Exogenous erythropoietin increases hematological status, fat oxidation, and aerobic performance in males following prolonged strenuous training.

This study investigated the effects of EPO on hemoglobin (Hgb) and hematocrit (Hct), time trial (TT) performance, substrate oxidation, and skeletal muscle phenotype throughout 28 days of strenuous exercise. Eight males completed this longitudinal controlled exercise and feeding study using EPO (50 IU/kg body mass) 3×/week for 28 days. Hgb, Hct, and TT performance were assessed PRE and on Days 7, 14, 21, and 27 of EPO. Rested/fasted muscle obtained PRE and POST EPO were analyzed for gene expression, protein signaling, fiber type, and capillarization. Substrate oxidation and glucose turnover were assessed during 90-min of treadmill load carriage (LC; 30% body mass; 55 ± 5% V̇O2peak) exercise using indirect calorimetry, and 6-6-[2H2]-glucose PRE and POST. Hgb and Hct increased, and TT performance improved on Days 21 and 27 compared to PRE (p < 0.05). Energy expenditure, fat oxidation, and metabolic clearance rate during LC increased (p < 0.05) from PRE to POST. Myofiber type, protein markers of mitochondrial biogenesis, and capillarization were unchanged PRE to POST. Transcriptional regulation of mitochondrial activity and fat metabolism increased from PRE to POST (p < 0.05). These data indicate EPO administration during 28 days of strenuous exercise can enhance aerobic performance through improved oxygen carrying capacity, whole-body and skeletal muscle fat metabolism.

Notch 2 signaling contributes to intestinal eosinophil adaptations in steady-state and tissue burden following oral allergen challenge.

Eosinophils function as inflammatory effectors in allergic diseases but also contribute to tissue homeostasis in steady state. Emerging data are revealing tissue eosinophils to be adaptive cells, imprinted by their local tissue microenvironment and exhibiting distinct functional phenotypes that may contribute to their homeostatic versus inflammatory capacities. However, signaling pathways that regulate eosinophil tissue adaptations remain elusive. Notch signaling is an evolutionarily conserved pathway that mediates differential cell fate programming of both pre- and post-mitotic immune cells. This study investigated a role for notch receptor 2 signaling in regulating eosinophil functions and tissue phenotype in both humans and mice. Notch 2 receptors were constitutively expressed and active in human blood eosinophils. Pharmacologic neutralization of notch 2 in ex vivo stimulated human eosinophils altered their activated transcriptome and prevented their cytokine-mediated survival. Genetic ablation of eosinophil-expressed notch 2 in mice diminished steady-state intestine-specific eosinophil adaptations and impaired their tissue retention in a food allergic response. In contrast, notch 2 had no effect on eosinophil phenotype or tissue inflammation within the context of allergic airways inflammation, suggesting notch 2-dependent regulation of eosinophil phenotype and function is specific to the gut. These data reveal notch 2 signaling as a cell-intrinsic mechanism that contributes to eosinophil survival, function, and intestine-specific adaptations. The notch 2 pathway may represent a viable strategy to reprogram eosinophil functional phenotypes in gastrointestinal eosinophil-associated diseases.

Improvement of fatigue in generalised myasthenia gravis with zilucoplan.

BACKGROUND: Fatigue is a debilitating symptom of myasthenia gravis (MG). The impact of fatigue on MG can be assessed by Quality of Life in Neurological Disorders (Neuro-QoL) Short Form Fatigue scale. Transformation of raw Neuro-QoL fatigue scores to T-scores is a known approach for facilitating clinical interpretation of clinically meaningful and fatigue severity thresholds. METHODS: In the Phase 3, double-blind, placebo-controlled RAISE study (NCT04115293), adults with acetylcholine receptor autoantibody-positive generalised MG (MG Foundation of America Disease Class II-IV) were randomised 1:1 to daily subcutaneous zilucoplan 0.3 mg/kg or placebo for 12 weeks. Patients completing RAISE could opt to receive zilucoplan 0.3 mg/kg in an ongoing, open-label extension study, RAISE-XT (NCT04225871). In this post-hoc analysis, we evaluated the long-term effect of zilucoplan on fatigue in RAISE patients who entered RAISE-XT. We report change in Neuro-QoL Short Form Fatigue T-scores and fatigue severity levels from RAISE baseline to Week 60. RESULTS: Mean Neuro-QoL Short Form Fatigue T-scores improved from baseline to Week 12 in the zilucoplan group (n = 86) with a clinically meaningful difference versus placebo (n = 88; least squares mean difference: - 3.61 (nominal p-value = 0.0060]), and these improvements continued further to Week 60. At Week 12, more patients on zilucoplan (n = 34, 47.2%) experienced improvements in ≥ 1 fatigue severity level from baseline versus placebo (n = 23, 28.4%; p = 0.017). At Week 60, most (n = 55, 65.5%) patients had mild fatigue or none. CONCLUSION: Treatment with zilucoplan demonstrated statistical and clinically meaningful improvements in fatigue scores and severity versus placebo during RAISE, which were sustained to Week 60 in RAISE-XT.

Orai inhibition modulates pulmonary ILC2 metabolism and alleviates airway hyperreactivity in murine and humanized models.

Ca2+ entry via Ca2+ release-activated Ca2+ (CRAC) channels is a predominant mechanism of intracellular Ca2+ elevation in immune cells. Here we show the immunoregulatory role of CRAC channel components Orai1 and Orai2 in Group 2 innate lymphoid cells (ILC2s), that play crucial roles in the induction of type 2 inflammation. We find that blocking or genetic ablation of Orai1 and Orai2 downregulates ILC2 effector function and cytokine production, consequently ameliorating the development of ILC2-mediated airway inflammation in multiple murine models. Mechanistically, ILC2 metabolic and mitochondrial homeostasis are inhibited and lead to the upregulation of reactive oxygen species production. We confirm our findings in human ILC2s, as blocking Orai1 and Orai2 prevents the development of airway hyperreactivity in humanized mice. Our findings have a broad impact on the basic understanding of Ca2+ signaling in ILC2 biology, providing potential insights into the development of therapies for the treatment of allergic and atopic inflammatory diseases.

High-fat ketogenic diets and ketone monoester supplements differentially affect substrate metabolism during aerobic exercise.

Chronically adhering to high-fat ketogenic diets or consuming ketone monoester supplements elicits ketosis. Resulting changes in substrate metabolism appear to be drastically different between ketogenic diets and ketone supplements. Consuming a ketogenic diet increases fatty acid oxidation with concomitant decreases in endogenous carbohydrate oxidation. Increased fat oxidation eventually results in an accumulation of circulating ketone bodies, which are metabolites of fatty acids that serve as an alternative source of fuel. Conversely, consuming ketone monoester supplements rapidly increases circulating ketone body concentrations that typically exceed those achieved by adhering to ketogenic diets. Rapid increases in ketone body concentrations with ketone monoester supplementation elicit a negative feedback inhibition that reduces fatty acid mobilization during aerobic exercise. Supplement-derived ketosis appears to have minimal impact on sparing of muscle glycogen or minimizing of carbohydrate oxidation during aerobic exercise. This review will discuss the substrate metabolic and associated aerobic performance responses to ketogenic diets and ketone supplements.

Enhancing autophagy in CD11c+ antigen-presenting cells as a therapeutic strategy for acute respiratory distress syndrome.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe clinical disorders that mainly develop from viral respiratory infections, sepsis, and chest injury. Antigen-presenting cells play a pivotal role in propagating uncontrolled inflammation and injury through the excess secretion of pro-inflammatory cytokines and recruitment of immune cells. Autophagy, a homeostatic process that involves the degradation of cellular components, is involved in many processes including lung inflammation. Here, we use a polyinosinic-polycytidylic acid (poly(I:C))-induced lung injury mouse model to mimic viral-induced ALI/ARDS and show that disruption of autophagy in macrophages exacerbates lung inflammation and injury, whereas autophagy induction attenuates this process. Therefore, induction of autophagy in macrophages can be a promising therapeutic strategy in ALI/ARDS.

Telerehabilitation Initiated Early in Post-Stroke Recovery: A Feasibility Study.

BACKGROUND: Enhanced neural plasticity early after stroke suggests the potential to improve outcomes with intensive rehabilitation therapy. Most patients do not get such therapy, however, due to limited access, changing rehabilitation therapy settings, low therapy doses, and poor compliance. OBJECTIVE: To examine the feasibility, safety, and potential efficacy of an established telerehabilitation (TR) program after stroke initiated during admission to an inpatient rehabilitation facility (IRF) and completed in the patient's home. METHODS: Participants with hemiparetic stroke admitted to an IRF received daily TR targeting arm motor function in addition to usual care. Treatment consisted of 36, 70-minute sessions (half supervised by a licensed therapist via videoconference), over a 6-week period, that included functional games, exercise videos, education, and daily assessments. RESULTS: Sixteen participants of 19 allocated completed the intervention (age 61.3 ± 9.4 years; 6 female; baseline Upper Extremity Fugl-Meyer [UEFM] score 35.9 ± 6.4 points, mean ± SD; NIHSS score 4 (3.75, 5.25), median, IQR; intervention commenced 28.3 ± 13.0 days post-stroke). Compliance was 100%, retention 84%, and patient satisfaction 93%; 2 patients developed COVID-19 and continued TR. Post-intervention UEFM improvement was 18.1 ± 10.9 points (P < .0001); Box and Blocks, 22.4 ± 9.8 blocks (P = .0001). Digital motor assessments, acquired daily in the home, were concordant with these gains. The dose of rehabilitation therapy received as usual care during this 6-week interval was 33.9 ± 20.3 hours; adding TR more than doubled this to 73.6 ± 21.8 hours (P < .0001). Patients enrolled in Philadelphia could be treated remotely by therapists in Los Angeles. CONCLUSIONS: These results support feasibility, safety, and potential efficacy of providing intense TR therapy early after stroke. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov; NCT04657770.

Ketone Monoester Plus Carbohydrate Supplementation Does Not Alter Exogenous and Plasma Glucose Oxidation or Metabolic Clearance Rate During Exercise in Men Compared with Carbohydrate Alone.

BACKGROUND: Increasing ß-hydroxybutyrate (ßHB) availability through ketone monoester (KE) plus carbohydrate supplementation is suggested to enhance physical performance by sparing glucose use during exercise. However, no studies have examined the effect of ketone supplementation on glucose kinetics during exercise. OBJECTIVES: This exploratory study primarily aimed to determine the effect of KE plus carbohydrate supplementation on glucose oxidation during steady-state exercise and physical performance compared with carbohydrate alone. METHODS: Using a randomly assigned, crossover design, 12 men consumed 573 mg KE/kg body mass plus 110 g glucose (KE+CHO) or 110 g glucose (CHO) before and during 90 min of steady-state treadmill exercise [54 ± 3% peak oxygen uptake (V˙O2peak)] wearing a weighted vest (30% body mass; 25 ± 3 kg). Glucose oxidation and turnover were determined using indirect calorimetry and stable isotopes. Participants performed an unweighted time to exhaustion (TTE; 85% V˙O2peak) after steady-state exercise and a weighted (25 ± 3 kg) 6.4 km time trial (TT) the next day after consuming a bolus of KE+CHO or CHO. Data were analyzed by paired t-tests and mixed model ANOVA. RESULTS: ßHB concentrations were higher (P < 0.05) after exercise [2.1 mM (95% CI: 1.6, .6)] and the TT [2.6 mM (2.1, 3.1)] in KE+CHO compared with CHO. TTE was lower [-104 s (-201, -8)], and TT performance was slower [141 s (19,262)] in KE+CHO than in CHO (P < 0.05). Exogenous [-0.01 g/min (-0.07, 0.04)] and plasma [-0.02 g/min (-0.08, 0.04)] glucose oxidation and metabolic clearance rate {MCR [0.38 mg·kg-1·min-1 (-0.79, 1.54)]} were not different, and glucose rate of appearance [-0.51 mg·kg-1·min-1 (-0.97, -0.04)], and disappearance [-0.50 mg·kg-1·min-1 (-0.96, -0.04)] were lower (P < 0.05) in KE+CHO compared with CHO during steady-state exercise. CONCLUSIONS: In the current study, rates of exogenous and plasma glucose oxidation and MCR were not different between treatments during steady-state exercise, suggesting blood glucose utilization is similar between KE+CHO and CHO. KE+CHO supplementation also results in lower physical performance compared with CHO alone. This trial was registered at www. CLINICALTRIALS: gov as NCT04737694.

Cross-sectional imaging evaluation of atypical and uncommon extra-nodal head and neck Non-Hodgkin lymphoma: Case series.

Extra-nodal Non-Hodgkin lymphoma (ENHL) of the head and neck is not uncommon and has variable clinical and imaging presentations. It represents about 25% of extra-nodal lymphomas. In addition, lymphoma is the third most common malignancy of the head and neck just after squamous cell carcinoma (SCC) and salivary gland neoplasms. Unlike SCC, ENHL usually presents as a well-defined mass in the oral cavity, along the pharyngeal mucosa, sinonasal cavity, orbit, and other different neck spaces. One of the common presentations of ENHL is the glandular type which can arise within the salivary or thyroid glands as marginal zone non-Hodgkin lymphoma. ENHL can infiltrate the bone resembling high grade osseous malignancies. Rarely, ENHL can present as perineural spread without definitive mass and manifest clinically with several neuropathies. In this case series, we presented different imaging features and presentation of ENHL of the head and neck. The knowledge of various presentations of ENHL of the head and neck can help early diagnosis and prompt management of these patients' population.

Metabolic Adaptations and Substrate Oxidation are Unaffected by Exogenous Testosterone Administration during Energy Deficit in Men.

INTRODUCTION/PURPOSE: The effects of testosterone on energy and substrate metabolism during energy deficit are unknown. The objective of this study was to determine the effects of weekly testosterone enanthate (TEST; 200 mg·wk -1 ) injections on energy expenditure, energy substrate oxidation, and related gene expression during 28 d of energy deficit compared with placebo (PLA). METHODS: After a 14-d energy balance phase, healthy men were randomly assigned to TEST ( n = 24) or PLA ( n = 26) for a 28-d controlled diet- and exercise-induced energy deficit (55% below total energy needs by reducing energy intake and increasing physical activity). Whole-room indirect calorimetry and 24-h urine collections were used to measure energy expenditure and energy substrate oxidation during balance and deficit. Transcriptional regulation of energy and substrate metabolism was assessed using quantitative reverse transcription-polymerase chain reaction from rested/fasted muscle biopsy samples collected during balance and deficit. RESULTS: Per protocol design, 24-h energy expenditure increased ( P < 0.05) and energy intake decreased ( P < 0.05) in TEST and PLA during deficit compared with balance. Carbohydrate oxidation decreased ( P < 0.05), whereas protein and fat oxidation increased ( P < 0.05) in TEST and PLA during deficit compared with balance. Change (∆; deficit minus balance) in 24-h energy expenditure was associated with ∆activity factor ( r = 0.595), but not ∆fat-free mass ( r = 0.147). Energy sensing (PRKAB1 and TP53), mitochondria (TFAM and COXIV), fatty acid metabolism (CD36/FAT, FABP, CPT1b, and ACOX1) and storage (FASN), and amino acid metabolism (BCAT2 and BCKHDA) genes were increased ( P < 0.05) during deficit compared with balance, independent of treatment. CONCLUSIONS: These data demonstrate that increased physical activity and not exogenous testosterone administration is the primary determinate of whole-body and skeletal muscle metabolic adaptations during diet- and exercise-induced energy deficit.

Amputation for Complex Regional Pain Syndrome: Meta-Analysis and Validation of a Histopathology Scoring System.

OBJECTIVE: Pathology can provide crucial insights into the etiology of disease. The goal of this review is to evaluate the rigor of histopathology reports of Complex Regional Pain Syndrome (CRPS). METHODS: A systematic search of multiple databases identified papers that described amputation for CRPS with pathology findings. Control pathology articles were randomly chosen from the same journals. Landmark articles in Surgical Pathology were previously identified. Papers were categorized by the use of histology: Anatomic (microscopic description), Diagnostic (binary result), and Substrate (special studies only). A novel Histopathology Score assigned 1 point for each of 10 History elements and 15 Pathology elements. All articles were scored and analyzed by appropriate statistics. RESULTS: The search identified 22 CRPS, 50 Control and 50 Landmark articles. Multivariable analysis of the Pathology Score showed a significantly higher score for Anatomic vs Non-Anatomic papers (Incidence Rate Ratio (IRR) 1.54, P < .001) and Landmark vs CRPS articles (IRR 1.39, P value .003). CRPS papers reported some elements infrequently: diagnostic criteria (31.8%), routine stain (50%), any clinic-pathologic correlation (40.9%), and sample size >2 (27.3%). CONCLUSIONS: The Pathology Score is a useful quality assessment tool to evaluate studies. As expected, Anatomic papers scored significantly higher than Non-Anatomic papers. CRPS papers had small sample sizes (median 1) and infrequent reporting of diagnostic criteria, routine stain, any clinical pathologic correlation. These particular elements are crucial for analyzing and reviewing pathologic features. The analysis explains why it is quite difficult to write a meaningful systematic review of CRPS histology at this time.

Human PD-1 agonist treatment alleviates neutrophilic asthma by reprogramming T cells.

BACKGROUND: Neutrophilic asthma is associated with disease severity and corticosteroid insensitivity. Novel therapies are required to manage this life-threatening asthma phenotype. Programmed cell death protein-1 (PD-1) is a key homeostatic modulator of the immune response for T-cell effector functions. OBJECTIVE: We sought to investigate the role of PD-1 in the regulation of acute neutrophilic inflammation in a murine model of airway hyperreactivity (AHR). METHODS: House dust mite was used to induce and compare neutrophilic AHR in wild-type and PD-1 knockout mice. Then, the therapeutic potential of a human PD-1 agonist was tested in a humanized mouse model in which the PD-1 extracellular domain is entirely humanized. Single-cell RNA sequencing and flow cytometry were mainly used to investigate molecular and cellular mechanisms. RESULTS: PD-1 was highly induced on pulmonary T cells in our inflammatory model. PD-1 deficiency was associated with an increased neutrophilic AHR and high recruitment of inflammatory cells to the lungs. Consistently, PD-1 agonist treatment dampened AHR, decreased neutrophil recruitment, and modulated cytokine production in a humanized PD-1 mouse model. Mechanistically, we demonstrated at the transcriptional and protein levels that the inhibitory effect of PD-1 agonist is associated with the reprogramming of pulmonary effector T cells that showed decreased number and activation. CONCLUSIONS: PD-1 agonist treatment is efficient in dampening neutrophilic AHR and lung inflammation in a preclinical humanized mouse model.

Wound swabs versus biopsies to detect methicillin resistant Staphylococcus aureus in experimental equine wounds.

OBJECTIVE: To compare: (1) the load and diversity of cultivatable bacterial species isolated from tissue biopsies with cultures from surface swabs, and (2) the ability of each technique to detect methicillin-resistant Staphylococcus aureus (MRSA) in a model of MRSA-infected equine wounds. STUDY DESIGN: Experimental in vivo study. ANIMALS: Three light-breed adult horses. METHODS: Four 2.5 × 2.5 cm full-thickness skin wounds were created on the dorsolateral aspect of each forelimb. Five days later, each wound was inoculated with a pure culture of MRSA (ATCC 43300). One hundred microlitres of 0, 5 × 108 , 5 × 109 or 5 × 1010 colony forming units (CFU)/ml was used to inoculate each wound. Surface swabs (Levine technique) and tissue biopsy samples (3 mm punch biopsy) were obtained at 2, 7, 14, and 21 days after inoculation. Quantitative aerobic culture was performed using routine clinical techniques. RESULTS: A similar bacterial profile was identified from the culture of each wound-sampling technique and there was moderate correlation (R = 0.49, P < .001) between the bacterial bioburdens. Agreement was fair (κ = 0.31; 95% CI, 0.129-0.505) between the sampling techniques in identification of MRSA. Methicillin-resistant Staphylococcus aureus was isolated more frequently (P = .016) from cultures of tissue biopsies (79%; 76/96) than from surface swabs (62%; 60/96). CONCLUSION: Bacterial load and diversity did not differ between sampling techniques but MRSA was detected more often from the cultures of tissue biopsies. CLINICAL SIGNIFICANCE: Tissue biopsy should be preferred to culture swab in wounds where MRSA is suspected.

Carbohydrate intake in recovery from aerobic exercise differentiates skeletal muscle microRNA expression.

Posttranscriptional regulation by microRNA (miRNA) facilitates exercise and diet-induced skeletal muscle adaptations. However, the impact of diet on miRNA expression during postexercise recovery remains unclear. The objective of this study was to examine the effects of consuming carbohydrate or a nutrient-free control on skeletal muscle miRNA expression during 3 h of recovery from aerobic exercise. Using a randomized, crossover design, seven men (means ± SD, age: 21 ± 3 yr; body mass: 83 ± 13 kg; V̇o2peak: 43 ± 2 mL/kg/min) completed two-cycle ergometry glycogen depletion trials followed by 3 h of recovery while consuming either carbohydrate (CHO: 1 g/kg/h) or control (CON: nutrient free). Muscle biopsy samples were obtained under resting fasted conditions at baseline and at the end of the 3-h recovery (REC) period. miRNA expression was determined using unbiased RT-qPCR microarray analysis. Trials were separated by 7 days. Twenty-five miRNAs were different (P < 0.05) between CHO and CON at REC, with Let7i-5p and miR-195-5p being the most predictive of treatment. In vitro overexpression of Let7i-5p and miR-195-p5 in C2C12 skeletal muscle cells decreased (P < 0.05) the expression of protein breakdown (Foxo1, Trim63, Casp3, and Atf4) genes, ubiquitylation, and protease enzyme activity compared with control. Energy sensing (Prkaa1 and Prkab1) and glycolysis (Gsy1 and Gsk3b) genes were lower (P < 0.05) with Let7i-5p overexpression compared with miR-195-5p and control. Fat metabolism (Cpt1a, Scd1, and Hadha) genes were lower (P < 0.05) in miR-195-5p than in control. These data indicate that consuming CHO after aerobic exercise alters miRNA profiles compared with CON, and these differences may govern mechanisms facilitating muscle recovery.NEW & NOTEWORTHY Results provide novel insight into effects of carbohydrate intake on the expression of skeletal muscle microRNA during early recovery from aerobic exercise and reveal that Let7i-5p and miR-195-5p are important regulators of skeletal muscle protein breakdown to aid in facilitating muscle recovery.

PD-L2 controls peripherally induced regulatory T cells by maintaining metabolic activity and Foxp3 stability.

Regulatory T (Treg) cells are central to limit immune responses to allergens. Here we show that PD-L2 deficiency prevents the induction of tolerance to ovalbumin and control of airway hyperreactivity, in particular by limiting pTreg numbers and function. In vitro, PD-1/PD-L2 interactions increase iTreg numbers and stability. In mice lacking PD-L2 we find lower numbers of splenic pTregs at steady state, producing less IL-10 upon activation and with reduced suppressive activity. Remarkably, the numbers of splenic pTregs are restored by adoptively transferring PD-L2high dendritic cells to PD-L2KO mice. Functionally, activated pTregs lacking PD-L2 show lower Foxp3 expression, higher methylation of the Treg-Specific Demethylation Region (TSDR) and a decreased Tricarboxylic Acid (TCA) cycle associated with a defect in mitochondrial function and ATP production. Consequently, pyruvate treatment of PD-L2KO mice partially restores IL-10 production and airway tolerance. Together, our study highlights the importance of the PD-1/PD-L2 axis in the control of metabolic pathways regulating pTreg Foxp3 stability and suppressive functions, opening up avenues to further improve mucosal immunotherapy.

Testosterone undecanoate administration prevents declines in fat-free mass but not physical performance during simulated multi-stressor military operations.

Male military personnel conducting strenuous operations experience reduced testosterone concentrations, muscle mass, and physical performance. Pharmacological restoration of normal testosterone concentrations may attenuate performance decrements by mitigating muscle mass loss. Previously, administering testosterone enanthate (200 mg/wk) during 28 days of energy deficit prompted supraphysiological testosterone concentrations and lean mass gain without preventing isokinetic/isometric deterioration. Whether administering a practical dose of testosterone protects muscle and performance during strenuous operations is undetermined. The objective of this study was to test the effects of a single dose of testosterone undecanoate on body composition and military-relevant physical performance during a simulated operation. After a 7-day baseline phase (P1), 32 males (means ± SD; 77.1 ± 12.3 kg, 26.5 ± 4.4 yr) received a single dose of either testosterone undecanoate (750 mg; TEST) or placebo (PLA) before a 20-day simulated military operation (P2), followed by a 23-day recovery (P3). Assessments included body composition and physical performance at the end of each phase and circulating endocrine biomarkers throughout the study. Total and free testosterone concentrations in TEST were greater than PLA throughout most of P2 (P < 0.05), but returned to P1 values during P3. Fat-free mass (FFM) was maintained from P1 to P2 in TEST (means ± SE; 0.41 ± 0.65 kg, P = 0.53), but decreased in PLA (-1.85 ± 0.69 kg, P = 0.01) and recovered in P3. Regardless of treatment, total body mass and fat mass decreased from P1 to P2 (P < 0.05), but did not fully recover by P3. Physical performance decreased during P2 (P < 0.05) and recovered by P3, regardless of treatment. In conclusion, administering testosterone undecanoate before a simulated military operation protected FFM but did not prevent decrements in physical performance.NEW & NOTEWORTHY This study demonstrated that a single intramuscular dose of testosterone undecanoate (750 mg) administered to physically active males before a 20-day simulated, multi-stressor military operation increased circulating total and free testosterone concentrations within normal physiological ranges and spared FFM. However, testosterone administration did not attenuate decrements in physical performance across multiple measures of power, strength, anaerobic or aerobic capacity.

Effects of Testosterone on Mixed-Muscle Protein Synthesis and Proteome Dynamics During Energy Deficit.

CONTEXT: Effects of testosterone on integrated muscle protein metabolism and muscle mass during energy deficit are undetermined. OBJECTIVE: The objective was to determine the effects of testosterone on mixed-muscle protein synthesis (MPS), proteome-wide fractional synthesis rates (FSR), and skeletal muscle mass during energy deficit. DESIGN: This was a randomized, double-blind, placebo-controlled trial. SETTING: The study was conducted at Pennington Biomedical Research Center. PARTICIPANTS: Fifty healthy men. INTERVENTION: The study consisted of 14 days of weight maintenance, followed by a 28-day 55% energy deficit with 200 mg testosterone enanthate (TEST, n = 24) or placebo (PLA, n = 26) weekly, and up to 42 days of ad libitum recovery feeding. MAIN OUTCOME MEASURES: Mixed-MPS and proteome-wide FSR before (Pre), during (Mid), and after (Post) the energy deficit were determined using heavy water (days 1-42) and muscle biopsies. Muscle mass was determined using the D3-creatine dilution method. RESULTS: Mixed-MPS was lower than Pre at Mid and Post (P < 0.0005), with no difference between TEST and PLA. The proportion of individual proteins with numerically higher FSR in TEST than PLA was significant by 2-tailed binomial test at Post (52/67; P < 0.05), but not Mid (32/67; P > 0.05). Muscle mass was unchanged during energy deficit but was greater in TEST than PLA during recovery (P < 0.05). CONCLUSIONS: The high proportion of individual proteins with greater FSR in TEST than PLA at Post suggests exogenous testosterone exerted a delayed but broad stimulatory effect on synthesis rates across the muscle proteome during energy deficit, resulting in muscle mass accretion during subsequent recovery.

Effect of High-Protein Diets on Integrated Myofibrillar Protein Synthesis before Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Pilot Study.

Increasing dietary protein intake during periods of muscle disuse may mitigate the resulting decline in muscle protein synthesis (MPS). The purpose of this randomized pilot study was to determine the effect of increased protein intake during periods of disuse before anterior cruciate ligament (ACL) reconstruction on myofibrillar protein synthesis (MyoPS), and proteolytic and myogenic gene expression. Six healthy, young males (30 ± 9 y) were randomized to consume a high-quality, optimal protein diet (OP; 1.9 g·kg−1·d−1) or adequate protein diet (AP; 1.2 g·kg−1·d−1) for two weeks before ACL reconstruction. Muscle biopsies collected during surgery were used to measure integrated MyoPS during the intervention (via daily deuterium oxide ingestion) and gene expression at the time of surgery. MyoPS tended to be higher, with a large effect size in OP compared to AP (0.71 ± 0.1 and 0.54 ± 0.1%·d−1; p = 0.076; g = 1.56). Markers of proteolysis and myogenesis were not different between groups (p > 0.05); however, participants with greater MyoPS exhibited lower levels of MuRF1 gene expression compared to those with lower MyoPS (r = −0.82, p = 0.047). The data from this pilot study reveal a potential stimulatory effect of increased daily protein intake on MyoPS during injury-mediated disuse conditions that warrants further investigation.

Near-roadway air pollution, immune cells and adipokines among obese young adults.

BACKGROUND: Air pollution has been associated with metabolic disease and obesity. Adipokines are potential mediators of these effects, but studies of air pollution-adipokine relationships are inconclusive. Macrophage and T cells in adipose tissue (AT) and blood modulate inflammation; however, the role of immune cells in air pollution-induced dysregulation of adipokines has not been studied. We examined the association between air pollution exposure and circulating and AT adipokine concentrations, and whether these relationships were modified by macrophage and T cell numbers in the blood and AT. METHODS: Fasting blood and abdominal subcutaneous AT biopsies were collected from 30 overweight/obese 18-26 year-old volunteers. Flow cytometry was used to quantify T effector (Teff, inflammatory) and regulatory (Treg, anti-inflammatory) lymphocytes and M1 [inflammatory] and M2 [anti-inflammatory]) macrophage cell number. Serum and AT leptin and adiponectin were measured using enzyme-linked immunosorbent assay (ELISA). Exposure to near-roadway air pollution (NRAP) from freeway and non-freeway vehicular sources and to regional particulate matter, nitrogen dioxide and ozone were estimated for the year prior to biopsy, based on participants' residential addresses. Linear regression models were used to examine the association between air pollution exposures and adipokines and to evaluate effect modification by immune cell counts. RESULTS: An interquartile increase in non-freeway NRAP exposure during 1 year prior to biopsy was associated with higher leptin levels in both serum [31.7% (95% CI: 10.4, 52.9%)] and AT [19.4% (2.2, 36.6%)]. Non-freeway NRAP exposure effect estimates were greater among participants with greater than median Teff/Treg ratio and M1/M2 ratio in blood, and with greater M1 counts in AT. No adipokine associations with regional air pollutants were found. DISCUSSION: Our results suggest that NRAP may increase serum leptin levels in obese young adults, and this association may be promoted in a pro-inflammatory immune cell environment in blood and AT.

Autophagy impairment in liver CD11c+ cells promotes non-alcoholic fatty liver disease through production of IL-23.

There has been a global increase in rates of obesity with a parallel epidemic of non-alcoholic fatty liver disease (NAFLD). Autophagy is an essential mechanism involved in the degradation of cellular material and has an important function in the maintenance of liver homeostasis. Here, we explore the effect of Autophagy-related 5 (Atg5) deficiency in liver CD11c+ cells in mice fed HFD. When compared to control mice, Atg5-deficient CD11c+ mice exhibit increased glucose intolerance and decreased insulin sensitivity when fed HFD. This phenotype is associated with the development of NAFLD. We observe that IL-23 secretion is induced in hepatic CD11c+ myeloid cells following HFD feeding. We demonstrate that both therapeutic and preventative IL-23 blockade alleviates glucose intolerance, insulin resistance and protects against NAFLD development. This study provides insights into the function of autophagy and IL-23 production by hepatic CD11c+ cells in NAFLD pathogenesis and suggests potential therapeutic targets.