Pgc-1α controls epidermal stem cell fate and skin repair by sustaining NAD+ homeostasis during aging.

OBJECTIVE: The epidermal barrier is renewed by the activation, proliferation, and differentiation of keratinocyte stem cells after injury and aging impedes this repair process through undefined mechanisms. We previously identified a gene signature of metabolic dysfunction in aged murine epidermis, but the precise regulators of epidermal repair and age-related growth defects are not well established. Aged mouse models as well as mice with conditional epidermal loss of the metabolic regulator peroxisome proliferator-activated receptor gamma coactivator-1 alpha (Pgc-1α) were used to explore the cellular pathways which control skin repair after injury and stress. METHODS: Aged mice or those with epidermal Pgc-1α deletion (epiPgc-1α KO) and young or Pgc1afl/fl controls were subjected to wound injury, UVB exposure or the inflammatory agent TPA. In vivo and ex vivo analyses of wound closure, skin structure, cell growth and stem cell differentiation were used to understand changes in epidermal re-growth and repair resulting from aging or Pgc-1α loss. RESULTS: Aging impairs epidermal re-growth during wound healing and results in lower expression of Pgc-1α. Mice with conditional deletion of epidermal Pgc-1α exhibit greater inflammation- and UVB-induced cell differentiation, reduced proliferation, and slower wound healing. epiPgc-1α KO mice also displayed reduced keratinocyte NAD+ levels, shorter telomeres, and greater poly ADP-ribosylation, resulting in enhanced stress-stimulated p53 and p21 signaling. When NAD+ was reduced by Pgc-1α loss or pharmacologic inhibition of NAD+ synthesis, there was reduced stress-induced proliferation, increased differentiation, and protection against DNA damage via enhanced epidermal shedding. Similarly, aged mice exhibit disrupted epidermal NAD+ homeostasis and enhanced p53 activation, resulting in p21 growth arrest after wounding. NAD+ precursor treatment restores epidermal growth from old skin to that of young. CONCLUSIONS: Our studies identify a novel role for epidermal Pgc-1α in controlling epidermal repair via its regulation of cellular NAD+ and downstream effects on p53-driven growth arrest. We also establish that parallel mechanisms are evident in aged epidermis, showing that NAD+ signaling is an important controller of physiologic skin repair and that dysfunction of this pathway contributes to age-related wound repair defects.

AMPK Inhibits mTOR-Driven Keratinocyte Proliferation after Skin Damage and Stress.

Epidermal keratinocytes (KCs) rapidly proliferate to repair the skin barrier, and a strict control of division is necessary for healthy tissue homeostasis. However, the pathways that restrain proliferation after epidermal stress are not known. AMPK is an important signaling mediator of energy metabolism previously associated with skin stress and cancer; yet, its explicit impact on KC growth is not known. To examine the requirement of epidermal AMPK in physiologic skin repair, we genetically deleted AMPK within all adult, keratin 14‒expressing KCs of mice. AMPK loss resulted in hyperproliferation and hyperactive mTOR signaling after acute wounding, UVB exposure, and phorbol ester application. This excessive division could be completely blocked by the mTORC1 inhibitor rapamycin. Moreover, we establish that the diabetes drug metformin depends on AMPK to suppress stress-induced KC proliferation. Collectively, these findings show that KC AMPK restrains mTORC1 to control epidermal proliferation after tissue injury.

Genetic deletion of mast cell serotonin synthesis prevents the development of obesity and insulin resistance.

Obesity is linked with insulin resistance and is characterized by excessive accumulation of adipose tissue due to chronic energy imbalance. Increasing thermogenic brown and beige adipose tissue futile cycling may be an important strategy to increase energy expenditure in obesity, however, brown adipose tissue metabolic activity is lower with obesity. Herein, we report that the exposure of mice to thermoneutrality promotes the infiltration of white adipose tissue with mast cells that are highly enriched with tryptophan hydroxylase 1 (Tph1), the rate limiting enzyme regulating peripheral serotonin synthesis. Engraftment of mast cell-deficient mice with Tph1-/- mast cells or selective mast cell deletion of Tph1 enhances uncoupling protein 1 (Ucp1) expression in white adipose tissue and protects mice from developing obesity and insulin resistance. These data suggest that therapies aimed at inhibiting mast cell Tph1 may represent a therapeutic approach for the treatment of obesity and type 2 diabetes.

The exercise cytokine interleukin-15 rescues slow wound healing in aged mice.

Impaired wound healing in elderly individuals increases infection risk and prolongs surgical recovery, but current treatment options are limited. Low doses of interleukin-15 (IL-15) that mimic exercise responses in the circulation improve skin structure and increase mitochondria in uninjured aged skin, suggesting that IL-15 is an essential mitochondrial signal for healing that is lost during aging. Here we used gene microarray analysis of old and young murine epidermal stem cells and demonstrate that aging results in a gene signature characteristic of bioenergetic dysfunction. Intravenous IL-15 treatment rescued chronological aging-induced healing defects and restored youthful wound closure in old, sedentary mice. Additionally, exercise-mediated improvements in the healing of aged skin depend upon circulating IL-15. We show that IL-15 induces signal transducer and activator of transcription 3 (STAT3) signaling characteristic of young animals, reduces markers of growth arrest, and increases keratinocyte and fibroblast growth. Moreover, exercise or exercise-mimicking IL-15 treatment rescued the age-associated decrease in epidermal mitochondrial complex IV activity. Overall, these results indicate that IL-15 or its analogs represent promising therapies for treating impaired wound healing in elderly patients.

Anti-GRP78 autoantibodies induce endothelial cell activation and accelerate the development of atherosclerotic lesions.

The 78-kDa glucose-regulated protein (GRP78) is an ER molecular chaperone that aids in protein folding and secretion. However, pathological conditions that cause ER stress can promote the relocalization of GRP78 to the cell surface (csGRP78), where it acts as a signaling receptor to promote cancer progression. csGRP78 also possesses antigenic properties, leading to the production of anti-GRP78 autoantibodies, which contribute to tumor growth. In contrast, the presence and role of anti-GRP78 autoantibodies in atherosclerosis is unknown. Here, we show that atherosclerotic-prone ApoE-/- mice develop circulating anti-GRP78 autoantibodies that bind to csGRP78 on lesion-resident endothelial cells. Moreover, GRP78-immunized ApoE-/- mice exhibit a marked increase in circulating anti-GRP78 autoantibody titers that correlated with accelerated lesion growth. Mechanistically, engagement of anti-GRP78 autoantibodies with csGRP78 on human endothelial cells activated NF-κB, thereby inducing the expression of ICAM-1 and VCAM-1, a process blocked by NF-κB inhibitors. Disrupting the autoantibody/csGRP78 complex with enoxaparin, a low-molecular-weight heparin, reduced the expression of adhesion molecules and attenuated lesion growth. In conclusion, anti-GRP78 autoantibodies play a crucial role in atherosclerosis development, and disruption of the interaction between anti-GRP78 autoantibodies and csGRP78 represents a therapeutic strategy.

Identification of Substance-involved Emergency Department Visits Using Data From the National Hospital Care Survey.

This report describes the development of methods to identify emergency department (ED) visits involving substance use. Two different algorithms are compared using claims data from the 2013 National Hospital Care Survey (NHCS), a facility-based survey. While NHCS was designed to produce national estimates, this report is based on 2013 data, which are not nationally representative.

Prescription Opioid Use, Misuse, and Use Disorders in U.S. Adults: 2015 National Survey on Drug Use and Health.

BACKGROUND: Despite the continuing epidemic of opioid misuse, data on the prevalence of prescription opioid use, misuse, and use disorders are limited. OBJECTIVE: To estimate the prevalence of prescription opioid use, misuse, and use disorders and motivations for misuse among U.S. adults. DESIGN: Survey. SETTING: The 2015 National Survey on Drug Use and Health (NSDUH). PARTICIPANTS: 72 600 eligible civilian, noninstitutionalized adults were selected for NSDUH, and 51 200 completed the survey interview. MEASUREMENTS: Prescription opioid use, misuse, and use disorders. RESULTS: Weighted NSDUH estimates suggested that, in 2015, 91.8 million (37.8%) U.S. civilian, noninstitutionalized adults used prescription opioids; 11.5 million (4.7%) misused them; and 1.9 million (0.8%) had a use disorder. Among adults with prescription opioid use, 12.5% reported misuse; of these, 16.7% reported a prescription opioid use disorder. The most commonly reported motivation for misuse was to relieve physical pain (63.4%). Misuse and use disorders were most commonly reported in adults who were uninsured, were unemployed, had low income, or had behavioral health problems. Among adults with misuse, 59.9% reported using opioids without a prescription, and 40.8% obtained prescription opioids for free from friends or relatives for their most recent episode of misuse. LIMITATION: Cross-sectional, self-reported data. CONCLUSION: More than one third of U.S. civilian, noninstitutionalized adults reported prescription opioid use in 2015, with substantial numbers reporting misuse and use disorders. Relief from physical pain was the most commonly reported motivation for misuse. Economic disadvantage and behavioral health problems may be associated with prescription opioid misuse. The results suggest a need to improve access to evidence-based pain management and to decrease excessive prescribing that may leave unused opioids available for potential misuse. PRIMARY FUNDING SOURCE: U.S. Department of Health and Human Services.

Analysis of temporal variation in human masticatory cycles during gum chewing.

OBJECTIVE: The study investigated modulation of fast and slow opening (FO, SO) and closing (FC, SC) chewing cycle phases using gum-chewing sequences in humans. DESIGN: Twenty-two healthy adult subjects participated by chewing gum for at least 20s on the right side and at least 20s on the left side while jaw movements were tracked with a 3D motion analysis system. Jaw movement data were digitized, and chewing cycle phases were identified and analysed for all chewing cycles in a complete sequence. RESULTS: All four chewing cycle phase durations were more variant than total cycle durations, a result found in other non-human primates. Significant negative correlations existed between the opening phases, SO and FO, and between the closing phases, SC and FC; however, there was less consistency in terms of which phases were negatively correlated both between subjects, and between chewing sides within subjects, compared with results reported in other species. CONCLUSIONS: The coordination of intra-cycle phases appears to be flexible and to follow complex rules during gum-chewing in humans. Alternatively, the observed intra-cycle phase relationships could simply reflect: (1) variation in jaw kinematics due to variation in how gum was handled by the tongue on a chew-by-chew basis in our experimental design or (2) by variation due to data sampling noise and/or how phases were defined and identified.

Effort-Shape and kinematic assessment of bodily expression of emotion during gait.

The purpose of this study was to identify the movement characteristics associated with positive and negative emotions experienced during walking. Joy, contentment, anger, sadness, and neutral were elicited in 16 individuals, and motion capture data were collected as they walked while experiencing the emotions. Observers decoded the target emotions from side and front view videos of the walking trials; other observers viewed the same videos to rate the qualitative movement features using an Effort-Shape analysis. Kinematic analysis was used to quantify body posture and limb movements during walking with the different emotions. View did not affect decoding accuracy except for contentment, which was slightly enhanced with the front view. Walking speed was fastest for joy and anger, and slowest for sadness. Although walking speed may have accounted for increased amplitude of hip, shoulder, elbow, pelvis and trunk motion for anger and joy compared to sadness, neck and thoracic flexion with sadness, and trunk extension and shoulder depression with joy were independent of gait speed. More differences among emotions occurred with the Effort-Shape rather than the kinematic analysis, suggesting that observer judgments of Effort-Shape characteristics were more sensitive than the kinematic outcomes to differences among emotions.

A mouse model for spondyloepiphyseal dysplasia congenita with secondary osteoarthritis due to a Col2a1 mutation.

Progeny of mice treated with the mutagen N-ethyl-N-nitrosourea (ENU) revealed a mouse, designated Longpockets (Lpk), with short humeri, abnormal vertebrae, and disorganized growth plates, features consistent with spondyloepiphyseal dysplasia congenita (SEDC). The Lpk phenotype was inherited as an autosomal dominant trait. Lpk/+ mice were viable and fertile and Lpk/Lpk mice died perinatally. Lpk was mapped to chromosome 15 and mutational analysis of likely candidates from the interval revealed a Col2a1 missense Ser1386Pro mutation. Transient transfection of wild-type and Ser1386Pro mutant Col2a1 c-Myc constructs in COS-7 cells and CH8 chondrocytes demonstrated abnormal processing and endoplasmic reticulum retention of the mutant protein. Histology revealed growth plate disorganization in 14-day-old Lpk/+ mice and embryonic cartilage from Lpk/+ and Lpk/Lpk mice had reduced safranin-O and type-II collagen staining in the extracellular matrix. The wild-type and Lpk/+ embryos had vertical columns of proliferating chondrocytes, whereas those in Lpk/Lpk mice were perpendicular to the direction of bone growth. Electron microscopy of cartilage from 18.5 dpc wild-type, Lpk/+, and Lpk/Lpk embryos revealed fewer and less elaborate collagen fibrils in the mutants, with enlarged vacuoles in the endoplasmic reticulum that contained amorphous inclusions. Micro-computed tomography (CT) scans of 12-week-old Lpk/+ mice revealed them to have decreased bone mineral density, and total bone volume, with erosions and osteophytes at the joints. Thus, an ENU mouse model with a Ser1386Pro mutation of the Col2a1 C-propeptide domain that results in abnormal collagen processing and phenotypic features consistent with SEDC and secondary osteoarthritis has been established.

Emergency department visits for antiviral adverse events during the 2009 H1N1 influenza pandemic.

The 2009 pandemic influenza A (H1N1) outbreak was associated with an increased use of antiviral agents and highlighted the role of population-based monitoring for related adverse drug events (ADEs). An ongoing, nationally representative emergency department-based surveillance system was used to identify and characterize ADEs during the pandemic. Active surveillance for ADEs successfully provided timely, population-based data during the pandemic. Increases in antiviral ADEs paralleled increases in prescribing. Type and severity of ADEs were similar across all seasons.

Effect of registration on cyclical kinematic data.

Given growing interest in functional data analysis (FDA) as a useful method for analyzing human movement data, it is critical to understand the effects of standard FDA procedures, including registration, on biomechanical analyses. Registration is used to reduce phase variability between curves while preserving the individual curve's shape and amplitude. The application of three methods available to assess registration could benefit those in the biomechanics community using FDA techniques: comparison of mean curves, comparison of average RMS values, and assessment of time-warping functions. Therefore, the present study has two purposes. First, the necessity of registration applied to cyclical data after time normalization is assessed. Second, we illustrate the three methods for evaluating registration effects. Masticatory jaw movements of 22 healthy adults (2 males, 21 females) were tracked while subjects chewed a gum-based pellet for 20s. Motion data were captured at 60 Hz with two gen-locked video cameras. Individual chewing cycles were time normalized and then transformed into functional observations. Registration did not affect mean curves and warping functions were linear. Although registration decreased the RMS, indicating a decrease in inter-subject variability, the difference was not statistically significant. Together these results indicate that registration may not always be necessary for cyclical chewing data. An important contribution of this paper is the illustration of three methods for evaluating registration that are easy to apply and useful for judging whether the extra data manipulation is necessary.

Active immune response protects Stat6VT transgenic mice from developing a lymphoproliferative disorder.

Stat6 is a transcription factor that regulates important cellular processes such as proliferation, differentiation, and survival through mediating IL-4 and IL-13 signaling. Importantly, increasing evidence indicates of a role for Stat6 in lymphoproliferative disorders. Mice expressing a constitutively active form of Stat6 (Stat6VT) primarily in T lymphocytes were generated, and it has been recently described that a small percentage (approximately 5%) of these mice develop a spontaneous lymphoproliferative disorder (LPD) resulting in dramatic splenomegaly and altered splenic cell populations. Here, we report that Stat6VT mice housed in a non-pathogen-free environment have an increased incidence (37%) of the LPD. Additionally, examination of the expression of Stat6-regulated genes known to have roles in tumorigenesis demonstrated that there appears to be no one genetic alteration common to lymphocytes from Stat6VT/LPD mice. Interestingly, however, uniform exposure to antigen via immunization resulted in complete abrogation of the LPD in Stat6VT mice.

Randomised trial comparing ocular lubricants and polyacrylamide hydrogel dressings in the prevention of exposure keratopathy in the critically ill.

PURPOSE: To compare the cost and effectiveness of the two most popular forms of eye care in intensive care, ocular lubricant (Lacrilube) and polyacrylamide hydrogel dressings (Geliperm); for the prevention of exposure keratopathy in the critically ill. METHODS: A prospective randomised contralateral eye study was conducted at the Intensive Care Unit (ICU), Royal London Hospital, London, UK. Eighty eyes of 40 patients were recruited. Each patient received both Lacrilube and Geliperm allocated at random to different sides. A daily ophthalmology ward round was conducted. The outcome measures included the greatest palpebral aperture length, conjunctival oedema, and any exposure keratopathy. RESULTS: There was no statistically significant difference in the maximum corneal exposure score between the eyes treated with Lacrilube and Geliperm (P = 0.38). No significant difference in degree of chemosis or palpebral aperture was identified. CONCLUSIONS: Our data suggest that Geliperm is as effective as Lacrilube in the prevention of exposure keratopathy in the critically ill. We also note that nursing staff must be fully trained in its application for eye care.

Changes in maternal age in England and Wales--implications for Down syndrome.

The risk of having a pregnancy with Down syndrome increases with maternal age. The percentage of all births in England and Wales to mothers aged 35 and over increased from 9% in 1989 to 19% in 2003. A 51% increase in the numbers of pregnancies with Down syndrome has been observed over the same time period (from 954 to 1440). Due to improvements in antenatal screening for Down syndrome and the subsequent termination of affected pregnancies, the total number of births with Down syndrome decreased from 770 in 1989 to 609 in 2003. However the number of births with Down syndrome to women aged 35 and over increased from 186 in 1989 to 310 in 2003 because of the increasing number of pregnancies amongst these women.

Safety and pharmacokinetic effects of TNP-470, an angiogenesis inhibitor, combined with paclitaxel in patients with solid tumors: evidence for activity in non-small-cell lung cancer.

PURPOSE: Preclinical studies suggested that the antiangiogenic agent TNP-470 was synergistic with cytotoxic therapy. TNP-470 was administered with paclitaxel to adults with solid tumors to define the safety and optimal dose of the combination regimen and to assess pharmacokinetic interactions. PATIENTS AND METHODS: Thirty-two patients were enrolled chronologically onto one of two treatment arms. Arm A involved a fixed TNP-470 dose with escalating doses of paclitaxel, and Arm B involved a fixed paclitaxel dose with escalating doses of TNP-470. Paclitaxel and TNP-470 pharmacokinetics were evaluated along with toxicity. RESULTS: The combination of TNP-470 administered at 60 mg/m(2) three times per week and paclitaxel 225 mg/m(2) administered over 3 hours every 3 weeks was defined as both the maximum-tolerated dose and the optimal dose. Myelosuppression was similar to that expected with paclitaxel alone. Mild to moderate neurocognitive impairment was observed; however, the majority of changes were subclinical and reversible as determined by prestudy and poststudy neuropsychiatric test results. A clinically insignificant decrease of paclitaxel clearance was observed for the combination. Median survival for all patients was 14.1 months. Partial responses were reported in eight (25%) of 32 patients and in six (38%) of 16 patients with NSCLC, 60% of whom had received prior chemotherapy. CONCLUSION: The combination of TNP-470 and paclitaxel, each at full single-agent dose, seems well tolerated, with minimal pharmacokinetic interaction between the two agents. Further studies of TNP-470 with chemotherapy regimens are warranted in NSCLC and other solid tumors.