Intravitreally injected anti-VEGF antibody reduces brown fat in neonatal mice

Anti-vascular endothelial growth factor (VEGF) agents are the mainstay treatment for various angiogenesis-related retinal diseases. Currently, bevacizumab, a recombinant humanized anti-VEGF antibody, is trailed in retinopathy of prematurity, a vasoproliferative retinal disorder in premature infants. However, the risks of systemic complications after intravitreal injection of anti-VEGF antibody in infants are not well understood. In this study, we show that intravitreally injected anti-VEGF antibody is transported into the systemic circulation into the periphery where it reduces brown fat in neonatal C57BL/6 mice. A considerable amount of anti-VEGF antibody was detected in serum after intravitreal injection. Furthermore, in interscapular brown adipose tissue, we found lipid droplet accumulation, decreased VEGF levels, loss of vascular network, and decreased expression of mitochondriarelated genes, Ppargc1a and Ucp1, all of which are characteristics of "whitening" of brown fat. With increasing age and body weight, brown fat restored its morphology and vascularity. Our results show that there is a transient, but significant impact of intravitreally administered anti-VEGF antibody on brown adipose tissue in neonatal mice. We suggest that more attention should be focused on the metabolic and developmental significance of brown adipose tissue in bevacizumab treated retinopathy of prematurity infants. Copyright

BCAA catabolism in brown fat controls energy homeostasis through SLC25A44.

Branched-chain amino acid (BCAA; valine, leucine and isoleucine) supplementation is often beneficial to energy expenditure; however, increased circulating levels of BCAA are linked to obesity and diabetes. The mechanisms of this paradox remain unclear. Here we report that, on cold exposure, brown adipose tissue (BAT) actively utilizes BCAA in the mitochondria for thermogenesis and promotes systemic BCAA clearance in mice and humans. In turn, a BAT-specific defect in BCAA catabolism attenuates systemic BCAA clearance, BAT fuel oxidation and thermogenesis, leading to diet-induced obesity and glucose intolerance. Mechanistically, active BCAA catabolism in BAT is mediated by SLC25A44, which transports BCAAs into mitochondria. Our results suggest that BAT serves as a key metabolic filter that controls BCAA clearance via SLC25A44, thereby contributing to the improvement of metabolic health

TonEBP/NFAT5 promotes obesity and insulin resistance by epigenetic suppression of white adipose tissue beiging

Tonicity-responsive enhancer binding protein (TonEBP or NFAT5) is a regulator of cellular adaptation to hypertonicity, macrophage activation and T-cell development. Here we report that TonEBP is an epigenetic regulator of thermogenesis and obesity. In mouse subcutaneous adipocytes, TonEBP expression increases > 50-fold in response to high-fat diet (HFD) feeding. Mice with TonEBP haplo-deficiency or adipocyte-specific TonEBP deficiency are resistant to HFD-induced obesity and metabolic defects (hyperglycemia, hyperlipidemia, and hyperinsulinemia). They also display increased oxygen consumption, resistance to hypothermia, and beiging of subcutaneous fat tissues. TonEBP suppresses the promoter of beta 3-adrenoreceptor gene, a critical regulator of lipolysis and thermogenesis, in ex vivo and cultured adipocytes. This involves recruitment of DNMT1 DNA methylase and methylation of the promoter. In human subcutaneous adipocytes TonEBP expression displays a correlation with body mass index but an inverse correlation with beta 3-adrenoreceptor expression. Thus, TonEBP is an attractive therapeutic target for obesity, insulin resistance, and hyperlipidemia

Low temperature exposure induces browning of bone marrow stem cell derived adipocytes in vitro

Brown and beige adipocytes are characterised as expressing the unique mitochondrial uncoupling protein (UCP)1 for which the primary stimulus in vivo is cold exposure. The extent to which cold-induced UCP1 activation can also be achieved in vitro, and therefore perform a comparable cellular function, is unknown. We report an in vitro model to induce adipocyte browning using bone marrow (BM) derived mesenchymal stem cells (MSC), which relies on differentiation at 32°C instead of 37°C. The low temperature promoted browning in adipogenic cultures, with increased adipocyte differentiation and upregulation of adipogenic and thermogenic factors, especially UCP1. Cells exhibited enhanced uncoupled respiration and metabolic adaptation. Cold-exposed differentiated cells showed a marked translocation of leptin to adipocyte nuclei, suggesting a previously unknown role for leptin in the browning process. These results indicate that BM-MSC can be driven to forming beige-like adipocytes in vitro by exposure to a reduced temperature. This in vitro model will provide a powerful tool to elucidate the precise role of leptin and related hormones in hitherto functions in the browning process

Elevated [11C]-D-Deprenyl Uptake in Chronic Whiplash Associated Disorder Suggests Persistent Musculoskeletal Inflammation

There are few diagnostic tools for chronic musculoskeletal pain as structural imaging methods seldom reveal pathological alterations. This is especially true for Whiplash Associated Disorder, for which physical signs of persistent injuries to the neck have yet to be established. Here, we sought to visualize inflammatory processes in the neck region by means Positron Emission Tomography using the tracer 11C-D-deprenyl, a potential marker for inflammation. Twenty-two patients with enduring pain after a rear impact car accident (Whiplash Associated Disorder grade II) and 14 healthy controls were investigated. Patients displayed significantly elevated tracer uptake in the neck, particularly in regions around the spineous process of the second cervical vertebra. This suggests that whiplash patients have signs of local persistent peripheral tissue inflammation, which may potentially serve as a diagnostic biomarker. The present investigation demonstrates that painful processes in the periphery can be objectively visualized and quantified with PET and that 11C-D-deprenyl is a promising tracer for these purposes

Non-Invasive Quantification of White and Brown Adipose Tissues and Liver Fat Content by Computed Tomography in Mice

OBJECTIVES: Obesity and its distribution pattern are important factors for the prediction of the onset of diabetes in humans. Since several mouse models are suitable to study the pathophysiology of type 2 diabetes the aim was to validate a novel computed tomograph model (Aloka-Hitachi LCT-200) for the quantification of visceral, subcutaneous, brown and intrahepatic fat depots in mice. METHODS: Different lean and obese mouse models (C57BL/6, B6.V-Lep(ob), NZO) were used to determine the most adequate scanning parameters for the detection of the different fat depots. The data were compared with those obtained after preparation and weighing the fat depots. Liver fat content was determined by biochemical analysis. RESULTS: The correlations between weights of fat tissues on scale and weights determined by CT were significant for subcutaneous (r(2) = 0.995), visceral (r(2) = 0.990) and total white adipose tissue (r(2) = 0.992). Moreover, scans in the abdominal region, between lumbar vertebrae L4 to L5 correlated with whole-body fat distribution allowing experimenters to reduce scanning time and animal exposure to radiation and anesthesia. Test-retest reliability and measurements conducted by different experimenters showed a high reproducibility in the obtained results. Intrahepatic fat content estimated by CT was linearly related to biochemical analysis (r(2) = 0.915). Furthermore, brown fat mass correlated well with weighted brown fat depots (r(2) = 0.952). In addition, short-term cold-expose (4 °C, 4 hours) led to alterations in brown adipose tissue attributed to a reduction in triglyceride content that can be visualized as an increase in Hounsfield units by CT imaging. CONCLUSION: The 3D imaging of fat by CT provides reliable results in the quantification of total, visceral, subcutaneous, brown and intrahepatic fat in mice. This non-invasive method allows the conduction of longitudinal studies of obesity in mice and therefore enables experimenters to investigate the onset of complex diseases such as diabetes and obesity

Relationships between cardiorespiratory fitness/muscular strength and 18F-fluorodeoxyglucose uptake in brown adipose tissue after exposure to cold in young, sedentary adults

Humans have metabolically active brown adipose tissue (BAT). However, what is the relation between exercise or physical activity with this tissue remains controversial. Therefore, the main aim of the present study is to examine whether cardiorespiratory fitness and muscular strength are associated with brown adipose tissue (BAT) volume and activity after exposure to cold in young, sedentary adults. Cardiorespiratory fitness was determined in 119 young, healthy, sedentary adults (68% women, age 21.9 ± 2.1 years, body mass index 25 ± 4.8 kg/m2) via the maximum treadmill exercise test, and their muscular strength assessed by the handgrip strength test and the 1-repetition maximum bench and leg press tests. Some days later, all subjects were exposed to 2 h of personalized exposure to cold and their cold-induced BAT volume and activity determined by a combination of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography and computed tomography scan. Cardiorespiratory fitness was associated with neither the BAT volume nor BAT activity (P ≥ 0.05). However, handgrip strength with respect to lean body mass was positively (though weakly) associated with BAT activity as represented by the 18F-FDG mean standardised uptake value (SUV) (β = 3.595, R2 = 0.039, P = 0.031) and SUVpeak value (β = 15.314, R2 = 0.037, P = 0.035). The above relationships remained after adjusting for several confounders. No other associations were found. Handgrip strength with respect to lean body mass is positively associated with BAT activity (SUVmean and SUVpeak) in young adults after exposure to cold - but only weakly. Further studies are needed to reveal the relationship between muscular fitness and human BAT characteristics.This study was supported by the Spanish Ministry of Economy and Competitiveness via the Fondo de Investigación Sanitaria del Instituto de Salud Carlos III (PI13/01393), Retos de la Sociedad (DEP2016-79512-R) and European Regional Development Funds (ERDF), the Spanish Ministry of Education (FPU13/04365 and FPU14/04172), the Fundación Iberoamericana de Nutrición (FINUT), the Redes Temáticas de Investigación Cooperativa RETIC (Red SAMID RD16/0022), the AstraZeneca HealthCare Foundation, the University of Granada Plan Propio de Investigación 2016 -Excellence actions: Unit of Excellence on Exercise and Health (UCEES) - and Plan Propio de Investigación 2018 - Programa Contratos-Puente, and the Junta de Andalucía, Consejería de Conocimiento, Investigación y Universidades (ERDF: SOMM17/6107/UGR)

Altered adipocyte differentiation and unbalanced autophagy in type 2 Familial Partial Lipodystrophy: an in vitro and in vivo study of adipose tissue browning

Type-2 Familial Partial Lipodystrophy is caused by LMNA mutations. Patients gradually lose subcutaneous fat from the limbs, while they accumulate adipose tissue in the face and neck. Several studies have demonstrated that autophagy is involved in the regulation of adipocyte differentiation and the maintenance of the balance between white and brown adipose tissue. We identified deregulation of autophagy in laminopathic preadipocytes before induction of differentiation. Moreover, in differentiating white adipocyte precursors, we observed impairment of large lipid droplet formation, altered regulation of adipose tissue genes, and expression of the brown adipose tissue marker UCP1. Conversely, in lipodystrophic brown adipocyte precursors induced to differentiate, we noticed activation of autophagy, formation of enlarged lipid droplets typical of white adipocytes, and dysregulation of brown adipose tissue genes. In agreement with these in vitro results indicating conversion of FPLD2 brown preadipocytes toward the white lineage, adipose tissue from FPLD2 patient neck, an area of brown adipogenesis, showed a white phenotype reminiscent of its brown origin. Moreover, in vivo morpho-functional evaluation of fat depots in the neck area of three FPLD2 patients by PET/CT analysis with cold stimulation showed the absence of brown adipose tissue activity. These findings highlight a new pathogenetic mechanism leading to improper fat distribution in lamin A-linked lipodystrophies and show that both impaired white adipocyte turnover and failure of adipose tissue browning contribute to disease.We thank FPLD2 patients for donating biological samples. We thank the Italian Network for Laminopathies and the European Consortium of Lipodystrophies (ECLip) for support and helpful discussion. We thank Aurelio Valmori for the technical support. The studies were supported by Rizzoli Orthopedic Institute “5 per mille” 2014 project to MC, AIProSaB project 2016 and Fondazione Del Monte di Bologna e Ravenna grant 2015–2016 “New pharmacological approaches in bone laminopathies based on the use of antibodies neutralizing TGF beta 2” to GL. GL is also supported by PRIN MIUR project 2015FBNB5Y.S

Epitaxial growth of perovskite oxide films facilitated by oxygen vacancies

The authors would like to thank P. Yudin for valuable discussions, N. Nepomniashchaia for VASE studies, and S. Cichon for XPS analysis. The authors acknowledge support from the Czech Science Foundation (Grant No. 19-09671S), the European Structural and Investment Funds and the Ministry of Education, Youth and Sports of the Czech Republic through Programme ‘‘Research, Development and Education’’ (Project No. SOLID21 CZ.02.1.01/0.0/0.0/16-019/0000760), and ERA NET project Sun2Chem (E. K. and L. R.). Calculations have been done on the LASC Cluster in the ISSP UL.Single-crystal epitaxial films of technologically important and scientifically intriguing multifunctional ABO3 perovskite-type metal oxides are essential for advanced applications and understanding of these materials. In such films, a film-substrate misfit strain enables unprecedented crystal phases and unique properties that are not available in their bulk counterparts. However, the prerequisite growth of strained epitaxial films is fundamentally restricted by misfit relaxation. Here we demonstrate that introduction of a small oxygen deficiency concurrently stabilizes epitaxy and increases lattice strain in thin films of archetypal perovskite oxide SrTiO3. By combining experimental and theoretical methods, we found that lattice distortions around oxygen vacancies lead to anisotropic local stresses, which interact with the misfit strain in epitaxial films. Consequently, specific crystallographic alignments of the stresses are energetically favorable and can facilitate epitaxial growth of strained films. Because anisotropic oxygen-vacancy stresses are inherent to perovskite-type and many other oxides, we anticipate that the disclosed phenomenon of epitaxial stabilization by oxygen vacancies is relevant for a very broad range of functional oxides.This work is licensed under CC BY, CC BY-NC licenses.Czech Science Foundation (Grant No. 19-09671S); European Structural and Investment Funds and the Ministry of Education, Youth and Sports of the Czech Republic through Programme ‘‘Research, Development and Education’’ (Project No. SOLID21 CZ.02.1.01/0.0/0.0/16-019/0000760), and ERA NET project Sun2Chem; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART²

Ablations of Ghrelin and Ghrelin Receptor Exhibit Differential Metabolic Phenotypes and Thermogenic Capacity during Aging

mice are adaptive. mice.Our data therefore suggest that GHS-R ablation activates adaptive thermogenic function(s) in BAT and increases EE, thereby enabling the retention of a lean phenotype. This is the first direct evidence that the ghrelin signaling pathway regulates fat-burning BAT to affect energy balance during aging. This regulation is likely mediated through an as-yet-unidentified new ligand of GHS-R