Fkh1 and Fkh2 bind multiple chromosomal elements in the S. cerevisiae genome with distinct specificities and cell cycle dynamics

Forkhead box (FOX) transcription factors regulate a wide variety of cellular functions in higher eukaryotes, including cell cycle control and developmental regulation. In Saccharomyces cerevisiae, Forkhead proteins Fkh1 and Fkh2 perform analogous functions, regulating genes involved in cell cycle control, while also regulating mating-type silencing and switching involved in gamete development. Recently, we revealed a novel role for Fkh1 and Fkh2 in the regulation of replication origin initiation timing, which, like donor preference in mating-type switching, appears to involve long-range chromosomal interactions, suggesting roles for Fkh1 and Fkh2 in chromatin architecture and organization. To elucidate how Fkh1 and Fkh2 regulate their target DNA elements and potentially regulate the spatial organization of the genome, we undertook a genome-wide analysis of Fkh1 and Fkh2 chromatin binding by ChIP-chip using tiling DNA microarrays. Our results confirm and extend previous findings showing that Fkh1 and Fkh2 control the expression of cell cycle-regulated genes. In addition, the data reveal hundreds of novel loci that bind Fkh1 only and exhibit a distinct chromatin structure from loci that bind both Fkh1 and Fkh2. The findings also show that Fkh1 plays the predominant role in the regulation of a subset of replication origins that initiate replication early, and that Fkh1/2 binding to these loci is cell cycle-regulated. Finally, we demonstrate that Fkh1 and Fkh2 bind proximally to a variety of genetic elements, including centromeres and Pol III-transcribed snoRNAs and tRNAs, greatly expanding their potential repertoire of functional targets, consistent with their recently suggested role in mediating the spatial organization of the genome

Global alterations to the choroid plexus blood-CSF barrier in amyotrophic lateral sclerosis

© 2020 The Author(s). The choroid plexus (CP) is a highly vascularized structure located in the ventricles that forms the blood-CSF barrier (BCSFB) and separates the blood from the cerebrospinal fluid (CSF). In addition to its role as a physical barrier, the CP functions in CSF secretion, transport of nutrients into the central nervous system (CNS) and a gated point of entry of circulating immune cells into the CNS. Aging and neurodegeneration have been reported to affect CP morphology and function and increase protein leakage from blood to the CSF. Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease associated with both upper and lower motor neuron loss, as well as altered proteomic and metabolomic signatures in the CSF. The role of the BCSFB and the CP in ALS is unknown. Here we describe a transcriptomic and ultrastructural analysis of BCSFB and CP alterations in human postmortem tissues from ALS and non-neurologic disease controls. ALS-CP exhibited widespread disruptions in tight junctional components of the CP epithelial layer and vascular integrity. In addition, we detected loss of pericytes around ALS blood vessels, accompanied by activation of platelet aggregation markers vWF and Fibrinogen, reminiscent of vascular injury. To investigate the immune component of ALS-CP, we conducted a comprehensive analysis of cytokines and chemokine panels in CP lysates and found a significant down-regulation of M-CSF and V-CAM1 in ALS, as well as up-regulation of VEGF-A protein. This phenotype was accompanied by an infiltration of MERTK positive macrophages into the parenchyma of the ALS-CP when compared to controls. Taken together, we demonstrate widespread structural and functional disruptions of the BCSFB in human ALS increasing our understanding of the disease pathology and identifying potential new targets for ALS therapeutic development

Sexual behavior research on a Cohort of gay men, 1984–1990: Can we predict how men will respond to interventions?

In 1984, over 1000 gay and bisexual men volunteered to participate in both the Chicago Multicenter AIDS Cohort Study (MACS) and a companion psychosocial study, the Coping and Change Study (CCS). Participants in the semiannual Chicago MACS/CCS evaluations comprise the largest cohort of high-risk men under continuous medical, behavioral, and psychosocial observation. Chicago MACS/CCS researchers prospectively chart the sexual behavior change patterns of the cohort and relate those behavioral changes to psychosocial correlates and actual HIV infection risk. This report summarizes the behavioral natural history of the Chicago MACS/CCS cohort from 1984 to 1990, focusing on receptive anal sex practices and use patterns for alcohol and the most frequently used recreational drugs. As these are prospective observational and not controlled intervention studies, psychosocial correlates of sexual behavior change by members of the cohort are suggestive of factors influencing behavior change rather than indicative of causal relationships. However, the voluntary availability to participants in the Chicago MACS/CCS of HIV-1 antibody test results beginning in late 1985 provided the opportunity to examine whether demographic, psychosocial, or behavioral factors were indicators of sexual behavior change following disclosure and counseling about HIV-1 serostatus. Recommendations for promotion and maintenance of safer sexual behavior for the long run, and limitations in the generalizability of these findings to the much more diverse populations of men who have sex with other men conclude this article.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44099/1/10508_2005_Article_BF01541496.pd

A prospective study of alcohol consumption and HIV acquisition among injection drug users

Estimate the effect of alcohol consumption on HIV acquisition while appropriately accounting for confounding by time-varying risk factors

Determinants of alcohol consumption in HIV-uninfected injection drug users

We assess the association between time fixed and time varying participant characteristics and subsequent alcohol consumption in 1,968 injection drug users (median age 37 years, 28% female, 90% African-American) followed semi-annually from 1988 to 2008. Median alcohol consumption was seven drinks per week at study entry (first and third quartile: 1, 26) with 36% reporting binge drinking. Alcohol consumption and binge drinking decreased over follow-up. Older individuals and women reported consuming fewer drinks per week. Higher typical alcohol consumption was reported by those participants who reported in the prior six months: non-injection cocaine use, injection drug use, having one or more sex partners, or among men, a same sex partner. Associations were generally similar for drinks per week and binge drinking. This study demonstrates that in a large urban cohort of persons with a history of injection drug use, risky drug use and sexual risk behavior are associated with subsequent alcohol consumption

Computational chemical analysis of unconjugated bilirubin anions and insights into pKa values clarification

The pKa, the negative logarithm of the acid dissociation equilibrium constant, of the carboxylic acid groups of unconjugated bilirubin in water is a discussed issue because there are quite different experimental values reported. Using quantum mechanical calculations we have studied the conformational behavior of unconjugated bilirubin species (in gas phase and in solution modeled implicitly and explicitly) to provide evidence that may clarify pKa values because of its pathophysiological relevance. Our results show that rotation of carboxylate group, which is not restricted, settles it in a suitable place to establish stronger interactions that stabilizes the monoanion and the dianion to be properly solvated, demonstrating that the rationalization used to justify the high pKa values of unconjugated bilirubin is inappropriate. Furthermore, low unconjugated bilirubin (UCB) pKa values were estimated from a linear regression analysis.Fil: Vega Hissi, Esteban Gabriel. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Quimica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Estrada, Mario Rinaldo. Universidad Nacional de San Luis. Facultad de Quimica, Bioquimica y Farmacia. Departamento de Quimica; ArgentinaFil: Lavecchia, Martín José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Química Inorgánica; ArgentinaFil: Pis Diez, Reinaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico La Plata. Centro de Química Inorgánica; Argentin

Long-Term Effectiveness and Safety of Childhood Growth Hormone Treatment in Noonan Syndrome

Introduction: Few data exist on long-term growth hormone (GH) treatment in patients with Noonan syndrome (NS). Objective: To evaluate the effectiveness and safety of GH treatment in NS in clinical practice. Methods: Height gain, near-adult height (NAH), and safety were assessed in 2 complementary non-interventional studies: NordiNet® IOS and ANSWER. The safety analysis included 412 patients, and the effectiveness analysis included 84 GH-treated patients (male, n = 67) with ≥4 years’ height standard deviation score (HSDS) data. HSDS was determined using national reference (NR) and NS-specific (NSS) data. Results: The mean (SD) baseline age was 8.38 (3.57) years; HSDS, −2.76 (1.03); GH dose, 41.6 (11.1) µg/kg/day. The mean (SD) HSDS increase from baseline (ΔHSDS) was 0.49 (0.37) (first year), 0.79 (0.58) (second year), and 1.01 (0.60) (third year) (NR). The mean (SD) HSDS at year 3 was −1.66 (1.00) (NR; 1.06 [1.12] [NSS]). Twenty-four patients achieved NAH. The mean (SD) NAH SDS (NR) was −1.51 (0.60) (154.90 [3.21] cm) in females and −1.79 (1.09) (165.61 [7.19] cm) in males; 70.8% (17/24) had NAH SDS ≥ −2. Adverse drug reactions and GH-unrelated serious adverse events (n = 34) were reported in 22/412 (5.3%) patients. Four neoplasms and 3 cases of scoliosis were reported; no cardiovascular adverse events occurred. Conclusions: GH-treated children with NS achieved substantial height gain during the first 3 years of follow-up. Overall, 24 patients achieved NAH, with 70.8% having NAH SDS ≥ –2. There was no evidence to support a higher prevalence of neoplasm, or cardiac or other comorbidities.publishedVersio

Modulation of Mrp1 (ABCc1) and Pgp (ABCb1) by Bilirubin at the Blood-CSF and Blood-Brain Barriers in the Gunn Rat

Accumulation of unconjugated bilirubin (UCB) in the brain causes bilirubin encephalopathy. Pgp (ABCb1) and Mrp1 (ABCc1), highly expressed in the blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB) respectively, may modulate the accumulation of UCB in brain. We examined the effect of prolonged exposure to elevated concentrations of UCB on expression of the two transporters in homozygous, jaundiced (jj) Gunn rats compared to heterozygous, not jaundiced (Jj) littermates at different developmental stages (2, 9, 17 and 60 days after birth). BBB Pgp protein expression was low in both jj and Jj pups at 9 days (about 16–27% of adult values), despite the up-regulation in jj animals (2 and 1.3 fold higher than age matched Jj animals at P9 and P17–P60, respectively); Mrp1 protein expression was barely detectable. Conversely, at the BCSFB Mrp1 protein expression was rather high (60–70% of the adult values) in both jj and Jj at P2, but was markedly (50%) down-regulated in jj pups starting at P9, particularly in the 4th ventricle choroid plexuses: Pgp was almost undetectable. The Mrp1 protein down regulation was accompanied by a modest up-regulation of mRNA, suggesting a translational rather than a transcriptional inhibition. In vitro exposure of choroid plexus epithelial cells obtained from normal rats to UCB, also resulted in a down-regulation of Mrp1 protein. These data suggest that down-regulation of Mrp1 protein at the BSCFB, resulting from a direct effect of UCB on epithelial cells, may impact the Mrp1-mediated neuroprotective functions of the blood-cerebrospinal fluid barrier and actually potentiate UCB neurotoxicity