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1.
Am J Transplant ; 20(2): 422-429, 2020 02.
Article in English | MEDLINE | ID: mdl-31605562

ABSTRACT

Morbid obesity is a barrier to kidney transplant in patients with end-stage renal disease (ESRD). Laparoscopic sleeve gastrectomy (SG) is an increasingly considered intervention, but the safety and long-term outcomes are uncertain. We reviewed prospectively collected data on patients with ESRD and chronic kidney disease (CKD) undergoing SG from 2011 to 2018. There were 198 patients with ESRD and 45 patients with CKD (stages 1-4) who met National Institutes of Health guidelines for bariatric surgery and underwent SG; 72% and 48% achieved a body mass index of ≤ 40 and ≤ 35 kg/m2 , respectively. The mean percentages of total weight loss and excess weight loss were 18.9 ± 10.8% and 38.2 ± 20.3%, respectively. SG reduced hypertension (85.8% vs 52.1%), decreased antihypertensive medication use (1.6 vs 1.0) (P < .01 each), and reduced incidence of diabetes (59.6% vs 32.5%, P < .01). Of the 71 patients with ESRD who achieved a body mass index of ≤ 40 kg/m2 , 45 were waitlisted and received a kidney transplant, whereas 10 remain on the waitlist. Mortality rate after SG was 1.8 per 100 patient-years, compared with 7.3 for non-SG. Patients with stage 3a or 3b CKD exhibited improved glomerular filtration rate (43.5 vs 58.4 mL/min, P = .01). In conclusion, SG safely improves transplant candidacy while providing significant, sustainable effects on weight loss, reducing medical comorbidities, and possibly improving renal function in stage 3 patients.


Subject(s)
Gastrectomy , Kidney Failure, Chronic/complications , Obesity, Morbid/surgery , Adult , Aged , Female , Follow-Up Studies , Gastrectomy/methods , Humans , Kidney Failure, Chronic/mortality , Kidney Failure, Chronic/surgery , Kidney Transplantation , Male , Middle Aged , Obesity, Morbid/complications , Obesity, Morbid/mortality , Prospective Studies , Time-to-Treatment , Treatment Outcome , Waiting Lists , Weight Loss
2.
Ecotoxicology ; 29(9): 1399-1408, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32785887

ABSTRACT

While large-scale oil spills can cause acute mortality events in birds, there is increasing evidence that sublethal oil exposure can trigger physiological changes that have implications for individual performance and survival. Therefore, improved methods for identifying small amounts of oil on birds are needed. Because ultraviolet (UV) light can be used to identify thin crude oil films in water and on substrate that are not visually apparent under normal lighting conditions, we hypothesized that UV light could be useful for detecting small amounts of oil present on the plumage of birds. We evaluated black skimmers (Rynchops niger), brown pelicans (Pelecanus occidentalis), clapper rails (Rallus crepitans), great egrets (Ardea alba), and seaside sparrows (Ammodramus maritimus) exposed to areas affected by the Deepwater Horizon oil spill in the Gulf of Mexico as well as from reference areas from 20 June, 2010 to 23 February, 2011. When visually assessed without UV light, 19.6% of birds evaluated from areas affected by the spill were determined to be oiled (previously published data), whereas when examined under UV light, 56.3% of the same birds were determined to have oil exposure. Of 705 individuals examined in areas potentially impacted by the spill, we found that fluorescence under UV light assessment identified 259 oiled birds that appeared to be oil-free on visual exam, supporting its utility as a simple tool for improving detection of modestly oiled birds in the field. Further, UV assessment revealed an increase in qualitative severity of oiling (approximate % of body surface oiled) in 40% of birds compared to what was determined on visual exam. Additionally, black skimmers, brown pelicans, and great egrets exposed to oil as determined using UV light experienced oxidative injury to erythrocytes, had decreased numbers of circulating erythrocytes, and showed evidence of a regenerative hematological response in the form of increased reticulocytes. This evidence of adverse effects was similar to changes identified in birds with oil exposure as determined by visual examination without UV light, and is consistent with hemolytic anemia likely caused by oil exposure. Thus, UV assessment proved useful for enhancing detection of birds exposed to oil, but did not increase detection of birds experiencing clinical signs of anemia compared to standard visual oiling assessment. We conclude that UV light evaluation can help identify oil exposure in many birds that would otherwise be identified visually as unexposed during oil spill events.


Subject(s)
Environmental Monitoring/methods , Petroleum Pollution , Petroleum , Water Pollutants, Chemical , Animals , Birds , Gulf of Mexico , Ultraviolet Rays
3.
Liver Transpl ; 25(11): 1673-1681, 2019 11.
Article in English | MEDLINE | ID: mdl-31518478

ABSTRACT

Obesity has become an epidemic in the United States over the past decade, and recent studies have shown this trend in the liver transplantation (LT) population. These patients may be candidates for laparoscopic sleeve gastrectomy (LSG) to promote significant and sustained weight loss to prevent recurrence of nonalcoholic steatohepatitis. However, safety remains a concern, and efficacy in this setting is uncertain. A single-institution database from 2014 to 2018 was queried for patients undergoing LSG following LT. The selection criteria for surgery were consistent with National Institutes of Health guidelines, and patients were at least 6 months after LT. A total of 15 patients (median age, 59.0 years; Caucasian, 86.7%; and female, 60%) underwent LSG following LT. Median time from LT to LSG was 2.2 years with a median follow-up period of 2.6 years. The median hospital length of stay (LOS) was 2 days after LSG. Mortality and rate of liver allograft rejection was 0, and there was 1 postoperative complication (a surgical site infection). Following LSG, body mass index (BMI) decreased from 42.7 to 35.9 kg/m2 (P < 0.01), and in 12 patients with at least 1 year of follow-up, the total body weight loss was 20.6%. Following LSG in patients with diabetes, the median daily insulin requirements decreased from 98 (49-118) to 0 (0-29) units/day (P = 0.02), and 60% discontinued insulin. Post-LT patients had a similar decrease in BMI and reduction in comorbidities at 1 year compared with a matched non-LT patient cohort. In the largest patient series to date, we show that LSG following LT is safe, effective, and does not increase the incidence of liver allograft rejection. Larger longer-term studies are needed to confirm underlying metabolic changes following LSG.


Subject(s)
Bariatric Surgery/adverse effects , Graft Rejection/epidemiology , Liver Transplantation/adverse effects , Non-alcoholic Fatty Liver Disease/surgery , Obesity, Morbid/surgery , Secondary Prevention/methods , Bariatric Surgery/methods , Female , Gastrectomy/adverse effects , Gastrectomy/methods , Graft Rejection/etiology , Graft Rejection/prevention & control , Humans , Incidence , Laparoscopy/adverse effects , Laparoscopy/statistics & numerical data , Length of Stay , Male , Middle Aged , Non-alcoholic Fatty Liver Disease/etiology , Non-alcoholic Fatty Liver Disease/prevention & control , Obesity, Morbid/complications , Postoperative Period , Retrospective Studies , Secondary Prevention/statistics & numerical data , Surgical Wound Infection/epidemiology , Surgical Wound Infection/etiology , Time-to-Treatment , Treatment Outcome , Weight Loss
4.
J Neurosci ; 37(1): 184-193, 2017 01 04.
Article in English | MEDLINE | ID: mdl-28053040

ABSTRACT

Organismal stress initiates a tightly orchestrated set of responses involving complex physiological and neurocognitive systems. Here, we present evidence for glucagon-like peptide 1 (GLP-1)-mediated paraventricular hypothalamic circuit coordinating the global stress response. The GLP-1 receptor (Glp1r) in mice was knocked down in neurons expressing single-minded 1, a transcription factor abundantly expressed in the paraventricular nucleus (PVN) of the hypothalamus. Mice with single-minded 1-mediated Glp1r knockdown had reduced hypothalamic-pituitary-adrenal axis responses to both acute and chronic stress and were protected against weight loss associated with chronic stress. In addition, regional Glp1r knockdown attenuated stress-induced cardiovascular responses accompanied by decreased sympathetic drive to the heart. Finally, Glp1r knockdown reduced anxiety-like behavior, implicating PVN GLP-1 signaling in behavioral stress reactivity. Collectively, these findings support a circuit whereby brainstem GLP-1 activates PVN signaling to mount an appropriate whole-organism response to stress. These results raise the possibility that dysfunction of this system may contribute to stress-related pathologies, and thereby provide a novel target for intervention. SIGNIFICANCE STATEMENT: Dysfunctional stress responses are linked to a number of somatic and psychiatric diseases, emphasizing the importance of precise neuronal control of effector pathways. Pharmacological evidence suggests a role for glucagon-like peptide-1 (GLP-1) in modulating stress responses. Using a targeted knockdown of the GLP-1 receptor in the single-minded 1 neurons, we show dependence of paraventricular nucleus GLP-1 signaling in the coordination of neuroendocrine, autonomic, and behavioral responses to acute and chronic stress. To our knowledge, this is the first direct demonstration of an obligate brainstem-to-hypothalamus circuit orchestrating general stress excitation across multiple effector systems. These findings provide novel information regarding signaling pathways coordinating central control of whole-body stress reactivity.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/genetics , Histone-Lysine N-Methyltransferase/genetics , Repressor Proteins/genetics , Signal Transduction/genetics , Stress, Psychological/physiopathology , Acute Disease , Animals , Anxiety/etiology , Anxiety/genetics , Anxiety/psychology , Behavior, Animal , Chronic Disease , Eating , Glucagon-Like Peptide-1 Receptor/genetics , Heart Rate/genetics , Hypothalamo-Hypophyseal System/physiopathology , Male , Mice , Mice, Knockout , Paraventricular Hypothalamic Nucleus , Pituitary-Adrenal System/physiopathology , Stress, Psychological/psychology , Swimming/psychology
5.
Am J Hematol ; 91(12): 1195-1201, 2016 12.
Article in English | MEDLINE | ID: mdl-27648808

ABSTRACT

Hemolysis is a key feature of sickle cell anemia (HbSS). Direct quantitation of hemolysis could be used as an objective outcome in clinical trials of new therapeutics for HbSS and would also enable better human studies of the pathogenesis of complications of HbSS that are ostensibly hemolysis-related, such as pulmonary hypertension. However, contemporary human studies in HbSS have used only surrogate markers of hemolysis rather than direct measurements of RBC survival. We directly quantified hemolysis in HbSS by measuring survival of an age cohort of RBCs labeled with a stable isotope, administered orally as 15 N-glycine, a metabolic precursor of heme. The atomic excess of 15 N in heme extracted from blood was monitored by mass spectrometry over time. We performed 13 labeling experiments in 11 individuals with HbSS. Mean RBC survival was 31.9 days (range 14.1-53.6). Both HbF level, a known determinant of hemolysis, and absolute reticulocyte count (ARC), an index of the marrow's response to hemolysis, correlated with directly measured RBC survival (r = 0.61, P < 0.002; r = -0.84, P < 0.001). However, commonly used biochemical surrogates of hemolysis (LDH, AST, bilirubin, and plasma free hemoglobin) did not correlate with directly measured RBC survival. These biochemical surrogates should be interpreted cautiously, at best, in clinical trials and human physiologic studies in HbSS. ARC was the best correlate of total hemolysis, but only 70% of the variation in RBC survival was reflected in this marker. If greater accuracy is required in human studies, 15 N-glycine RBC labeling can directly and accurately quantify hemolysis. Am. J. Hematol. 91:1195-1201, 2016. © 2016 Wiley Periodicals, Inc.


Subject(s)
Anemia, Sickle Cell/pathology , Biomarkers/blood , Cell Survival , Erythrocytes/pathology , Hemolysis , Nitrogen Isotopes/administration & dosage , Adolescent , Adult , Female , Fetal Hemoglobin , Glycine/administration & dosage , Humans , Isotope Labeling , Male , Mass Spectrometry , Reticulocyte Count , Young Adult
6.
Am J Hematol ; 90(1): 50-55, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25293624

ABSTRACT

HbA1c is commonly used to monitor glycemic control. However, there is growing evidence that the relationship between HbA1c and mean blood glucose (MBG) is influenced by variation in red blood cell (RBC) lifespan in hematologically normal individuals. Correction of HbA1c for mean RBC age (MRBC ) requires a noninvasive, accurate, and affordable method to measure RBC survival. In this study, we evaluated whether a stable isotope approach would satisfy these requirements. RBC lifespan and MRBC were determined in a group of nine hematologically normal diabetic and nondiabetic subjects using oral (15) N-glycine to label heme in an age cohort of RBC. The MRBC was 58.7 ± 9.1 (2SD) days and RBC lifespan was 106 ± 21 (2SD) days. This degree of variation (±15-20%) is consistent with previous studies using other techniques. In a subset of seven subjects, MRBC determined with the biotin label technique were available from approximately five years prior, and strongly correlated with the stable isotope values (R(2) = 0.79). This study suggests that the MRBC is stable over time but varies substantially among individuals, and supports the importance of its variation in HbA1c interpretation. The characteristics of the stable isotope method support its suitability for studies to directly evaluate the impact of variation in MRBC on the interpretation of HbA1c.


Subject(s)
Cellular Senescence , Diabetes Mellitus/blood , Erythrocytes/cytology , Glycated Hemoglobin/analysis , Glycine/administration & dosage , Blood Glucose/analysis , Cell Survival , Erythrocytes/metabolism , Female , Glycine/chemistry , Heme/chemistry , Humans , Male , Nitrogen Isotopes
7.
Am J Physiol Endocrinol Metab ; 307(9): E784-92, 2014 Nov 01.
Article in English | MEDLINE | ID: mdl-25159330

ABSTRACT

Meal-fed (MF) rats with access to food for only 4 consecutive hours during the light cycle learn to eat large meals to maintain energy balance. MF animals develop behavioral and endocrine changes that permit glucose tolerance despite increased meal size. We hypothesized that enhanced activity of the enteroinsular axis mediates glucose homeostasis during MF. Cohorts of rats were allocated to MF or ad libitum (AL) regimens for 2-4 wk. Insulin secretion and glucose tolerance were determined after oral carbohydrate and intraperitoneal (ip) and intravenous (iv) glucose. MF rats ate less than AL in the first week but maintained a comparable weight trajectory thereafter. MF rats had decreased glucose excursions after a liquid mixed meal (AUC: MF 75 ± 7, AL 461 ± 28 mmol·l⁻¹·min, P < 0.001), with left-shifted insulin secretion (AUC(0-15): MF 31.0 ± 4.9, AL 9.6 ± 4.4 pM·min, P < 0.02), which peaked before a significant rise in blood glucose. Both groups had comparable fasting glucagon levels, but postprandial responses were lower with MF. However, neither intestinal expression of proGIP and proglucagon mRNA nor plasma incretin levels differed between MF and AL groups. There were no differences in the insulin response to ip or iv glucose between MF and AL rats. These findings demonstrate that MF improves oral glucose tolerance and is associated with significant changes in postprandial islet hormone secretion. Because MF enhanced ß-cell function during oral but not parenteral carbohydrate administration, and was not accounted for by changes in circulating incretins, these results support a neural mechanism of adaptive insulin secretion.


Subject(s)
Allostasis , Feeding Behavior , Glucose Intolerance/drug therapy , Insulin/metabolism , Islets of Langerhans/metabolism , Meals , Neurosecretory Systems/physiopathology , Animals , Behavior, Animal , Gastric Inhibitory Polypeptide/genetics , Gastric Inhibitory Polypeptide/metabolism , Glucagon/blood , Glucagon/genetics , Glucagon/metabolism , Glucose Intolerance/blood , Glucose Intolerance/metabolism , Glucose Intolerance/physiopathology , Hyperglycemia/prevention & control , Ileum/metabolism , Incretins/blood , Incretins/metabolism , Insulin/blood , Insulin Secretion , Intestinal Mucosa/metabolism , Islets of Langerhans/innervation , Jejunum/metabolism , Male , Organ Specificity , Postprandial Period , Proglucagon/genetics , Proglucagon/metabolism , Rats, Long-Evans
8.
Am J Physiol Endocrinol Metab ; 306(4): E424-32, 2014 Feb 15.
Article in English | MEDLINE | ID: mdl-24368666

ABSTRACT

Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) are effective weight loss surgeries that also improve glucose metabolism. Rapid, early rises of circulating insulin and glucagon-like peptide-1 (GLP-1) concentrations following food ingestion are characteristic of these procedures. The purpose of the current study was to test the hypothesis that postprandial hormone release is due to increased nutrient emptying from the stomach. Radioscintigraphy and chemical and radiolabeled tracers were used to examine gastric emptying in rat models of VSG and RYGB surgery. Intraduodenal nutrient infusions were used to assess intestinal GLP-1 secretion and nutrient sensitivity in VSG rats compared with shams. Five minutes after a nutrient gavage, the stomachs of RYGB and VSG rats were completely emptied, whereas only 6.1% of the nutrient mixture had emptied from sham animals. Gastric pressure was increased in VSG animals, and rats with this procedure did not inhibit gastric emptying normally in response to increasing caloric loads of dextrose or corn oil, and they did not respond to neural or endocrine effectors of gastric motility. Finally, direct infusion of liquid nutrients into the duodenum caused significantly greater GLP-1 release in VSG compared with shams, indicating that increases in GLP-1 secretion after VSG are the result of both greater gastric emptying rates and altered responses at the level of the intestine. These findings demonstrate greatly accelerated gastric emptying in rat models of RYGB and VSG. In VSG this is likely due to increased gastric pressure and reduced responses to inhibitory feedback from the intestine.


Subject(s)
Gastrectomy/methods , Gastric Emptying/physiology , Gastric Mucosa/metabolism , Glucagon-Like Peptide 1/metabolism , Postprandial Period/physiology , Animals , Body Weight/drug effects , Body Weight/physiology , Exenatide , Gastric Emptying/drug effects , Gastric Mucosa/drug effects , Hypoglycemic Agents/pharmacology , Male , Peptides/pharmacology , Rats , Rats, Long-Evans , Stomach/drug effects , Venoms/pharmacology
9.
Prim Care Diabetes ; 18(2): 151-156, 2024 04.
Article in English | MEDLINE | ID: mdl-38172007

ABSTRACT

AIMS: Although diabetes management decisions in primary care are typically based largely on HbA1c, mismatches between HbA1c and other measures of glycemia that are increasingly more available present challenges to optimal management. This study aimed to assess a systematic approach to identify the frequency of mismatches of potential clinical significance amongst various measures of glycemia in a primary care setting. METHODS: Following screening to exclude conditions known to affect HbA1c interpretation, HbA1c, and fructosamine were obtained and repeated after ∼90 days on 53 adults with prediabetes or type 2 diabetes. A subset of 13 participants with repeat labs wore continuous glucose monitoring (CGM) for 10 days. RESULTS: As expected, HbA1c and fructosamine only modestly correlated (initial R2 = 0.768/repeat R2 = 0.655). The HbA1c/fructosamine mismatch frequency of ± 0.5% (using the following regression HbA1c = 0.015 *fructosamine + 2.994 calculated from the initial sample) was 27.0%. Of the 13 participants with CGM data, HbA1c and CGM-based Glucose Management Indicator correlated at R2 = 0.786 with a mismatch frequency of ± 0.5% at 46.2% compared to a HbA1c/fructosamine mismatch frequency of ± 0.5% at 30.8%. CONCLUSIONS: HbA1c is frequently mismatched with fructosamine and CGM data. As each of the measures has strengths and weaknesses, the utilization of multiple different measures of glycemia may be informative for diabetes assessment in the clinical setting.


Subject(s)
Diabetes Mellitus, Type 2 , Adult , Humans , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/therapy , Glycated Hemoglobin , Blood Glucose , Blood Glucose Self-Monitoring , Fructosamine , Primary Health Care
10.
J Immunol ; 186(8): 4693-706, 2011 Apr 15.
Article in English | MEDLINE | ID: mdl-21402899

ABSTRACT

IFN-α is known to play a key role in autoimmunity, but the mechanisms are uncertain. Although the induction of autoimmunity by IFN-α is consistent with primarily immunomodulatory effects, the high frequency of nonautoimmune inflammation suggests other mechanisms. We used thyroiditis as a model to dissect these possibilities. IFN-α treatment of cultured thyrocytes increased expression of thyroid differentiation markers, thyroglobulin, thyroid-stimulating hormone receptor, thyroid peroxidase, and sodium iodide transporter. RNAseq analysis demonstrated that pathways of Ag presentation, pattern recognition receptors, and cytokines/chemokines were also stimulated. These changes were associated with markedly increased nonapoptotic thyroid cell death, suggesting direct toxicity. To corroborate these in vitro findings, we created transgenic mice with thyroid-specific overexpression of IFN-α under control of the thyroglobulin promoter. Transgenic mice developed marked inflammatory thyroid destruction associated with immune cell infiltration of thyroid and surrounding tissues leading to profound hypothyroidism, findings consistent with our in vitro results. In addition, transgenic mice thyroids showed upregulation of pathways similar to those observed in cultured thyrocytes. In particular, expression of granzyme B, CXCL10, a subset of the tripartite motif-containing family, and other genes involved in recruitment of bystander cytotoxic immune responses were increased. Pathways associated with apoptosis and autophagy were not induced. Taken together, our data demonstrate that the induction of tissue inflammation and autoimmunity by IFN-α involves direct tissue toxic effects as well as provocation of destructive bystander immune responses.


Subject(s)
Autoimmunity/immunology , Immune System/immunology , Interferon-alpha/immunology , Thyroid Gland/immunology , Animals , Cell Line , Cells, Cultured , Dose-Response Relationship, Drug , Female , Gene Expression/drug effects , Gene Expression Profiling , Humans , Immune System/cytology , Immune System/metabolism , Interferon-alpha/genetics , Interferon-alpha/pharmacology , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Inbred CBA , Mice, Transgenic , Rats , Receptor, Interferon alpha-beta/genetics , Reverse Transcriptase Polymerase Chain Reaction , Thyroid Gland/cytology , Thyroid Gland/metabolism , Thyroiditis/genetics , Thyroiditis/metabolism , Time Factors
11.
Acad Med ; 98(10): 1120-1130, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37200479

ABSTRACT

A combination of forces have markedly increased challenges to research-active faculty achieving sustained success. This article describes how one department at the University of Cincinnati College of Medicine (UCCOM) implemented a strategic plan, the Research Initiative Supporting Excellence at the University of Cincinnati (RISE-UC), to promote the research activity of its research-active faculty, fiscal year (FY) 2011-FY 2021. RISE-UC was implemented and regularly updated to address evolving needs. RISE-UC supported faculty members pursuing research via fiscal and administrative services to grow a critical mass of investigators; establish a shared governance model; create pathways for developing physician-scientists; develop discrete and targeted internal research funding; establish an Academic Research Service (ARS) unit (as infrastructure to support research); enhance faculty member mentorship; and recognize, celebrate, and reward research success. RISE-UC was informed by shared governance and resulted in substantial increases in total size of the faculty and external funding. More than 50% of Physician-Scientist Training Program graduates are active researchers at UCCOM. The internal awards program realized a return on investment of ~16.4-fold, and total external direct cost research funds increased from ~$55,400,000 (FY 2015) to ~$114,500,000 (FY 2021). The ARS assisted in the submission of 57 grant proposals and provided services faculty members generally found very helpful or helpful. The peer-mentoring group for early-career faculty members resulted in 12 of 23 participants receiving major grant funding (≥ $100,000; spring 2017-spring 2021) from sources including National Institutes of Health awards, Department of Defense funding, Veterans Affairs funding, and foundation awards. Research recognition included ~$77,000/year in incentive payments to faculty members for grant submissions and grants awarded. RISE-UC is an example of a comprehensive approach to promote research faculty member success and may serve as a model for other institutions with similar aspirations.


Subject(s)
Medicine , Mentoring , United States , Humans , Faculty , Mentors , National Institutes of Health (U.S.)
12.
Sci Adv ; 9(19): eadf8549, 2023 05 10.
Article in English | MEDLINE | ID: mdl-37163604

ABSTRACT

Lymphangioleiomyomatosis (LAM) is a rare, progressive lung disease that predominantly affects women. LAM cells carry TSC1/TSC2 mutations, causing mTORC1 hyperactivation and uncontrolled cell growth. mTORC1 inhibitors stabilize lung function; however, sustained efficacy requires long-term administration, and some patients fail to tolerate or respond to therapy. Although the genetic basis of LAM is known, mechanisms underlying LAM pathogenesis remain elusive. We integrated single-cell RNA sequencing and single-nuclei ATAC-seq of LAM lungs to construct a gene regulatory network controlling the transcriptional program of LAM cells. We identified activation of uterine-specific HOX-PBX transcriptional programs in pulmonary LAMCORE cells as regulators of cell survival depending upon HOXD11-PBX1 dimerization. Accordingly, blockage of HOXD11-PBX1 dimerization by HXR9 suppressed LAM cell survival in vitro and in vivo. PBX1 regulated STAT1/3, increased the expression of antiapoptotic genes, and promoted LAM cell survival in vitro. The HOX-PBX gene network provides promising targets for treatment of LAM/TSC mTORC1-hyperactive cancers.


Subject(s)
Gene Regulatory Networks , Homeodomain Proteins , Lymphangioleiomyomatosis , Humans , Single-Cell Analysis , Lymphangioleiomyomatosis/metabolism , Lymphangioleiomyomatosis/pathology , Transcription Factors/metabolism , Lung/metabolism , Lung/pathology , Animals , Rats , Neoplasm Metastasis , Multiomics , Female
13.
JCI Insight ; 8(9)2023 05 08.
Article in English | MEDLINE | ID: mdl-36927688

ABSTRACT

Tuberous sclerosis complex (TSC) is characterized by multisystem, low-grade neoplasia involving the lung, kidneys, brain, and heart. Lymphangioleiomyomatosis (LAM) is a progressive pulmonary disease affecting almost exclusively women. TSC and LAM are both caused by mutations in TSC1 and TSC2 that result in mTORC1 hyperactivation. Here, we report that single-cell RNA sequencing of LAM lungs identified activation of genes in the sphingolipid biosynthesis pathway. Accordingly, the expression of acid ceramidase (ASAH1) and dihydroceramide desaturase (DEGS1), key enzymes controlling sphingolipid and ceramide metabolism, was significantly increased in TSC2-null cells. TSC2 negatively regulated the biosynthesis of tumorigenic sphingolipids, and suppression of ASAH1 by shRNA or the inhibitor ARN14976 (17a) resulted in markedly decreased TSC2-null cell viability. In vivo, 17a significantly decreased the growth of TSC2-null cell-derived mouse xenografts and short-term lung colonization by TSC2-null cells. Combined rapamycin and 17a treatment synergistically inhibited renal cystadenoma growth in Tsc2+/- mice, consistent with increased ASAH1 expression and activity being rapamycin insensitive. Collectively, the present study identifies rapamycin-insensitive ASAH1 upregulation in TSC2-null cells and tumors and provides evidence that targeting aberrant sphingolipid biosynthesis pathways has potential therapeutic value in mechanistic target of rapamycin complex 1-hyperactive neoplasms, including TSC and LAM.


Subject(s)
Lung Neoplasms , Tuberous Sclerosis , Humans , Mice , Female , Animals , Tuberous Sclerosis/drug therapy , Tumor Suppressor Proteins/genetics , Up-Regulation , Acid Ceramidase/genetics , Acid Ceramidase/metabolism , Acid Ceramidase/therapeutic use , Lung Neoplasms/pathology , Sirolimus/pharmacology , Mechanistic Target of Rapamycin Complex 1/metabolism , Mice, Knockout
14.
J Biochem ; 170(6): 699-711, 2022 Jan 07.
Article in English | MEDLINE | ID: mdl-34244779

ABSTRACT

Since the discovery of nucleotides over 100 years ago, extensive studies have revealed the importance of nucleotides for homeostasis, health and disease. However, there remains no established method to investigate quantitatively and accurately intact nucleotide incorporation into RNA and DNA. Herein, we report a new method, Stable-Isotope Measure Of Influxed Ribonucleic Acid Index (SI-MOIRAI), for the identification and quantification of the metabolic fate of ribonucleotides and their precursors. SI-MOIRAI, named after Greek goddesses of fate, combines a stable isotope-labelling flux assay with mass spectrometry to enable quantification of the newly synthesized ribonucleotides into r/m/tRNA under a metabolic stationary state. Using glioblastoma (GBM) U87MG cells and a patient-derived xenograft (PDX) GBM mouse model, SI-MOIRAI analyses showed that newly synthesized GTP was particularly and disproportionally highly utilized for rRNA and tRNA synthesis but not for mRNA synthesis in GBM in vitro and in vivo. Furthermore, newly synthesized pyrimidine nucleotides exhibited a significantly lower utilization rate for RNA synthesis than newly synthesized purine nucleotides. The results reveal the existence of discrete pathways and compartmentalization of purine and pyrimidine metabolism designated for RNA synthesis, demonstrating the capacity of SI-MOIRAI to reveal previously unknown aspects of nucleotide biology.


Subject(s)
Glioblastoma/metabolism , Nucleotides/metabolism , RNA, Neoplasm/metabolism , Animals , Cell Line, Tumor , Heterografts , Humans , Mass Spectrometry , Mice , Neoplasm Transplantation
15.
Ann Biomed Eng ; 50(11): 1488-1497, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35507229

ABSTRACT

The relationship between head impact and subsequent brain injury for American football players is not well-defined, especially for youth. The objective of this study is to quantify and assess Head Impact Exposure (HIE) metrics among youth and collegiate football players. This multi-season study enrolled 639 unique athletes (354 collegiate; 285 youth, ages 9-14), recording 476,209 head impacts (367,337 collegiate; 108,872 youth) over 971 sessions (480 collegiate; 491 youth). Youth players experienced 43 and 65% fewer impacts per competition and practice, respectively, and lower impact magnitudes compared to collegiate players (95th percentile peak linear acceleration (PLA, g) competition: 45.6 vs 61.9; 95th percentile PLA practice: 42.6 vs 58.8; 95th percentile peak rotational acceleration (PRA, rad·s-2) competition: 2262 vs 4422; 95th percentile PRA practice: 2081 vs 4052; 95th percentile HITsp competition: 25.4 vs 32.8; 95th percentile HITsp practice: 23.9 vs 30.2). Impacts during competition were more frequent and of greater magnitude than during practice at both levels. Quantified comparisons of head impact frequency and magnitude between youth and collegiate athletes reveal HIE differences as a function of age, and expanded insight better informs the development of age-appropriate guidelines for helmet design, prevention measures, standardized testing, brain injury diagnosis, and recovery management.


Subject(s)
Brain Concussion , Brain Injuries , Football , Adolescent , Humans , Child , Football/injuries , Head Protective Devices , Acceleration , Head , Polyesters , Biomechanical Phenomena
17.
Neurotrauma Rep ; 2(1): 503-511, 2021.
Article in English | MEDLINE | ID: mdl-34901945

ABSTRACT

Symptom inventories are generally only collected after a suspected concussion, but regular in-season monitoring may allude to clinical symptoms associated with repetitive subconcussive impacts and potential undiagnosed concussions. Despite sex-specific differences in symptom presentation and outcome of concussion, no return-to-play protocol takes sex into account. The objective of this study was to monitor a cohort of contact-sport athletes and compare the frequency and severity of in-season concussion-like symptom reporting between sexes. Graded symptom checklists from 144 female and 104 male athlete-seasons were administered weekly to quantify the effect of subconcussive impacts on frequency and severity of in-season symptom reporting. In-season, mean symptom severity score (SSS) (p = 0.026, mean difference of 1.8), mean number of symptoms (p = 0.044, mean difference of 0.9), max SSS (p < 0.001, mean difference of 19.2), and max number of symptoms (p < 0.001, mean difference of 6.8) were higher in the females. The females' survey results showed differences between elevated and concussed SSS (p < 0.005, mean difference of 28.1) and number of symptoms reported (p = 0.001, mean difference of 6.6). The males did not have a difference in SSS (p = 0.97, mean difference of 1.12) nor in number of symptoms (p = 0.35, mean difference of 1.96) from elevated to concussed athletes. Rugby players report concussion-like symptoms in the absence of a diagnosed concussion in-season. Female athletes reported elevated symptom frequencies with greater severities than the males, but both sexes reported considerable levels throughout the season.

18.
J Biol Chem ; 284(49): 34231-43, 2009 Dec 04.
Article in English | MEDLINE | ID: mdl-19776016

ABSTRACT

Previously, we have shown that statistical synergism between amino acid variants in thyroglobulin (Tg) and specific HLA-DR3 pocket sequence signatures conferred a high risk for autoimmune thyroid disease (AITD). Therefore, we hypothesized that this statistical synergism mirrors a biochemical interaction between Tg peptides and HLA-DR3, which is key to the pathoetiology of AITD. To test this hypothesis, we designed a recombinant HLA-DR3 expression system that was used to express HLA-DR molecules harboring either AITD susceptibility or resistance DR pocket sequences. Next, we biochemically generated the potential Tg peptidic repertoire available to HLA-DR3 by separately treating 20 purified human thyroglobulin samples with cathepsins B, D, or L, lysosomal proteases that are involved in antigen processing and thyroid biology. Sequences of the cathepsin-generated peptides were then determined by matrix-assisted laser desorption ionization time-of-flight-mass spectroscopy, and algorithmic means were employed to identify putative AITD-susceptible HLA-DR3 binders. From four predicted peptides, we identified two novel peptides that bound strongly and specifically to both recombinant AITD-susceptible HLA-DR3 protein and HLA-DR3 molecules expressed on stably transfected cells. Intriguingly, the HLA-DR3-binding peptides we identified had a marked preference for the AITD-susceptibility DR signatures and not to those signatures that were AITD-protective. Structural analyses demonstrated the profound influence that the pocket signatures have on the interaction of HLA-DR molecules with Tg peptides. Our study suggests that interactions between Tg and discrete HLA-DR pocket signatures contribute to the initiation of AITD.


Subject(s)
Gene Expression Regulation , HLA-DR3 Antigen/metabolism , Recombinant Proteins/chemistry , Algorithms , Animals , Autoimmune Diseases , Cathepsins/chemistry , Cell Line , HeLa Cells , Histocompatibility Antigens Class II , Humans , Peptides/chemistry , Rats , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Thyroglobulin/chemistry , Thyroid Diseases/immunology , Thyroid Gland/metabolism
19.
Blood ; 112(10): 4284-91, 2008 Nov 15.
Article in English | MEDLINE | ID: mdl-18694998

ABSTRACT

Although red blood cell (RBC) life span is a known determinant of percentage hemoglobin A1c (HbA1c), its variation has been considered insufficient to affect clinical decisions in hematologically normal persons. However, an unexplained discordance between HbA1c and other measures of glycemic control can be observed that could be, in part, the result of differences in RBC life span. To explore the hypothesis that variation in RBC life span could alter measured HbA1c sufficiently to explain some of this discordance, we determined RBC life span using a biotin label in 6 people with diabetes and 6 nondiabetic controls. Mean RBC age was calculated from the RBC survival curve for all circulating RBCs and for labeled RBCs at multiple time points as they aged. In addition, HbA1c in magnetically isolated labeled RBCs and in isolated transferrin receptor-positivereticulocytes was used to determine the in vivo synthetic rate of HbA1c. The mean age of circulating RBCs ranged from 39 to 56 days in diabetic subjects and 38 to 60 days in nondiabetic controls. HbA1c synthesis was linear and correlated with mean whole blood HbA1c (R(2) = 0.91). The observed variation in RBC survival was large enough to cause clinically important differences in HbA1c for a given mean blood glucose.


Subject(s)
Cellular Senescence , Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 2/blood , Erythrocytes/metabolism , Glycated Hemoglobin/metabolism , Adult , Blood Glucose/metabolism , Cell Survival , Female , Humans , Male , Middle Aged
20.
J Econ Entomol ; 113(1): 375-384, 2020 02 08.
Article in English | MEDLINE | ID: mdl-31755524

ABSTRACT

Over the last several decades, low-income public housing facilities have been known to be infested with particularly large German cockroach populations. These populations persist even though the housing pest control contracts often require, and pay for, IPM practices to be used in their facilities. When Virginia Tech researchers began reviewing public housing contracts in Virginia and North Carolina, it was easy to see why these 'IPM programs' were not successful. Many of these 'low-bidder' contracts do not allow the technician enough time in each apartment to assess the size of the pest population. In addition, these pest management contracts did not require German cockroach population monitoring, even though all IPM programs are based on assessments of the pest population. There was a clear need for an effective, easy to apply cockroach management program in U.S. public housing authorities. This study determined the long-term efficacy of an Assessment-based Pest Management (APM) program for German cockroach control in U.S. public housing facilities. Specifically, we evaluated an APM program where the residents were not asked to clean or prepare for treatment, and where overnight cockroach trap counts were used to determine the volume of gel bait that would be applied. The APM baiting program was conducted for 15 mo in three housing authorities. In all three housing authorities, cockroach populations in test units were typically reduced by >90%. German cockroach infestations were even eliminated from 49 of the 65 (75%) test units during this study.


Subject(s)
Blattellidae , Insecticides , Animals , Insect Control , North Carolina , Public Housing , Virginia
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