A Slc38a8 Mouse Model of FHONDA Syndrome Faithfully Recapitulates the Visual Deficits of Albinism Without Pigmentation Defects.

Purpose: We aimed to generate and phenotype a mouse model of foveal hypoplasia, optic nerve decussation defects, and anterior segment dysgenesis (FHONDA), a rare disease associated with mutations in Slc38a8 that causes severe visual alterations similar to albinism without affecting pigmentation. Methods: The FHONDA mouse model was generated with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technology using an RNA guide targeting the Scl38a8 murine locus. The resulting mice were backcrossed to C57BL/6J. Melanin content was measured using spectrophotometry. Retinal cell architecture was analyzed through light and electron microscopy. Retinal projections to the brain were evaluated with anterograde labelling in embryos and adults. Visual function was assessed by electroretinography (ERG) and the optomotor test (OT). Results: From numerous Slc38a8 mouse mutant alleles generated, we selected one that encodes a truncated protein (p.196Pro*, equivalent to p.199Pro* in the human protein) closely resembling a mutant allele described in patients (p.200Gln*). Slc38a8 mutant mice exhibit wild-type eye and coat pigmentation with comparable melanin content. Subcellular abnormalities were observed in retinal pigment epithelium cells of Slc38a8 mutant mice. Anterograde labeling experiments of retinal projections in embryos and adults showed a reduction of ipsilateral fibers. Functional visual analyses revealed a decreased ERG response in scotopic conditions and a reduction of visual acuity in mutant mice measured by OT. Conclusions: Slc38a8 mutant mice recapitulate the phenotype of patients with FHONDA concerning their normal pigmentation and their abnormal visual system, in the latter being a hallmark of all types of albinism. These mice will be helpful in better understanding the pathophysiology of this genetic condition.

Genetics of non-syndromic and syndromic oculocutaneous albinism in human and mouse.

Oculocutaneous albinism (OCA) is the most frequent presentation of albinism, a heterogeneous rare genetic condition generally associated with variable alterations in pigmentation and with a profound visual impairment. There are non-syndromic and syndromic types of OCA, depending on whether the gene product affected impairs essentially the function of melanosomes or, in addition, that of other lysosome-related organelles (LROs), respectively. Syndromic OCA can be more severe and associated with additional systemic consequences, beyond pigmentation and vision alterations. In addition to OCA, albinism can also be presented without obvious skin and hair pigmentation alterations, in ocular albinism (OA), and a related genetic condition known as foveal hypoplasia, optic nerve decussation defects, and anterior segment dysgenesis (FHONDA). In this review, we will focus only in the genetics of skin pigmentation in OCA, both in human and mouse, updating our current knowledge on this subject.

Exploring the SAR of the ß-Ketoacyl-ACP Synthase Inhibitor GSK3011724A and Optimization around a Genotoxic Metabolite.

In the course of optimizing a novel indazole sulfonamide series that inhibits ß-ketoacyl-ACP synthase (KasA) of Mycobacterium tuberculosis, a mutagenic aniline metabolite was identified. Further lead optimization efforts were therefore dedicated to eliminating this critical liability by removing the embedded aniline moiety or modifying its steric or electronic environment. While the narrow SAR space against the target ultimately rendered this goal unsuccessful, key structural knowledge around the binding site of this underexplored target for TB was generated to inform future discovery efforts.

Easy-To-Synthesize Spirocyclic Compounds Possess Remarkable in Vivo Activity against Mycobacterium tuberculosis.

Society urgently needs new, effective medicines for the treatment of tuberculosis. To kick-start the required hit-to-lead campaigns, the libraries of pharmaceutical companies have recently been evaluated for starting points. The GlaxoSmithKline (GSK) library yielded many high-quality hits, and the associated data were placed in the public domain to stimulate engagement by the wider community. One such series, the spiro compounds, are described here. The compounds were explored by a combination of traditional in-house research and open source methods. The series benefits from a particularly simple structure and a short associated synthetic chemistry route. Many members of the series displayed striking potency and low toxicity, and highly promising in vivo activity in a mouse model was confirmed with one of the analogues. Ultimately the series was discontinued due to concerns over safety, but the associated data remain public domain, empowering others to resume the series if the perceived deficiencies can be overcome.

Synthesis, antimycobacterial activity and influence on mycobacterial InhA and PknB of 12-membered cyclodepsipeptides.

In recent years, several small natural cyclopeptides and cyclodepsipeptides were reported to have antimycobacterial activity. Following this lead, a synthetic pathway was developed for a small series of 12-membered ring compounds with one amide and two ester bonds (cyclotridepsipeptides). Within the series, the ring system proved to be necessary for growth inhibition of Mycobacterium smegmatis and Mycobacterium tuberculosis in the low micromolar range. Open-chain precursors and analogues were inactive. The compounds modulated autophosphorylation of the mycobacterial protein kinase B (PknB). PknB inhibitors were active at µM concentration against mycobacteria while inducers were inactive. PknB regulates the activity of the mycobacterial reductase InhA, the target of isoniazid. The activity of the series against Mycobacterium bovis BCG InhA overexpressing strains was indistinguishable from that of the parental strain suggesting that they do not inhibit InhA. All substances were not cytotoxic (HeLa > 5 µg/ml) and did not show any significant antiproliferative effect (HUVEC > 5 µg/ml; K-562 > 5 µg/ml). Within the scope of this study, the molecular target of this new type of small cyclodepsipeptide was not identified, but the data suggest interaction with PknB or other kinases may partly cause the activity.

Pomalidomide in the treatment of multiple myeloma: design, development and place in therapy.

Multiple myeloma is a very heterogeneous disease with variable survival. Despite recent progress and the widespread use of new agents, patients with relapsed and refractory disease have a poor outcome. Immunomodulatory drugs play a key role in both the front-line and the relapsed/refractory setting. The combination of pomalidomide (POM) and dexamethasone is safe and effective in relapsed and refractory patients, even in those with high-risk cytogenetic features. Furthermore, it can be used in most patients without the need to adjust according to the degree of renal failure. In order to further improve the results, POM-based triplet therapies are currently used. This article highlights the most relevant issues of POM and POM-based combinations in the relapsed/refractory multiple myeloma setting, from a pharmacological and clinical point of view.

N-Benzyl-4-((heteroaryl)methyl)benzamides: A New Class of Direct NADH-Dependent 2-trans Enoyl-Acyl Carrier Protein Reductase (InhA) Inhibitors with Antitubercular Activity.

Isoniazid (INH) remains one of the cornerstones of antitubercular chemotherapy for drug-sensitive strains of M. tuberculosis bacteria. However, the increasing prevalence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains containing mutations in the KatG enzyme, which is responsible for the activation of INH into its antitubercular form, have rendered this drug of little or no use in many cases of drug-resistant tuberculosis. Presented herein is a novel family of antitubercular direct NADH-dependent 2-trans enoyl-acyl carrier protein reductase (InhA) inhibitors based on an N-benzyl-4-((heteroaryl)methyl)benzamide template; unlike INH, these do not require prior activation by KatG. Given their direct InhA target engagement, these compounds should be able to circumvent KatG-related resistance in the clinic. The lead molecules were shown to be potent inhibitors of InhA and showed activity against M. tuberculosis bacteria. This new family of inhibitors was found to be chemically tractable, as exemplified by the facile synthesis of analogues and the establishment of structure-activity relationships. Furthermore, a co-crystal structure of the initial hit with the enzyme is disclosed, providing valuable information toward the design of new InhA inhibitors for the treatment of MDR/XDR tuberculosis.

A Focused Screen Identifies Antifolates with Activity on Mycobacterium tuberculosis.

Antifolates are widely used to treat several diseases but are not currently used in the first-line treatment of tuberculosis, despite evidence that some of these molecules can target Mycobacterium tuberculosis (Mtb) bacilli in vitro. To identify new antifolate candidates for animal-model efficacy studies of tuberculosis, we paired knowledge and tools developed in academia with the infrastructure and chemistry resources of a large pharmaceutical company. Together we curated a focused library of 2508 potential antifolates, which were then tested for activity against live Mtb. We identified 210 primary hits, confirmed the on-target activity of potent compounds, and now report the identification and characterization of 5 hit compounds, representative of 5 different chemical scaffolds. These antifolates have potent activity against Mtb and represent good starting points for improvement that could lead to in vivo efficacy studies.

Encoded library technology as a source of hits for the discovery and lead optimization of a potent and selective class of bactericidal direct inhibitors of Mycobacterium tuberculosis InhA.

Tuberculosis (TB) is one of the world's oldest and deadliest diseases, killing a person every 20 s. InhA, the enoyl-ACP reductase from Mycobacterium tuberculosis, is the target of the frontline antitubercular drug isoniazid (INH). Compounds that directly target InhA and do not require activation by mycobacterial catalase peroxidase KatG are promising candidates for treating infections caused by INH resistant strains. The application of the encoded library technology (ELT) to the discovery of direct InhA inhibitors yielded compound 7 endowed with good enzymatic potency but with low antitubercular potency. This work reports the hit identification, the selected strategy for potency optimization, the structure-activity relationships of a hundred analogues synthesized, and the results of the in vivo efficacy studies performed with the lead compound 65.

Human herpesvirus-6 and cytomegalovirus DNA in liver donor biopsies and their correlation with HLA matches and acute cellular rejection.

UNLABELLED: Herpesvirus reactivation is common after liver transplantation. OBJECTIVE: Analyze the presence of cytomegalovirus (HCMV) and human herpesvirus-6 (HHV-6) DNA in liver donor biopsies, seeking to better understand issues involving human donor leukocyte antigens (HLA)-A, B and DR, as well as correlations with acute cellular rejection. METHODS: Fifty-nine liver transplantation patients were investigated for the presence of HCMV and HHV-6 DNA in liver donor biopsies, using the Nested-PCR technique. The clinical donor information and HLA matches were obtained from the São Paulo State Transplant System. The recipients' records regarding acute cellular rejection were studied. RESULTS: Seven (11.8%) biopsies were positive for HCMV DNA and 29 (49%) were positive for HHV-6 DNA. In 14 donors with HLA-DR 15 nine had HHV-6 DNA positive liver biopsy with a tendency for significant association (p=0.09), 22 recipients developed acute cellular rejection and 9/22 were positive for HLA-DR 15 (p=0.03; χ(2)=4.51), which was statistically significant in univariate analysis and showed a tendency after multivariate analysis (p=0.08). CONCLUSION: HHV-6 DNA was prevalent in liver donors studied as well as HLA-DR 15. These findings suggest that patients with HLA-DR 15 in liver donor biopsies develop more rejection after liver transplantation.

Evaluation of five DNA extraction methods for detection of H. pylori in formalin-fixed paraffin-embedded (FFPE) liver tissue from patients with hepatocellular carcinoma.

Since Helicobacter spp. DNA was identified in liver tissue resected from patients with hepatocelullar carcinoma (HCC), researchers have suggested a role of this bacterium in hepatic carcinogenesis. Archives of formalin-fixed, paraffin-embedded (FFPE) tissues represent an extraordinary source for clinical studies providing many advantages. However, DNA extraction from FFPE tissues is laborious, time-consuming and still remains a challenge. The aim of this study was to evaluate five protocols for DNA extraction from FFPE liver obtained from patients with HCC in order to detect Helicobacter pylori DNA. These methods were: (1) QIAamp FFPE Tissue Kit, (2) QIAamp DNA Mini Kit, (3) Wizard SV Genomic DNA Purification System, (4) RealiaPrep FFPE gDNA Miniprep System and (5) phenol-chloroform. H. pylori detection was performed using 16S rRNA gene amplification by PCR. The highest total amount of DNA was obtained using the phenol-chloroform method. Analyses of 16S rRNA gene amplification did not show statistically significant differences among the methods (p=0.466), although the highest percentage of positive cases (70%) was found in samples extracted with phenol-chloroform. We suggest that of the five methods evaluated, phenol/chloroform is the most suitable for detection of H. pylori in FFPE liver from patients with HCC.

Human herpesvirus 6 in donor biopsies associated with the incidence of clinical cytomegalovirus disease and hepatitis C virus recurrence.

BACKGROUND: Reactivation of cytomegalovirus (CMV) and human herpesvirus 6 (HHV-6), as well as the recurrence of hepatitis C virus (HCV), occurs in the post liver transplantation period. However, their correlations remain questionable. The objectives of this study were to analyze the presence of CMV DNA and HHV-6 DNA in pre-transplant and post-transplant liver graft biopsies and to determine any correlations with CMV disease and HCV recurrence. METHODS: Forty-one liver transplant recipients were followed up in the post-transplant period. The presence of CMV DNA and HHV-6 DNA was detected by nested PCR. RESULTS: Four patients (4/41, 9.8%) were positive for CMV DNA in pre-transplant biopsies and three of them remained positive after transplantation; 11 patients became positive in the post-transplant biopsies (p=0.06). Fifteen (15/41, 36.6%) patients were positive for HHV-6 DNA in pre-transplant biopsies and 11 of these remained positive after transplantation. Another 11 patients became positive after the surgery (p=0.05). CMV disease occurred in 17 recipients; 10 of these 17 (58.8%) patients were positive for HHV-6 DNA in pre-transplant biopsies and they continued positive after transplantation (p=0.0128). Twenty-eight patients were transplanted due to hepatitis C; 12 of these patients had recurrence of the virus, and HHV-6 was positive in nine of the 12 (75%) patients (p=0.049). CONCLUSIONS: Recipients with HHV-6 DNA in pre-transplant graft biopsies remained positive post transplantation, showing a possible risk for post-transplant allograft loss because there was an association between HHV-6 and recurrent HCV and CMV disease.

Detección molecular del gen BCR-ABL por RT-PCR en niños costarricenses con leucemia

Molecular detection of the BCR-ABL gen by RT-PCR In Costa Rican children with leukemia. Many leukemias could have chromosomic translocations and according to the transcripts formed by the genes involved, the patients present an specific phenotype of the leukemia. We show the first results of the investigation of the gen BCR-ABL using RT-PCR, in order to look for the t(9;22)(q34;q11) in pediatric leukemic children. We studied in total 55 patients, 6 (10.9%) of them were positive for that translocation. Two (3.63%) of the positive children had ALL and the other 4 (7.27%) presented CML, the genotyping analysis of the transcript was studied in these children. With the introduction of this methodology as part of the routine studies, the leukemic children could get in the future an specific diagnosis, that will be important to classify them in prognostic categories and to improve the detection of minimal residual disease. Rev. Biol. Trop. 56 (4): 1613-1618. Epub 2008 December 12.

Muchas leucemias pueden presentar traslocaciones cromosómicas, las cuales, de acuerdo a los transcriptos formados por los genes involucrados, originará un fenotipo leucémica variable. En este trabajo se muestran los primeros resultados de pacientes pediátricos con leucemia, a los cuales se les hizo el estudio molecular por RT-PCR y el genotipaje para el gen BCR-ABL producto de la t(9;22)(q34;q11). De las 55 muestras estudiadas, 6 (10.9%) fueron positivas para el transcripto mencionado. De las 6 positivas, 2(3.63%) de esos pacientes tenían LLA y 4 (7.27%) eran LMC. La introducción de esta metodología en el manejo rutinario de los niños con leucemia, servirá para establecer un diagnóstico más preciso, un pronóstico más certero y un seguimiento adecuado de la enfermedad mínima residual.

[Molecular detection of the BCR-ABL gen by RT-PCR in Costa Rican children with leukemia]. / Detección molecular del gen BCR-ABL por RT-PCR en niños costarricenses con leucemia.

Many leukemias could have chromosomic translocations and according to the transcripts formed by the genes involved, the patients present an specific phenotype of the leukemia. We show the first results of the investigation of the gen BCR-ABL using RT-PCR, in order to look for the t(9;22)(q34;q11) in pediatric leukemic children. We studied in total 55 patients, 6 (10.9%) of them were positive for that translocation. Two (3.63%) of the positive children had ALL and the other 4 (7.27%) presented CML, the genotyping analysis of the transcript was studied in these children. With the introduction of this methodology as part of the routine studies, the leukemic children could get in the future an specific diagnosis, that will be important to classify them in prognostic categories and to improve the detection of minimal residual disease.

The mother superior mutation ablates foxd3 activity in neural crest progenitor cells and depletes neural crest derivatives in zebrafish.

The zebrafish mutation mother superior (mosm188) leads to a depletion of neural crest (NC) derivatives including the craniofacial cartilage skeleton, the peripheral nervous system (sympathetic neurons, dorsal root ganglia, enteric neurons), and pigment cells. The loss of derivatives is preceded by a reduction in NC-expressed transcription factors, snail1b, sox9b, sox10, and a specific loss of foxd3 expression in NC progenitor cells. We employed genetic linkage analysis and physical mapping to place the mosm188 mutation on zebrafish chromosome 6 in the vicinity of the foxd3 gene. Furthermore, we found that mosm188 does not complement the sym1/foxd3 mutation, indicating that mosm188 resides within the foxd3 locus. Injection of PAC clones containing the foxd3 gene into mosm188 embryos restored foxd3 expression in NC progenitors and suppressed the mosm188 phenotype. However, sequencing the foxd3 transcribed area in mosm188 embryos did not reveal nucleotide changes segregating with the mosm188 phenotype, implying that the mutation most likely resides outside the foxd3-coding region. Based on these findings, we propose that the mosm188 mutation perturbs a NC-specific foxd3 regulatory element. Further analysis of mosm188 mutants and foxd3 morphants revealed that NC cells are initially formed, suggesting that foxd3 function is required to maintain the pool of NC progenitors.

Obtención de un extracto plaguicida de Gliricidia sepium (Jaq) Steud bajo la irradiación con microondas / Obtention of a pesticide extract from Gliridia sepium (Jacq) Steud under the irradiation of microwaves

Los plaguicidas botánicos representan una vía alternativa para el control de plagas tanto por su efectividad como por el bajo costo de su preparación, su fácil obtención y que en general no contaminan el medio ambiente. En el presente trabajo se prepararon extractos de las hojas de Gliricidia sepium por técnicas tradicionales y no convencional. Esta última con el empleo de la energía de las microondas que resultó ser más rápida y se obtuvieron mejores resultados. Se evaluó la actividad biológica de los extractos acuosos frente a plagas que afectan considerablemente el rendimiento de importantes cosechas con buenos resultados