Affinity maturation of antibodies requires a unique process of targeted mutation that allows changes to accumulate in the antibody genes while the rest of the genome is protected from off-target ...mutations that can be oncogenic. This targeting requires that the same deamination event be repaired either by a mutagenic or a high-fidelity pathway depending on the genomic location. We have previously shown that the BRCT domain of the DNA-damage sensor PARP-1 is required for mutagenic repair occurring in the context of IgH and IgL diversification in the chicken B cell line DT40. Here we show that immunoprecipitation of the BRCT domain of PARP-1 pulls down Ku70 and the DNA–PK complex although the BRCT domain of PARP-1 does not bind DNA, suggesting that this interaction is not DNA dependent. Through sequencing the
IgL variable region in PARP-1
−/− cells that also lack Ku70 or Lig4, we show that Ku70 or Lig4 deficiency restores GCV to PARP-1
−/− cells and conclude that the mechanism by which PARP-1 is promoting mutagenic repair is by inhibiting high-fidelity repair which would otherwise be mediated by Ku70 and Lig4.
Single-gene mutations that disrupt mitochondrial respiratory chain function in Caenorhabditis elegans change patterns of protein expression and metabolites. Our goal was to develop useful molecular ...fingerprints employing adaptable techniques to recognize mitochondrial defects in the electron transport chain. We analyzed mutations affecting complex I, complex II, or ubiquinone synthesis and discovered overarching patterns in the response of C. elegans to mitochondrial dysfunction across all of the mutations studied. These patterns are in KEGG pathways conserved from C. elegans to mammals, verifying that the nematode can serve as a model for mammalian disease. In addition, specific differences exist between mutants that may be useful in diagnosing specific mitochondrial diseases in patients.
Aging alters numerous aspects of circadian biology, including the amplitude of rhythms generated by the suprachiasmatic nuclei (SCN) of the hypothalamus, the site of the central circadian pacemaker ...in mammals, and the response of the pacemaker to environmental stimuli such as light. Although previous studies have described molecular correlates of these behavioral changes, to date only 1 study in rats has attempted to determine if there are age-related changes in the expression of genes that comprise the circadian clock itself. We used in situ hybridization to examine the effects of age on the circadian pattern of expression of a subset of the genes that comprise the molecular machinery of the circadian clock in golden hamsters. Here we report that age alters the 24-h expression profile of Clock and its binding partner Bmal1 in the hamster SCN. There is no effect of age on the 24-h profile of either Per1 or Per2 when hamsters are housed in constant darkness. We also found that light pulses, which induce smaller phase shifts in old animals than in young, lead to decreased induction of Per1, but not of Per2, in the SCN of old hamsters.
1 Center for Circadian Biology
and Medicine, Department of Neurobiology and Physiology, Northwestern
University, Evanston, Illinois 60208 and
2 Department of
Neurology, Northwestern University ...Medical School, Chicago, Illinois
60211
Shift work is associated with increased
cardiovascular morbidity and mortality. Whereas it has been suggested
that continuous shifting of the circadian clock/sleep-wake cycle may
have negative effects on health, there is very little experimental
evidence to support such a hypothesis. Cardiomyopathic Syrian hamsters were either maintained on a fixed light-dark (LD) cycle
( n = 31) or were subjected to a 12-h
phase shift in the LD cycle on a weekly basis
( n = 32). The duration of the life
span was recorded for each animal. Chronic reversal of the external LD
cycle at weekly intervals resulted in a significant decrease in the
survival time in cardiomyopathic hamsters with the median life span
being reduced by 11%. Disrupting normal circadian rhythmicity in an
animal susceptible to early mortality due to cardiac disease results in
a further decrease in longevity. The deleterious effects of the chronic phase shifts in the LD cycle in cardiomyopathic hamsters may be related
to reports of increased cardiovascular morbidity and mortality in
humans engaged in shift work.
rhythms; shift work; longevity; cardiac disease
PURPOSE: To evaluate long-term risk factors for progression or stability in patients with primary open-angle glaucoma.
METHOD: We retrospectively included consecutively reviewed patients who had ...primary open-angle glaucoma for at least 5 years in this multicenter trial. Historical and clinical factors in these patients were evaluated for their association with stability or progression of the glaucoma.
RESULTS: We included 218 patients in this study; of these, 34 progressed over an average length of follow-up of 45.5 ± 30.0 months, and 184 were stable over an average of 72.8 ± 18.3 months. The mean intraocular pressure over the follow-up period for the progressed group was 19.5 ± 3.8 mm Hg and for the stable group 17.2 ± 3.1 mm Hg (
P = .001). The average standard deviation of individual intraocular pressures was greater in the progressed group (5.1 mm Hg) than the stable group (3.9 mm Hg,
P = .012). Baseline characteristics indicating a greater potential to progress were a larger cup-to-disk ratio (
P < .001), a greater number of medications (
P = .02), older age (
P .007), and worse visual acuity (
P = .003). However, no difference was observed in pressure levels that prevented progression in these subpopulations compared with the total sample size.
CONCLUSIONS: This study suggests that lowering the intraocular pressure is important in the treatment of primary open-angle glaucoma to help prevent long-term progression. Lowering the pressure, however, is not uniformly effective in preventing progression. Additionally, risk factors for progression do not further help identify pressure levels that prevent worsening of glaucoma.
BackgroundBrain metastases (BrMs) are a devastating complication of solid tumors. Despite improvements in tumor detection and local treatment as well as the introduction of new therapies including ...immune checkpoint blockade (ICB) and targeted therapies, the clinical benefit is observed only for a subset of BrMs patients.1–3 A better understanding of this disease is needed to develop more effective patient selection strategies and therapeutics.MethodsIn this study, multidisciplinary molecular and proteomic approaches were applied on to the peripheral blood and tumor tissues derived from primary lesions and BrMs from patients with melanoma, lung, breast, and renal cancer to evaluate in depth the tumor immune portrait behind BrMs biology.ResultsThe tumor microenvironment (TME) of melanoma brain metastasis (MBM) appeared to be less immunogenic when compared to the TME of primary melanoma (PM), based on less infiltration of NK and NKT cells. However, higher infiltration of CD8+, antigen presenting cells, and B cells was observed in MBM when compared to BrMs derived from other solid tumors (non-MBM). Conversely, increased infiltration of Tregs and neutrophils was found in non-MBM compared with MBM. Interestingly, the presence of immature early tertiary lymphoid structures (TLS), as another hallmark of the TME of MBM, was supported by molecular and proteomic evaluations. Furthermore, proteomic analysis revealed higher infiltration of CD8+ and CD20+ cells in MBM to be associated with longer overall survival (OS). Curiously, the presence of immature early TLS structures in a MBM patient with longer OS compared to a MBM case with lower OS also emphasizes the potential influence of TLS formation in MBM patient survival and/or response to immunotherapy. These observations suggest that presence of TLS may have a strong association or even play a functional role in the immune control of MBM.ConclusionsTaken together these results suggest that the TME of BrMs plays a pivotal role in the pathogenesis and therapeutic resistance of BrMs derived from different solid tumors.AcknowledgementsThe authors thank patients, their families, the Rosalie and Harold Rae Brown Family Foundation and the Borstein Family Foundation for their support.ReferencesTawbi HA, Forsyth PA, Algazi A, Hamid O, Hodi FS, Moschos SJ, Khushalani NI, Lewis K, Lao CD, Postow MA. Combined nivolumab and ipilimumab in melanoma metastatic to the brain. New England Journal of Medicine 2018; 379 :722–730.Tawbi HA, Forsyth PA, Hodi FS, Algazi AP, Hamid O, Lao CD, Moschos SJ, Atkins MB, Lewis K, Postow MA. Long-term outcomes of patients with active melanoma brain metastases treated with combination nivolumab plus ipilimumab (CheckMate 204): final results of an open-label, multicentre, phase 2 study. The Lancet Oncology 2021; 22 :1692–1704.Goldberg SB, Schalper KA, Gettinger SN, Mahajan A, Herbst RS, Chiang AC, Lilenbaum R, Wilson FH, Omay SB, James BY. Pembrolizumab for management of patients with NSCLC and brain metastases: long-term results and biomarker analysis from a non-randomised, open-label, phase 2 trial. The Lancet Oncology 2020; 21 :655–663.Ethics ApprovalSamples were procured under studies approved by Providence Saint Joseph Health Institutional Review Board or Western Copernicus Group Institutional Review Board. All specimens evaluated were derived from consenting patients.
The US Agency for International Development (USAID) receives directives and funding through the appropriation process, though until recently, global surgery was not included in its mission. ...Nevertheless, an estimated five billion people lack access to safe, timely, and affordable surgical care, in large part due to lack of economic resources. Using coalition-based advocacy, the G4 Alliance successfully developed and submitted language that was incorporated into the 2020 Appropriations report language, directing USAID to financially support global surgery. This has significant implications for global surgical investment, yet few advocates are aware of the 2020 Appropriations language, let alone how they can utilize it now to advance global surgery in their respective countries. Here, we describe how advocates navigate the US appropriations process and the ways USAID funds are obtained for the purposes of global health. We also highlight the importance of coalition-based advocacy and provide guidance in how to increase success.
Disease‐specific funding activism in the US has required health social movements (HSMs) to draw on both structural and cultural resources in order to persuade audiences and to redefine dominant ...conceptions of disease. Using a social constructionist analysis of Congressional testimony and media accounts of breast cancer funding activism between 1990–1993, this paper demonstrates that the use of culturally resonant frames served as an important cultural resource for breast cancer activists in the early 1990s. The breast cancer movement's use of three interconnected and culturally resonant frames aided the movement in redefining breast cancer as a problem of individual women to a major public health problem in need of governmental attention. This research contributes to both social movement and HSM scholarship by demonstrating that cultural resources, in the form of movement frames, are as central to social movement analysis as structural resources.
A statistical model is presented for computing probabilities that proteins are present in a sample on the basis of peptides assigned to tandem mass (MS/MS) spectra acquired from a proteolytic digest ...of the sample. Peptides that correspond to more than a single protein in the sequence database are apportioned among all corresponding proteins, and a minimal protein list sufficient to account for the observed peptide assignments is derived using the expectation−maximization algorithm. Using peptide assignments to spectra generated from a sample of 18 purified proteins, as well as complex H. influenzae and Halobacterium samples, the model is shown to produce probabilities that are accurate and have high power to discriminate correct from incorrect protein identifications. This method allows filtering of large-scale proteomics data sets with predictable sensitivity and false positive identification error rates. Fast, consistent, and transparent, it provides a standard for publishing large-scale protein identification data sets in the literature and for comparing the results obtained from different experiments.
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