Glucocorticoid and Adrenergic Receptor Distribution Across Human Organs and Tissues: A Map for Stress Transduction.

OBJECTIVE: Psychosocial stress is transduced into disease risk through energy-dependent release of hormones from the hypothalamic-pituitary-adrenal and sympathetic-adrenal-medullary axes. The levels of glucocorticoid and adrenergic hormones, together with the sensitivity of tissues to their signaling, define stress responses. To understand existing pathways responsible for the psychobiological transduction of stressful experiences, we provide a quantitative whole-body map of glucocorticoid and adrenergic receptor (AR) expression. METHODS: We systematically examined gene expression levels for the glucocorticoid receptor (GR), α- and ß-ARs (AR-α1B, AR-α2B AR-ß2, and AR-ß3), across 55 different organs using the Human Protein Atlas and Human Proteome Map datasets. Given that mitochondria produce the energy required to respond to stress, we leveraged the Human Protein Atlas and MitoCarta3.0 data to examine the link between stress hormone receptor density and mitochondrial gene expression. Finally, we tested the functional interplay between GR activation and AR expression in human fibroblast cells. RESULTS: The GR was expressed ubiquitously across all investigated organ systems, whereas AR subtypes showed lower and more localized expression patterns. Receptor co-regulation, meaning the correlated gene expression of multiple stress hormone receptors, was found between GR and AR-α1B, as well as between AR-α1B and AR-α2B. In cultured human fibroblasts, activating the GR selectively increased AR-ß2 and AR-α1B expression. Consistent with the known energetic cost of stress responses, GR and AR expressions were positively associated with the expression of specific mitochondrial pathways. CONCLUSIONS: Our results provide a cartography of GR and AR expression across the human body. Because stress-induced GR and AR signaling triggers energetically expensive cellular pathways involving energy-transforming mitochondria, the tissue-specific expression and co-expression patterns of hormone receptor subtypes may in part determine the resilience or vulnerability of different organ systems.

Efficient generation of lower induced motor neurons by coupling Ngn2 expression with developmental cues.

Human pluripotent stem cells (hPSCs) are a powerful tool for disease modeling of hard-to-access tissues (such as the brain). Current protocols either direct neuronal differentiation with small molecules or use transcription-factor-mediated programming. In this study, we couple overexpression of transcription factor Neurogenin2 (Ngn2) with small molecule patterning to differentiate hPSCs into lower induced motor neurons (liMoNes/liMNs). This approach induces canonical MN markers including MN-specific Hb9/MNX1 in more than 95% of cells. liMNs resemble bona fide hPSC-derived MN, exhibit spontaneous electrical activity, express synaptic markers, and can contact muscle cells in vitro. Pooled, multiplexed single-cell RNA sequencing on 50 hPSC lines reveals reproducible populations of distinct subtypes of cervical and brachial MNs that resemble their in vivo, embryonic counterparts. Combining small molecule patterning with Ngn2 overexpression facilitates high-yield, reproducible production of disease-relevant MN subtypes, which is fundamental in propelling our knowledge of MN biology and its disruption in disease.

Production of large, defined genome modifications in rats by targeting rat embryonic stem cells.

Rats were more frequently used than mice to model human disease before mouse embryonic stem cells (mESCs) revolutionized genetic engineering in mice. Rat ESCs (rESCs) were first reported over 10 years ago, yet they are not as frequently used as mESCs. CRISPR-based gene editing in zygotes is widely used in rats but is limited by the difficulty of inserting or replacing DNA sequences larger than about 10 kb. We report here the generation of germline-competent rESC lines from several rat strains. These rESC lines maintain their potential for germline transmission after serial targeting with bacterial artificial chromosome (BAC)-based targeting vectors, and CRISPR-Cas9 cutting can increase targeting efficiency. Using these methods, we have successfully replaced entire rat genes spanning up to 101 kb with the human ortholog.

Population-scale analysis of common and rare genetic variation associated with hearing loss in adults.

To better understand the genetics of hearing loss, we performed a genome-wide association meta-analysis with 125,749 cases and 469,497 controls across five cohorts. We identified 53/c loci affecting hearing loss risk, including common coding variants in COL9A3 and TMPRSS3. Through exome sequencing of 108,415 cases and 329,581 controls, we observed rare coding associations with 11 Mendelian hearing loss genes, including additive effects in known hearing loss genes GJB2 (Gly12fs; odds ratio [OR] = 1.21, P = 4.2 × 10-11) and SLC26A5 (gene burden; OR = 1.96, P = 2.8 × 10-17). We also identified hearing loss associations with rare coding variants in FSCN2 (OR = 1.14, P = 1.9 × 10-15) and KLHDC7B (OR = 2.14, P = 5.2 × 10-30). Our results suggest a shared etiology between Mendelian and common hearing loss in adults. This work illustrates the potential of large-scale exome sequencing to elucidate the genetic architecture of common disorders where both common and rare variation contribute to risk.

Homozygous ALS-linked FUS P525L mutations cell- autonomously perturb transcriptome profile and chemoreceptor signaling in human iPSC microglia.

Amyotrophic lateral sclerosis is a fatal disease pathologically typified by motor and cortical neurodegeneration as well as microgliosis. The FUS P525L mutation is highly penetrant and causes ALS cases with earlier disease onset and more aggressive progression. To date, how P525L mutations may affect microglia during ALS pathogenesis had not been explored. In this study, we engineered isogenic control and P525L mutant FUS in independent human iPSC lines and differentiated them into microglia-like cells. We report that the P525L mutation causes FUS protein to mislocalize from the nucleus to cytoplasm. Homozygous P525L mutations perturb the transcriptome profile in which many differentially expressed genes are associated with microglial functions. Specifically, the dysregulation of several chemoreceptor genes leads to altered chemoreceptor-activated calcium signaling. However, other microglial functions such as phagocytosis and cytokine release are not significantly affected. Our study underscores the cell-autonomous effects of the ALS-linked FUS P525L mutation in a human microglia model.

A High-Content Screen Identifies TPP1 and Aurora B as Regulators of Axonal Mitochondrial Transport.

Dysregulated axonal trafficking of mitochondria is linked to neurodegenerative disorders. We report a high-content screen for small-molecule regulators of the axonal transport of mitochondria. Six compounds enhanced mitochondrial transport in the sub-micromolar range, acting via three cellular targets: F-actin, Tripeptidyl peptidase 1 (TPP1), or Aurora Kinase B (AurKB). Pharmacological inhibition or small hairpin RNA (shRNA) knockdown of each target promotes mitochondrial axonal transport in rat hippocampal neurons and induced pluripotent stem cell (iPSC)-derived human cortical neurons and enhances mitochondrial transport in iPSC-derived motor neurons from an amyotrophic lateral sclerosis (ALS) patient bearing one copy of SOD1A4V mutation. Our work identifies druggable regulators of axonal transport of mitochondria, provides broadly applicable methods for similar image-based screens, and suggests that restoration of proper axonal trafficking of mitochondria can be achieved in human ALS neurons.

Transplantation of wild-type mouse hematopoietic stem and progenitor cells ameliorates deficits in a mouse model of Friedreich's ataxia.

Friedreich's ataxia (FRDA) is an incurable autosomal recessive neurodegenerative disease caused by reduced expression of the mitochondrial protein frataxin due to an intronic GAA-repeat expansion in the FXN gene. We report the therapeutic efficacy of transplanting wild-type mouse hematopoietic stem and progenitor cells (HSPCs) into the YG8R mouse model of FRDA. In the HSPC-transplanted YG8R mice, development of muscle weakness and locomotor deficits was abrogated as was degeneration of large sensory neurons in the dorsal root ganglia (DRGs) and mitochondrial capacity was improved in brain, skeletal muscle, and heart. Transplanted HSPCs engrafted and then differentiated into microglia in the brain and spinal cord and into macrophages in the DRGs, heart, and muscle of YG8R FRDA mice. We observed the transfer of wild-type frataxin and Cox8 mitochondrial proteins from HSPC-derived microglia/macrophages to FRDA mouse neurons and muscle myocytes in vivo. Our results show the HSPC-mediated phenotypic rescue of FRDA in YG8R mice and suggest that this approach should be investigated further as a strategy for treating FRDA.

Time for critically ill patients to regain mobility after early mobilization in the intensive care unit and transition to a general inpatient floor.

PURPOSE: The purpose of this study is to determine if patient mobility achievements in an intensive care unit (ICU) setting are sustained during subsequent phases of hospitalization, specifically after transferring to inpatient floors and on the day of hospital discharge. MATERIALS AND METHODS: The study is an analysis of adult patients who stayed in the ICU for 48 hours or more during the second quarter of 2013. The study sample included 182 patients who transferred to a general inpatient floor after the ICU stay. RESULTS: Patients experienced an average delay of 16 hours to regain or exceed chair level of mobility and 7 hours to regain ambulation level after transferring to an inpatient floor. One third of patients ambulated in the ICU, and those patients had significantly shorter post-ICU and hospital stays compared with patients who did not ambulate in the ICU. Delays in regaining mobility on the floor were modestly associated with initial Morse Fall Score and being male. CONCLUSIONS: Mobility progression through the hospital course is imperative to improving patient outcomes. Study findings show the need for improvement in maintaining early ICU mobilization achievement during the crucial phase between ICU stay and hospital discharge.

Inupiaq Elders study: aspects of aging among male and female elders.

OBJECTIVES: To determine if age and gender subsets of Inupiaq Elders living in urban and rural locations present different characteristics of self-reported health, physical and mental functioning, functioning of daily activities, body mass index, nutrient intake and food insecurity. STUDY DESIGN: Quantitative, comparative survey of 100 Inupiaq Elders, 52 living in 2 north-western Alaska communities, and 48 living in Anchorage. All participants were community-dwelling, non-institutionalized individuals. METHODS: Surveys were one-to-one in an oral conversational format using tested instruments. RESULTS: For all age groups, mean fat intake was 37%. Rural groups reported higher vitality scores. The most commonly reported physical limitation was walking. Rural males of 50-59 years reported the highest level of food insecurity, calorie intake and rates of smoking but also the highest SF-12 Mental Functioning Composite Scores (MCS) and Physical Functioning Scores (PCS). Of urban males 50-59, half reported hypertension, the highest percentage of all groups, and 41% reported eating less than 2 meals per day. Urban males > or = 60 years reported the highest number of Activities of Daily Living (ADLs). Females 50-59 reported the highest self-reported health status and the lowest depression scores. Older rural women > or = 60 years reported higher SF-12 MCS and SF-12 PCS than their urban cohorts, but reported the most Instrumental Activities of Daily Living (IADLs). Older urban women > or = 60 years had the lowest mean calorie intake. CONCLUSIONS: Rural Inupiaq villages provide positive environments for aging well. Reinforcing and enhancing services to assist Native Elders in rural locations might enhance their quality of aging more so than moving them to urban communities.

Potential future studies on the nutritional status among indigenous peoples in Alaska and the Russian Far East: preliminary assessment of the Social Transition in the North data set.

OBJECTIVE: The purpose of this assessment is to examine the nutrition-related health data collected during the Social Transitions of the North (STN) study for understanding cultural differences between nations and the impact on nutritional status. METHODS: The nutrition data in the STN study was collected in two regions of Alaska (Northwest Arctic and the Aleutian Islands) and in two regions of the Russian Far East (Kamchatka and Chukotka). The health questionnaire explored several factors that may contribute to identifying the nutritional status of the study populations. These factors were appetite, weight, subsistence food consumption, vitamin or mineral supplements use self-perception of health, special diets, and number of meals consumed with relatives. RESULTS: US populations were heavier than the Russian population (p = 0.0001). Both the Alaskan and Russian populations are frequent users of subsistence foods. The US respondents reported consuming 75% or more of the total protein as subsistence protein more often (40%) than the Russian respondents (25%). CONCLUSION: US respondents perceive themselves as healthier than their Russian counterparts. The US respondents consumed greater amounts of subsistence foods in general, and more of their diet over the year is made up of Native protein.

Comparison of BMI and body fat determinations in rural Alaska women: results of the WIC Healthy Mom Survey, Summer 2001.

OBJECTIVES: Evaluate two field methods to assess body composition of rural Alaska women. Excess body fat has been correlated with chronic diseases. METHODS: This exploratory study used an orally administered survey of a self-selected sample from five rural Alaskan villages. Electrical impedance technique was used to determine percent of body fat. Body Mass Index (BMI) was calculated based on clinically obtained height and weight and compared to historical data by geographical regions. Self-reported health data and fingerstick screenings were used to assess health status. RESULTS: The body mass index tool assessed more women at excessive weight than did the percent body fat assessment tool. Fingerstick screenings for glucose, cholesterol, and hemoglobin were generally found to be in normal ranges. CONCLUSIONS: Percent of body fat may be more accurate to determine weight status for many Alaska Native women. Historical body mass indices may indicate periods of prolonged limited food supplies for a geographic region.