DNA polymerase θ protects leukemia cells from metabolically induced DNA damage.

Leukemia cells accumulate DNA damage, but altered DNA repair mechanisms protect them from apoptosis. We showed here that formaldehyde generated by serine/1-carbon cycle metabolism contributed to the accumulation of toxic DNA-protein crosslinks (DPCs) in leukemia cells, especially in driver clones harboring oncogenic tyrosine kinases (OTKs: FLT3(internal tandem duplication [ITD]), JAK2(V617F), BCR-ABL1). To counteract this effect, OTKs enhanced the expression of DNA polymerase theta (POLθ) via ERK1/2 serine/threonine kinase-dependent inhibition of c-CBL E3 ligase-mediated ubiquitination of POLθ and its proteasomal degradation. Overexpression of POLθ in OTK-positive cells resulted in the efficient repair of DPC-containing DNA double-strand breaks by POLθ-mediated end-joining. The transforming activities of OTKs and other leukemia-inducing oncogenes, especially of those causing the inhibition of BRCA1/2-mediated homologous recombination with and without concomitant inhibition of DNA-PK-dependent nonhomologous end-joining, was abrogated in Polq-/- murine bone marrow cells. Genetic and pharmacological targeting of POLθ polymerase and helicase activities revealed that both activities are promising targets in leukemia cells. Moreover, OTK inhibitors or DPC-inducing drug etoposide enhanced the antileukemia effect of POLθ inhibitor in vitro and in vivo. In conclusion, we demonstrated that POLθ plays an essential role in protecting leukemia cells from metabolically induced toxic DNA lesions triggered by formaldehyde, and it can be targeted to achieve a therapeutic effect.

Heart Transplant Human Leukocyte Antigen Matching in the Modern Era.

BACKGROUND: Although numerous reports have studied the consequences of human leukocyte antigen (HLA) mismatching in renal transplantation, there are limited and outdated data analyzing this association in thoracic organ transplantation. Therefore, our study reviewed the impact of HLA mismatching at both the total and the loci levels in the modern-era heart-transplant procedure on survival and chronic rejection outcomes. METHODS: We performed a retrospective analysis of adult patients after heart transplant by using the United Network for Organ Sharing database from January 2005-July 2021. Total HLA and HLA-A, HLA-B and HLA-DR mismatches were analyzed. Survival and cardiac allograft vasculopathy were the outcomes of interest during a 10-year follow-up period using Kaplan-Meier curves, log-rank tests and multivariable regression models. RESULTS: A total of 33,060 patients were included in this study. Recipients with a high degree of HLA mismatching had increased incidences of acute organ rejection. There were no significant differences in mortality rates among any of the total or loci level groups. Similarly, there were no significant differences between total HLA mismatch groups in time to first cardiac allograft vasculopathy, though mismatching at the HLA-DR locus was associated with an increased risk of cardiac allograft vasculopathy. CONCLUSION: Our analysis suggests that HLA mismatch is not a significant predictor of survival in the modern era. Overall, the clinical implications of this study provide reassuring data for the continued use of non-HLA-matched donors in an effort to increase the donor pool. If HLA matching is to be considered for heart transplant donor-recipient selection, matching at the HLA-DR locus should take priority due to its association with cardiac allograft vasculopathy.

Preclinical safety and biodistribution of CRISPR targeting SIV in non-human primates.

In this study, we demonstrate the safety and utility of CRISPR-Cas9 gene editing technology for in vivo editing of proviral DNA in ART-treated, virally controlled simian immunodeficiency virus (SIV) infected rhesus macaques, an established model for HIV infection. EBT-001 is an AAV9-based vector delivering SaCas9 and dual guide RNAs designed to target multiple regions of the SIV genome: the viral LTRs, and the Gag gene. The results presented here demonstrate that a single IV inoculation of EBT-001 at each of 3 dose levels (1.4 × 1012, 1.4 × 1013 and 1.4 × 1014 genome copies/kg) resulted in broad and functional biodistribution of AAV9-EBT-001 to known tissue reservoirs of SIV. No off-target effects or abnormal pathology were observed, and animals returned to their normal body weight after receiving EBT-001. Importantly, the macaques that received the 2 highest doses of EBT-001 showed improved absolute lymphocyte counts as compared to antiretroviral-treated controls. Taken together, these results demonstrate safety, biodistribution, and in vivo proviral DNA editing following IV administration of EBT-001, supporting the further development of CRISPR-based gene editing as a potential therapeutic approach for HIV in humans.

Transmitted/founder SHIV.D replicates in the brain, causes neuropathogenesis, and persists on combination antiretroviral therapy in rhesus macaques.

A biologically relevant non-human primate (NHP) model of HIV persistence in the central nervous system (CNS) is necessary. Most current NHP/SIV models of HIV infection fail to recapitulate viral persistence in the CNS without encephalitis or fail to employ viruses that authentically represent the ongoing HIV-1 pandemic. Here, we demonstrate viral replication in the brain and neuropathogenesis after combination antiretroviral therapy (ART) in rhesus macaques (RMs) using novel macrophage-tropic transmitted/founder (TF) simian-human immunodeficiency virus SHIV.D.191,859 (SHIV.D). Quantitative immunohistochemistry (IHC) and DNA/RNAscope in situ hybridization (ISH) were performed on three brain regions from six SHIV.D-infected RMs; two necropsied while viremic, two during analytical treatment interruptions, and two on suppressive ART. We demonstrated myeloid-mediated neuroinflammation, viral replication, and proviral DNA in the brain in all animals. These results demonstrate that TF SHIV.D models native HIV-1 CNS replication, pathogenesis, and persistence on ART in rhesus macaques.

Single nucleotide polymorphisms in aquaporin-4 associate with cognitive impairment status in people with HIV.

Neurocognitive impairments are more frequent in people with HIV (PWH) compared to their uninfected counterparts. HIV-associated neurocognitive disorder (HAND) is a spectrum disorder and up to 50% of PWH are reported to suffer from HAND. Altered waste clearance from the brain, chronic neuroinflammation and impaired metabolic processes may contribute to abnormal aging in PWH and are more common among those who suffer from HAND. Thus, it is important to identify earlier predictors for development of HAND. A key contributor to cognitive impairment in HIV and in Alzheimer's disease (AD) is formation and accumulation of aberrant proteins including hyperphosphorylated Tau (pTau). Previous data from AD and traumatic brain injury studies report that impaired waste clearance from the brain contributes in part to cognitive impairments. Evidence suggests that the aquaporin 4 (aqp4) gene may have an important role in waste clearance from the brain as single nucleotide polymorphisms (SNPs) in aqp4 have been reported to associate with changes in cognitive decline in AD patients. Given some similarities between HAND and AD, we assessed potential associations of several aqp4 SNPS with cognitive impairment in PWH. Our data show that homozygous carriers of the minor allele in SNPs rs3875089 and rs3763040 had significantly lower neuropsychological test Z-scores in multiple domains compared to the other genotypes. Interestingly, this decrease in Z-scores was only observed in PWH and not in HIV-control participants. Conversely, homozygosity of the minor allele of rs335929 associated with better executive function in PWH. Based on these data, tracking large cohorts of PWH to determine if the presence of these SNPs associate with cognitive changes during disease progression is of interest. Furthermore, screening PWH for SNPs that may be associated with cognitive impairment risk after diagnosis could be considered in alignment with traditional treatment plans to potentially work on skills in areas shown to have cognitive decline with these SNPs present.

Incidence and predictors of acute limb ischemia in acute myocardial infarction complicated by cardiogenic shock.

OBJECTIVE: To describe the incidence and predictors of acute limb ischemia (ALI) in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS). METHODS: Patients with index hospitalizations for AMI complicated by cardiogenic shock from 2016 to 2019 in the US National Readmission Database were identified. We evaluated the incidence of ALI and its associated mortality, length of stay, and cost of hospitalization. We used multivariable logistic regression to determine independent predictors of ALI in this population. RESULTS: A total of 84,615 patients had AMI complicated by cardiogenic shock and 1302 (1.54%) developed ALI. The rates of ALI increased from 1.29% in 2016 to 1.66% in 2019 (P ≤ .002). The use of microaxial mechanical circulatory support increased from 2.25% in 2016 to 13.36% in 2019 (P = .0001). The major predictors of ALI included peripheral arterial disease (odds ratio [OR], 7.34; 95% confidence interval [CI], 6.12-8.81), venoarterial extracorporeal membrane oxygenation (OR, 4.40; 95% CI, 3.19-6.07), and microaxial mechanical circulatory support (OR, 3.12; 95% CI, 2.74-3.55). ALI in patients with cardiogenic shock was associated higher mortality (39.20% vs 33.53%; P ≤ .0001). CONCLUSIONS: This nationwide observational study shows that ALI is an important complication of AMI with cardiogenic shock. This complication is associated with higher mortality. In addition to peripheral artery disease, the use of mechanical circulatory devices was associated with significantly higher rates of ALI.

Benefit of Kidney Transplantation for Post Lung Transplantation Renal Failure.

INTRODUCTION: Nephrotoxicity is a significant side effect of thoracic transplantation. Many lung transplant patients will require subsequent renal transplantation (KAL). Recently, simultaneous lung/kidney transplants (SLuK) have become an attractive option for patients with end-stage renal disease at the time of lung transplantation. This article explores SLuK outcomes compared to conventional KAL, as well as outcomes among KAL patients against those were KAL listed but never transplanted. MATERIALS AND METHODS: The United Network for Organ Sharing/the Organ Procurement and Transportation Network database was used to identify SLuK patients (n = 74), KAL transplants (n = 456), and patients who were listed for KAL but were never transplanted (n = 626). Significance was determined by chi2, Wilcoxon rank sum test, or independent t-tests. Death-censored graft survival for subgroups was estimated using Kaplan-Meier with log-rank for significance. Analyses were completed using SPSS Statistics 28. RESULTS: The SLuK cohort was older (P = 0.04), more likely diabetic (P < 0.001), and had shorter life expectancies (P < 0.001) than KAL patients. Of those SLuK transplants within 5 y, 84% of patients were alive 1 y post transplant and 82% were alive 3 y post-transplant (compared to 74.6% and 60.3% of overall SLuK). Patients who did undergo KAL were younger and had a lower body mass index (both P < 0.001) compared to those who did not. Those who received a kidney had increased survival times compared to WL patients (P < 0.001). CONCLUSIONS: Conventional KAL transplants are still favorable for average lung recipients. However, recent improvements have made SLuK an option for patients with renal dysfunction. Those patients who were able to receive KAL transplants were better surgical candidates than those who remained on the waitlist.

Factors associated with door-in-door-out times in large vessel occlusion stroke patients undergoing endovascular therapy.

INTRODUCTION: In the management of large vessel occlusion stroke (LVOS), patients are frequently evaluated first at a non-endovascular stroke center and later transferred to an endovascular stroke center (ESC) for endovascular treatment (EVT). The door-in-door-out time (DIDO) is frequently used as a benchmark for transferring hospitals though there is no universally accepted nor evidenced-based DIDO time. The goal of this study was to identify factors affecting DIDO times in LVOS patients who ultimately underwent EVT. METHODS: The Optimizing Prehospital Use of Stroke Systems of Care-Reacting to Changing Paradigms (OPUS-REACH) registry is comprised of all LVOS patients who underwent EVT at one of nine endovascular centers in the Northeast United States between 2015 and 2020. We queried the registry for all patients who were transferred from a non-ESC to one of the nine ESCs for EVT. Univariate analysis was performed using t-tests to obtain a p value. A priori, we defined a p value of <0.05 as significant. Multiple logistic regression was conducted to determine the association of variables to estimate an odds ratio. RESULTS: 511 patients were included in the final analysis. The mean DIDO times for all patients was 137.8 min. Vascular imaging and treatment at a non-certified stroke center were associated with longer DIDO times by 23 and 14 min, respectively. On multivariate analyses, the acquisition of vascular imaging was associated with 16 additional minutes spent at the non-ESC while presentation to a non-stroke certified hospital was associated with 20 additional minutes spent at the transferring hospital. The administration of intravenous thrombolysis (IVT) was associated with 15 min less spent at the non-ESC. DISCUSSION: Vascular imaging and non-stroke certified stroke centers were associated with longer DIDO times. Non-ESCs should integrate vascular imaging into their workflow as feasible to reduce DIDO times. Further work examining other details regarding the transfer process such as transfer via ground or air, could help further identify opportunities to improve DIDO times.

Sex-specific responses to slow progressive pressure overload in a large animal model of HFpEF.

Approximately 50% of all heart failure (HF) diagnoses can be classified as HF with preserved ejection fraction (HFpEF). HFpEF is more prevalent in females compared with males, but the underlying mechanisms are unknown. We previously showed that pressure overload (PO) in male felines induces a cardiopulmonary phenotype with essential features of human HFpEF. The goal of this study was to determine if slow progressive PO induces distinct cardiopulmonary phenotypes in females and males in the absence of other pathological stressors. Female and male felines underwent aortic constriction (banding) or sham surgery after baseline echocardiography, pulmonary function testing, and blood sampling. These assessments were repeated at 2 and 4 mo postsurgery to document the effects of slow progressive pressure overload. At 4 mo, invasive hemodynamic studies were also performed. Left ventricle (LV) tissue was collected for histology, myofibril mechanics, extracellular matrix (ECM) mass spectrometry, and single-nucleus RNA sequencing (snRNAseq). The induced pressure overload (PO) was not different between sexes. PO also induced comparable changes in LV wall thickness and myocyte cross-sectional area in both sexes. Both sexes had preserved ejection fraction, but males had a slightly more robust phenotype in hemodynamic and pulmonary parameters. There was no difference in LV fibrosis and ECM composition between banded male and female animals. LV snRNAseq revealed changes in gene programs of individual cell types unique to males and females after PO. Based on these results, both sexes develop cardiopulmonary dysfunction but the phenotype is somewhat less advanced in females.NEW & NOTEWORTHY We performed a comprehensive assessment to evaluate the effects of slow progressive pressure overload on cardiopulmonary function in a large animal model of heart failure with preserved ejection fraction (HFpEF) in males and females. Functional and structural assessments were performed at the organ, tissue, cellular, protein, and transcriptional levels. This is the first study to compare snRNAseq and ECM mass spectrometry of HFpEF myocardium from males and females. The results broaden our understanding of the pathophysiological response of both sexes to pressure overload. Both sexes developed a robust cardiopulmonary phenotype, but the phenotype was equal or a bit less robust in females.

It's Not About the Money: Continued Treatment and Survival Outcome Disparities in Minority Rectal Cancer Patients After Controlling for Socioeconomic Factors.

BACKGROUND: While the disparities for minority patients with cancer have been well established, few studies have illustrated disparities in cancer outcomes while controlling for potential confounding factors. The current study was designed to address these confounding variables and how they influence the treatment and survival time for patients with rectal cancer. METHODS: Using the Surveillance, Epidemiology, and End Results database, black and Hispanic patients were compared with white patients with rectal cancer for the rates of chemotherapy, radiation, and surgery in addition to survival time after diagnosis. Following this analysis, confounding variables were controlled for and analysis was repeated with groups of comparable demographic variables. RESULTS: Before controlling for confounding variables, there were significant differences in treatment and survival for both Hispanic and black patients compared with white. Following matching, black patients continued to have lower rates of treatment and shorter survival times. CONCLUSIONS: These differences in treatment methods and survival outcomes for minorities, particularly black patients, highlight the need for more advocacy and focus on these underrepresented populations with rectal cancer.

Lung Transplant Type and Donor Age in Idiopathic Pulmonary Fibrosis: A Single Center Study.

BACKGROUD: Idiopathic pulmonary fibrosis (IPF) accounts for a marked proportion of diagnoses on the US lung transplant (LTx) list. The effects of single (SLT) versus double LTx (DLT) and lung donor age on survival in IPF remain unclear and were investigated in this study. METHODS: We retrospectively assessed survival of LTx recipients with IPF at a single institution from February 2012-March 2020. Survival was analyzed and compared between LTx types (SLT and DLT), donor ages, and the combined groups (LTx type & donor age) using Kaplan-Meier survival analysis and compared by log-rank test. P-values less than 0.05 were considered significant. RESULTS: Of 744 LTx patients at our institution, 307 (41.3%) were diagnosed with IPF, of which 208 (67.8%) were SLT, and 97 (31.6%) were DLT (2 excluded patients underwent heart-lung transplantation). There was no significant difference in survival due to LTx type (P = 0.41) or for patients with donor age <50 or ≥50 y (P = 0.46). Once stratified by both LTx type and donor age, analysis showed no significant difference in survival between the four groups (P = 0.69). CONCLUSIONS: With ethical consideration for organ allocation, as the average age of the US population increases, donor lungs aged ≥50 are an increasingly useful resource in LTx. Our findings suggest donor age and LTx type do not significantly affect survival. Therefore, SLT, and donor lungs aged ≥50 ought to be more readily considered as non-inferior options for LTx in patients with IPF.

Anastomotic Suturing Techniques and Their Association With Post-Lung Transplantation Complications.

INTRODUCTION: Currently, standard practice is to use the continuous suturing technique on the bronchial anastomosis during lung transplantation. This study used a large cohort to investigate and contrast continuous and interrupted suturing techniques, comparing survival outcomes and occurrence of postoperative bronchial complications to examine if utilization of interrupted suturing has merit. METHODS: Survival outcomes of 740 single-center lung transplant recipients over 8 y (February 2012-March 2020) were compared by suturing techniques: either continuous or interrupted at the bronchial anastomosis. Clinical parameters and demographics were compared between two suturing groups, with P values < 0.05 considered significant. The groups were compared for postoperative morbidity, including need for bronchial interventions. Survival was compared using Kaplan-Meier curves and log-rank tests. Cox regression analysis was run with statistically significant variables to study association with survival. RESULTS: Of the 740 patients, 462 received the continuous suturing technique and 278 received the interrupted suturing technique. Most demographic and clinical data were not statistically significant between the two groups, and those that were significant were not associated with worse survival outcomes, with the exception of the variable diagnosis. Bronchial complications were comparable between the continuous and interrupted groups (12.6% versus 10.4%, P = 0.382). Extracorporeal membrane oxygenation (ECMO) use did not differ significantly between the two groups (P = 0.12). The Kaplan-Meier curve showed comparable survival between groups (P = 0.98), and Cox regression analysis showed that only diagnosis, bronchial complications, and ECMO utilization were associated with different survival outcomes. Chronic obstructive pulmonary disorder was shown to be associated with more favorable survival outcomes as opposed to idiopathic pulmonary fibrosis and the category "other". The need for ECMO and the occurrence of a bronchial complication were also associated with worse survival outcomes. CONCLUSIONS: Both techniques showed reasonable post-transplant outcomes, as our study demonstrated similar survival outcomes and bronchial complication rates.

Electronic Cigarettes Induce Mitochondrial DNA Damage and Trigger TLR9 (Toll-Like Receptor 9)-Mediated Atherosclerosis.

OBJECTIVE: Electronic cigarette (e-cig) use has recently been implicated in promoting atherosclerosis. In this study, we aimed to investigate the mechanism of e-cig exposure accelerated atherosclerotic lesion development. Approach and Results: Eight-week-old ApoE-/- mice fed normal laboratory diet were exposed to e-cig vapor (ECV) for 2 hours/day, 5 days/week for 16 weeks. We found that ECV exposure significantly induced atherosclerotic lesions as examined by Oil Red O staining and greatly upregulated TLR9 (toll-like receptor 9) expression in classical monocytes and in the atherosclerotic plaques, which the latter was corroborated by enhanced TLR9 expression in human femoral artery atherosclerotic plaques from e-cig smokers. Intriguingly, we found a significant increase of oxidative mitochondria DNA lesion in the plasma of ECV-exposed mice. Administration of TLR9 antagonist before ECV exposure not only alleviated atherosclerosis and the upregulation of TLR9 in plaques but also attenuated the increase of plasma levels of inflammatory cytokines, reduced the plaque accumulation of lipid and macrophages, and decreased the frequency of blood CCR2+ (C-C chemokine receptor type 2) classical monocytes. Surprisingly, we found that cytoplasmic mitochondrial DNA isolated from ECV extract-treated macrophages can enhance TLR9 activation in reporter cells and the induction of inflammatory cytokine could be suppressed by TLR9 inhibitor in macrophages. CONCLUSIONS: E-cig increases level of damaged mitochondrial DNA in circulating blood and induces the expression of TLR9, which elevate the expression of proinflammatory cytokines in monocyte/macrophage and consequently lead to atherosclerosis. Our results raise the possibility that intervention of TLR9 activation is a potential pharmacological target of ECV-related inflammation and cardiovascular diseases.

Optimizing Abdominoplasty Surgical Site Morbidity Profiling Through an Effective and Nationally Validated Risk Scoring System.

BACKGROUND: Abdominoplasty complication rates are among the highest for cosmetic surgery. We sought to create a validated scoring system to predict the likelihood of wound complications after abdominoplasty using a national multi-institutional database. METHODS: Patients who underwent abdominoplasty in the American College of Surgeons National Surgical Quality Improvement Program 2007-2019 database were analyzed for surgical site complications, a composite outcome of wound disruption, and surgical site infections. The cohort was randomly divided into a 60% testing and a 40% validation sample. Multivariable logistic regression analysis was performed to identify independent predictors of complications using the testing sample (n = 11,294). The predictors were weighted according to ß coefficients to develop an integer-based clinical risk score. This system was validated using receiver operating characteristic analysis of the validation sample (n = 7528). RESULTS: A total of 18,822 abdominoplasty procedures were identified. The proportion of patients who developed a composite surgical site complication was 6.8%. Independent risk factors for composite surgical site complication included inpatient procedure (P < 0.01), smoking (P < 0.01), American Society of Anesthesiologists class ≥3 (P < 0.01), and body mass index ≥25.0 and ≤18.0 kg/m2 (P < 0.01). African American race was a protective factor against surgical site complications (P < 0.01). The factors were integrated into a scoring system, ranging from -5 to 42, and the receiver operating characteristic analysis revealed an area under the curve of 0.71. CONCLUSIONS: We present a validated scoring system for postoperative 30-day surgical site morbidity after abdominoplasty. This system will enable surgeons to optimize patient selection to decrease morbidity and unnecessary healthcare expenditure.

Nationally Validated Scoring System to Predict Unplanned Reoperation and Readmission after Breast Reduction.

BACKGROUND: Reduction mammoplasty continues to be a commonly sought procedure with complication rates ranging from 4.3 to 8.2%. In the current study, we sought to identify the clinical and preoperative risk factors for unplanned reoperation and readmission within the first postoperative month on a national scale. METHODS: Patients who underwent reduction mammoplasty from the ACS-NSQIP 2012-2019 database were analyzed to determine rates of reoperation and readmission within 30 days of the initial breast surgery. The cohort was divided into 60 and 40% random testing and validation samples. A multivariable logistic regression analysis was then performed to isolate independent factors of unplanned readmission and reoperation using the testing sample (n = 22,743). The predictors were weighted according to beta coefficients to develop an integer-based clinical risk score predictive of complications. This system was then validated using receiver operating characteristics (ROC) analysis of the validation sample (n = 15,162). RESULTS: A total of 37,905 reduction mammoplasties were analyzed. 1.3% of patients had an unplanned readmission. Independent risk factors for unplanned readmission included age older than the median of 44 years (p < 0.01), inpatient procedure (p < 0.01), smoking (p < 0.01), hypertension (p = 0.01), COPD (p < 0.05), BMI ≥ 35 (p < 0.01), and operation time greater than the median of 142 minutes ( p < 0.01). The factors were integrated into a scoring system, ranging from 0 to 36, and an ROC analysis revealed an area under the curve of 0.66. 1.9% of patients underwent unplanned reoperation. Independent risk factors for unplanned reoperation in this population included age older than the median of 44 years (p < 0.01), inpatient status (p < 0.01), and a history of bleeding disorders (p < 0.05). The factors were integrated into a scoring system, ranging from 0 to 25, and the ROC analysis revealed an area under the curve of 0.61. CONCLUSIONS: We present a validated scoring system to better inform patients about their risk for unplanned reoperation and readmission following reduction mammoplasty. This system will enable surgeons to optimize patient selection and interventions in order to decrease morbidity and unnecessary health-care expenditure. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Molecular Markers in Maternal Blood Exosomes Allow Early Detection of Fetal Alcohol Spectrum Disorders.

Prenatal alcohol exposure can cause developmental abnormalities (fetal alcohol spectrum disorders; FASD), including small eyes, face and brain, and neurobehavioral deficits. These cannot be detected early in pregnancy with available imaging techniques. Early diagnosis could facilitate development of therapeutic interventions. Banked human fetal brains and eyes at 9−22 weeks' gestation were paired with maternal blood samples, analyzed for morphometry, protein, and RNA expression, and apoptotic signaling. Alcohol (EtOH)-exposed (maternal self-report) fetuses were compared with unexposed controls matched for fetal age, sex, and maternal race. Fetal brain-derived exosomes (FB-E) were isolated from maternal blood and analyzed for protein, RNA, and apoptotic markers. EtOH use by mothers, assessed by self-report, was associated with reduced fetal eye diameter, brain size, and markers of synaptogenesis. Brain caspase-3 activity was increased. The reduction in eye and brain sizes were highly correlated with amount of EtOH intake and caspase-3 activity. Levels of several biomarkers in FB-E, most strikingly myelin basic protein (MBP; r > 0.9), correlated highly with morphological abnormalities. Reduction in FB-E MBP levels was highly correlated with EtOH exposure (p < 1.0 × 10−10). Although the morphological features of FAS appear long before they can be detected by live imaging, FB-E in the mother's blood may contain markers, particularly MBP, that predict FASD.

Ethanol-mediated alterations in oligodendrocyte differentiation in the developing brain.

INTRODUCTION: Alterations of white matter integrity and subsequent white matter structural deficits are consistent findings in Fetal Alcohol Syndrome (FAS), but knowledge regarding the molecular mechanisms underlying these abnormalities is incomplete. Experimental rodent models of FAS have shown dysregulation of cytokine expression leading to apoptosis of oligodendrocyte precursor cells (OPCs) and altered oligodendrocyte (OL) differentiation, but whether this is representative of human FAS pathogenesis has not been determined. METHODS: Fetal brain tissue (12.2-21.4 weeks gestation) from subjects undergoing elective termination of pregnancy was collected according to an IRB-approved protocol. Ethanol (EtOH) exposure status was classified based on a detailed face-to-face questionnaire adapted from the National Institute on Alcohol Abuse and Alcoholism Prenatal Alcohol and Sudden Infant Death Syndrome and Stillbirth (PASS) study. Twenty EtOH-exposed fetuses were compared with 20 gestational age matched controls. Cytokine and OPC marker mRNA expression was quantified by Real-Time Polymerase chain reaction (qRT-PCR). Patterns of protein expression of OPC markers and active Capase-3 were studied by Fluorescence Activated Cell Sorting (FACS). RESULTS: EtOH exposure was associated with reduced markers of cell viability, OPC differentiation, and OL maturation, while early OL differentiation markers were unchanged or increased. Expression of mRNAs for proteins specific to more mature forms of OL lineage (platelet-derived growth factor α (PDGFRα) and myelin basic protein (MBP) was lower in the EtOH group than in controls. Expression of the multifunctional growth and differentiation-promoting growth factor IGF-1, which is essential for normal development, also was reduced. Reductions were not observed for markers of early stages of OL differentiation, including Nuclear transcription factor NK-2 homeobox locus 2 (Nkx2.2). Expression of mRNAs for the proinflammatory cytokine, tumor necrosis factor-α (TNFα), and several proinflammatory chemokines was higher in the EtOH group compared to controls, including: Growth regulated protein alpha/chemokine (C-X-C motif) ligand 1 (GRO-α/CXCL1), Interleukin 8/chemokine (C-X-C motif) ligand 8 (IL8/CXCL8), Chemokine (C-X-C motif) ligand 6/Granulocyte chemotactic protein 2 (CXCL16/GCP2), epithelial-derived neutrophil-activating protein 78/chemokine (C-X-C motif) ligand 5 (ENA-78/CXCL5), monocyte chemoattractant protein-1 (MCP-1). EtOH exposure also was associated with an increase in the proportion of cells expressing markers of early stage OPCs, such as A2B5 and NG2. Finally, apoptosis (measured by caspase-3 activation) was increased substantially in the EtOH group compared to controls. CONCLUSION: Prenatal EtOH exposure is associated with excessive OL apoptosis and/or delayed OL maturation in human fetal brain. This is accompanied by markedly dysregulated expression of several chemokines and cytokines, in a pattern predictive of increased OL cytotoxicity and reduced OL differentiation. These findings are consistent with findings in animal models of FAS.

Venoarterial Extracorporeal Membrane Oxygenation in Massive Pulmonary Embolism-Related Cardiac Arrest: A Systematic Review.

OBJECTIVE: Management of patients experiencing massive pulmonary embolism-related cardiac arrest is controversial. Venoarterial extracorporeal membranous oxygenation has emerged as a potential therapeutic option for these patients. We performed a systematic review assessing survival and predictors of mortality in patients with massive PE-related cardiac arrest with venoarterial extracorporeal membranous oxygenation use. DATA SOURCES: A literature search was started on February 16, 2020, and completed on March 16, 2020, using PubMed, Embase, Cochrane Central, Cinahl, and Web of Science. STUDY SELECTION: We included all available literature that reported survival to discharge in patients managed with venoarterial extracorporeal membranous oxygenation for massive PE-related cardiac arrest. DATA EXTRACTION: We extracted patient characteristics, treatment details, and outcomes. DATA SYNTHESIS: About 301 patients were included in our systemic review from 77 selected articles (total screened, n = 1,115). About 183 out of 301 patients (61%) survived to discharge. Patients (n = 51) who received systemic thrombolysis prior to cannulation had similar survival compared with patients who did not (67% vs 61%, respectively; p = 0.48). There was no significant difference in risk of death if PE was the primary reason for admission or not (odds ratio, 1.62; p = 0.35) and if extracorporeal membranous oxygenation cannulation occurred in the emergency department versus other hospital locations (odds ratio, 2.52; p = 0.16). About 53 of 60 patients (88%) were neurologically intact at discharge or follow-up. Multivariate analysis demonstrated three-fold increase in the risk of death for patients greater than 65 years old (adjusted odds ratio, 3.08; p = 0.03) and six-fold increase if cannulation occurred during cardiopulmonary resuscitation (adjusted odds ratio, 5.67; p = 0.03). CONCLUSIONS: Venoarterial extracorporeal membranous oxygenation has an emerging role in the management of massive PE-related cardiac arrest with 61% survival. Systemic thrombolysis preceding venoarterial extracorporeal membranous oxygenation did not confer a statistically significant increase in risk of death, yet age greater than 65 and cannulation during cardiopulmonary resuscitation were associated with a three- and six-fold risks of death, respectively.

Tyrosine kinase inhibitor-induced defects in DNA repair sensitize FLT3(ITD)-positive leukemia cells to PARP1 inhibitors.

Mutations in FMS-like tyrosine kinase 3 (FLT3), such as internal tandem duplications (ITDs), can be found in up to 23% of patients with acute myeloid leukemia (AML) and confer a poor prognosis. Current treatment options for FLT3(ITD)-positive AMLs include genotoxic therapy and FLT3 inhibitors (FLT3i's), which are rarely curative. PARP1 inhibitors (PARP1i's) have been successfully applied to induce synthetic lethality in tumors harboring BRCA1/2 mutations and displaying homologous recombination (HR) deficiency. We show here that inhibition of FLT3(ITD) activity by the FLT3i AC220 caused downregulation of DNA repair proteins BRCA1, BRCA2, PALB2, RAD51, and LIG4, resulting in inhibition of 2 major DNA double-strand break (DSB) repair pathways, HR, and nonhomologous end-joining. PARP1i, olaparib, and BMN673 caused accumulation of lethal DSBs and cell death in AC220-treated FLT3(ITD)-positive leukemia cells, thus mimicking synthetic lethality. Moreover, the combination of FLT3i and PARP1i eliminated FLT3(ITD)-positive quiescent and proliferating leukemia stem cells, as well as leukemic progenitors, from human and mouse leukemia samples. Notably, the combination of AC220 and BMN673 significantly delayed disease onset and effectively reduced leukemia-initiating cells in an FLT3(ITD)-positive primary AML xenograft mouse model. In conclusion, we postulate that FLT3i-induced deficiencies in DSB repair pathways sensitize FLT3(ITD)-positive AML cells to synthetic lethality triggered by PARP1i's. Therefore, FLT3(ITD) could be used as a precision medicine marker for identifying AML patients that may benefit from a therapeutic regimen combining FLT3 and PARP1i's.

GDF11 Decreases Pressure Overload-Induced Hypertrophy, but Can Cause Severe Cachexia and Premature Death.

RATIONALE: Possible beneficial effects of GDF11 (growth differentiation factor 11) on the normal, diseased, and aging heart have been reported, including reversing aging-induced hypertrophy. These effects have not been well validated. High levels of GDF11 have also been shown to cause cardiac and skeletal muscle wasting. These controversies could be resolved if dose-dependent effects of GDF11 were defined in normal and aged animals as well as in pressure overload-induced pathological hypertrophy. OBJECTIVE: To determine dose-dependent effects of GDF11 on normal hearts and those with pressure overload-induced cardiac hypertrophy. METHODS AND RESULTS: Twelve- to 13-week-old C57BL/6 mice underwent transverse aortic constriction (TAC) surgery. One-week post-TAC, these mice received rGDF11 (recombinant GDF11) at 1 of 3 doses: 0.5, 1.0, or 5.0 mg/kg for up to 14 days. Treatment with GDF11 increased plasma concentrations of GDF11 and p-SMAD2 in the heart. There were no significant differences in the peak pressure gradients across the aortic constriction between treatment groups at 1 week post-TAC. Two weeks of GDF11 treatment caused dose-dependent decreases in cardiac hypertrophy as measured by heart weight/tibia length ratio, myocyte cross-sectional area, and left ventricular mass. GDF11 improved cardiac pump function while preventing TAC-induced ventricular dilation and caused a dose-dependent decrease in interstitial fibrosis (in vivo), despite increasing markers of fibroblast activation and myofibroblast transdifferentiation (in vitro). Treatment with the highest dose (5.0 mg/kg) of GDF11 caused severe body weight loss, with significant decreases in both muscle and organ weights and death in both sham and TAC mice. CONCLUSIONS: Although GDF11 treatment can reduce pathological cardiac hypertrophy and associated fibrosis while improving cardiac pump function in pressure overload, high doses of GDF11 cause severe cachexia and death. Use of GDF11 as a therapy could have potentially devastating actions on the heart and other tissues.