The Th17 immune response plays a key role in autoimmune diseases such as multiple sclerosis (MS) and inflammatory bowel disease (IBD). Expression of Th17-related genes in inflamed tissues has been ...reported in autoimmune diseases. However, values are frequently obtained using invasive methods. We aimed to identify biomarkers of MS in an accessible sample, such as blood, by quantifying the relative expression of 91 Th17-related genes in CD4+ T lymphocytes from patients with MS during a relapse or during a remitting phase. We also compared our findings with those of healthy controls. After confirmation in a validation cohort, expression of
and
mRNAs was decreased in remitting disease (-2.3-fold and -1.3-fold, respectively) and relapsing disease (-2.2-fold and -1.3-fold, respectively). No differential expression was observed for other SMAD7-related genes, namely,
,
, and
. Under-regulation of
and
was also observed in another autoimmune disease, Crohn's disease (CD) (-4.6-fold, -1.6-fold, respectively), suggesting the presence of common markers for autoimmune diseases. In addition, expression of
, and
were also decreased in CD (-2.2-fold, -1.4-fold, -1.6-fold, and -1.6-fold, respectively). Our study suggests that expression of
and
mRNA in blood samples are markers for MS and CD, and
, and
for CD. These genes could prove useful as markers of autoimmune diseases, thus obviating the need for invasive methods.
Despite more than three decades of intense effort, no anti‐Ras therapies have reached clinical application. Contributing to this failure has been an underestimation of Ras complexity and a dearth of ...structural information. In this regard, recent studies have revealed the highly dynamic character of the Ras surface and the existence of transient pockets suitable for small‐molecule binding, opening up new possibilities for the development of Ras modulators. Herein, a novel Ras inhibitor (compound 12) is described that selectively impairs mutated Ras activity in a reversible manner without significantly affecting wild‐type Ras, reduces the Ras–guanosine triphosphate (GTP) levels, inhibits the activation of the mitogen‐activated protein kinase (MAPK) pathway, and exhibits remarkable cytotoxic activity in Ras‐driven cellular models. The use of molecular dynamics simulations and NMR spectroscopy experiments has enabled the molecular bases responsible for the interactions between compound 12 and Ras protein to be explored. The new Ras inhibitor binds partially to the GTP‐binding region and extends into the adjacent hydrophobic pocket delimited by switch II. Hence, Ras inhibitor 12 could represent a new compound for the development of more efficacious drugs to target Ras‐driven cancers; a currently unmet clinical need.
All bound up: The oncogenic activity of mutated Ras is impaired by a new inhibitor, which reduces the Ras–guanosine triphosphate (GTP) levels, inhibits the mitogen‐activated protein kinase (MAPK) pathway, and is cytotoxic in Ras‐driven cellular models (see figure). This new inhibitor adds to the scarce number of compounds available to fight Ras‐driven cancers; a currently unmet clinical need.
Cell division protein FtsZ can form single-stranded filaments with a cooperative behavior by self-switching assembly. Subsequent condensation and bending of FtsZ filaments are important for the ...formation and constriction of the cytokinetic ring. PC190723 is an effective bactericidal cell division inhibitor that targets FtsZ in the pathogen Staphylococcus aureus and Bacillus subtilis and does not affect Escherichia coli cells, which apparently binds to a zone equivalent to the binding site of the antitumor drug taxol in tubulin (Haydon, D. J., Stokes, N. R., Ure, R., Galbraith, G., Bennett, J. M., Brown, D. R., Baker, P. J., Barynin, V. V., Rice, D. W., Sedelnikova, S. E., Heal, J. R., Sheridan, J. M., Aiwale, S. T., Chauhan, P. K., Srivastava, A., Taneja, A., Collins, I., Errington, J., and Czaplewski, L. G. (2008) Science 312, 1673–1675). We have found that the benzamide derivative PC190723 is an FtsZ polymer-stabilizing agent. PC190723 induced nucleated assembly of Bs-FtsZ into single-stranded coiled protofilaments and polymorphic condensates, including bundles, coils, and toroids, whose formation could be modulated with different solution conditions. Under conditions for reversible assembly of Bs-FtsZ, PC190723 binding reduced the GTPase activity and induced the formation of straight bundles and ribbons, which was also observed with Sa-FtsZ but not with nonsusceptible Ec-FtsZ. The fragment 2,6-difluoro-3-methoxybenzamide also induced Bs-FtsZ bundling. We propose that polymer stabilization by PC190723 suppresses in vivo FtsZ polymer dynamics and bacterial division. The biochemical action of PC190723 on FtsZ parallels that of the microtubule-stabilizing agent taxol on the eukaryotic structural homologue tubulin. Both taxol and PC190723 stabilize polymers against disassembly by preferential binding to each assembled protein. It is yet to be investigated whether both ligands target structurally related assembly switches.
Angiogenesis is a requirement for the sustained growth and proliferation of solid tumors, and the development of new compounds that induce a sustained inhibition of the proangiogenic signaling ...generated by tumor hypoxia still remains as an important unmet need. In this work, we describe a new antiangiogenic compound (22) that inhibits proangiogenic signaling under hypoxic conditions in breast cancer cells. Compound 22 blocks the MAPK pathway, impairs cellular migration under hypoxic conditions, and regulates a set of genes related to angiogenesis. These responses are mediated by HIF-1α, since the effects of compound 22 mostly disappear when its expression is knocked-down. Furthermore, administration of compound 22 in a xenograft model of breast cancer produced tumor growth reductions ranging from 46 to 55% in 38% of the treated animals without causing any toxic side effects. Importantly, in the responding tumors, a significant reduction in the number of blood vessels was observed, further supporting the mechanism of action of the compound. These findings provide a rationale for the development of new antiangiogenic compounds that could eventually lead to new drugs suitable for the treatment of some types of tumors either alone or in combination with other agents.
Chronic infection with hepatitis B virus (HBV) is strongly associated with hepatocellular carcinoma (HCC), and the viral HBx protein plays a crucial role in the pathogenesis of liver tumors. Because ...the protooncogene pituitary tumor–transforming gene 1 (PTTG1) is overexpressed in HCC, we investigated the regulation of this protein by HBx. We analyzed PTTG1 expression levels in liver biopsies from patients chronically infected with HBV, presenting different disease stages, and from HBx transgenic mice. PTTG1 was undetectable in biopsies from chronic hepatitis B patients or from normal mouse livers. In contrast, hyperplastic livers from transgenic mice and biopsies from patients with cirrhosis, presented PTTG1 expression which was found mainly in HBx‐expressing hepatocytes. PTTG1 staining was further increased in HCC specimens. Experiments in vitro revealed that HBx induced a marked accumulation of PTTG1 protein without affecting its messenger RNA levels. HBx expression promoted the inhibition of PTTG1 ubiquitination, which in turn impaired its degradation by the proteasome. Glutathione S‐transferase pull‐down and co‐immunoprecipitation experiments demonstrated that the interaction between PTTG1 and the Skp1–Cul1–F‐box ubiquitin ligase complex (SCF) was partially disrupted, possibly through a mechanism involving protein–protein interactions of HBx with PTTG1 and/or SCF. Furthermore, confocal analysis revealed that HBx colocalized with PTTG1 and Cul1. We propose that HBx promotes an abnormal accumulation of PTTG1, which may provide new insights into the molecular mechanisms of HBV‐related pathogenesis of progressive liver disease leading to HCC development. (HEPATOLOGY 2010;51:777–787.)
Endoglin is a proliferation‐associated and hypoxia‐inducible protein expressed in endothelial cells. The levels of soluble circulating endoglin and their prognostic significance in patients with ...acute myocardial infarction (AMI) are not known. In this observational prospective study serum endoglin levels were measured by ELISA in 183 AMI patients upon admission to hospital and 48 hrs later and in 72 healthy controls. Endoglin levels in AMI patients on admission were significantly lower than in healthy controls (4.25 ± 0.99 ng/ml versus 4.59 ± 0.87 ng/ml; P= 0.013), and decreased further in the first 48 hours (3.65 ± 0.76 ng/ml, P < 0.001). Upon follow‐up (median 319 days), patients who died had a significantly greater decrease in serum endoglin level over the first 48 hrs than those who survived (1.03 ± 0.91 versus 0.54 ± 0.55 ng/ml; P= 0.025). Endoglin decrease was an independent predictor of short‐term (30 days) (hazard ratio 2.33;95% CI = 1.27–4.23; P= 0.006) cardiovascular mortality, and also predicts overall cardiovascular mortality during the follow‐up (median 319 days) in AMI patients (hazard ratio 2.13;95% CI = 1.20–3.78; P= 0.01). In conclusion, early changes in serum endoglin may predict mortality after AMI.
It is unclear whether norfloxacin predisposes to infections by multidrug-resistant organisms (MDROs). We aimed to evaluate if patients with cirrhosis receiving norfloxacin prophylaxis at the time of ...the diagnosis of bacterial infections were more likely to present a multidrug-resistant isolate than those without prophylaxis. This is a cross-sectional study of hospitalized patients with cirrhosis and bacterial infections from Argentina and Uruguay (NCT03919032) from September 2018 to December 2020. The outcome variable was a multidrug-resistant bacterial infection. We used inverse probability of treatment weighting to estimate the odds ratio (OR) of norfloxacin on infection caused by MDROs considering potential confounders. Among the 472 patients from 28 centers, 53 (11%) were receiving norfloxacin at the time of the bacterial infection. Patients receiving norfloxacin had higher MELD-sodium, were more likely to have ascites or encephalopathy, to receive rifaximin, beta-blockers, and proton-pump inhibitors, to have a nosocomial or health-care-associated infection, prior bacterial infections, admissions to critical care units or invasive procedures, and to be admitted in a liver transplant center. In addition, we found that 13 (24.5%) patients with norfloxacin and 90 (21.5%) of those not receiving it presented infections caused by MDROs (adjusted OR 1.55; 95% CI: 0.60–4.03;
p
= 0.360). The use of norfloxacin prophylaxis at the time of the diagnosis of bacterial infections was not associated with multidrug resistance. These results help empiric antibiotic selection and reassure the current indication of norfloxacin prophylaxis in well-selected patients.
Study registration number: NCT03919032
Human tandem-repeat-type galectin-9 is a potent adhesion/growth-regulatory effector via lectin capacity of its N- and C-terminal domains. This bioactivity prompted further crystallographic study of ...the N-domain, combined with analysis in solution. Binding of lactose markedly increased the N-domain's resistance to thermal denaturation. Crystallography revealed its intimate contact profile, besides detecting an extension of the β-sandwich fold by an antiparallel β-strand F0 aligned to the C-terminal F1 strand. Ligand accommodation in its low-energy conformation leads to a movement of Arg87's side chain. As consequence, the ligand's glucose moiety and Arg87 become hydrogen bonded. The resulting predictions for spatial parameters in solution were verified by determining (a) the pattern of magnetization transfer from the protein to protons of lactose and Forssman disaccharide by NMR spectroscopy and (b) the ellipticity changes at wavelengths characteristic for Trp/Tyr residues in near-UV CD spectroscopy. Whereas solid-phase assays confirmed a previously noted tendency for homo- and heterotypic aggregation, gel filtration and ultracentrifugation disclosed monomeric status in solution, in line with crystallographic data. Using cell mutants with defects in glycosylation, this lectin domain was shown to preferentially bind N-glycans without α2,3-sialylation. Since proximal promoter sequences were delineated to diverge markedly among galectin genes and resulting differences in expression profiles were exemplarily documented immunohistochemically, the intrafamily diversification appears to have assigned this protein to a characteristic expression and activity profile among galectins. Our data thus take the crystallographic information to the level of the lectin in solution and in tissues by a strategic combination of spectroscopic and cell/histochemical assays.
Respiratory syncytial virus (RSV) is an important cause of hospitalization and death in infants worldwide. Most RSV deaths occur in developing countries, where burden and risk factors for ...life-threatening illness are unclear.
We defined the burden of life-threatening (O(2) saturation O(2) sat ≤ 87%) and fatal RSV infection, and characterized risk factors for life-threatening disease in hospitalized children. Special emphasis was placed on studying the impact of dietary habits during pregnancy. We hypothesized that dietary preferences, differing from those of our remote ancestors, would negatively impact children's pulmonary health. For instance, a diet rich in carbohydrates is a signature of recent millennia and typical of low-income populations, heavily burdened by life-threatening RSV disease.
Prospective study in a catchment population of 56,560 children under 2 years of age during the RSV season in Argentina. All children with respiratory signs and O(2) sat less than 93% on admission were included.
Among 1,293 children with respiratory infections, 797(61.6%) were infected with RSV: 106 of these had life-threatening disease; 1.9 per 1,000 children (95% confidence interval CI, 1.5-2.2/1,000) under 24 months. A total of 22 hospitalized children died (9 RSV(+)), 26 died at home due to acute respiratory infection (14 attributed to RSV); all were under 12 months old. The annual attributable mortality rate for RSV was 0.7 per 1,000 infants (95% CI, 0.4-1.1/1,000). Life-threatening disease was dose-dependently associated with carbohydrate ingestion during pregnancy (adjusted odds ratio from 3.29 95% CI, 1.15-9.44 to 7.36 95% CI, 2.41-22.5 versus the lowest quartile).
Life-threatening and fatal RSV infections are a heavy burden on infants in the developing world. Diets rich in carbohydrates during pregnancy are associated with these severe outcomes.
The Hispanic/Latino population has greater risk (estimated >50%) of developing type 2 diabetes (T2D) and developing it at a younger age. The American Diabetes Association estimates costs of diagnosed ...diabetes in 2017 was $327 billion; with medical costs 2.3x higher than patients without diabetes. The purpose of this manuscript is to describe the methodology utilized in a randomized controlled trial aimed at evaluating the efficacy of a diabetes telemanagement (DTM) program for Hispanic/Latino patients with T2D. The intent is to provide information for future investigators to ensure that this study can be accurately replicated.
This study was a randomized controlled trial with 240 participants. Eligible patients (Hispanic/Latino, aged 18+, living with T2D) were randomized to Comprehensive Outpatient Management (COM) or DTM. DTM was comprised of usual care, including routine clinic visits every three months, as well as: Biometrics (a tablet, blood glucose meter, blood pressure monitor, and scale); Weekly Video Visits (facilitated in the patient's preferred language); and Educational Videos (including culturally congruent diabetes self-management education and quizzes). COM consisted of usual care including routine clinic visits every three months. For this study, COM patients received a glucometer, glucose test strips, and lancets. Establishing a therapeutic nurse-patient relationship was a fundamental component of our study for both groups. First contact (post-enrollment) centered on ensuring that patients and caregivers understood the program, building trust and rapport, creating a non-judgmental environment, determining language preference, and establishing scheduling availability (including evenings and weekends). DTM were provided with a tablet which allowed for self-paced education through videos and weekly video visits. The research team and Community Advisory Board identified appropriate educational video content, which was incorporated in diabetes educational topics. Video visits allowed us to assess patient involvement, motivation, and nonverbal communication. Communicating in Spanish, and awareness of diverse Hispanic/Latino backgrounds was critical, as using relevant and commonly-used terms can increase adherence and improve outcomes. Shared decision-making was encouraged to make realistic health care choices.
Key elements discussed above provide a framework for future dissemination of an evidence-based DTM intervention to meet the needs of underserved Hispanic/Latino people living with T2D.
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