Endothelial Drp1 Couples VEGF-induced Redox Signaling with Glycolysis Through Cysteine Oxidation to Drive Angiogenesis.

Angiogenesis plays a vital role for postnatal development and tissue repair following ischemia. Reactive oxygen species (ROS) generated by NADPH oxidases (NOXes) and mitochondria act as signaling molecules that promote angiogenesis in endothelial cells (ECs) which mainly relies on aerobic glycolysis for ATP production. However, the connections linking redox signaling with glycolysis are not well understood. The GTPase Drp1 is a member of the dynamin superfamily that moves from cytosol to mitochondria through posttranslational modifications to induce mitochondrial fission. The role of Drp1 in ROS-dependent VEGF signaling and angiogenesis in ECs has not been previously described. Here, we identify an unexpected function of endothelial Drp1 as a redox sensor, transmitting VEGF-induced H 2 O 2 signals to enhance glycolysis and angiogenesis. Loss of Drp1 expression in ECs inhibited VEGF-induced angiogenic responses. Mechanistically, VEGF rapidly induced the NOX4-dependent sulfenylation (CysOH) of Drp1 on Cys 644 , promoting disulfide bond formation with the metabolic kinase AMPK and subsequent sulfenylation of AMPK at Cys 299 / 304 via the mitochondrial fission-mitoROS axis. This cysteine oxidation of AMPK, in turn, enhanced glycolysis and angiogenesis. In vivo , mice with EC-specific Drp1 deficiency or CRISPR/Cas9-engineered "redox-dead" (Cys to Ala) Drp1 knock-in mutations exhibited impaired retinal angiogenesis and post-ischemic neovascularization. Our findings uncover a novel role for endothelial Drp1 in linking VEGF-induced mitochondrial redox signaling to glycolysis through a cysteine oxidation-mediated Drp1-AMPK redox relay, driving both developmental and reparative angiogenesis.

Myeloid Drp1 Deficiency Limits Revascularization in Ischemic Muscles via Inflammatory Macrophage Polarization and Metabolic Reprograming.

In the preclinical model of peripheral arterial disease (PAD), M2-like anti-inflammatory macrophage polarization and angiogenesis are required for revascularization. The regulation of cell metabolism and inflammation in macrophages is tightly linked to mitochondrial dynamics. Drp1, a mitochondrial fission protein, has shown context-dependent macrophage phenotypes with both pro- and anti-inflammatory characteristics. However, the role of macrophage Drp1 in reparative neovascularization remains unexplored. Here we show that Drp1 expression was significantly increased in F4/80+ macrophages within ischemic muscle at day 3 following hindlimb ischemia (HLI), an animal model of PAD. Myeloid-specific Drp1 -/- mice exhibited reduced limb perfusion recovery, angiogenesis and muscle regeneration after HLI. These effects were concomitant with enhancement of pro-inflammatory M1-like macrophages, p-NFkB, and TNFα levels, while showing reduction in anti-inflammatory M2-like macrophages and p-AMPK in ischemic muscle of myeloid Drp1 -/- mice. In vitro, Drp1 -/- macrophages under hypoxia serum starvation (HSS), an in vitro PAD model, demonstrated enhanced glycolysis via reducing p-AMPK as well as mitochondrial dysfunction and excessive mitochondrial ROS, resulting in increased M1-gene and reduced M2-gene expression. Conditioned media from HSS-treated Drp1 -/- macrophages exhibited increased secretion of pro-inflammatory cytokines and suppressed angiogenic responses in cultured endothelial cells. Thus, Drp1 deficiency in macrophages under ischemia drives inflammatory metabolic reprogramming and macrophage polarization, thereby limiting revascularization in experimental PAD.

Safety and yield of percutaneous liver biopsy in adults and children with chronic hepatitis B: Results from a prospective, multicenter study.

BACKGROUND: Prospective data regarding the safety and yield of liver biopsy in both adults and children with chronic hepatitis B are limited. The aim of this study is to report safety, yield, and complication rates among adults and children with chronic hepatitis B undergoing percutaneous liver biopsy. METHODS: Data on the indication for procedural characteristics and complication rate for liver biopsies performed as part of the Hepatitis B Research Network were prospectively recorded on a study case report form and analyzed in aggregate. RESULTS: Among 2506 adult and pediatric subjects enrolled in the Hepatitis B Research Network between 2011 and 2018, 465 (19%) underwent 491 liver biopsies for clinical or research reasons. Adequate liver tissue was obtained in 98% of the procedures. In total, there were 32 complications reported for 24 biopsies: 23 biopsies with 30 complications in adults and 1 biopsy with 2 complications in children. Pain (n=19) and vasovagal reaction (n=6) were the most common complications. There were 7 serious adverse events, including an arterioportal venous fistula, a pneumothorax, 4 cases of bleeding, and severe pain with no associated condition. There were no deaths. CONCLUSIONS: These data demonstrate that percutaneous liver biopsy is associated with a high yield of tissue (98%) and a rate of serious complications of 1.4% in both children and adults with chronic HBV. These results support the focused use of liver biopsy in the evaluation of novel treatments in development for chronic hepatitis B.

Employee Perceptions of the Effective Adoption of AI Principles.

This study examines employee perceptions on the effective adoption of artificial intelligence (AI) principles in their organizations. 49 interviews were conducted with employees of 24 organizations across 11 countries. Participants worked directly with AI across a range of positions, from junior data scientist to Chief Analytics Officer. The study found that there are eleven components that could impact the effective adoption of AI principles in organizations: communication, management support, training, an ethics office(r), a reporting mechanism, enforcement, measurement, accompanying technical processes, a sufficient technical infrastructure, organizational structure, and an interdisciplinary approach. The components are discussed in the context of business code adoption theory. The findings offer a first step in understanding potential methods for the effective adoption of AI principles in organizations.

Psychological Burden and Gender Differences in Methamphetamine-Dependent Individuals in Treatment.

BACKGROUND AND OBJECTIVES: Little is known about gender differences in methamphetamine (METH)-dependent users. The objective of this study was to examine potential gender differences in four domains: drug use history, psychological burden, current symptomology, and coping strategy. METHODS: One hundred twenty four METH-dependent individuals (men; n = 75) were enrolled from substance use treatment programs. Participants filled out detailed questionnaires in the four domains. RESULTS: Men reported earlier first alcohol and drug use than women, but there was no difference in the age of first METH use or frequency of METH use. Women reported experiencing problems because of METH use at a younger age. Women were also more likely to have injected METH in the past year and they reported greater severity of drug problems compared to men. METH-dependent women had greater psychological burden, reported more use of an emotional-coping strategy, and had greater childhood emotional and sexual trauma. CONCLUSIONS: Overall, this study suggests that, unlike many other illicit drugs, severity of use and problems associated with use were not elevated in METH-dependent men compared to women. In fact, several factors indicated more severe patterns of use or risk factors in women.

PRE-OPERATIVE LOW BACK PAIN NEGATIVELY AFFECTS SELF-REPORTED FUNCTION IN INDIVIDUALS UNDERGOING HIP ARTHROSCOPY.

BACKGROUND/PURPOSE: Low back pain (LBP) is a common source of disability in adults and highly prevalent in patients with painful hip pathology. Persistent LBP after hip arthroplasty is associated with lower self-reported function, however, the effect of pre-operative LBP in patients undergoing hip arthroscopy for FAI has not been evaluated. The purpose of this study was to determine whether improvements in self-reported hip function following arthroscopic surgery for femoroacetabular impingement (FAI) differed between those with and without reports of pre-operative low back pain. STUDY DESIGN: Cohort. METHODS: Three hundred eighteen subjects undergoing primary hip arthroscopy for clinically and radiographically-confirmed FAI were recruited and consented. One hundred fifty-six of these subjects completed the International Hip Outcomes Tool (iHOT-33) and the Hip Outcome Score Activities of Daily Living Subscale (HOS-ADL) before, and six and 12 months after surgery. Subjects were grouped based on the self-reported presence or absence of LBP prior to arthroscopy. A repeated measures analysis of variance was used to determine the effects of time and low back pain on iHOT-33 and HOS-ADL scores. RESULTS: Seventy-five of 156 subjects (48.1%) reported LBP prior to surgery. A main effect of time was found for both outcome measures (p<0.001), demonstrating improvement in self-reported outcomes over the testing period. There was a main effect of group for the iHOT-33 (LBP: 52.0 [47.9,56.0]; no LBP 57.9 [53.9,61.8]; p = 0.043) but not for the HOS-ADL (LBP: 75.2 [72.2,78.2]; no LBP 78.8 [75.9,81.7]; p = 0.088) indicating that subjects with pre-operative LBP had poorer self-reported function per the iHOT-33 compared to those without LBP. CONCLUSION: Self-reported hip function scores improved regardless of the presence of pre-operative LBP; however subjects with LBP reported poorer self-reported function per the iHOT-33 as compared to those without LBP up to 12 months post-operatively. LEVEL OF EVIDENCE: 3c.

Rituximab in the treatment of refractory adult and juvenile dermatomyositis and adult polymyositis: a randomized, placebo-phase trial.

OBJECTIVE: To assess the safety and efficacy of rituximab in a randomized, double-blind, placebo-phase trial in adult and pediatric myositis patients. METHODS: Adults with refractory polymyositis (PM) and adults and children with refractory dermatomyositis (DM) were enrolled. Entry criteria included muscle weakness and ≥2 additional abnormal values on core set measures (CSMs) for adults. Juvenile DM patients required ≥3 abnormal CSMs, with or without muscle weakness. Patients were randomized to receive either rituximab early or rituximab late, and glucocorticoid or immunosuppressive therapy was allowed at study entry. The primary end point compared the time to achieve the International Myositis Assessment and Clinical Studies Group preliminary definition of improvement (DOI) between the 2 groups. The secondary end points were the time to achieve ≥20% improvement in muscle strength and the proportions of patients in the early and late rituximab groups achieving the DOI at week 8. RESULTS: Among 200 randomized patients (76 with PM, 76 with DM, and 48 with juvenile DM), 195 showed no difference in the time to achieving the DOI between the rituximab late (n = 102) and rituximab early (n = 93) groups (P = 0.74 by log rank test), with a median time to achieving a DOI of 20.2 weeks and 20.0 weeks, respectively. The secondary end points also did not significantly differ between the 2 treatment groups. However, 161 (83%) of the randomized patients met the DOI, and individual CSMs improved in both groups throughout the 44-week trial. CONCLUSION: Although there were no significant differences in the 2 treatment arms for the primary and secondary end points, 83% of adult and juvenile myositis patients with refractory disease met the DOI. The role of B cell-depleting therapies in myositis warrants further study, with consideration for a different trial design.

Trauma and substance use disorders in rural and urban veterans.

CONTEXT: Disparities in the prevalence, morbidity, and mortality of multiple mental health conditions have been described between rural and urban populations. However, there is limited information regarding differences in exposure to trauma and trauma-related mental health conditions in these populations. Given the number of veterans who are returning to rural communities after serving in Operation Enduring Freedom and Operation Iraqi Freedom, differences in trauma exposure are of particular relevance. Trauma exposure is related to a variety of mental health disorders including substance use disorders (SUD). PURPOSE: The objectives of this preliminary study were to describe lifetime military and nonmilitary trauma and to compare trauma history between rural and urban veterans in SUD treatment. METHODS: Sixty adults in SUD treatment were enrolled at 3 Veterans Health Administration sites in Nebraska over a 3-month period in 2008. Subjects completed an interview with study staff, which assessed SUD diagnoses and childhood, lifetime, and military trauma. Rural or urban status was determined by self-report of childhood residence. Childhood trauma, lifetime trauma, and response to military trauma were compared between rural and urban veterans. FINDINGS: Although there were no significant differences in trauma exposure between rural and urban groups, there was an association between specific types of trauma and measures typically associated with increased substance abuse severity and poorer SUD treatment outcome. CONCLUSION: This is the first study, to our knowledge, which compared trauma exposure between rural and urban veterans and identified an association between childhood trauma exposure and multiple SUD treatment attempts.

Bupropion and nicotine patch as smoking cessation aids in alcoholics.

This is a double-blind placebo-controlled study of sustained-release bupropion as a smoking cessation aid in alcoholics undergoing treatment for their alcoholism. Participants (N=58) were enrolled within 1 week of entry into alcohol treatment from community and Veterans Affairs Substance Use Disorder programs. All participants received nicotine patch and were invited to attend a smoking cessation lecture and group. Cigarette smoking and alcohol outcomes were measured at 6 months. Bupropion when added to nicotine patch did not improve smoking outcomes. One third of participants on bupropion reported discontinuing the drug during weeks 1-4. Participants reported cigarette outcomes with nicotine patch that are similar to those seen in the general population. All study participants significantly reduced cigarette use. Comorbid affective disorder or antipersonality disorder did not affect outcomes. Alcohol outcomes were improved in those who discontinued cigarettes.

Assessing the validity of self-reported medication adherence in hepatitis C treatment.

OBJECTIVE: To assess the validity of self-reported medication adherence provided by individuals in treatment for hepatitis C virus (HCV) infection with a regimen of peginterferon and ribavirin. METHODS: Adherence was evaluated prospectively among 196 African American and 205 white subjects enrolled in Virahep-C (Viral Resistance to Antiviral Therapy of Chronic Hepatitis C), a treatment study for genotype 1 HCV infection. Adherence to the prescribed dose was measured by 2 methods: self-report questions administered during multiple clinic visits, using a touch screen computer; and recordings of bottle openings, using an electronic monitor placed inside the cap of prescription containers. Self-reported responses were compared with the electronic monitor data. Nonparametric tests were used to test the association between adherence measures at 4, 12, 24, 36, and 48 weeks of treatment. RESULTS: The estimated proportion of participants who were adherent prior to a given visit ranged from 85% to 97% (ribavirin) and 97% to 100% (peginterferon) by self report and from 69% to 90% (ribavirin) and 84% to 100% (peginterferon) by electronic monitors. For ribavirin, the percentage of cases in which the 2 measurement methods agreed varied from 68% to 90%; peginterferon agreement was from 84% to 100%. Overall, adherence was higher for peginterferon than for ribavirin but decreased over time for both medications. Self-reported adherence was usually higher than that assessed by electronic measures, and the level of discrepancy increased during the course of treatment. CONCLUSIONS: Adherence to peginterferon and ribavirin decreased gradually during therapy but remained relatively high. Simple self-reported measures can be used to screen for nonadherence to HCV drug therapy, but should be considered as overestimation of the actual amounts taken.

Methamphetamine use in rural Midwesterners.

Methamphetamine use has been characterized as a "rural" drug; however, little is known about rural methamphetamine use disorders (MUD). This study describes and compares characteristics of rural and urban patients with MUD. Rural study participants reported earlier first regular use of methamphetamine, more alcoholism, more intravenous use, and a greater number of cigarettes/day, and were more likely to report methamphetamine-related psychotic symptoms. Rural methamphetamine users report multiple factors that may contribute to medical and psychiatric complications and worsen their prognosis. This is of significant concern given the limited substance abuse, mental health, and specialty care available in most rural Midwestern communities.

Dependence of endoplasmic reticulum-associated degradation on the peptide binding domain and concentration of BiP.

ER-associated degradation (ERAD) removes defective and mis-folded proteins from the eukaryotic secretory pathway, but mutations in the ER lumenal Hsp70, BiP/Kar2p, compromise ERAD efficiency in yeast. Because attenuation of ERAD activates the UPR, we screened for kar2 mutants in which the unfolded protein response (UPR) was induced in order to better define how BiP facilitates ERAD. Among the kar2 mutants isolated we identified the ERAD-specific kar2-1 allele (Brodsky et al. J. Biol. Chem. 274, 3453-3460). The kar2-1 mutation resides in the peptide-binding domain of BiP and decreases BiP's affinity for a peptide substrate. Peptide-stimulated ATPase activity was also reduced, suggesting that the interdomain coupling in Kar2-1p is partially compromised. In contrast, Hsp40 cochaperone-activation of Kar2-1p's ATPase activity was unaffected. Consistent with UPR induction in kar2-1 yeast, an ERAD substrate aggregated in microsomes prepared from this strain but not from wild-type yeast. Overexpression of wild-type BiP increased substrate solubility in microsomes obtained from the mutant, but the ERAD defect was exacerbated, suggesting that simply retaining ERAD substrates in a soluble, retro-translocation-competent conformation is insufficient to support polypeptide transit to the cytoplasm.

The role of sequential and concurrent sexual relationships in the risk of sexually transmitted diseases among adolescents.

PURPOSE: To explore whether patterns of sexual relationships, such as sequential (nonoverlapping in time) or concurrent (overlapping in time), are more important indicators of sexually transmitted disease (STD) risk among adolescents than number of sexual partners. METHODS: Data from 4,707 sexually active adolescents from the National Longitudinal Study of Adolescent Health were analyzed based on reported heterosexual relationships during the past 18 months. Adolescents were categorized as engaging in single, sequential, or concurrent sexual relationships. Demographic, behavioral, and social characteristics of each group were compared and multivariate logistic models were fit to determine STD risk associated with sexual relationship patterns and overall number of sexual partners during this same time period. RESULTS: Thirty-five percent of sexually active teens had more than one partner in the past 18 months, and 40% of these multiple partnerships were overlapping or concurrent in time. Teens in sequential and concurrent relationships reported lower condom use and a higher degree of regret of having sex owing to alcohol use than those in single relationships. Teens in concurrent relationships also reported the lowest self-efficacy to use contraceptives. Teens in sequential or concurrent relationships were more likely to report an STD than single-relationship teens (odds ratio 2.3 and 3.9, respectively); however, they were not statistically different from each other. Number of sexual partners during this same time period was not associated with STD risk once relationship pattern was considered. CONCLUSIONS: Adolescents who engage in sequential or concurrent sexual relationships differ in some important demographic, behavioral, and social characteristics and, when compared with those who engage in single relationships, have a significantly greater risk for STDs over and above the number of sexual partners.