Persistent neuroinflammation and functional deficits in a murine model of decompression sickness.

We hypothesized that early intra-CNS responses in a murine model of decompression sickness (DCS) would be reflected by changes in the microparticles (MPs) that exit the brain via the glymphatic system, and due to systemic responses the MPs would cause inflammatory changes lasting for many days leading to functional neurological deficits. Elevations on the order of 3-fold of blood-borne inflammatory MPs, neutrophil activation, glymphatic flow and neuroinflammation in cerebral cortex and hippocampus were found in mice at 12 days after exposure to 760 kPa of air for 2 hours. Mice also exhibited a significant decline in memory and locomotor activity, as assessed by novel object recognition and rotarod testing. Similar inflammatory changes in blood, neuroinflammation and functional impairments were initiated in naïve mice by injection of filamentous (F-) actin-positiveMPs, but not F-actin-negative MPs,obtained from decompressed mice. We conclude that high pressure/decompression stress establishes a systemic inflammatory process that results in prolonged neuroinflammation and functional impairments in the mouse decompression model.

Innovative Wound Healing Hydrogel Containing Chicken Feather Keratin and Soy Isoflavone Genistein: In Vivo Studies.

The current study was performed to isolate keratin from chicken feathers with an intention to develop a keratin-genistein wound-healing hydrogel, along with its in vivo analysis. Pre-formulation aspects were analysed by using FTIR; SEM; HPTLC, while gel was characterized for gel strength, viscosity, spreadability, drug content, etc. Additionally, an in vivo study along with biochemical factors against pro-inflammatory factors and histopathological studies were conducted to determine possible wound-healing and anti-inflammatory effects. Pre-formulation studies revealed the presence of amide bonds with region of dense fibrous keratin and an internal porous network in extracted keratin, which corresponds with standard keratin. Evaluation of optimised keratin-genistein hydrogel indicated the development of neutral, non-sticky hydrogel which spread evenly on the skin. In vivo studies in rats indicate higher degrees of wound-healing in combined hydrogel (94.65%) for a duration of 14 days as compared to an individual hydrogel formulation with the development of the epidermis and excessive proliferation of fibrous connective tissue indicating wound repair. Furthermore, the hydrogel inhibited the overexpression of IL-6 gene along with other pro-inflammatory factors, indicating its anti-inflammatory effects. In order to find out the possibility of closure of wounds and anti-inflammatory properties of the novel product, an in vivo investigation into the healing of wounds in laboratory animals was carried out through biochemical (ELISA and qRT-PCR) analyses against inflammatory markers (IL-2, IL-6, IL-1, IL-10, and COX-2) and histopathological (liver, skin, and the kidneys) investigations. Based on the results, we conclude that keratin-genistein hydrogel is a promising therapeutic molecule for the management of wound repair.

SARS-CoV-2 infection is associated with anti-desmoglein 2 autoantibody detection.

Post-acute cardiac sequelae, following SARS-CoV-2 infection, are well recognized as complications of COVID-19. We have previously shown the persistence of autoantibodies against antigens in skin, muscle, and heart in individuals following severe COVID-19; the most common staining on skin tissue displayed an inter-cellular cement pattern consistent with antibodies against desmosomal proteins. Desmosomes play a critical role in maintaining the structural integrity of tissues. For this reason, we analyzed desmosomal protein levels and the presence of anti-desmoglein (DSG) 1, 2, and 3 antibodies in acute and convalescent sera from patients with COVID-19 of differing clinical severity. We find increased levels of DSG2 protein in sera from acute COVID-19 patients. Furthermore, we find that DSG2 autoantibody levels are increased significantly in convalescent sera following severe COVID-19 but not in hospitalized patients recovering from influenza infection or healthy controls. Levels of autoantibody in sera from patients with severe COVID-19 were comparable to levels in patients with non-COVID-19-associated cardiac disease, potentially identifying DSG2 autoantibodies as a novel biomarker for cardiac damage. To determine if there was any association between severe COVID-19 and DSG2, we stained post-mortem cardiac tissue from patients who died from COVID-19 infection. This confirmed DSG2 protein within the intercalated discs and disruption of the intercalated disc between cardiomyocytes in patients who died from COVID-19. Our results reveal the potential for DSG2 protein and autoimmunity to DSG2 to contribute to unexpected pathologies associated with COVID-19 infection.

DOE-Assisted Formulation, Optimization, and Characterization of Tioconazole-Loaded Transferosomal Hydrogel for the Effective Treatment of Atopic Dermatitis: In Vitro and In Vivo Evaluation.

The present study was performed to determine the therapeutic effects of tioconazole (Tz)-loaded novel transferosome carriers (TFs) for the treatment of atopic dermatitis (AD). METHOD: Tioconazole transferosomes suspension (TTFs) was formulated and optimized using a 32 factorial design. After that, the optimized batch of TTFs loaded into Carbopol 934 and sodium CMC was prepared with hydrogel and noted as TTFsH. Subsequently, it was evaluated for pH, spread ability, drug content, in vitro drug release, viscosity, in vivo scratching and erythema score, skin irritation, and histopathology study. RESULT: The optimized batch of TTFs (B4) showed the values of vesicle size, flux, and entrapment efficiency to be 171.40 ± 9.03 nm, 48.23 ± 0.42, and 93.89 ± 2.41, respectively. All batches of TTFsH showed sustained drug release for up to 24 h. The F2 optimized batch released Tz in an amount of 94.23 ± 0.98% with a flux of 47.23 ± 0.823 and followed the Higuchi kinetic model. The in vivo studies provided evidence that the F2 batch of TTFsH was able to treat atopic dermatitis (AD) by reducing the erythema and the scratching score compared to that of the marketed formulation (Candiderm cream, Glenmark). The histopathology study supported the result of the erythema and scratching score study with intact skin structure. It showed that a formulated low dose of TTFsH was safe and biocompatible to both the dermis and the epidermis layer of skin. CONCLUSION: Thus, a low dose of F2-TTFsH is a promising tool that effectively targeted the skin for the topical delivery of Tz to treat atopic dermatitis symptoms.

Elevations of Extracellular Vesicles and Inflammatory Biomarkers in Closed Circuit SCUBA Divers.

Blood-borne extracellular vesicles and inflammatory mediators were evaluated in divers using a closed circuit rebreathing apparatus and custom-mixed gases to diminish some diving risks. "Deep" divers (n = 8) dove once to mean (±SD) 102.5 ± 1.2 m of sea water (msw) for 167.3 ± 11.5 min. "Shallow" divers (n = 6) dove 3 times on day 1, and then repetitively over 7 days to 16.4 ± 3.7 msw, for 49.9 ± 11.9 min. There were statistically significant elevations of microparticles (MPs) in deep divers (day 1) and shallow divers at day 7 that expressed proteins specific to microglia, neutrophils, platelets, and endothelial cells, as well as thrombospondin (TSP)-1 and filamentous (F-) actin. Intra-MP IL-1ß increased by 7.5-fold (p < 0.001) after day 1 and 41-fold (p = 0.003) at day 7. Intra-MP nitric oxide synthase-2 (NOS2) increased 17-fold (p < 0.001) after day 1 and 19-fold (p = 0.002) at day 7. Plasma gelsolin (pGSN) levels decreased by 73% (p < 0.001) in deep divers (day 1) and 37% in shallow divers by day 7. Plasma samples containing exosomes and other lipophilic particles increased from 186% to 490% among the divers but contained no IL-1ß or NOS2. We conclude that diving triggers inflammatory events, even when controlling for hyperoxia, and many are not proportional to the depth of diving.

Neuroinflammation with increased glymphatic flow in a murine model of decompression sickness.

This project investigated glial-based lymphatic (glymphatic) function and its role in a murine model of decompression sickness (DCS). DCS pathophysiology is traditionally viewed as being related to gas bubble formation from insoluble gas on decompression. However, a body of work implicates a role for a subset of inflammatory extracellular vesicles, 0.1 to 1 µm microparticles (MPs) that are elevated in human and rodent models in response to high gas pressure and rise further after decompression. Herein, we describe immunohistochemical and Western blot evidence showing that following high air pressure exposure, there are elevations of astrocyte NF-κB and microglial-ionized calcium-binding adaptor protein-1 (IBA-1) along with fluorescence contrast and MRI findings of an increase in glymphatic flow. Concomitant elevations of central nervous system-derived MPs coexpressing thrombospondin-1 (TSP) drain to deep cervical nodes and then to blood where they cause neutrophil activation. A new set of blood-borne MPs are generated that express filamentous actin at the surface that exacerbate neutrophil activation. Blood-brain barrier integrity is disrupted due to activated neutrophil sequestration that causes further astrocyte and microglial perturbation. When postdecompression node or blood MPs are injected into naïve mice, the same spectrum of abnormalities occur and they are blocked with coadministration of antibody to TSP. We conclude that high pressure/decompression causes neuroinflammation with an increased glymphatic flow. The resulting systemic liberation of TSP-expressing MPs sustains the neuroinflammatory cycle lasting for days.NEW & NOTEWORTHY A murine model of central nervous system (CNS) decompression sickness demonstrates that high gas pressure activates astrocytes and microglia triggering inflammatory microparticle (MP) production. Thrombospondin-expressing MPs are released from the CNS via enhanced glymphatic flow to the systemic circulation where they activate neutrophils. Secondary production of neutrophil-derived MPs causes further cell activation and neutrophil adherence to the brain microvasculature establishing a feed-forward neuroinflammatory cycle.

Blood-Borne Microparticles Are an Inflammatory Stimulus in Type 2 Diabetes Mellitus.

The proinflammatory state associated with diabetes mellitus (DM) remains poorly understood. We found patients with DM have 3- to 14-fold elevations of blood-borne microparticles (MPs) that bind phalloidin (Ph; Ph positive [+] MPs), indicating the presence of F-actin on their surface. We hypothesized that F-actin-coated MPs were an unrecognized cause for DM-associated proinflammatory status. Ph+MPs, but not Ph-negative MPs, activate human and murine (Mus musculus) neutrophils through biophysical attributes of F-actin and membrane expression of phosphatidylserine (PS). Neutrophils respond to Ph+MPs via a linked membrane array, including the receptor for advanced glycation end products and CD36, PS-binding membrane receptors. These proteins in conjunction with TLR4 are coupled to NO synthase 1 adaptor protein (NOS1AP). Neutrophil activation occurs because of Ph+MPs causing elevations of NF-κB and Src kinase (SrcK) via a concurrent increased association of NO synthase 2 and SrcK with NOS1AP, resulting in SrcK S-nitrosylation. We conclude that NOS1AP links PS-binding receptors with intracellular regulatory proteins. Ph+MPs are alarmins present in normal human plasma and are increased in those with DM and especially those with DM and a lower-extremity ulcer.

Procedural and long-term outcome among patients undergoing expedited trans-catheter aortic valve replacement.

OBJECTIVE: Patients with rapidly deteriorating clinical status due to severe aortic stenosis are often referred for expedited transcatheter aortic valve replacement (TAVR). Data regarding the outcome of such interventions is limited. We aimed to evaluate the outcome of patients undergoing expedited TAVR. DESIGN AND SETTING: Data were derived from the Israeli Multicenter Registry. SUBJECTS: Subjects were divided into two groups based on procedure urgency: patients who were electively hospitalized for the procedure (N = 3140) and those who had an expedited TAVR (N = 142). Procedural and periprocedural complication rates were significantly higher among patients with an expedited indication for TAVR compared to those having an elective procedure: valve malposition 4.6% versus 0.6% (p < 0.001), procedural cardiopulmonary resuscitation 4.3% versus 1.0% (p = 0.007), postprocedure myocardial infarction 2.0% versus 0.4% (p = 0.002), and stage 3 acute kidney injury 3.0% versus 1.1%, (p < 0.001). Patients with expedited indication for TAVR had significantly higher in hospital mortality (5.6% vs. 1.4%, p = 0.003). Kaplan-Meier's survival analysis showed that patients undergoing expedited TAVR had higher 3-year mortality rates compared to patients undergoing an elective TAVR procedure (p < 0.001). Multivariate analysis found that patients with expedited indication had fourfolds increased risk of in-hospital mortality (odds ratio: 4.07, p = 0.001), and nearly twofolds increased risk of mortality at 3-year (hazard ratio: 1.69, p = 0.001) compared to those having an elective procedure. CONCLUSION: Patients with expedited indications for TAVR suffer from poor short- and long-term outcomes. It is important to characterize and identify these patients before the deterioration to perform TAVR in a fast-track pathway to minimize their procedural risk.

MCL-1 interacts with MOF and BID to regulate H4K16 acetylation and homologous recombination repair.

The Participation of myeloid cell leukemia-1 (MCL-1), an antiapoptotic protein, in DNA repair and homologous recombination (HR) is not well understood. This study tests whether MCL-1 interacts with Males absent On First (MOF) to regulate H4K16 acetylation that promotes HR repair in response to replication stress induced by Hydroxyurea (HU) treatment. Co-immunoprecipitation of FLAG-MCL-1 from cancer cells treated with HU pulls down a complex of MCL-1, MOF and BH3-interacting domain death agonist (BID). The same complex is pulled down in cells treated with HU that express FLAG-MOF. MCL-1 regulates H4K16 acetylation during HU-induced replication stress since knockdown of MCL-1 decreases H4K16 acetylation while re-expression of MCL-1 restores H4K16 acetylation. Furthermore, knockdown of BID rescues the clonogenic survival in MCL-1 depleted cells in response to replication stress which is associated with decreased Caspase 3/7 activity compared to MCL-1 depleted cells. Cells depleted in both MCL-1 and BID display increased HR repair efficiency by direct repeats-green fluorescent protein assay and in response to HU exhibit increased ATR, Chk1, and RPA phosphorylation relative to MCL-1 depleted cells. This study uncovers that MCL-1 cooperates with MOF and regulates HR repair through H4K16 acetylation. Further, this study determines that MCL-1 and BID cooperate to regulate the crosstalk between HR repair and apoptosis.

Double-blind, placebo-controlled evaluation of biorest liposomal alendronate in diabetic patients undergoing PCI: The BLADE-PCI trial.

BACKGROUND: Diabetes mellitus (DM) is an important predictor of neointimal hyperplasia (NIH) and adverse clinical outcomes after percutaneous coronary intervention (PCI). LABR-312, a novel intravenous formulation of liposomal alendronate, has been shown in animal models to decrease NIH at vascular injury sites and around stent struts. The aim of the Biorest Liposomal Alendronate Administration for Diabetic Patients Undergoing Drug-Eluting Stent Percutaneous Coronary Intervention trial was to assess the safety, effectiveness, and dose response of LABR-312 administered intravenously at the time of PCI withDES in reducing NIH as measured by optical coherence tomography postprocedure in patients with DM. METHODS: Patients with DM were randomized to a bolus infusion of LABR-312 vs placebo at the time of PCI. Dose escalation of LABR-312 in the study arm was given: 0.01 mg, 0.03 mg, and 0.08 mg. The primary endpoint was the in-stent %NIH volume at 9 months as measured by optical coherence tomography. RESULTS: From September 2016 to December 2017, 271 patients with DM undergoing PCI were enrolled; 136 patients were randomized to LABR-312 infusion and 135 patients were randomized to placebo. At 9-month follow-up, no difference was seen in the primary endpoint of %NIH between LABR-312 and placebo (13.3% ± 9.2 vs 14.6% ± 8.5, P = .35). No differences were present with the varying LABR-312 doses. Clinical outcomes at 9 months were similar between groups. CONCLUSIONS: Among patients with DM undergoing PCI with drug-eluting stents, a bolus of LABR-312 injected systematically at the time of intervention did not result in a lower rate in-stent %NIH volume at 9-month follow-up.

A Restriction Endonuclease-Based Assay to Distinguish NANOGP8 Retrogene from Parental NANOG.

NANOG is an embryonic transcription factor, which gets reexpressed in cancer stem or tumor initiating cells. NANOGP8, a retrogene belonging to the NANOG family, is predominantly expressed in cancer cells and shows very high similarity with NANOG both at the nucleotide and at the protein level. The high similarity makes it extremely challenging to distinguish between these two transcription factors. Here we describe a highly efficient restriction endonuclease-based assay, which is performed on cDNA and allows to distinguish NANOGP8 from NANOG. This assay is critical to understand the specific role of NANOGP8 in cancer stemness, which in turn helps to unravel the therapeutic potential of targeting this undruggable transcription factor through gene therapy, for treatment of various cancers.

Outcome of patients with prior coronary bypass surgery admitted with an acute coronary syndrome.

BACKGROUND: Patients with prior coronary artery bypass graft surgery (CABG) are at increased risk for recurrent cardiovascular ischaemic events. Advances in management have improved prognosis of patients with acute coronary syndrome (ACS), yet it is not known whether similar trends exist in patients with prior CABG. AIM: Examine temporal trends in the prevalence, treatment and clinical outcomes of patients with prior CABG admitted with ACS. METHODS: Time-dependent analysis of patients with or without prior CABG admitted with an ACS who enrolled in the ACS Israeli Surveys between 2000 and 2016. Surveys were divided into early (2000-2008) and late (2010-2016) time periods. Outcomes included 30 days major adverse cardiac events (30d MACE) (death, myocardial infarction, stroke, unstable angina, stent thrombosis, urgent revascularisation) and 1-year mortality. RESULTS: Among 15 152 patients with ACS, 1506 (9.9%) had a prior CABG. Patients with prior CABG were older (69 vs 63 years), had more comorbidities and presented more with non-ST elevation-ACS (82% vs 51%). Between time periods, utilisation of antiplatelets, statins and percutaneous interventions significantly increased in both groups (p<0.001 for each). The rate of 30d MACE decreased in patients with (19.1%-12.4%, p=0.001) and without (17.4%-9.5%, p<0.001) prior CABG. However, 1-year mortality decreased only in patients without prior CABG (10.5% vs 7.4%, p<0.001) and remained unchanged in patients with prior CABG. Results were consistent after propensity matching. CONCLUSIONS: Despite an improvement in the management and prognosis of patients with ACS in the last decade, the rate of 1-year mortality of patients with prior CABG admitted with an ACS remained unchanged.

Validation of cardiac damage classification and addition of albumin in a large cohort of patients undergoing transcatheter aortic valve replacement.

AIMS: We aimed to validate a new scoring system based on extent of cardiac damage for risk stratification in patients undergoing transcatheter aortic valve replacement (TAVR) in a real-world cohort and to examine the addition of baseline albumin in risk assessment. METHODS AND RESULTS: We investigated 2608 patients undergoing TAVR. Subjects were divided into five groups based on their echocardiography findings. Patients were further assessed by incorporating baseline albumin. Multivariable analysis demonstrated that each increase in stage was associated with significant increased risk of 1-year mortality (HR 1.37, 95%CI 1.23-1.54, p < .001). Among patients at increased stage (3-4), incorporation of baseline of albumin identified the highest risk group, such that each 1 decrement in albumin levels was associated with more than triple increase in mortality among patients at stage 3 and 4 (HR 2.77, 95% CI 1.48-5.18, p-value = .001). CONCLUSIONS: Cardiac damage classification is validated in a real-world cohort of patients undergoing TAVR. Incorporation of low baseline albumin may further identify patients at the highest risk group. CONDENSTED ABSTRACT: We evaluated 2608 patients undergoing transcatheter aortic valve replacement (TAVR) in order to validate a new scoring system dividing patients in to 5 stages (0-4) based on extent of cardiac damage. Patients were further assessed by incorporating baseline albumin. Multivariable analysis demonstrated that each increase in stage was associated with significant increased risk of 1-year mortality. Furthermore, among patients at increased stage (3-4), incorporation of baseline of albumin identified the highest risk group, such that each 1 decrement in albumin levels was associated with more than triple increase in mortality among patients at stage 3 and 4.

Adenovirus and Oxaliplatin cooperate as agnostic sensitizers for immunogenic cell death in colorectal carcinoma.

Treatments with cytotoxic agents or viruses may cause Immunogenic Cell Death (ICD) that immunize tumor-bearing hosts but do not cause complete regression of tumor. We postulate that combining two ICD inducers may cause durable regression in immunocompetent mice. ICD was optimized in vitro by maximizing calreticulin externalization in human colorectal carcinoma (CRC) cells by exposure to mixtures of Oxaliplatin (OX) and human adenovirus (AdV). Six mm diameter CT26 or 4T1 carcinomas in flanks of BALB/c mice were injected once intratumorally (IT) with OX, AdV or their mixture. Tumor growth, Tumor-Infiltrating Lymphocytes (TIL), nodal cytotoxicity, and rejection of a viable cell challenge were measured. Tumors injected IT once with an optimum mixture of 80 µM OX - AdV 25 Multiplicity of Infection (MOI) in PBS buffer were 17-29% the volume of control tumors. When buffer was changed from PBS to 5% dextrose in water (D5W), volumes of tumors injected IT with 80 µM OX-AdV 25 MOI were 10% while IT OX or AdV alone were 32% and 40% the volume of IT buffer-treated tumors. OX-AdV IT increased CD3+ TIL by 4-fold, decreased CD8+ PD-1+ TIL from 79% to 19% and induced cytotoxicity to CT26 cells in draining node lymphocytes while lymphocytes from CT26-bearing untreated mice were not cytotoxic. OX-AdV IT in D5W caused complete regression in 40% of mice. Long-term survivors rejected a contralateral challenge of CT26. The buffer for Oxaliplatin is critical. The two ICD inducer mixture is promising as an agnostic sensitizer for carcinomas like colorectal carcinoma.

Management of liver complications in sickle cell disease.

Liver disease is an important cause of morbidity and mortality in patients with sickle cell disease (SCD). Despite this, the natural history of liver disease is not well characterized and the evidence basis for specific therapeutic intervention is not robust. The spectrum of clinical liver disease encountered includes asymptomatic abnormalities of liver function; acute deteriorations in liver function, sometimes with a dramatic clinical phenotype; and decompensated chronic liver disease. In this paper, the pathophysiology and clinical presentation of patients with acute and chronic liver disease will be outlined. Advice will be given regarding initial assessment and investigation. The evidence for specific medical and surgical interventions will be reviewed, and management recommendations made for each specific clinical presentation. The potential role for liver transplantation will be considered in detail.

The Liver in Sickle Cell Disease.

Patients with sickle cell disease can develop liver disease as a result of intrahepatic sickling of erythrocytes, viral hepatitis and iron overload secondary to multiple blood transfusions, and gallstone disease as a result of chronic hemolysis. The spectrum of clinical liver disease is wide and often multifactorial. Some patients develop cirrhosis that may progress to end-stage liver failure. Limited evidence exists for medical treatments. Exchange blood transfusions may improve outcomes in the acute liver syndromes. Liver transplantation may be an option for chronic liver disease. The role for prophylactic cholecystectomy in preventing complications of gallstone disease is controversial.

Repurposing of mTOR Complex Inhibitors Attenuates MCL-1 and Sensitizes to PARP Inhibition.

MCL-1, a member of the antiapoptotic BCL-2 family, is a prosurvival protein with an essential DNA repair function. This study aims to test whether inhibition of protein synthesis by mTOR complex (mTORC) inhibitors depletes MCL-1, suppresses homologous recombination (HR) repair, and sensitizes cancer cells to PARP inhibitors. Treatment with everolimus decreases MCL-1 in colorectal carcinomas and small cell lung cancer (SCLC) cells but not glioblastoma multiforme (GBM) cells with a PTEN mutational background. However, AZD2014, a dual mTORC inhibitor, depletes MCL-1 in GBMs. Further, we show that everolimus decreases 4EBP1 phosphorylation only in colorectal carcinoma, whereas AZD2014 decreases 4EBP1 phosphorylation in both colorectal carcinoma and GBM cells. Combination therapy using everolimus or AZD2014 with olaparib inhibits the growth of clone A and U87-MG xenografts in in vivo and decreases clonogenic survival in in vitro compared with monotherapy. Reintroduction of MCL-1 rescues the survival of cancer cells in response to combination of everolimus or AZD2014 with olaparib. Treatment of cells with mTORC inhibitors and olaparib increases γ-H2AX and 53BP1 foci, decreases BRCA1, RPA, and Rad51 foci, impairs phosphorylation of ATR/Chk1 kinases, and induces necroptosis. In summary, mTORC inhibitors deplete MCL-1 to suppress HR repair and increase sensitivity to olaparib both in in vitro and in xenografts. IMPLICATIONS: Targeting the DNA repair activity of MCL-1 in in vivo for cancer therapy has not been tested. This study demonstrates that depleting MCL-1 sensitizes cancer cells to PARP inhibitors besides eliciting necroptosis, which could stimulate antitumor immunity to improve the therapeutic intervention of cancers.

SMARCAD1 Phosphorylation and Ubiquitination Are Required for Resection during DNA Double-Strand Break Repair.

The chromatin remodeling factor SMARCAD1, an SWI/SNF ATPase family member, has a role in 5' end resection at DNA double-strand breaks (DSBs) to produce single-strand DNA (ssDNA), a critical step for subsequent checkpoint and repair factor loading to remove DNA damage. However, the mechanistic details of SMARCAD1 coupling to the DNA damage response and repair pathways remains unknown. Here we report that SMARCAD1 is recruited to DNA DSBs through an ATM-dependent process. Depletion of SMARCAD1 reduces ionizing radiation (IR)-induced repairosome foci formation and DSB repair by homologous recombination (HR). IR induces SMARCAD1 phosphorylation at a conserved T906 by ATM kinase, a modification essential for SMARCAD1 recruitment to DSBs. Interestingly, T906 phosphorylation is also important for SMARCAD1 ubiquitination by RING1 at K905. Both these post-translational modifications are critical for regulating the role of SMARCAD1 in DNA end resection, HR-mediated repair, and cell survival after DNA damage.

Long-Term Outcomes of 560 Consecutive Patients Treated With Transcatheter Aortic Valve Implantation and Propensity Score-Matched Analysis of Early- Versus New-Generation Valves.

Transcatheter aortic valve implantation (TAVI) is an established treatment for severe aortic stenosis in patients at high or prohibitive surgical risk. Nevertheless, long-term clinical and echocardiographic data are still lacking. We carried out an analysis of 560 consecutive patients who underwent TAVI at our institution from 2008 to 2016 to evaluate temporal changes in TAVI characteristics, predictors of 1-year and long-term outcomes, and to compare the performance of the early- and new-generation valve systems. With time, we have adopted lower risk threshold for patient selection and have been using conscious sedation and transfemoral access preferentially (p <0.001 for all). The incidence of greater than mild PVL decreased from 16% to 7.6%, p = 0.029. Within 5 years, 47% of the patients died, the majority (78%) due to noncardiac causes. Independent predictors of 1-year death included periprocedural aspects (i.e., vascular complications, stroke, and PVL), whereas death occurring later than 1 year was solely related to baseline co-morbidities. Transvalvular gradients and residual regurgitation remained nonclinically significant for up to 5 years of follow-up. New-generation valves were associated with less PVL compared with propensity score-matched early-generation valves (p <0.001). In conclusion, TAVI utilization at our institution has progressed to include lower risk patients with transfemoral access becoming applicable in the great majority. Poor long-term survival is attributable to population factors rather than to procedural factors. Intermediate- and long-term hemodynamics are excellent. PVL has diminished significantly with the new-generation valves. Efforts to improve long- and short-term outcomes remain a therapeutic challenge.

MCL-1 Depletion Impairs DNA Double-Strand Break Repair and Reinitiation of Stalled DNA Replication Forks.

Myeloid cell leukemia 1 (MCL-1) is a prosurvival BCL-2 protein family member highly expressed in hematopoietic stem cells (HSCs) and regulated by growth factor signals that manifest antiapoptotic activity. Here we report that depletion of MCL-1 but not its isoform MCL-1S increases genomic instability and cell sensitivity to ionizing radiation (IR)-induced death. MCL-1 association with genomic DNA increased postirradiation, and the protein colocalized with 53BP1 foci. Postirradiation, MCL-1-depleted cells exhibited decreased γ-H2AX foci, decreased phosphorylation of ATR, and higher levels of residual 53BP1 and RIF1 foci, suggesting that DNA double-strand break (DSB) repair by homologous recombination (HR) was compromised. Consistent with this model, MCL-1-depleted cells had a reduced frequency of IR-induced BRCA1, RPA, and Rad51 focus formation, decreased DNA end resection, and decreased HR repair in the DR-GFP DSB repair model. Similarly, after HU induction of stalled replication forks in MCL-1-depleted cells, there was a decreased ability to subsequently restart DNA synthesis, which is normally dependent upon HR-mediated resolution of collapsed forks. Therefore, the present data support a model whereby MCL-1 depletion increases 53BP1 and RIF1 colocalization at DSBs, which inhibits BRCA1 recruitment, and sensitizes cells to DSBs from IR or stalled replication forks that require HR for repair.