CDK2 and PKA Mediated-Sequential Phosphorylation Is Critical for p19INK4d Function in the DNA Damage Response

DNA damage triggers a phosphorylation-based signaling cascade known as the DNA damage response. p19INK4d, a member of the INK4 family of CDK4/6 inhibitors, has been reported to participate in the DNA damage response promoting DNA repair and cell survival. Here, we provide mechanistic insight into the activation mechanism of p19INK4d linked to the response to DNA damage. Results showed that p19INK4d becomes phosphorylated following UV radiation, β-amyloid peptide and cisplatin treatments. ATM-Chk2/ATR-Chk1 signaling pathways were found to be differentially involved in p19INK4d phosphorylation depending on the type of DNA damage. Two sequential phosphorylation events at serine 76 and threonine 141 were identified using p19INK4d single-point mutants in metabolic labeling assays with 32P-orthophosphate. CDK2 and PKA were found to participate in p19INK4d phosphorylation process and that they would mediate serine 76 and threonine 141 modifications respectively. Nuclear translocation of p19INK4d induced by DNA damage was shown to be dependent on serine 76 phosphorylation. Most importantly, both phosphorylation sites were found to be crucial for p19INK4d function in DNA repair and cell survival. In contrast, serine 76 and threonine 141 were dispensable for CDK4/6 inhibition highlighting the independence of p19INK4d functions, in agreement with our previous findings. These results constitute the first description of the activation mechanism of p19INK4d in response to genotoxic stress and demonstrate the functional relevance of this activation following DNA damage

Fluid challenges in intensive care: the FENICE study A global inception cohort study

Fluid challenges (FCs) are one of the most commonly used therapies in critically ill patients and represent the cornerstone of hemodynamic management in intensive care units. There are clear benefits and harms from fluid therapy. Limited data on the indication, type, amount and rate of an FC in critically ill patients exist in the literature. The primary aim was to evaluate how physicians conduct FCs in terms of type, volume, and rate of given fluid; the secondary aim was to evaluate variables used to trigger an FC and to compare the proportion of patients receiving further fluid administration based on the response to the FC.This was an observational study conducted in ICUs around the world. Each participating unit entered a maximum of 20 patients with one FC.2213 patients were enrolled and analyzed in the study. The median [interquartile range] amount of fluid given during an FC was 500 ml (500-1000). The median time was 24 min (40-60 min), and the median rate of FC was 1000 [500-1333] ml/h. The main indication for FC was hypotension in 1211 (59 %, CI 57-61 %). In 43 % (CI 41-45 %) of the cases no hemodynamic variable was used. Static markers of preload were used in 785 of 2213 cases (36 %, CI 34-37 %). Dynamic indices of preload responsiveness were used in 483 of 2213 cases (22 %, CI 20-24 %). No safety variable for the FC was used in 72 % (CI 70-74 %) of the cases. There was no statistically significant difference in the proportion of patients who received further fluids after the FC between those with a positive, with an uncertain or with a negatively judged response.The current practice and evaluation of FC in critically ill patients are highly variable. Prediction of fluid responsiveness is not used routinely, safety limits are rarely used, and information from previous failed FCs is not always taken into account

Phase 1b study of venetoclax-obinutuzumab in previously untreated and relapsed/refractory chronic lymphocytic leukemia.

This single-arm, open-label, phase 1b study evaluated the maximum tolerated dose (MTD) of venetoclax when given with obinutuzumab and its safety and tolerability in patients with relapsed/refractory (R/R) or previously untreated (1L) chronic lymphocytic leukemia. Venetoclax dose initially was escalated (100-400 mg) in a 3+3 design to define the MTD combined with standard-dose obinutuzumab. Patients received venetoclax (Schedule A) or obinutuzumab (Schedule B) first to compare safety and determine dose/schedule for expansion. Venetoclax-obinutuzumab was administered for 6 cycles, followed by venetoclax monotherapy until disease progression (R/R) or fixed-duration 1 year of treatment (1L). 50 R/R and 32 1L patients were enrolled. No dose-limiting toxicities were observed. Safety, including incidence of tumor lysis syndrome (TLS), did not differ between schedules (2 laboratory TLS per schedule). Schedule B and 400 mg dose of venetoclax was chosen for expansion. The most common grade 3-4 adverse event was neutropenia (R/R, 58% of patients; 1L, 53%). Rates of grade 3-4 infections were 29% (R/R) and 13% (1L); no fatal infections occurred in 1L. All infusion-related reactions were grade 1-2, except for 2 grade 3 events. No clinical TLS was observed. Overall best response rate was 95% (CR/CRi, 37%) in R/R and 100% (CR/CRi, 78%) in 1L patients. Rate of undetectable (<10-4) minimal residual disease (MRD) in peripheral blood for R/R and 1L patients respectively was 64% and 91% ≥3 months after last obinutuzumab dose. Therapy with venetoclax and obinutuzumab had an acceptable safety profile and elicited durable responses and high rates of undetectable MRD. The study is registered to https://clinicaltrials.gov as NCT01685892

Prevalence of autoantibodies against cellular antigens in patients with HIV and leprosy coinfection in the Amazon region

Abstract Background Infectious agents can activate self-reactive T cells. In general, infections trigger various mechanisms, including a lack of auto-tolerance, induction of costimulatory molecules on antigen presenting cells, and molecular simulation, in addition to cross-reactions between microbial antigens and self-antigens. HIV and leprosy coinfections lead to self-immunity with the production of autoantibodies. However, not enough data on the immune behaviour associated with this coinfection are available. Therefore, this study focused on the detection of autoantibodies against cellular antigens (AACA) in individuals with HIV and leprosy coinfection in the Amazon region. Methods Patients were distributed into four groups according to their infections: (i) coinfection with HIV and leprosy (n = 23), (ii) infection with leprosy (n = 33), (iii) infection with HIV/AIDS (n = 25), and (iv) healthy blood donor controls (n = 100). AACA were identified by indirect immunofluorescence and the samples were tested using a commercial diagnosis kit containing the antinuclear antibody HEp-2. Results Morphologically, all stages of cell division were assessed in addition to the morphological features associated with the nuclear matrix, nucleolus, mitotic spindle, and cytoplasm. There was a high prevalence of AACA in the coinfection group (47.8%, n = 11) when compared with the control group of healthy blood donors (2.0%). The results showed predominantly cytoplasmic staining in all groups analysed, and no difference was observed between the presence or absence of AACA and the leprosy forms (paucibacillary and multibacillary) in the coinfection group. Conclusions The results of this study show that despite the tendency of coinfected patients to have higher levels of autoantibodies, no correlation was observed between clinical and laboratorial variables and morbidity associated with HIV and leprosy coinfections or the levels of AACA in the serum of coinfected patients. These data are important to elucidate this complex relationship between HIV and leprosy and thus improve the follow-up of these patients

Proteolysis of AKAP121 regulates mitochondrial activity during cellular hypoxia and brain ischaemia

A-kinase anchor protein 121 (AKAP121) assembles a multivalent signalling complex on the outer mitochondrial membrane that controls persistence and amplitude of cAMP and src signalling to mitochondria, and plays an essential role in oxidative metabolism and cell survival. Here, we show that AKAP121 levels are regulated post-translationally by the ubiquitin/proteasome pathway. Seven In-Absentia Homolog 2 (Siah2), an E3–ubiquitin ligase whose expression is induced in hypoxic conditions, formed a complex and degraded AKAP121. In addition, we show that overexpression of Siah2 or oxygen and glucose deprivation (OGD) promotes Siah2-mediated ubiquitination and proteolysis of AKAP121. Upregulation of Siah2, by modulation of the cellular levels of AKAP121, significantly affects mitochondrial activity assessed as mitochondrial membrane potential and oxidative capacity. Also during cerebral ischaemia, AKAP121 is degraded in a Siah2-dependent manner. These findings reveal a novel mechanism of attenuation of cAMP/PKA signaling, which occurs at the distal sites of signal generation mediated by proteolysis of an AKAP scaffold protein. By regulating the stability of AKAP121-signalling complex at mitochondria, cells efficiently and rapidly adapt oxidative metabolism to fluctuations in oxygen availability

Sex-Differences in the Pattern of Comorbidities, Functional Independence, and Mortality in Elderly Inpatients: Evidence from the RePoSI Register.

BACKGROUND: The RePoSi study has provided data on comorbidities, polypharmacy, and sex dimorphism in hospitalised elderly patients. METHODS: We retrospectively analysed data collected from the 2010, 2012, 2014, and 2016 data sets of the RePoSi register. The aim of this study was to explore the sex-differences and to validate the multivariate model in the entire dataset with an expanded follow-up at 1 year. RESULTS: Among 4714 patients, 51% were women and 49% were men. The disease distribution showed that diabetes, coronary artery disease, chronic obstructive pulmonary disease, chronic kidney disease, and malignancy were more frequent in men but that hypertension, anaemia, osteoarthritis, depression, and diverticulitis disease were more common in women. Severity and comorbidity indexes according to the Cumulative Illness Rating Scale (CIRS-s and CIRS-c) were higher in men, while cognitive impairment, mood disorders, and disability in daily life measured by the Barthel Index (BI) were worse in women. In the multivariate analysis, BI, CIRS, and malignancy significantly increased the risk of death in men at the 1-year follow-up, while age was independently associated with mortality in women. CONCLUSIONS: Our study highlighted the relevance and the validity of our previous predictive model in the identification of sex dimorphism in hospitalised elderly patients underscoring the need of sex-personalised health-care