase.

The endogenous opioid system regulates pain through local release of neuropeptides and modulation of their action on opioid receptors. However, the effect of opioid peptides, the enkephalins, is short-lived due to their rapid hydrolysis by enkephalin-degrading enzymes. In turn, an innovative approach to the management of pain would be to increase the local concentration and prolong the stability of enkephalins by preventing their inactivation by neural enkephalinases such as puromycin-sensitive aminopeptidase (PSA). Our previous structure-activity relationship studies offered the S-diphenylmethyl cysteinyl derivative of puromycin (20) as a nanomolar inhibitor of PSA. This chemical class, however, suffered from undesirable metabolism to nephrotoxic puromycin aminonucleoside (PAN). To prevent such toxicity, we designed and synthesized 5'-chloro substituted derivatives. The compounds retained the PSA inhibitory potency of the corresponding 5'-hydroxy analogs and had improved selectivity toward PSA. In vivo treatment with the lead compound 19 caused significantly reduced pain response in antinociception assays, alone and in combination with Met-enkephalin. The analgesic effect was reversed by the opioid antagonist naloxone, suggesting the involvement of opioid receptors. Further, PSA inhibition by compound 19 in brain slices caused local increase in endogenous enkephalin levels, corroborating our rationale. Pharmacokinetic assessment of compound 19 showed desirable plasma stability and identified the cysteinyl sulfur as the principal site of metabolic liability. We gained additional insight into inhibitor-PSA interactions by molecular modeling, which underscored the importance of bulky aromatic amino acid in puromycin scaffold. The results of this study strongly support our rationale for the development of PSA inhibitors for effective pain management.

A study of the association between single nucleotide polymorphisms of the endoplasmic reticulum aminopeptidase 2 (ERAP2) gene and the risk of ankylosing spondylitis in Egyptians.

BACKGROUND: Ankylosing spondylitis (AS) is often regarded as the prototypical manifestation of spondylo-arthropathies that prevalently involves the axial skeleton with the potential attribution of ERAP2 polymorphisms to AS predisposition. The purpose of this study was to determine the genetic association between ERAP2 gene rs2910686, and rs2248374 single nucleotide polymorphisms (SNPs) and the risk of ankylosing spondylitis in the Egyptian population. METHODS AND RESULTS: A cross-sectional work involved 200 individuals: 100 AS individuals diagnosed based on modified New York criteria in 1984 with 100 healthy controls matched in age and gender. The study included a comprehensive evaluation of historical data, clinical examinations, and evaluation of the activity of the disease using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). A comprehensive laboratory and radiological evaluation were conducted, accompanied by an assessment and genotyping of the ERAP2 gene variants rs2248374 and rs2910686. This genotyping was performed utilizing a real-time allelic discrimination methodology.Highly statistically substantial variations existed among the AS patients and the healthy control group regarding rs2910686 and rs2248374 alleles. There was a statistically significant difference between rs2910686 and rs2248374 regarding BASDAI, BASFI, mSASSS, ASQoL, V.A.S, E.S.R, and BASMI in the active AS group. CONCLUSIONS: ERAP2 gene SNPs have been identified as valuable diagnostic biomarkers for AS patients in the Egyptian population being a sensitive and non-invasive approach for AS diagnosis especially rs2910686. Highly statistically significant variations existed among the AS patients and the healthy control group regarding rs2910686 alleles and genotypes.Further research is recommended to explore the potential therapeutic implications of these SNPs.

Synthesis and Evaluation of diaryl ether modulators of the leukotriene A4 hydrolase aminopeptidase activity.

Activation of the aminopeptidase (AP) activity of leukotriene A4 hydrolase (LTA4H) presents a potential therapeutic strategy for resolving chronic inflammation. Previously, ARM1 and derivatives were found to activate the AP activity using the alanine-p-nitroanilide (Ala-pNA) as a reporter group in an enzyme kinetics assay. As an extension of this previous work, novel ARM1 derivatives were synthesized using a palladium-catalyzed Ullmann coupling reaction and screened using the same assay. Analogue 5, an aminopyrazole (AMP) analogue of ARM1, was found to be a potent AP activator with an AC50 of 0.12 µM. An X-ray crystal structure of LTA4H in complex with AMP was refined at 2.7 Å. Despite its AP activity with Ala-pNA substrate, AMP did not affect hydrolysis of the previously proposed natural ligand of LTA4H, Pro-Gly-Pro (PGP). This result highlights a discrepancy between the hydrolysis of more conveniently monitored chromogenic synthetic peptides typically employed in assays and endogenous peptides. The epoxide hydrolase (EH) activity of AMP was measured in vivo and the compound significantly reduced leukotriene B4 (LTB4) levels in a murine bacterial pneumonia model. However, AMP did not enhance survival in the murine pneumonia model over a 14-day period. A liver microsome stability assay showed metabolic stability of AMP. The results suggested that accelerated Ala-pNA cleavage is not sufficient for predicting therapeutic potential, even when the full mechanism of activation is known.

A current view of mitochondria damage and the diversity of lipopigment inclusions in neuronal ceroid lipofuscinose type 2 from rectal biopsy.

Neuronal ceroid lipofuscinoses (NCLs) are a growing group of neurodegenerative storage diseases, in which specific features are sought to facilitate the creation of a universal diagnostic algorithm in the future. In our ultrastructural studies, the group of NCLs was represented by the CLN2 disease caused by a defect in the TPP1 gene encoding the enzyme tripeptidyl-peptidase 1. A 3.5-year-old girl was affected by this disease. Due to diagnostic difficulties, the spectrum of clinical, enzymatic, and genetic tests was extended to include analysis of the ultrastructure of cells from a rectal biopsy. The aim of our research was to search for pathognomonic features of CLN2 and to analyse the mitochondrial damage accompanying the disease. In the examined cells of the rectal mucosa, as expected, filamentous deposits of the curvilinear profile (CVP) type were found, which dominated quantitatively. Mixed deposits of the CVP/fingerprint profile (FPP) type were observed less frequently in the examined cells. A form of inclusions of unknown origin, not described so far in CLN2 disease, were wads of osmophilic material (WOMs). They occurred alone or co-formed mixed deposits. In addition, atypically damaged mitochondria were observed in muscularis mucosae. Their deformed cristae had contact with inclusions that looked like CVPs. Considering the confirmed role of the c subunit of the mitochondrial ATP synthase in the formation of filamentous lipopigment deposits in the group of NCLs, we suggest the possible significance of other mitochondrial proteins, such as mitochondrial contact site and cristae organizing system (MICOS), in the formation of these deposits. The presence of WOMs in the context of searching for ultrastructural pathognomonic features in CLN2 disease also requires further research.

A needle in a haystack? The impact of a targeted epilepsy gene panel in the identification of a treatable but rapidly progressive metabolic epilepsy: CLN2 disease.

BACKGROUND: Neuronal ceroid lipofuscinoses (NCL) are a group of autosomal recessive, inherited, lysosomal, and neurodegenerative diseases that causes progressive dementia, seizures, movement disorders, language delay/regression, progressive visual failure, and early death. Neuronal ceroid lipofuscinosis type 2 (CLN2), caused by biallelic pathogenic variants of the TPP1 gene, is the only NCL with an approved targeted therapy. The laboratory diagnosis of CLN2 is established through highly specific tests, leading to diagnostic delays and eventually hampering the provision of specific treatment for patients with CLN2. Epilepsy is a common and clinically-identifiable feature among NCLs, and seizure onset is the main driver for families to seek medical care. OBJECTIVE: To evaluate the results of the Latin America Epilepsy and Genetics Program, an epilepsy gene panel, as a comprehensive tool for the investigation of CLN2 among other genetic causes of epilepsy. METHODS: A total of 1,284 patients with epilepsy without a specific cause who had at least 1 symptom associated with CLN2 were screened for variants in 160 genes associated with epilepsy or metabolic disorders presenting with epilepsy through an epilepsy gene panel. RESULTS: Variants of the TPP1 gene were identified in 25 individuals (1.9%), 21 of them with 2 variants. The 2 most frequently reported variants were p.Arg208* and p.Asp276Val, and 2 novel variants were detected in the present study: p.Leu308Pro and c.89 + 3G > C Intron 2. CONCLUSION: The results suggest that these genetic panels can be very useful tools to confirm or exclude CLN2 diagnosis and, if confirmed, provide disease-specific treatment for the patients.

ANTECEDENTES: As lipofuscinoses ceroides neuronais (neuronal ceroid lipofuscinoses, NCLs, em inglês) são um grupo de doenças autossômicas recessivas, hereditárias, lisossomais e neurodegenerativas que causam demência progressiva, crises epiléticas, distúrbios de movimento, atraso/regressão da linguagem, deficiência visual progressiva e morte precoce. A lipofuscinose ceroide neuronal tipo 2 (neuronal ceroid lipofuscinosis type 2, CLN2, em inglês), causada por variantes patogênicas bialélicas do gene TPP1, é a única com terapia-alvo aprovada. O diagnóstico laboratorial é realizado por testes específicos, o que leva a atrasos diagnósticos e, consequentemente, prejudica a disponibilização de tratamento. A epilepsia é uma característica comum e clinicamente identificável entre as NCLs, e o início das convulsões é o principal motivo para as famílias buscarem atendimento médico. OBJETIVO: Avaliar os resultados do Programa de Epilepsia e Genética da América Latina, um painel genético, como uma ferramenta abrangente para a investigação de CLN2 entre outras causas genéticas de epilepsia. MéTODOS: Um total de 1.284 pacientes com epilepsia sem uma causa específica e que tinham pelo menos 1 sintoma associado à CLN2 foram rastreados em busca de variantes em 160 genes associados à epilepsia ou a distúrbios metabólicos que apresentam epilepsia, por meio de um painel genético. RESULTADOS: Variantes do gene TPP1 foram identificadas em 25 indivíduos (1,9%), sendo que ; 21 apresentavam duas variantes. As duas variantes mais frequentes foram p.Arg208* e p.Asp276Val, e duas variantes novas foram detectadas neste: p.Leu308Pro e c.89 + 3G > C Intron 2. CONCLUSãO: Os resultados sugerem que os painéis genéticos de epilepsia podem ser uma ferramenta útil para confirmar ou excluir o diagnóstico de CLN2 e, se confirmado, fornecer tratamento específico para os pacientes.

On-target, dual aminopeptidase inhibition provides cross-species antimalarial activity.

To combat the global burden of malaria, development of new drugs to replace or complement current therapies is urgently required. Here, we show that the compound MMV1557817 is a selective, nanomolar inhibitor of both Plasmodium falciparum and Plasmodium vivax aminopeptidases M1 and M17, leading to inhibition of end-stage hemoglobin digestion in asexual parasites. MMV1557817 can kill sexual-stage P. falciparum, is active against murine malaria, and does not show any shift in activity against a panel of parasites resistant to other antimalarials. MMV1557817-resistant P. falciparum exhibited a slow growth rate that was quickly outcompeted by wild-type parasites and were sensitized to the current clinical drug, artemisinin. Overall, these results confirm MMV1557817 as a lead compound for further drug development and highlights the potential of dual inhibition of M1 and M17 as an effective multi-species drug-targeting strategy.IMPORTANCEEach year, malaria infects approximately 240 million people and causes over 600,000 deaths, mostly in children under 5 years of age. For the past decade, artemisinin-based combination therapies have been recommended by the World Health Organization as the standard malaria treatment worldwide. Their widespread use has led to the development of artemisinin resistance in the form of delayed parasite clearance, alongside the rise of partner drug resistance. There is an urgent need to develop and deploy new antimalarial agents with novel targets and mechanisms of action. Here, we report a new and potent antimalarial compound, known as MMV1557817, and show that it targets multiple stages of the malaria parasite lifecycle, is active in a preliminary mouse malaria model, and has a novel mechanism of action. Excitingly, resistance to MMV15578117 appears to be self-limiting, suggesting that development of the compound may provide a new class of antimalarial.

Ceroid lipofuscinosis type 2 disease: Effective presymptomatic therapy-Oldest case of a presymptomatic enzyme therapy.

Neuronal ceroid lipofuscinosis type 2 (CLN2) disease is a rare, lysosomal storage disorder that causes pediatric onset neurodegenerative disease. It is characterized by mutations in the TPP1 gene. Symptoms begin between 2 and 4 years of age with loss of previously acquired motor, cognitive, and language abilities. Cerliponase alfa, a recombinant human TPP1 enzyme, is the only approved therapy. We report the first presymptomatic cerliponase alfa intraventricular treatment in a familial case of CLN2 related to a classical TPP1 variant. Sister 1 presented with motor, cognitive, and language decline and progressive myoclonic epilepsy since the age of 3 years, evolved with severe diffuse encephalopathy, received no specific treatment, and died at 11 years. Sister 2 had a CLN2 presymptomatic diagnosis and has been treated with cerliponase since she was 12 months old. She is now 6 years 8 months and has no CLN2 symptom except one generalized seizure 1 year ago. No serious adverse event has occurred. Repeated Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition standardized index scores are heterogeneous in the extremely low to low average ranges. Mean length of utterances, a global index of sentence complexity, showed a delay, but a gradual improvement. The reported case enhances the major contribution of presymptomatic diagnosis and significant middle-term treatment benefit for patients with CLN2.