Architecture of the outbred brown fat proteome defines regulators of metabolic physiology.

Brown adipose tissue (BAT) regulates metabolic physiology. However, nearly all mechanistic studies of BAT protein function occur in a single inbred mouse strain, which has limited the understanding of generalizable mechanisms of BAT regulation over physiology. Here, we perform deep quantitative proteomics of BAT across a cohort of 163 genetically defined diversity outbred mice, a model that parallels the genetic and phenotypic variation found in humans. We leverage this diversity to define the functional architecture of the outbred BAT proteome, comprising 10,479 proteins. We assign co-operative functions to 2,578 proteins, enabling systematic discovery of regulators of BAT. We also identify 638 proteins that correlate with protection from, or sensitivity to, at least one parameter of metabolic disease. We use these findings to uncover SFXN5, LETMD1, and ATP1A2 as modulators of BAT thermogenesis or adiposity, and provide OPABAT as a resource for understanding the conserved mechanisms of BAT regulation over metabolic physiology.

Characterization of transcript enrichment and detection bias in single-nucleus RNA-seq for mapping of distinct human adipocyte lineages.

Single-cell RNA sequencing (scRNA-seq) enables molecular characterization of complex biological tissues at high resolution. The requirement of single-cell extraction, however, makes it challenging for profiling tissues such as adipose tissue, for which collection of intact single adipocytes is complicated by their fragile nature. For such tissues, single-nucleus extraction is often much more efficient and therefore single-nucleus RNA sequencing (snRNA-seq) presents an alternative to scRNA-seq. However, nuclear transcripts represent only a fraction of the transcriptome in a single cell, with snRNA-seq marked with inherent transcript enrichment and detection biases. Therefore, snRNA-seq may be inadequate for mapping important transcriptional signatures in adipose tissue. In this study, we compare the transcriptomic landscape of single nuclei isolated from preadipocytes and mature adipocytes across human white and brown adipocyte lineages, with whole-cell transcriptome. We show that snRNA-seq is capable of identifying the broad cell types present in scRNA-seq at all states of adipogenesis. However, we also explore how and why the nuclear transcriptome is biased and limited, as well as how it can be advantageous. We robustly characterize the enrichment of nuclear-localized transcripts and adipogenic regulatory lncRNAs in snRNA-seq, while also providing a detailed understanding for the preferential detection of long genes upon using this technique. To remove such technical detection biases, we propose a normalization strategy for a more accurate comparison of nuclear and cellular data. Finally, we show successful integration of scRNA-seq and snRNA-seq data sets with existing bioinformatic tools. Overall, our results illustrate the applicability of snRNA-seq for the characterization of cellular diversity in the adipose tissue.

Pain control in thoracic oncology.

This review of pain management in lung cancer is based on the presentation of four cases of thoracic oncology patients with pain at various stages of their disease. The approach will be multidisciplinary, involving a thoracic oncologist, radiologist, thoracic and orthopaedic spine surgeon, radiation therapist, pain medicine specialist, and palliative care specialist. This multispecialty approach to the management of different painful presentations in thoracic oncology will demonstrate the complexity of each case and the improved patient outcomes which result from the involvement of different disciplines working in concert.In the USA, Europe and other countries, palliative care specialists often become rapidly involved in the management of these patients, coordinating social care and providing psychological support.Thoracic and orthopaedic spine subspecialists provide surgical methods to control tumour invasion, and improve quality of life and preservation of function in settings of even diffuse metastatic disease. Similarly, thoracic oncology and radiation therapists utilise both therapeutic and palliative chemotherapeutic and radiation therapy regimens to prolong and improve quality of life.The pain medicine specialist can, in addition to medication management, offer a variety of interventional approaches including unique drug delivery systems such as epidural analgesia, regional anaesthesia techniques, and intrathecal pumps, as well as neuromodulation techniques and neurolytic or neuroablative procedures.In the USA, these specialists complete an additional fellowship year in pain medicine following the completion of an anaesthesiology, physical medicine and rehabilitation, neurology or psychiatry residency. These programmes are accredited by the Accreditation Council for Graduate Medical Education, or ACGME (www.acgme.org).

MicroRNA-455 regulates brown adipogenesis via a novel HIF1an-AMPK-PGC1α signaling network.

Brown adipose tissue (BAT) dissipates chemical energy as heat and can counteract obesity. MicroRNAs are emerging as key regulators in development and disease. Combining microRNA and mRNA microarray profiling followed by bioinformatic analyses, we identified miR-455 as a new regulator of brown adipogenesis. miR-455 exhibits a BAT-specific expression pattern and is induced by cold and the browning inducer BMP7. In vitro gain- and loss-of-function studies show that miR-455 regulates brown adipocyte differentiation and thermogenesis. Adipose-specific miR-455 transgenic mice display marked browning of subcutaneous white fat upon cold exposure. miR-455 activates AMPKα1 by targeting HIF1an, and AMPK promotes the brown adipogenic program and mitochondrial biogenesis. Concomitantly, miR-455 also targets the adipogenic suppressors Runx1t1 and Necdin, initiating adipogenic differentiation. Taken together, the data reveal a novel microRNA-regulated signaling network that controls brown adipogenesis and may be a potential therapeutic target for human metabolic disorders.

Trans-cranial motor evoked potential detection of femoral nerve injury in trans-psoas lateral lumbar interbody fusion.

Trans-psoas lateral lumbar interbody fusion (LLIF) is frequently associated with neurological complications, limiting its value as a less invasive procedure. The routine use of EMG neuromonitoring has been inadequate to detect iatrogenic injuries; significant postoperative deficits have gone undetected by EMG. An effective way to monitor for these intraoperative neurological events is not yet well established. To our knowledge, detection of lumbar plexus injury during LLIF by trans-cranial motor evoked potentials (MEP) without corresponding change in EMG has not been reported in the literature. Three cases are presented to illustrate the potential utility of trans-cranial MEP monitoring during trans-psoas LLIF. We introduce a modified intraoperative neuro-monitoring (IONM) protocol for LLIF surgery, which includes MEP in addition to spontaneous and triggered EMG. Postoperative neurological outcome was correlated with the IONM findings. In each case, loss of quadriceps MEP signals occurred during LLIF at L4/L5, and after prolonged retraction (27, 25 and 61 min respectively). The EMG, however, did not show any abnormal activity. Two patients had post-operative quadriceps weakness, concordant with MEP data. The third patient, in whom the MEP signals returned to normal after expeditious removal of the retractor, did not exhibit quadriceps weakness, also concordant with MEP data. These cases contribute to the developing perception that stand-alone EMG nerve monitoring is not adequate for trans-psoas surgery. The addition of MEP may improve the sensitivity of IONM during trans-psoas surgery. Multimodality IONM may offer the opportunity to intervene on evolving iatrogenic nerve injuries, and may reduce the incidence of adverse postoperative findings.

ADRA1A-Gαq signalling potentiates adipocyte thermogenesis through CKB and TNAP.

Noradrenaline (NA) regulates cold-stimulated adipocyte thermogenesis1. Aside from cAMP signalling downstream of ß-adrenergic receptor activation, how NA promotes thermogenic output is still not fully understood. Here, we show that coordinated α1-adrenergic receptor (AR) and ß3-AR signalling induces the expression of thermogenic genes of the futile creatine cycle2,3, and that early B cell factors, oestrogen-related receptors and PGC1α are required for this response in vivo. NA triggers physical and functional coupling between the α1-AR subtype (ADRA1A) and Gαq to promote adipocyte thermogenesis in a manner that is dependent on the effector proteins of the futile creatine cycle, creatine kinase B and tissue-non-specific alkaline phosphatase. Combined Gαq and Gαs signalling selectively in adipocytes promotes a continual rise in whole-body energy expenditure, and creatine kinase B is required for this effect. Thus, the ADRA1A-Gαq-futile creatine cycle axis is a key regulator of facultative and adaptive thermogenesis.

Walking Biomechanics and Spine Loading in Patients With Symptomatic Lumbar Spinal Stenosis.

Symptomatic lumbar spinal stenosis is a leading cause of pain and mobility limitation in older adults. It is clinically believed that patients with lumbar spinal stenosis adopt a flexed trunk posture or bend forward and alter their gait pattern to improve tolerance for walking. However, a biomechanical assessment of spine posture and motion during walking is broadly lacking in these patients. The purpose of this study was to evaluate lumbar spine and pelvic sagittal angles and lumbar spine compressive loads in standing and walking and to determine the effect of pain and neurogenic claudication symptoms in patients with symptomatic lumbar spinal stenosis. Seven participants with symptomatic lumbar spinal stenosis, aged 44-82, underwent a 3D opto-electronic motion analysis during standing and walking trials in asymptomatic and symptomatic states. Passive reflective marker clusters (four markers each) were attached to participants at T1, L1, and S2 levels of the spine, with additional reflective markers at other spinal levels, as well as the head, pelvis, and extremities. Whole-body motion data was collected during standing and walking trials in asymptomatic and symptomatic states. The results showed that the spine was slightly flexed during walking, but this was not affected by symptoms. Pelvic tilt was not different when symptoms were present, but suggests a possible effect of more forward tilt in both standing (p = 0.052) and walking (p = 0.075). Lumbar spine loading during symptomatic walking was increased by an average of 7% over asymptomatic walking (p = 0.001). Our results did not show increased spine flexion (adopting a trunk-flexed posture) and only indicate a trend for a small forward shift of the pelvis during both symptomatic walking and standing. This suggests that provocation of symptoms in these patients does not markedly affect their normal gait kinematics. The finding of increased spine loading with provocation of symptoms supports our hypothesis that spine loading plays a role in limiting walking function in patients with lumbar spinal stenosis, but additional work is needed to understand the biomechanical cause of this increase.

Comparison of 5766 vertebral compression fractures treated with or without kyphoplasty.

BACKGROUND: The majority of the 700,000 osteoporotic vertebral compression fractures (VCFs) that occur annually in the United States affect women. The total treatment costs exceed $17 billion and approximate the total costs of breast cancer ($13 billion) and heart disease ($19 billion). Balloon-assisted percutaneous vertebral augmentation with bone cement (kyphoplasty) reportedly reduces VCF-related pain and accelerates return of independent functional mobility. Kyphoplasty may decrease overall cost of VCF treatment costs by reducing use of posttreatment medical resources. QUESTIONS/PURPOSES: We evaluated complications, mortality, posthospital disposition, and treatment costs of kyphoplasty compared with nonoperative treatment using the Nationwide Inpatient Sample database. METHODS: We identified 5766 VCFs (71% female) in patients 65 years of age or older with nonneoplastic VCF as the primary diagnosis in nonroutine hospital admissions; 15.3% underwent kyphoplasty. Demographic data, medical comorbidities, and fracture treatment type were recorded. Outcomes, including complications, mortality, posthospital disposition, and treatment costs, were compared for each treatment type. RESULTS: Women were more likely to be treated with kyphoplasty than were men. Patients undergoing kyphoplasty had comorbidity indices equivalent to those treated nonoperatively. Kyphoplasty was associated with a greater likelihood of routine discharge to home (38.4% versus 21.0% for nonoperative treatment), a lower rate of discharge to skilled nursing (26.1% versus 34.8%) or other facilities (35.7% versus 47.1%), a complication rate equivalent to nonoperative treatment (1.7% versus 1.0%), and a lower rate of in-hospital mortality (0.3% versus 1.6%). Kyphoplasty was associated with higher cost of hospitalization (mean $37,231 versus $20,112). CONCLUSIONS: Kyphoplasty for treatment of VCF in well-selected patients may accelerate the return of independent patient function as indicated by improved measures of hospital discharge. The initially higher cost of treatment may be offset by the reduced use of posthospital medical resources. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Validity of flexicurve and motion capture for measurements of thoracic kyphosis vs standing radiographic measurements.

Thoracic kyphosis varies among healthy adults and typically increases with age. Excessive kyphosis (hyperkyphosis) is associated with negative health. Spinal alignment also affects spine loading, with implications for conditions such as vertebral fractures and back pain. Valid measurements of kyphosis are necessary for clinical and research assessment of age-related posture changes, and to support improved biomechanical understating of spine conditions. Independent validation of non-radiographic techniques, however, remains limited. The goal of this study was to compare standing radiographic kyphosis measurements with non-radiographic measurements and predictions of thoracic kyphosis using flexicurve and motion analysis markers, in order to determine their validity. Thirteen non-radiographic measures of thoracic kyphosis were obtained in each of 40 adult subjects who also underwent standing radiographs of the thoracic spine. Measures included estimates derived by fitting of polynomials or circles to the non-radiographic data, as well as predictions calculated using previously published methods. Intra-class correlations (ICC) and root-mean square errors (RMSEs) were calculated between radiographic and non-radiographic measures to determine validity. Most non-radiographic estimates of kyphosis show similar, weak to moderate levels of validity when compared to radiographic measurements, and RMSEs ranging from 8.0° to 20.8°. Unbiased estimates of radiographic measurements with moderate to good ICCs were identified, however, based on marker measurements, and new prediction equations were created with similar validity that also account for age and body habitus. Clinical significance: These non-radiographic measurements of thoracic kyphosis can be applied to clinical practice or to clinical studies with recognition of specific limitations.

Current Strategies for Reconstruction of Soft Tissue Defects of the Spine.

Spinal surgery has been revolutionized by advances in instrumentation, bone graft substitutes, and perioperative care. Extensive dissection, creation of large areas of dead space, and the use of instrumentation in compromised patients, however, predisposes to high rates of wound complications. Postoperative wound complications in patients undergoing complex spinal surgery can have devastating sequelae, including hardware exposure, meningitis, and unplanned reoperation. Recognition of high-risk patients and prediction of wound closure difficulties, combined with preemptive reconstructive surgical strategies may prevent complications. The purpose of this review is to discuss the principles of spine wound management and provide a synopsis of the soft tissue reconstructive strategies utilized in spinal surgery. We review the senior author's preferred reconstructive algorithm for the management of these complex wounds, in addition to outcomes data relating to the timing of reconstructive surgery.

Between-session reliability of opto-electronic motion capture in measuring sagittal posture and 3-D ranges of motion of the thoracolumbar spine.

This study evaluated between-session reliability of opto-electronic motion capture to measure trunk posture and three-dimensional ranges of motion (ROM). Nineteen healthy participants aged 24-74 years underwent spine curvature, pelvic tilt and trunk ROM measurements on two separate occasions. Rigid four-marker clusters were attached to the skin overlying seven spinous processes, plus single markers on pelvis landmarks. Rigid body rotations of spine marker clusters were calculated to determine neutral posture and ROM in flexion, extension, total lateral bending (left-right) and total axial rotation (left-right). Segmental spine ROM values were in line with previous reports using opto-electronic motion capture. Intraclass correlation coefficients (ICC) and standard error of measurement (SEM) were calculated as measures of between-session reliability and measurement error, respectively. Retroreflective markers showed fair to excellent between-session reliability to measure thoracic kyphosis, lumbar lordosis, and pelvic tilt (ICC = 0.82, 0.63, and 0.54, respectively). Thoracic and lumbar segments showed highest reliabilities in total axial rotation (ICC = 0.78) and flexion-extension (ICC = 0.77-0.79) ROM, respectively. Pelvic segment showed highest ICC values in flexion (ICC = 0.78) and total axial rotation (ICC = 0.81) trials. Furthermore, it was estimated that four or fewer repeated trials would provide good reliability for key ROM outcomes, including lumbar flexion, thoracic and lumbar lateral bending, and thoracic axial rotation. This demonstration of reliability is a necessary precursor to quantifying spine kinematics in clinical studies, including assessing changes due to clinical treatment or disease progression.

Incineration of Nanoclay Composites Leads to Byproducts with Reduced Cellular Reactivity.

Addition of nanoclays into a polymer matrix leads to nanocomposites with enhanced properties to be used in plastics for food packaging applications. Because of the plastics' high stored energy value, such nanocomposites make good candidates for disposal via municipal solid waste plants. However, upon disposal, increased concerns related to nanocomposites' byproducts potential toxicity arise, especially considering that such byproducts could escape disposal filters to cause inhalation hazards. Herein, we investigated the effects that byproducts of a polymer polylactic acid-based nanocomposite containing a functionalized montmorillonite nanoclay (Cloisite 30B) could pose to human lung epithelial cells, used as a model for inhalation exposure. Analysis showed that the byproducts induced toxic responses, including reductions in cellular viability, changes in cellular morphology, and cytoskeletal alterations, however only at high doses of exposure. The degree of dispersion of nanoclays in the polymer matrix appeared to influence the material characteristics, degradation, and ultimately toxicity. With toxicity of the byproduct occurring at high doses, safety protocols should be considered, along with deleterious effects investigations to thus help aid in safer, yet still effective products and disposal strategies.

Predictors of Hospital Length of Stay and 30-Day Readmission in Cervical Spondylotic Myelopathy Patients: An Analysis of 3057 Patients Using the ACS-NSQIP Database.

BACKGROUND: Hospital length of stay (LOS), 30-day readmission rate, and other metrics are increasingly being used to evaluate quality of surgical care. The factors most relevant to cervical spondylotic myelopathy (CSM) are not yet established. OBJECTIVE: To identify perioperative factors associated with extended LOS and 30-day readmission following elective surgery for CSM. METHODS: Surgical CSM patients at institutions represented by the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) during 2010-2012 were included. Patients with fracture, 9 or more levels fused, or cancer were excluded. Extended LOS was defined as 75th percentile of the cohort. Univariate analysis and multivariate logistic regression identified predictors for extended LOS, 30-day readmission, and reoperation. Linear regression modeling was used to evaluate variables. RESULTS: Three thousand fifty-seven surgical CSM cases were isolated. Age (odds ratio [OR], 1.496), diabetes (OR, 1.691), American Society of Anesthesiologists (ASA) class (OR, 2.081), posterior surgical approach (OR, 2.695), and operative time (OR, 1.008) were all positive predictors (P < 0.05) for extended LOS (≥4 days). Thirty-two percent of the cohort (976 patients) had 30-day readmission data. Among these, 915 patients were not readmitted (93.8%), while 61 (6.2%) were readmitted. Diabetes (OR, 1.460) and ASA class (OR, 2.539) were significant positive predictors for hospital readmission. Age (OR, 0.918) was a negative predictor of re-operation in readmitted patients, and pulmonary comorbidities (OR, 4.584) were a positive predictor (P < 0.05). CONCLUSIONS: Patients with diabetes and higher ASA class were at increased risk for extended LOS and readmission within 30-days. Patients with increased operative time have greater risk for extended LOS. Preoperative pulmonary comorbidities increased reoperation risk, whereas increased age reduced the risk. Attention to these factors may benefit CSM patients.

The impact of mental health on patient-reported outcomes in cervical radiculopathy or myelopathy surgery.

Optimizing functional outcomes and disability status are essential for effective surgical treatment of cervical spine disorders. Mental impairment is common among patients with cervical spine complaints; yet little is known about the impact of baseline mental status with respect to overall patient-reported outcomes. This was a retrospective analysis of patients with cervical spondylosis with myelopathy(CM) or radiculopathy(CR: cervical disc herniation, stenosis, or spondylosis without myelopathy) at 2-year follow-ups. Patients were assessed for several health-related quality of life HRQOL) measures at baseline and 24-months post-operatively: Neck Disability Index (NDI), Visual Analog Scale(VAS), Short Form-36(SF) Physical(PCS) and Mental(MCS) Components. Patients were dichotomized by MCS score: LOW-MCS(SF-MCS < 40th percentile) vs. HIGH-MCS(SF-MCS > 60th percentile). Independent and paired t-tests compared improvement in each group for HIGH-MCS and LOW-MCS cohorts. 375 patients were analyzed(65.4yrs, 67.6%F). LOW-MCS radiculopathy patients showed significant improvement in NDI, VAS Neck and Arm Pain(p < 0.05). HIGH-MCS radiculopathy patients showed greater improvement in NDI score, VAS Neck and Arm Pain, and improvement in PCS(all p < 0.05). Comparing baseline and 2-year follow-up, LOW-MCS CM patients showed significant improvement in PCS, NDI, VAS Neck and Arm Pain(p < 0.05). HIGH-MCS myelopathy patients group showed marked improvement in NDI scores, VAS Neck and Arm Pain(p < 0.05). LOW-MCS CR patients were more likely to be less satisfied 2-years post-op(p < 0.001). Postoperative CR patients with lower baseline mental status saw less improvement and significantly worse outcomes than patients with higher baseline mental status. Improving baseline mental health may improve post-operative recovery. Implementing additional screening and care can optimize functional outcomes and disability status for patients with CR.

Invasiveness Index as a Predictor of Surgical Site Infection after Spinal Fusion, Revision Fusion, or Laminectomy.

OBJECTIVE To evaluate invasiveness index as a potential predictor of spine surgical site infection (SSI) after spinal fusion, revision fusion, or laminectomy. DESIGN Retrospective cohort study. SETTING Single, large, academic medical center. PATIENTS Adults undergoing spinal fusion, revision fusion, or laminectomy. METHODS Data were obtained from electronic hospital databases; cases of SSI were extracted from the infection control database using National Healthcare Safety Network (NHSN) definitions. For each case, an invasiveness index, determined by surgical approach, procedure, and number of spine levels treated, was calculated using current procedural terminology (CPT) billing codes. Statistical analyses were performed using univariate and multivariate logistic regression models. RESULTS In total, 3,143 patients met inclusion criteria, and 43 of these developed SSI. Multivariate regression showed that advanced age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.005-1.05, for each year of life) and invasiveness index (medium invasiveness index OR, 5.36; 95% CI, 1.92-14.96; high invasiveness index OR, 14.1; 95% CI, 4.38-45.43) were significant predictors of infection. In subgroup analyses of spinal fusion patients, morbid obesity (OR, 2.542; 95% CI, 1.08-5.99), trauma (OR, 2.41; 95% CI, 1.05-5.55), and invasiveness index (medium invasiveness index OR, 5.39; 95% CI, 1.56-18.61; high invasiveness index OR, 13.44; 95% CI, 3.28-55.01) were significant predictors of SSI. Models containing invasiveness index were compared to NHSN models and demonstrated similar performance. CONCLUSIONS Invasiveness index is a predictor of SSI after spinal fusion and performs similarly to NHSN models. Invasiveness index shows promise as a potential risk stratification tool that is easily calculated and is available preoperatively. Infect Control Hosp Epidemiol 2016:1-7.

Early Assessment and Correlations of Nanoclay's Toxicity to Their Physical and Chemical Properties.

Nanoclays' functionalization with organic modifiers increases their individual barrier properties, thermal stability, and mechanical properties and allows for ease of implementation in food packaging materials or medical devices. Previous reports have shown that, while organic modifiers integration between the layered mineral silicates leads to nanoclays with different degrees of hydrophobicity that become easily miscible in polymers, they could also pose possible effects at inhalation or ingestion routes of exposure. Through a systematic analysis of three organically modified and one pristine nanoclay, we aimed to relate for the first time the physical and chemical characteristics, determined via microscopical and spectroscopical techniques, with the potential of these nanoclays to induce deleterious effects in in vitro cellular systems, i.e. in immortalized and primary human lung epithelial cell lines. To derive information on how functionalization could lead to toxicological profiles throughout nanoclays' life cycle, both as-received and thermally degraded nanoclays were evaluated. Our analysis showed that the organic modifiers chemical composition influenced both the physical and chemical characteristics of the nanoclays as well as their toxicity. Overall, when cells were exposed to nanoclays with organic modifiers containing bioreactive groups, they displayed lower cellular numbers as well more elongated cellular morphologies relative to the pristine nanoclay and the nanoclay containing a modifier with long carbon chains. Additionally, thermal degradation caused loss of the organic modifiers as well as changes in size and shape of the nanoclays, which led to changes in toxicity upon exposure to our model cellular systems. Our study provides insight into the synergistic effects of chemical composition, size, and shape of the nanoclays and their toxicological profiles in conditions that mimic exposure in manufacturing and disposal environments, respectively, and can help aid in safe-by-design manufacturing of nanoclays with user-controlled functionalization and lower toxicity levels when food packaging applications are considered.

Optical visualisation of thermogenesis in stimulated single-cell brown adipocytes.

The identification of brown adipose deposits in adults has led to significant interest in targeting this metabolically active tissue for treatment of obesity and diabetes. Improved methods for the direct measurement of heat production as the signature function of brown adipocytes (BAs), particularly at the single cell level, would be of substantial benefit to these ongoing efforts. Here, we report the first application of a small molecule-type thermosensitive fluorescent dye, ERthermAC, to monitor thermogenesis in BAs derived from murine brown fat precursors and in human brown fat cells differentiated from human neck brown preadipocytes. ERthermAC accumulated in the endoplasmic reticulum of BAs and displayed a marked change in fluorescence intensity in response to adrenergic stimulation of cells, which corresponded to temperature change. ERthermAC fluorescence intensity profiles were congruent with mitochondrial depolarisation events visualised by the JC-1 probe. Moreover, the averaged fluorescence intensity changes across a population of cells correlated well with dynamic changes such as thermal power, oxygen consumption, and extracellular acidification rates. These findings suggest ERthermAC as a promising new tool for studying thermogenic function in brown adipocytes of both murine and human origins.

NFIA co-localizes with PPARγ and transcriptionally controls the brown fat gene program.

Brown fat dissipates energy as heat and protects against obesity. Here, we identified nuclear factor I-A (NFIA) as a transcriptional regulator of brown fat by a genome-wide open chromatin analysis of murine brown and white fat followed by motif analysis of brown-fat-specific open chromatin regions. NFIA and the master transcriptional regulator of adipogenesis, PPARγ, co-localize at the brown-fat-specific enhancers. Moreover, the binding of NFIA precedes and facilitates the binding of PPARγ, leading to increased chromatin accessibility and active transcription. Introduction of NFIA into myoblasts results in brown adipocyte differentiation. Conversely, the brown fat of NFIA-knockout mice displays impaired expression of the brown-fat-specific genes and reciprocal elevation of muscle genes. Finally, expression of NFIA and the brown-fat-specific genes is positively correlated in human brown fat. These results indicate that NFIA activates the cell-type-specific enhancers and facilitates the binding of PPARγ to control the brown fat gene program.

Effect of daily parathyroid hormone (1-34) on lumbar fusion in a rat model.

BACKGROUND CONTEXT: Despite numerous studies evaluating the anabolic effects of intermittent administration of parathyroid hormone (PTH) on bone, there are no published studies examining its effect on spinal fusion outcomes. PURPOSE: To determine the effect of daily injection of human recombinant PTH(1-34) on posterolateral lumbar fusions in a rat model. STUDY DESIGN: Prospective, case-controlled, preclinical animal study. OUTCOME MEASURES: Manual palpation and serum osteocalcin. METHODS: Single-level, intertransverse process spinal fusions were performed with iliac crest autograft in 56 Sprague-Dawley rats. Animals received daily injections of placebo or PTH(1-34). At 6 weeks, fusion masses were assessed by manual palpation. Serum osteocalcin levels were assessed in a subset of the animals. RESULTS: Manual palpation revealed the control group to have a fusion rate of 37% (10/27) and the PTH(1-34)-treated group to have a fusion rate of 52% (15/29). Mean serum osteocalcin levels were 59.8 and 88.6 ng/L for the control and PTH(1-34) groups, respectively. CONCLUSIONS: There was a trend towards greater fusion rate in the PTH(1-34) group as compared with the placebo group. Further, PTH(1-34) administration was associated with a significant increase in osteocalcin levels. Certainly, further investigations are warranted, as an injectable agent capable of increasing fusion rates would be of great clinical value.