A high throughput cell stretch device for investigating mechanobiology in vitro.

Mechanobiology is a rapidly advancing field, with growing evidence that mechanical signaling plays key roles in health and disease. To accelerate mechanobiology-based drug discovery, novel in vitro systems are needed that enable mechanical perturbation of cells in a format amenable to high throughput screening. Here, both a mechanical stretch device and 192-well silicone flexible linear stretch plate were designed and fabricated to meet high throughput technology needs for cell stretch-based applications. To demonstrate the utility of the stretch plate in automation and screening, cell dispensing, liquid handling, high content imaging, and high throughput sequencing platforms were employed. Using this system, an assay was developed as a biological validation and proof-of-concept readout for screening. A mechano-transcriptional stretch response was characterized using focused gene expression profiling measured by RNA-mediated oligonucleotide Annealing, Selection, and Ligation with Next-Gen sequencing. Using articular chondrocytes, a gene expression signature containing stretch responsive genes relevant to cartilage homeostasis and disease was identified. The possibility for integration of other stretch sensitive cell types (e.g., cardiovascular, airway, bladder, gut, and musculoskeletal), in combination with alternative phenotypic readouts (e.g., protein expression, proliferation, or spatial alignment), broadens the scope of high throughput stretch and allows for wider adoption by the research community. This high throughput mechanical stress device fills an unmet need in phenotypic screening technology to support drug discovery in mechanobiology-based disease areas.

CSB and SMARCAL1 compete for RPA32 at stalled forks and differentially control the fate of stalled forks in BRCA2-deficient cells.

CSB (Cockayne syndrome group B) and SMARCAL1 (SWI/SNF-related, matrix-associated, actin-dependent, regulator of chromatin, subfamily A-like 1) are DNA translocases that belong to the SNF2 helicase family. They both are enriched at stalled replication forks. While SMARCAL1 is recruited by RPA32 to stalled forks, little is known about whether RPA32 also regulates CSB's association with stalled forks. Here, we report that CSB directly interacts with RPA, at least in part via a RPA32C-interacting motif within the N-terminal region of CSB. Modeling of the CSB-RPA32C interaction suggests that CSB binds the RPA32C surface previously shown to be important for binding of UNG2 and SMARCAL1. We show that this interaction is necessary for promoting fork slowing and fork degradation in BRCA2-deficient cells but dispensable for mediating restart of stalled forks. CSB competes with SMARCAL1 for RPA32 at stalled forks and acts non-redundantly with SMARCAL1 to restrain fork progression in response to mild replication stress. In contrast to CSB stimulated restart of stalled forks, SMARCAL1 inhibits restart of stalled forks in BRCA2-deficient cells, likely by suppressing BIR-mediated repair of collapsed forks. Loss of CSB leads to re-sensitization of SMARCAL1-depleted BRCA2-deficient cells to chemodrugs, underscoring a role of CSB in targeted cancer therapy.

CSB Regulates Pathway Choice in Response to DNA Replication Stress Induced by Camptothecin.

Topoisomerase inhibitor camptothecin (CPT) induces fork stalling and is highly toxic to proliferating cells. However, how cells respond to CPT-induced fork stalling has not been fully characterized. Here, we report that Cockayne syndrome group B (CSB) protein inhibits PRIMPOL-dependent fork repriming in response to a low dose of CPT. At a high concentration of CPT, CSB is required to promote the restart of DNA replication through MUS81-RAD52-POLD3-dependent break-induced replication (BIR). In the absence of CSB, resumption of DNA synthesis at a high concentration of CPT can occur through POLQ-LIG3-, LIG4-, or PRIMPOL-dependent pathways, which are inhibited, respectively, by RAD51, BRCA1, and BRCA2 proteins. POLQ and LIG3 are core components of alternative end joining (Alt-EJ), whereas LIG4 is a core component of nonhomologous end joining (NHEJ). These results suggest that CSB regulates fork restart pathway choice following high-dosage CPT-induced fork stalling, promoting BIR but inhibiting Alt-EJ, NHEJ, and fork repriming. We find that loss of CSB and BRCA2 is a toxic combination to genomic stability and cell survival at a high concentration of CPT, which is likely due to accumulation of ssDNA gaps, underscoring an important role of CSB in regulating the therapy response in cancers lacking functional BRCA2.

Role of Cockayne Syndrome Group B Protein in Replication Stress: Implications for Cancer Therapy.

A variety of endogenous and exogenous insults are capable of impeding replication fork progression, leading to replication stress. Several SNF2 fork remodelers have been shown to play critical roles in resolving this replication stress, utilizing different pathways dependent upon the nature of the DNA lesion, location on the DNA, and the stage of the cell cycle, to complete DNA replication in a manner preserving genetic integrity. Under certain conditions, however, the attempted repair may lead to additional genetic instability. Cockayne syndrome group B (CSB) protein, a SNF2 chromatin remodeler best known for its role in transcription-coupled nucleotide excision repair, has recently been shown to catalyze fork reversal, a pathway that can provide stability of stalled forks and allow resumption of DNA synthesis without chromosome breakage. Prolonged stalling of replication forks may collapse to give rise to DNA double-strand breaks, which are preferentially repaired by homology-directed recombination. CSB plays a role in repairing collapsed forks by promoting break-induced replication in S phase and early mitosis. In this review, we discuss roles of CSB in regulating the sources of replication stress, replication stress response, as well as the implications of CSB for cancer therapy.

Cockayne syndrome group B protein uses its DNA translocase activity to promote mitotic DNA synthesis.

Mitotic DNA synthesis, also known as MiDAS, has been suggested to be a form of RAD52-dependent break-induced replication (BIR) that repairs under-replicated DNA regions of the genome in mitosis prior to chromosome segregation. Cockayne syndrome group B (CSB) protein, a chromatin remodeler of the SNF2 family, has been implicated in RAD52-dependent BIR repair of stalled replication forks. However, whether CSB plays a role in MiDAS has not been characterized. Here, we report that CSB functions epistatically with RAD52 to promote MiDAS at common fragile sites in response to replication stress, and prevents genomic instability associated with defects in MiDAS. We show that CSB is dependent upon the conserved phenylalanine at position 796 (F796), which lies in the recently-reported pulling pin that is required for CSB's translocase activity, to mediate MiDAS, suggesting that CSB uses its DNA translocase activity to promote MiDAS. Structural analysis reveals that CSB shares with a subset of SNF2 family proteins a translocase regulatory region (TRR), which is important for CSB's function in MiDAS. We further demonstrate that phosphorylation of S1013 in the TRR regulates the function of CSB in MiDAS and restart of stalled forks but not in fork degradation in BRCA2-deficient cells and UV repair. Taken together, these results suggest that the DNA translocase activity of CSB in vivo is likely to be highly regulated by post-translational modification in a context-specific manner.

Evaluation of a decision aid for the treatment of depression among college students.

Objective: Depression, and its treatment, is a concern among college students. Research indicates decision aids (DA) improve patients' treatment knowledge, decision making, and decisional conflict; however, it is unknown whether they are helpful for disseminating depression treatment information to college students. This study evaluated a DA for depression and its impact on college students' knowledge and treatment decision making. Methods: College students (N = 144) completed questionnaires pre-, post-, and at 1-month follow-up after reviewing an evidence-based DA for depression. Results: Participants rated the DA as highly acceptable and useful, and their knowledge increased at post-treatment and follow-up. However, treatment option presentation order influenced decision making. Conclusions: This DA is a useful and acceptable decision-making tool, and increased knowledge of depression and its treatment among college students. This study proposes a novel tool for educating college students about depression treatment, furthering our understanding of factors influencing treatment preferences.

Cockayne syndrome group B protein regulates fork restart, fork progression and MRE11-dependent fork degradation in BRCA1/2-deficient cells.

Cockayne syndrome group B (CSB) protein has been implicated in the repair of a variety of DNA lesions that induce replication stress. However, little is known about its role at stalled replication forks. Here, we report that CSB is recruited to stalled forks in a manner dependent upon its T1031 phosphorylation by CDK. While dispensable for MRE11 association with stalled forks in wild-type cells, CSB is required for further accumulation of MRE11 at stalled forks in BRCA1/2-deficient cells. CSB promotes MRE11-mediated fork degradation in BRCA1/2-deficient cells. CSB possesses an intrinsic ATP-dependent fork reversal activity in vitro, which is activated upon removal of its N-terminal region that is known to autoinhibit CSB's ATPase domain. CSB functions similarly to fork reversal factors SMARCAL1, ZRANB3 and HLTF to regulate slowdown in fork progression upon exposure to replication stress, indicative of a role of CSB in fork reversal in vivo. Furthermore, CSB not only acts epistatically with MRE11 to facilitate fork restart but also promotes RAD52-mediated break-induced replication repair of double-strand breaks arising from cleavage of stalled forks by MUS81 in BRCA1/2-deficient cells. Loss of CSB exacerbates chemosensitivity in BRCA1/2-deficient cells, underscoring an important role of CSB in the treatment of cancer lacking functional BRCA1/2.

Plasticity in Cervical Motor Circuits following Spinal Cord Injury and Rehabilitation.

Neuroplasticity is a robust mechanism by which the central nervous system attempts to adapt to a structural or chemical disruption of functional connections between neurons. Mechanical damage from spinal cord injury potentiates via neuroinflammation and can cause aberrant changes in neural circuitry known as maladaptive plasticity. Together, these alterations greatly diminish function and quality of life. This review discusses contemporary efforts to harness neuroplasticity through rehabilitation and neuromodulation to restore function with a focus on motor recovery following cervical spinal cord injury. Background information on the general mechanisms of plasticity and long-term potentiation of the nervous system, most well studied in the learning and memory fields, will be reviewed. Spontaneous plasticity of the nervous system, both maladaptive and during natural recovery following spinal cord injury is outlined to provide a baseline from which rehabilitation builds. Previous research has focused on the impact of descending motor commands in driving spinal plasticity. However, this review focuses on the influence of physical therapy and primary afferent input and interneuron modulation in driving plasticity within the spinal cord. Finally, future directions into previously untargeted primary afferent populations are presented.

The Winged Helix Domain of CSB Regulates RNAPII Occupancy at Promoter Proximal Pause Sites.

Cockayne syndrome group B protein (CSB), a member of the SWI/SNF superfamily, resides in an elongating RNA polymerase II (RNAPII) complex and regulates transcription elongation. CSB contains a C-terminal winged helix domain (WHD) that binds to ubiquitin and plays an important role in DNA repair. However, little is known about the role of the CSB-WHD in transcription regulation. Here, we report that CSB is dependent upon its WHD to regulate RNAPII abundance at promoter proximal pause (PPP) sites of several actively transcribed genes, a key step in the regulation of transcription elongation. We show that two ubiquitin binding-defective mutations in the CSB-WHD, which impair CSB's ability to promote cell survival in response to treatment with cisplatin, have little impact on its ability to stimulate RNAPII occupancy at PPP sites. In addition, we demonstrate that two cancer-associated CSB mutations, which are located on the opposite side of the CSB-WHD away from its ubiquitin-binding pocket, impair CSB's ability to promote RNAPII occupancy at PPP sites. Taken together, these results suggest that CSB promotes RNAPII association with PPP sites in a manner requiring the CSB-WHD but independent of its ubiquitin-binding activity. These results further imply that CSB-mediated RNAPII occupancy at PPP sites is mechanistically separable from CSB-mediated repair of cisplatin-induced DNA damage.

80 questions for UK biological security.

Multiple national and international trends and drivers are radically changing what biological security means for the United Kingdom (UK). New technologies present novel opportunities and challenges, and globalisation has created new pathways and increased the speed, volume and routes by which organisms can spread. The UK Biological Security Strategy (2018) acknowledges the importance of research on biological security in the UK. Given the breadth of potential research, a targeted agenda identifying the questions most critical to effective and coordinated progress in different disciplines of biological security is required. We used expert elicitation to generate 80 policy-relevant research questions considered by participants to have the greatest impact on UK biological security. Drawing on a collaboratively-developed set of 450 questions, proposed by 41 experts from academia, industry and the UK government (consulting 168 additional experts) we subdivided the final 80 questions into six categories: bioengineering; communication and behaviour; disease threats (including pandemics); governance and policy; invasive alien species; and securing biological materials and securing against misuse. Initially, the questions were ranked through a voting process and then reduced and refined to 80 during a one-day workshop with 35 participants from a variety of disciplines. Consistently emerging themes included: the nature of current and potential biological security threats, the efficacy of existing management actions, and the most appropriate future options. The resulting questions offer a research agenda for biological security in the UK that can assist the targeting of research resources and inform the implementation of the UK Biological Security Strategy. These questions include research that could aid with the mitigation of Covid-19, and preparation for the next pandemic. We hope that our structured and rigorous approach to creating a biological security research agenda will be replicated in other countries and regions. The world, not just the UK, is in need of a thoughtful approach to directing biological security research to tackle the emerging issues.

Patient Experiences with Colonoscopy: A Qualitative Study.

BACKGROUND: Patient perspectives have important roles in improving the quality of colonoscopy services. The purpose of this qualitative study was to obtain the perspectives of patients who recently had undergone colonoscopy procedures, about their experiences with bowel preparation, the procedure itself, and communication of follow-up results and recommendations. METHODS: We recruited adults who had undergone a colonoscopy, to participate in semistructured interviews. Interviews were audiotaped, transcribed and analyzed using inductive qualitative methods. RESULTS: Twenty-four adults (58% female) with an average age of 53.8 years participated. Results were categorized within the themes of bowel preparation, the colonoscopy procedure and communication of the results. Participants appreciated having clear consistent plain language messages about bowel preparation. Some participants experienced additional challenges to understanding, and navigating, colonoscopy procedures. At the time of the procedure, positive and reassuring interactions with, and between, members of the health care team, in addition to management of physical pain and discomfort, were important. Participants wanted clear and timely information about the results of their test. CONCLUSIONS: Understanding patients' needs for information and support can promote higher quality colonoscopy services. Our findings suggest that quality indicators should include: patients' perspectives of the clarity of bowel instructions; the need for supports that are not routinely provided; the extent to which concerns about the procedure are addressed; interactions with the endoscopy team; the endoscopy team's interactions with each other; comfort during the procedure, and the timeliness and clarity of results and follow-up instructions. These indicators should be included in annual patient surveys.

New Patient Education Video on Colonoscopy Preparation: Development and Evaluation Study.

BACKGROUND: Although several patient education materials on colonoscopy preparation exist, few studies have evaluated or compared them; hence, there is no professional consensus on recommended content or media to use. OBJECTIVE: This study aims to address this need by developing and evaluating a new video on colonoscopy preparation. METHODS: We developed a new video explaining split-dose bowel preparation for colonoscopy. Of similar content videos on the internet (n=20), the most favorably reviewed video among patient and physician advisers was used as the comparator for the study. A total of 232 individuals attending gastroenterology or urology clinics reviewed the new and comparator videos. The order of administration of the new and comparator videos was randomly counterbalanced to assess the impact of presentation order. Respondents rated each video on the following dimensions: information amount, clarity, trustworthiness, understandability, new or familiar information, reassurance, information learned, understanding from the patient's point of view, appeal, and the likelihood of recommending the video to others. RESULTS: Overall, 71.6% (166/232) of the participants preferred the new video, 25.0% (58/232) preferred the comparator video, and 3.4% (8/232) were not sure. Furthermore, 64.0% (71/111) of those who viewed the new video first preferred it, whereas 77.7% (94/121) of the participants who viewed the new video second preferred it. Multivariable logistic regression analysis also demonstrated that participants were more likely to prefer the new video if they had viewed it second. Participants who preferred the new video rated it as clearer and more trustworthy than those who preferred the comparator video. CONCLUSIONS: This study developed and assessed the strengths of a newly developed colonoscopy educational video.

Development of the Dietitian Integrated Evaluation Tool for Gluten-free Diets (DIET-GFD).

OBJECTIVES: Celiac disease (CD) treatment involves a gluten-free diet (GFD). There is no standardized tool for dietitians to objectively grade GFD adherence. This study aimed to develop a standardized tool for dietitians to evaluate and communicate GFD adherence. METHODS: Participants were recruited from the Manitoba Celiac Disease Cohort. Using a consensus process, an expert panel of gastroenterologists, dietitians, clinical health psychologists, and persons with CD developed the Dietitian Integrated Evaluation Tool for Gluten-free Diets (DIET-GFD). Two dietitians performed duplicate assessments of 27 newly diagnosed participants who had been advised to follow a GFD. The global adherence scale was further revised after panel discussions of the cases where there was uncertainty or discordance on dietitian ratings. Subsequently, the scoring system was evaluated using duplicate assessments of an additional 37 participants with CD. Interrater agreement was assessed using square-weight Cohen's kappa. RESULTS: The DIET-GFD includes features related to frequency and quantity of gluten ingestion based on self-reporting and food frequency evaluation, shopping and dining habits, how and where food is prepared and consumed, eating behaviors, and label reading skills. The DIET-GFD global assessment is reported using a 10-point ordinal descriptive scale, ranging from 1 (takes few precautions and regularly eats gluten) to 10 (no gluten in kitchen and rarely eats food prepared outside the home). The kappa of DIET-GFD global assessment was 0.845, which indicates excellent agreement. CONCLUSIONS: DIET-GFD is a useful tool for dietitians to evaluate GFD adherence. Further studies are needed to confirm that the score from the DIET-GFD is reliable across various settings.

Can individuals with celiac disease identify gluten-free foods correctly?

BACKGROUND & AIMS: Patients with celiac disease (CD) often report inadvertent gluten exposures and challenges reading labels. The most common cause of non-responsive CD is gluten exposure. We aimed to assess whether recently diagnosed CD patients can determine whether a food is gluten-free based on labeling, and to assess skills over time. A secondary aim was to identify factors associated with label reading proficiency. METHODS: Inception cohort with follow-up at 6, 12, and 24 months after diagnosis. Participants were asked to determine whether 25 food items were gluten-free based on labeling information. Diet adherence was assessed using the Celiac Diet Assessment Tool (CDAT) and the Gluten-Free Eating Assessment Tool (GF-EAT). 144 adults with newly diagnosed celiac disease were enrolled. The initial quiz at 6 months was completed by 83%. Quizzes were completed by 72% at 12 months and 70% at 24 months. RESULTS: Median overall accuracy scores were: 23/25, 24/25 and 21/25 at 6, 12 and 24 months respectively. Gluten-free products with explicit "gluten-free" claims had the fewest errors. Quiz scores were not correlated with tTG IgA levels, or CDAT or GF-EAT scores. Diet adherence was generally good (>85% with CDAT <13 suggesting adequate GFD adherence); however, at 24 months, only 11% reported no gluten exposure. CONCLUSIONS: CD patients may be unable to consistently choose gluten-free foods based on product labeling. Explicit identification of gluten-free products may be helpful. Label reading ability appears stable over time. Further studies are needed to evaluate whether erroneous label reading or misleading labels are associated with persistent villous atrophy.

Dexamethasone inhibits respiratory syncytial virus-driven mucus production while increasing viral replication without altering antiviral interferon signaling.

Respiratory syncytial virus (RSV) infection can cause mucus overproduction and bronchiolitis in infants leading to severe disease and hospitalization. As a therapeutic strategy, immune modulatory agents may help prevent RSV-driven immune responses that cause severe airway disease. We developed a high throughput screen to identify compounds that reduced RSV-driven mucin 5AC (Muc5AC) expression and identified dexamethasone. Despite leading to a pronounced reduction in RSV-driven Muc5AC, dexamethasone increased RSV infection in vitro and delayed viral clearance in mice. This correlated with reduced expression of a subset of immune response genes and reduced lymphocyte infiltration in vivo. Interestingly, dexamethasone increased RSV infection levels without altering antiviral interferon signaling. In summary, the immunosuppressive activities of dexamethasone had favorable inhibitory effects on RSV-driven mucus production yet prevented immune defense activities that limit RSV infection in vitro and in vivo. These findings offer an explanation for the lack of efficacy of glucocorticoids in RSV-infected patients.

CSB cooperates with SMARCAL1 to maintain telomere stability in ALT cells.

Elevated replication stress is evident at telomeres of about 10-15% of cancer cells, which maintain their telomeres via a homologous recombination (HR)-based mechanism, referred to as alternative lengthening of telomeres (ALT). How ALT cells resolve replication stress to support their growth remains incompletely characterized. Here, we report that CSB (also known as ERCC6) promotes recruitment of HR repair proteins (MRN, BRCA1, BLM and RPA32) and POLD3 to ALT telomeres, a process that requires the ATPase activity of CSB and is controlled by ATM- and CDK2-dependent phosphorylation. Loss of CSB stimulates telomeric recruitment of MUS81 and SLX4, components of the structure-specific MUS81-EME1-SLX1-SLX4 (MUS-SLX) endonuclease complex, suggesting that CSB restricts MUS-SLX-mediated processing of stalled forks at ALT telomeres. Loss of CSB coupled with depletion of SMARCAL1, a chromatin remodeler implicated in catalyzing regression of stalled forks, synergistically promotes not only telomeric recruitment of MUS81 but also the formation of fragile telomeres, the latter of which is reported to arise from fork stalling. These results altogether suggest that CSB-mediated HR repair and SMARCAL1-mediated fork regression cooperate to prevent stalled forks from being processed into fragile telomeres in ALT cells.

Tau overexpression exacerbates neuropathology after repeated mild head impacts in male mice.

Repeated mild traumatic brain injury (rmTBI) can lead to development of chronic traumatic encephalopathy (CTE), which is characterized by progressive neurodegeneration with presence of white matter damage, gliosis and hyper-phosphorylated tau. While animal models of rmTBI have been documented, few characterize the molecular pathogenesis and expression profiles of relevant injured brain regions. Additionally, while the usage of transgenic tau mice in rmTBI is prevalent, the effects of tau on pathological outcomes has not been well studied. Here we characterized a 42-impact closed-head rmTBI paradigm on 3-4 month old male C57BL/6 (WT) and Tau-overexpressing mice (Tau58.4). This injury paradigm resulted in chronic gliosis, T-cell infiltration, and demyelination of the optic nerve and associated white matter tracts at 1-month post-injury. At 3-months post-injury, Tau58.4 mice showed progressive neuroinflammation and neurodegeneration in multiple brain regions compared to WT mice. Corresponding to histopathology, RNAseq of the optic nerve tract at 1-month post-injury showed significant upregulation of inflammatory pathways and downregulation of myelin synthetic pathways in both genotypes. However, Tau58.4 mice showed additional changes in neurite development, protein processing, and cell stress. Comparisons with published transcriptomes of human Alzheimer's Disease and CTE revealed common signatures including neuroinflammation and downregulation of protein phosphatases. We next investigated the demyelination and T-cell infiltration phenotypes to determine whether these offer potential avenues for therapeutic intervention. Tau58.4 mice were treated with the histamine H3 receptor antagonist GSK239512 for 1-month post-injury to promote remyelination of white matter lesions. This restored myelin gene expression to sham levels but failed to repair the histopathologic lesions. Likewise, injured T-cell-deficient Rag2/Il2rg (R2G2) mice also showed evidence for inflammation and loss of myelin. However, unlike immune-competent mice, R2G2 mice had altered myeloid cell gene expression and fewer demyelinated lesions. Together this data shows that rmTBI leads to chronic white matter inflammatory demyelination and axonal loss exacerbated by human tau overexpression but suggests that immune-suppression and remyelination alone are insufficient to reverse damage.

Mutations Reducing In Vitro Susceptibility to Novel LpxC Inhibitors in Pseudomonas aeruginosa and Interplay of Efflux and Nonefflux Mechanisms.

Upregulated expression of efflux pumps, lpxC target mutations, LpxC protein overexpression, and mutations in fabG were previously shown to mediate single-step resistance to the LpxC inhibitor CHIR-090 in P. aeruginosa Single-step selection experiments using three recently described LpxC inhibitors (compounds 2, 3, and 4) and mutant characterization showed that these mechanisms affect susceptibility to additional novel LpxC inhibitors. Serial passaging of P. aeruginosa wild-type and efflux pump-defective strains using the LpxC inhibitor CHIR-090 or compound 1 generated substantial shifts in susceptibility and underscored the interplay of efflux and nonefflux mechanisms. Whole-genome sequencing of CHIR-090 passage mutants identified efflux pump overexpression, fabG mutations, and novel mutations in fabF1 and in PA4465 as determinants of reduced susceptibility. Two new lpxC mutations, encoding A214V and G208S, that reduce susceptibility to certain LpxC inhibitors were identified in these studies, and we show that these and other target mutations differentially affect different LpxC inhibitor scaffolds. Lastly, the combination of target alteration (LpxCA214V) and upregulated expression of LpxC was shown to be tolerated in P. aeruginosa and could mediate significant decreases in susceptibility.

CSB interacts with BRCA1 in late S/G2 to promote MRN- and CtIP-mediated DNA end resection.

CSB, a member of the SWI2/SNF2 superfamily, has been implicated in evicting histones to promote the DSB pathway choice towards homologous recombination (HR) repair. However, how CSB promotes HR repair remains poorly characterized. Here we demonstrate that CSB interacts with both MRE11/RAD50/NBS1 (MRN) and BRCA1 in a cell cycle regulated manner, with the former requiring its WHD and occurring predominantly in early S phase. CSB interacts with the BRCT domain of BRCA1 and this interaction is regulated by CDK-dependent phosphorylation of CSB on S1276. The CSB-BRCA1 interaction, which peaks in late S/G2 phase, is responsible for mediating the interaction of CSB with the BRCA1-C complex consisting of BRCA1, MRN and CtIP. While dispensable for histone eviction at DSBs, CSB phosphorylation on S1276 is necessary to promote efficient MRN- and CtIP-mediated DNA end resection, thereby restricting NHEJ and enforcing the DSB repair pathway choice to HR. CSB phosphorylation on S1276 is also necessary to support cell survival in response to DNA damage-inducing agents. These results altogether suggest that CSB interacts with BRCA1 to promote DNA end resection for HR repair and that although prerequisite, CSB-mediated histone eviction alone is insufficient to promote the pathway choice towards HR.

Inflammatory bowel disease patient profiles are related to specific information needs: A nationwide survey.

BACKGROUND: Inflammatory bowel diseases (IBD) is a heterogenous, lifelong disease, with an unpredictable and potentially progressive course, that may impose negative psychosocial impact on patients. While informed patients with chronic illness have improved adherence and outcomes, previous research showed that the majority of IBD patients receive insufficient information regarding their disease. The large heterogeneity of IBD and the wide range of information topics makes a one-size fits all knowledge resource overwhelming and cumbersome. We hypothesized that different patient profiles may have different and specific information needs, the identification of which will allow building personalized computer-based information resources in the future. AIM: To evaluate the scope of disease-related knowledge among IBD patients and determine whether different patient profiles drive unique information needs. METHODS: We conducted a nationwide survey addressing hospital-based IBD clinics. A Total of 571 patients completed a 28-item questionnaire, rating the amount of information received at time of diagnosis and the importance of information, as perceived by participants, for a newly diagnosed patient, and for the participants themselves, at current time. We performed an exploratory factor analysis of the crude responses aiming to create a number of representative knowledge domains (factors), and analyzed the responses of a set of 15 real-life patient profiles generated by the study team. RESULTS: Participants gave low ratings for the amount of information received at disease onset (averaging 0.9/5) and high ratings for importance, both for the newly diagnosed patients (mean 4.2/5) and for the participants themselves at current time (mean 3.5/5). Factor analysis grouped responses into six information-domains. The responses of selected profiles, compared with the rest of the participants, yielded significant associations (defined as a difference in rating of > 0.5 points with a P < 0.05). Patients with active disease showed a higher interest in work-disability, stress-coping, and therapy-complications. Patients newly diagnosed at age > 50, and patients with long-standing disease (> 10 years) showed less interest in work-disability. Patients in remission with mesalamine or no therapy showed less interest in all domains except for nutrition and long-term complications. CONCLUSION: We demonstrate unmet patient information needs. Analysis of various patient profiles revealed associations with specific information topics, paving the way for building patient-tailored information resources.