A novel anti-apoptotic role for Cdc42/ACK-1 signaling in neurons.

Neurodegenerative diseases such as amyotrophic lateral sclerosis, Alzheimer's and Parkinson's disease are caused by a progressive and aberrant destruction of neurons in the brain and spinal cord. These disorders lack effective long-term treatments that impact the underlying mechanisms of pathogenesis and as a result, existing options focus primarily on alleviating symptomology. Dysregulated programmed cell death (i.e., apoptosis) is a significant contributor to neurodegeneration, and is controlled by a number of different factors. Rho family GTPases are molecular switches with recognized importance in proper neuronal development and migration that have more recently emerged as central regulators of apoptosis and neuronal survival. Here, we investigated a role for the Rho GTPase family member, Cdc42, and its downstream effectors, in neuronal survival and apoptosis. We initially induced apoptosis in primary cultures of rat cerebellar granule neurons (CGNs) by removing both growth factor-containing serum and depolarizing potassium from the cell medium. We then utilized both chemical inhibitors and adenoviral shRNA targeted to Cdc42 to block the function of Cdc42 or its downstream effectors under either control or apoptotic conditions. Our in vitro studies demonstrate that functional inhibition of Cdc42 or its downstream effector, activated Cdc42-associated tyrosine kinase-1 (ACK-1), had no adverse effects on CGN survival under control conditions, but significantly sensitized neurons to cell death under apoptotic conditions. In conclusion, our results suggest a key pro-survival role for Cdc42/ACK-1 signaling in neurons, particularly in regulating neuronal susceptibility to pro-apoptotic stress such as that observed in neurodegenerative disorders.

Reduction in concentration of chromium (VI) by Lysinibacillus macroides isolated from sediments of the Chapala Lake, Mexico.

The Chapala Lake is one of the most polluted lakes in Mexico, due to the in flow of effluents from several industrial plants, the lake accumulates pollutants such as chromium(VI) which is considered important for aquatic ecosystem. This study aimed was to evaluate the ability to decrease the concentration of chromium (VI) by Lysinibacillus macroides 2(1B)104A, isolated from sediments of the Chapala Lake. The strain was identified through 16S rRNA sequencing and phylogenetic analysis. Results showed that this strain grows in concentrations of 50, 100, 200 and 300 mgL-1 Cr(VI), in pH ranging 6 to 7, showing 79.508% reduction in concentration 50 mgL-1, determining that the reduction occurs extracellularly. Likewise, it was observed that Lysinibacillus macroides reduced the concentration of Cr(IV) in the broth, it was not observed that the bacteria could sequester Cr(VI) in the membrane or intracellularly. However, it reduced the concentration of Cr(VI) in the broth. Lysinibacillus macroides 2(1B)104A isolate showed having the ability that decrease the concentration of Cr(VI), which makes it a viable options for bioremediation of water polluted with this metal.

Comparative genomics of a subset of Adherent/Invasive Escherichia coli strains isolated from individuals without inflammatory bowel disease.

There is increased evidence demonstrating the association between Crohn's Disease (CD), a type of Inflammatory Bowel Disease (IBD), and non-diarrheagenic Adherent/Invasive Escherichia coli (AIEC) isolates. AIEC strains are phenotypically characterized by their adhesion, invasion and intra-macrophage survival capabilities. In the present study, the genomes of five AIEC strains isolated from individuals without IBD (four from healthy donors and one from peritoneal liquid) were sequenced and compared with AIEC prototype strains (LF82 and NRG857c), and with extra-intestinal uropathogenic strain (UPEC CFT073). Non-IBD-AIEC strains showed an Average Nucleotide Identity up to 98% compared with control strains. Blast identities of the five non-IBD-AIEC strains were higher when compared to AIEC and UPEC reference strains than with another E. coli pathotypes, suggesting a relationship between them. The SNPs phylogeny grouped the five non-IBD-AIEC strains in one separated cluster, which indicates the emergence of these strains apart from the AIEC group. Additionally, four genomic islands not previously reported in AIEC strains were identified. An incomplete Type VI secretion system was found in non-IBD-AIEC strains; however, the Type II secretion system was complete. Several groups of genes reported in AIEC strains were searched in the five non-IBD-AIEC strains, and the presence of fimA, fliC, fuhD, chuA, irp2 and cvaC were confirmed. Other virulence factors were detected in non-IBD-AIEC strains, which were absent in AIEC reference strains, including EhaG, non-fimbrial adhesin 1, PapG, F17D-G, YehA/D, FeuC, IucD, CbtA, VgrG-1, Cnf1 and HlyE. Based on the differences in virulence determinants and SNPs, it is plausible to suggest that non-IBD AIEC strains belong to a different pathotype.

Dysregulation of Rac or Rho elicits death of motor neurons and activation of these GTPases is altered in the G93A mutant hSOD1 mouse model of amyotrophic lateral sclerosis.

Rho GTPases play a central role in neuronal survival; however, the antagonistic relationship between Rac and Rho in the regulation of motor neuron survival remains poorly defined. In the current study, we demonstrate that treatment with NSC23766, a selective inhibitor of the Rac-specific guanine nucleotide exchange factors, Tiam1 and Trio, is sufficient to induce the death of embryonic stem cell (ESC)-derived motor neurons. The mode of cell death is primarily apoptotic and is characterized by caspase-3 activation, de-phosphorylation of ERK5 and AKT, and nuclear translocation of the BH3-only protein Bad. As opposed to the inhibition of Rac, motor neuron cell death is also induced by constitutive activation of Rho, via a mechanism that depends on Rho kinase (ROCK) activity. Investigation of Rac and Rho in the G93A mutant, human Cu, Zn-superoxide dismutase (hSOD1) mouse model of amyotrophic lateral sclerosis (ALS), revealed that active Rac1-GTP is markedly decreased in spinal cord motor neurons of transgenic mice at disease onset and end-stage, when compared to age-matched wild type (WT) littermates. Furthermore, although there is no significant change in active RhoA-GTP, total RhoB displays a striking redistribution from motor neuron nuclei in WT mouse spinal cord to motor neuron axons in end-stage G93A mutant hSOD1 mice. Collectively, these data suggest that the intricate balance between pro-survival Rac signaling and pro-apoptotic Rho/ROCK signaling is critical for motor neuron survival and therefore, disruption in the balance of their activities and/or localization may contribute to the death of motor neurons in ALS.

Validation of the adjusted global antiphospholipid syndrome score in systemic lupus erythematosus patients in Argentina.

INTRODUCTION: Assessment of risk both for pregnancy morbidity and thrombosis in the presence of anti-phospholipid antibodies (aPL) is still a challenge in Systemic Lupus Erythematosus (SLE) patients. The Global Antiphospholipid Syndrome Score (GAPSS) takes into account the aPL profile (criteria and non-criteria aPL), the conventional cardiovascular risk factors and the autoimmune antibody profile. An adjusted model of the score (aGAPSS) excluding anti-phosphatidylserine/Prothrombin (aPS/PT), suggests that the score is able to stratify patients for their rate of events making it widely applicable in daily clinical practice. OBJECTIVE: To validate the aGAPSS in a multicentric cohort of SLE patients in Argentina. PATIENTS AND METHODS: consecutive SLE patients with and with andwithout thrombotic events from seven Rheumatologist centers were included. Traditional cardiovascular risk factors, aPL antibodies and medications received (aspirin, hydroxychloroquine and anticoagulation) were collected. The score aGAPSS was calculated for each patient at the last visit by adding together the points corresponding to the risk factors: 1 for hypertension, 3 for dyslipidemia, 4 for LA and B2GPI (IgM or IgG) antibodies and 5 for aCL (IgM or IgG) antibodies. The discriminative ability of the aGAPSS was calculated by measuring the area under the receiver operating characteristic curve (AUC). Multivariate logistic regression analysis was performed to examine the impact of multiple cardiovascular risk factors and laboratory parameters on the occurrence of thrombosis. RESULTS: Two hundred and ninety-six SLE patients were included. One-hundred and twenty-one patients (40.9%) presented thrombotic and/or pregnancy complications. Median aGAPSS was significantly higher in patients who experienced an event (thrombosis and/or pregnancy morbidity) compared with those without [4 (IQR 1-9) versus 1 (IQR 0-5); p < 0.001]. The best cut off point for the diagnosis of thrombosis and/or pregnancy complications was aGAPSS ≥4. Multivariate logistic regression analysis showed that aCL antibodies [OR 2.1 (95% CI 1.16-3.90); p = 0.015] were an independent risk factors for thrombotic events. CONCLUSIONS: This score is a simple tool, easy to apply to SLE patients in daily practice. The use of the aGAPSS could change the non-pharmacologic and pharmacologic treatment in higher risk patients to improve their survival.

Optic nerve coloboma as extension of the phenotype of 22q11.23 duplication syndrome: a case report.

BACKGROUND: 22q11.2 duplication syndrome (Dup22q11.2) has reduced penetrance and variable expressivity. Those affected may have intellectual disabilities, dysmorphic facial features, and ocular alterations such as ptosis, hypertelorism, nystagmus, and chorioretinal coloboma. The prevalence of this syndrome is unknown, there are only approximately 100 cases reported. However Dup22q11.2 should have a similar prevalence of DiGeorge syndrome (1 in each 4000 new-borns), in which the same chromosomal region that is duplicated in Dup22q11.2 is deleted. CASE PRESENTATION: We report a patient with intellectual disability, psychomotor development delay, hearing loss with disyllable pronunciation only, hyperactivity, self-harm, hetero-aggressive behaviour, facial dysmorphism, left facial paralysis, post-axial polydactyly, and for the first time in patients with Dup22q11.2, optic nerve coloboma and dysplasia in optic nerve. Array comparative genomic hybridization showed a 22q11.23 duplication of 1.306 million base pairs. CONCLUSIONS: New ocular findings in Dup22q11.2 syndrome, such as coloboma and dysplasia in the optic nerve, are reported here, contributing to the phenotypic characterization of a rarely diagnosed genetic syndrome. A complete characterization of the phenotype is necessary to increase the rate of clinical suspicion and then the genetic diagnostic. In addition, through bioinformatics analysis of the genes mapped to the 22q11.2 region, it is proposed that deregulation of the SPECC1L gene could be implicated in the development of ocular coloboma.

Adherent/invasive Escherichia coli (AIEC) isolates from asymptomatic people: new E. coli ST131 O25:H4/H30-Rx virotypes.

BACKGROUND: The widespread Escherichia coli clone ST131 implicated in multidrug-resistant infections has been recently reported, the majority belonging to O25:H4 serotype and classified into five main virotypes in accordance with the virulence genes carried. METHODS: Pathogenicity Islands I and II (PAI-I and PAI-II) were determined using conventional PCR protocols from a set of four E. coli CTXR ST131 O25:H4/H30-Rx strains collected from healthy donors' stool. The virulence genes patterns were also analyzed and compared them with the virotypes reported previously; then adherence, invasion, macrophage survival and biofilm formation assays were evaluated and AIEC pathotype genetic determinants were investigated. FINDINGS: Non-reported virulence patterns were found in our isolates, two of them carried satA, papA, papGII genes and the two-remaining isolates carried cnfI, iroN, satA, papA, papGII genes, and none of them belonged to classical ST131 virotypes, suggesting an endemic distribution of virulence genes and two new virotypes. The presence of PAI-I and PAI-II of Uropathogenic E. coli was determined in three of the four strains, furthermore adherence and invasion assays demonstrated higher degrees of attachment/invasion compared with the control strains. We also amplified intI1, insA and insB genes in all four samples. INTERPRETATION: The results indicate that these strains own non-reported virotypes suggesting endemic distribution of virulence genes, our four strains also belong to an AIEC pathotype, being this the first report of AIEC in México and the association of AIEC with healthy donors.

BfpI, BfpJ, and BfpK Minor Pilins Are Important for the Function and Biogenesis of Bundle-Forming Pili Expressed by Enteropathogenic Escherichia coli.

UNLABELLED: Enteropathogenic Escherichia coli (EPEC) remains a significant cause of infant diarrheal illness and associated morbidity and mortality in developing countries. EPEC strains are characterized by their ability to colonize the small intestines of their hosts by a multistep program involving initial loose attachment to intestinal epithelial cells followed by an intimate adhesion phase. The initial loose interaction of typical EPEC with host intestinal cells is mediated by bundle-forming pili (BFP). BFP are type 4b pili (T4bP) based on structural and functional properties shared with T4bP expressed by other bacteria. The major structural subunit of BFP is called bundlin, a T4b pilin expressed from the bfpA gene in the BFP operon, which contains three additional genes that encode the pilin-like proteins BfpI, BfpJ, and BfpK. In this study, we show that, in the absence of the BFP retraction ATPase (BfpF), BfpI, BfpJ, and BfpK are dispensable for BFP biogenesis. We also demonstrate that these three minor pilins are incorporated along with bundlin into the BFP filament and contribute to its structural integrity and host cell adhesive properties. The results confirm that previous findings in T4aP systems can be extended to a model T4bP such as BFP. IMPORTANCE: Bundle-forming pili contribute to the host colonization strategy of enteropathogenic Escherichia coli. The studies described here investigate the role for three minor pilin subunits in the structure and function of BFP in EPEC. The studies also suggest that these subunits could be antigens for vaccine development.

Structure of Clostridium difficile PilJ exhibits unprecedented divergence from known type IV pilins.

Type IV pili are produced by many pathogenic Gram-negative bacteria and are important for processes as diverse as twitching motility, cellular adhesion, and colonization. Recently, there has been an increased appreciation of the ability of Gram-positive species, including Clostridium difficile, to produce Type IV pili. Here we report the first three-dimensional structure of a Gram-positive Type IV pilin, PilJ, demonstrate its incorporation into Type IV pili, and offer insights into how the Type IV pili of C. difficile may assemble and function. PilJ has several unique structural features, including a dual-pilin fold and the incorporation of a structural zinc ion. We show that PilJ is incorporated into Type IV pili in C. difficile and present a model in which the incorporation of PilJ into pili exposes the C-terminal domain of PilJ to create a novel interaction surface.

Recovery from experimental parkinsonism by semaphorin-guided axonal growth of grafted dopamine neurons.

Cell therapy in animal models of Parkinson's disease (PD) is effective after intrastriatal grafting of dopamine (DA) neurons, whereas intranigral transplantation of dopaminergic cells does not cause consistent behavioral recovery. One strategy to promote axonal growth of dopaminergic neurons from the substantia nigra (SN) to the striatum is degradation of inhibitory components such as chondroitin sulphate proteoglycans (CSPG). An alternative is the guidance of DA axons by chemotropic agents. Semaphorins 3A and 3C enhance axonal growth of embryonic stem (ES) cell-derived dopaminergic neurons in vitro, while Semaphorin 3C also attracts them. We asked whether intranigral transplantation of DA neurons, combined with either degradation of CSPG or with grafts of Semaphorin 3-expressing cells, towards the striatum, is effective in establishing a new nigrostriatal dopaminergic pathway in rats with unilateral depletion of DA neurons. We found depolarization-induced DA release in dorsal striatum, DA axonal projections from SN to striatum, and concomitant behavioral improvement in Semaphorin 3-treated animals. These effects were absent in animals that received intranigral transplants combined with Chondroitinase ABC treatment, although partial degradation of CSPG was observed. These results are evidence that Semaphorin 3-directed long-distance axonal growth of dopaminergic neurons, resulting in behavioral improvement, is possible in adult diseased brains.

Severe infections in systemic necrotizing vasculitis.

Infections in patients with systemic vasculitis represent one of the main causes of mortality. Corticosteroid use, immunosuppressive therapy, age, associated organic involvement and dialysis dependence are risk factors of infection. OBJECTIVES: To determine the prevalence of severe infection and associated factors in patients diagnosed with ANCA-associated vasculitis (AAV) and Polyarteritis Nodosa (PAN). METHODS: retrospective study was conduced in a single rheumatology center (2000-2018). We included patients diagnosed with AAV (Granulomatosis with Polyangiitis (GPA), Eosinophilic Granulomatosis with Polyangiitis (EGPA) and Microscopic Polyangiitis (PAM) and Polyarteritis nodosa (PAN). Serious infectious events requiring hospitalisation or prolonged antibiotic/antiviral treatment, recurrent infection of Herpes Zoster Virus or opportunistic infections were evaluated. Sites of infection, isolated microorganisms and mortality related were analyzed. RESULTS: 105 patients were analyzed, follow-up time median 18 m, 58.7% were women and median age was 52 years. Types of vasculitis: 41.9% PAM, 16.2% EPGA, 40% GPA, 1.9% PAN. Constitutional, pulmonary, renal and otorhinolaryngology manifestations were the most frequent. PREVALENCE OF INFECTION: 34.2%, with a median of 3 months from diagnosis of vasculitis to the infectious event. Low respiratory tract (42.8%), sepsis (31.4%), and urinary tract (14.3%) were the most common sites of infections. Bacterial aetiology was the most prevalent (67.7%). Mortality at the first event was 14.3% and a 72.2% of patients were in the induction phase of treatment. Infectious events were significantly associated with age > 65 years (p = 0.030), presence of lung (p = 0.016) and renal involvement (p = 0.001), BVASv3 > 15, mortality (p = 0.0002). CONCLUSIONS: The prevalence of infection was 34.2%. Lower airway infections, septicemia and urinary tract infections were the most prevalent. Infections were associated with renal and pulmonary involvement, age older than 65 years and score BVAS > 15. Severe infections were associated with mortality, especially in elderly patients.

Effectiveness of methotrexate and leflunomide as corticoid-sparing drugs in patients with polymyalgia rheumatica.

Objectives: The need for glucocorticoid-sparing drugs (GCSD) remains an important issue and is an unmet need in the treatment of polymyalgia rheumatica (PMR). We therefore aimed to assess the effectiveness and safety of methotrexate (MTX) and of leflunomide (LEF) in daily clinical practice in PMR patients from Argentina. Methods: A multicentre and observational study (medical records review) of PMR patients seen between 2007 and 2023, who had at least three months of follow-up after starting a GCSD, either MTX or LEF, was performed. Results are expressed as medians and interquartile ranges [25th-75th (IQR)] for continuous variables and percentages for categorical ones. The two treatment groups were compared using χ2 test for categorical variables, Mann-Whitney U test for continuous variables and the log-rank test for time-to-event data. Crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using logistic regression. In all cases, a p-value <0.05 was considered statistically significant. Results: One-hundred and eighty-six patients (79% female) with a median age of 72 years (IQR, 65-77 years) were included. One-hundred and forty-three patients (77%) were prescribed MTX (15, IQR 10-15) and 43 (23%) LEF (20 mg, fixed dose). Flare-ups (relapses and recurrences) occurred in 13 patients (7%) and were comparable between both groups. Persistent GCSD intake was observed in 145 patients (78%). Glucocorticoid (GC) withdrawal was achieved in 67 of these 145 patients (46%) and this occurred more frequently in the LEF group (P = 0.001). Furthermore, time until prednisone discontinuation was shorter in the LEF-treated patients (4.7 months, IQR 3-20 on LEF versus 31.8 months, IQR 10-82 on MTX, P = 0.000). Remission was found more frequently in the LEF group (P = 0.003). In the multivariate analysis, the probability of remission was higher with LEF therapy (P = 0.010) and this finding persisted in the subgroup analysis who were followed up < 40 months (OR 3.12, 95% CI = 1.30-7.47, P = 0.011). Conclusions: This study demonstrated the clinical effectiveness of LEF and even its superiority in achieving remission when compared with MTX as GCSD in PMR patients. Further research is needed to support these findings.

Targeting the Impossible: A Review of New Strategies against Endospores.

Endospore-forming bacteria are ubiquitous, and their endospores can be present in food, in domestic animals, and on contaminated surfaces. Many spore-forming bacteria have been used in biotechnological applications, while others are human pathogens responsible for a wide range of critical clinical infections. Due to their resistant properties, it is challenging to eliminate spores and avoid the reactivation of latent spores that may lead to active infections. Furthermore, endospores play an essential role in the survival, transmission, and pathogenesis of some harmful strains that put human and animal health at risk. Thus, different methods have been applied for their eradication. Nevertheless, natural products are still a significant source for discovering and developing new antibiotics. Moreover, targeting the spore for clinical pathogens such as Clostridioides difficile is essential to disease prevention and therapeutics. These strategies could directly aim at the structural components of the spore or their germination process. This work summarizes the current advances in upcoming strategies and the development of natural products against endospores. This review also intends to highlight future perspectives in research and applications.

Immunocal® limits gliosis in mouse models of repetitive mild-moderate traumatic brain injury.

Successive traumatic brain injuries (TBIs) exacerbate neuroinflammation and oxidative stress. No therapeutics exist for populations at high risk of repetitive mild TBIs (rmTBIs). We explored the preventative therapeutic effects of Immunocal®, a cysteine-rich whey protein supplement and glutathione (GSH) precursor, following rmTBI and repetitive mild-moderate TBI (rmmTBI). Populations that suffer rmTBIs largely go undiagnosed and untreated; therefore, we first examined the potential therapeutic effect of Immunocal® long-term following rmTBI. Mice were treated with Immunocal® prior to, during, and following rmTBI induced by controlled cortical impact until analysis at 2 weeks, 2 months, and 6 months following the last rmTBI. Astrogliosis and microgliosis were measured in cortex at each time point and edema and macrophage infiltration by MRI were analyzed at 2 months post-rmTBI. Immunocal® significantly reduced astrogliosis at 2 weeks and 2 months post-rmTBI. Macrophage activation was observed at 2 months post-rmTBI but Immunocal® had no significant effect on this endpoint. We did not observe significant microgliosis or edema after rmTBI. The dosing regimen was repeated in mice subjected to rmmTBI; however, using this experimental paradigm, we examined the preventative therapeutic effects of Immunocal® at a much earlier timepoint because populations that suffer more severe rmmTBIs are more likely to receive acute diagnosis and treatment. Increases in astrogliosis, microgliosis, and serum neurofilament light (NfL), as well as reductions in the GSH:GSSG ratio, were observed 72 h post-rmmTBI. Immunocal® only significantly reduced microgliosis after rmmTBI. In summary, we report that astrogliosis persists for 2 months post-rmTBI and that inflammation, neuronal damage, and altered redox homeostasis present acutely following rmmTBI. Immunocal® significantly limited gliosis in these models; however, its neuroprotection was partially overwhelmed by repetitive injury. Treatments that modulate distinct aspects of TBI pathophysiology, used in combination with GSH precursors like Immunocal®, may show more protection in these repetitive TBI models.

Safety evaluation of the food enzyme inulinase from the genetically modified Aspergillus oryzae strain MUCL 44346.

The food enzyme inulinase (1-ß-d-fructan fructanohydrolase; EC 3.2.1.7) is produced with the genetically modified Aspergillus oryzae strain MUCL 44346 by PURATOS NV. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. It is intended to be used in the production of fructo-oligosaccharides (FOS) from inulin extracted from chicory roots. Dietary exposure to the food enzyme-total organic solids (TOS) was estimated to be up to 0.01 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90-day oral toxicity study in rats. The Panel identified a no observed adverse effect level (NOAEL) of 100 mg TOS/kg bw per day, which when compared with the estimated dietary exposure, resulted in a margin of exposure of at least 10,000. A search for the similarity of the amino acid sequence of the food enzyme to known allergens was made and two matches were found with tomato allergens. The Panel considered that, under the intended conditions of use, the risk of allergic reactions upon dietary exposure to this food enzyme, particularly in individuals sensitised to tomato, cannot be excluded. However, the likelihood of allergic reactions is expected not to exceed the likelihood of allergic reactions to tomato. As the prevalence of allergic reactions to tomato is low, also the likelihood of such reactions to occur to the food enzyme is low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Preliminary identification of pathogenic variants in an Afro-Colombian Raizal family with risk factors for glaucoma.

Objective: To identify pathogenic variants in an Afro-Colombian Raizal family with risk factors for glaucoma. Methods: In the present study, whole exome sequencing was performed on seven members of a Raizal family from the archipelago of San Andrés, Providencia, and Santa Catalina, in the Caribbean region of Colombia. Four of them had been diagnosed with glaucoma. In addition, two healthy volunteers from the island were included. Results: Of the 198 single nucleotide variants associated with glaucoma, previously reported by the DisGeNET database, four were identified in members of the Raizal family: rs11938093, rs7336216, rs3817672, and rs983034. Furthermore, single nucleotide variant rs983034 was identified in the Wnt ligand secretion mediator gene in all members of the family but not in healthy volunteers. Notably, WLS dysfunctions have been linked to pathology in the trabecular meshwork of the eye. Trabecular meshwork is an important regulator of the outflow of aqueous humor that maintains intraocular pressure (intraocular pressure) at normal levels. Damage to trabecular meshwork is associated with ocular hypertension, which leads to glaucoma progression. In relation to the other single nucleotide variants that were identified, their presence was confirmed in some members of the Raizal family. However, it is still unclear the pathophysiological cause that associates these single nucleotide variants with glaucoma. Conclusions: It was possible to identify four non-synonymous single nucleotide variants that predict significant damage to the structure and function of genes associated with glaucoma pathology in an Afro-Colombian.

Objetivo: Identificar las variantes patogénicas en una familia raizal afrocolombiana con factores de riesgo para el glaucoma. Métodos: En el presente estudio, se realizó una secuenciación de exoma completo en siete miembros de una familia Raizal del archipiélago de San Andrés, Providencia y Santa Catalina del Caribe colombiano. La mitad de ellos habían sido diagnosticados con glaucoma. Además, se incluyeron dos voluntarios sanos de la isla. Resultados: De las 198 variantes de un solo nucleótido (SNV) asociadas con el glaucoma, previamente informadas por la base de datos DisGeNET, se identificaron cuatro en los miembros de la familia Raizal: rs11938093, rs7336216, rs3817672 y rs983034. Ademas, en todos los miembros de la familia, pero no en voluntarios sanos, se identificó SNV rs983034 en el gen mediador de secreción de ligando Wnt (WLS). Notablemente, las disfunciones WLS se han relacionado con patologías en la red trabecular (TM) del ojo. TM es un regulador importante del flujo de salida del humor acuoso que mantiene la presión intraocular (presión intraocular) en niveles normales. El daño a la TM se asocia con hipertensión ocular que conduce a la progresión del glaucoma. En relación con los demás SNV identificados, se constató su presencia en algunos miembros de la familia Raizal. Sin embargo, aún no está clara la causa fisiopatológica que asocia estas SNV con el glaucoma. Conclusiones: Fue posible identificar cuatro SNVs no sinónimos con predicción de daño significativo en la estructura y función de genes asociados a patología de glaucoma en un afrocolombiano.

Regulatory control of the Escherichia coli O157:H7 lpf1 operon by H-NS and Ler.

Long polar fimbriae 1 (Lpf1) of Escherichia coli O157:H7 is a tightly regulated adhesin, with H-NS silencing the transcriptional expression of the lpf1 operon while Ler (locus of enterocyte effacement-encoded regulator) acts as an antisilencer. We mapped the minimal regulatory region of lpf1 required for H-NS- and Ler-mediated regulation and found that it is 79% AT rich. Three putative sites for H-NS binding were identified. Two of them, named silencer regulatory sequence 1 (SRS1) and SRS2, are located on a region that covers both of the lpf1 promoters (P1 and P2). The third putative H-NS binding site is located within the lpfA1 gene in a region extending from +258 bp to +545 bp downstream of ATG; however, this site does not seem to play a role in lpfA1 regulation under the conditions tested in this work. Ler was also found to interact with Ler binding sites (LBSs). Ler binding site 1 (LBS1) and LBS2 are located upstream of the two promoters. LBS1 overlaps SRS1, while LBS3 overlaps the P1 promoter and SRS2. Based on the experimental data, we propose that H-NS silences lpf1 expression by binding to both of the SRSs on the promoter region, forming an SRS-H-NS complex that prevents RNA polymerase-mediated transcription. A model of the regulation of the lpfA1 operon of E. coli O157:H7 by H-NS and Ler is discussed.

Slit-Robo signals regulate pioneer axon pathfinding of the tract of the postoptic commissure in the mammalian forebrain.

During early vertebrate forebrain development, pioneer axons establish a symmetrical scaffold descending longitudinally through the rostral forebrain, thus forming the tract of the postoptic commissure (TPOC). In mouse embryos, this tract begins to appear at embryonic day 9.5 (E9.5) as a bundle of axons tightly constrained at a specific dorsoventral level. We have characterized the participation of the Slit chemorepellants and their Robo receptors in the control of TPOC axon projection. In E9.5-E11.5 mouse embryos, Robo1 and Robo2 are expressed in the nucleus origin of the TPOC (nTPOC), and Slit expression domains flank the TPOC trajectory. These findings suggested that these proteins are important factors in the dorsoventral positioning of the TPOC axons. Consistently with this role, Slit2 inhibited TPOC axon growth in collagen gel cultures, and interfering with Robo function in cultured embryos induced projection errors in TPOC axons. Moreover, absence of both Slit1 and Slit2 or Robo1 and Robo2 in mutant mouse embryos revealed aberrant TPOC trajectories, resulting in abnormal spreading of the tract and misprojections into both ventral and dorsal tissues. These results reveal that Slit-Robo signaling regulates the dorsoventral position of this pioneer tract in the developing forebrain.

Prevalence of subclinical enthesopathy in patients with spondyloarthropathy: an ultrasound study.

BACKGROUND: Ultrasound has demonstrated to be a highly sensitive tool in the evaluation of entheses in spondyloarthropathy (SpA) patients and improves the ability of clinical examination to detect enthesopathy. OBJECTIVES: The objectives of the study were to determine the prevalence of subclinical enthesopathy in SpA patients and to evaluate the reliability of ultrasound in the detection of abnormal findings indicative of enthesopathy. METHODS: Six hundred lower-limb entheses were assessed in 60 SpA patients without known history of entheseal involvement. Sixty rheumatoid arthritis patients and 30 control subjects were included as control groups. Clinical examination and ultrasound were consecutively performed at each of the entheses to detect signs indicative of enthesopathy. Images from 20 SpA patients were stored and afterward evaluated to determine the reliability of abnormal ultrasound findings. RESULTS: Ultrasound detected a high prevalence of enthesopathy in SpA patients with respect to both rheumatoid arthritis patients and control subjects (P < 0.001 for both comparisons). In SpA patients, clinical examination detected enthesopathy in 56 (9.3%) of 600 entheses. In the remainder 544 clinically asymptomatic entheses (90.7%) (not painful and not swollen), ultrasound detected in 331 (60.8%) at least 1 ultrasound sign of enthesopathy. The intrareader and interreader agreement for all ultrasound abnormal findings was good to excellent. CONCLUSION: The present study demonstrates a higher sensitivity of ultrasound with respect to physical examination in the detection of signs indicative of enthesopathy in SpA patients with an adequate interreader and intrareader reliability. Further study is needed about the prognostic value of the ultrasound findings for predicting clinical onset of entheseal involvement.