The peroxisome proliferator-activated receptor-γ (PPAR-γ) is a nuclear receptor that is activated by lipids to induce the expression of genes involved in lipid and glucose metabolism, thereby converting nutritional signals into metabolic consequences. PPAR-γ is the target of the thiazolidinedione (TZD) class of insulin-sensitizing drugs, which have been widely prescribed to treat type 2 diabetes mellitus. A common side effect of treatment with TZDs is weight gain. Here we report a previously unknown role for central nervous system (CNS) PPAR-γ in the regulation of energy balance. We found that both acute and chronic activation of CNS PPAR-γ, by either TZDs or hypothalamic overexpression of a fusion protein consisting of PPAR-γ and the viral transcriptional activator VP16 (VP16-PPAR-γ), led to positive energy balance in rats. Blocking the endogenous activation of CNS PPAR-γ with pharmacological antagonists or reducing its expression with shRNA led to negative energy balance, restored leptin sensitivity in high-fat-diet (HFD)-fed rats and blocked the hyperphagic response to oral TZD treatment. These findings have implications for the widespread clinical use of TZD drugs and for understanding the etiology of diet-induced obesity.
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http://dx.doi.org/10.1038/nm.2349 | DOI Listing |
Astrobiology
January 2025
Department of Earth and Planetary Sciences, Birkbeck University of London, London, United Kingdom.
Eccentric planets may spend a significant portion of their orbits at large distances from their host stars, where low temperatures can cause atmospheric CO to condense out onto the surface, similar to the polar ice caps on Mars. The radiative effects on the climates of these planets throughout their orbits would depend on the wavelength-dependent albedo of surface CO ice that may accumulate at or near apoastron and vary according to the spectral energy distribution of the host star. To explore these possible effects, we incorporated a CO ice-albedo parameterization into a one-dimensional energy balance climate model.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
School of Integrated Circuits and Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing, 100084, China.
Perovskite semiconductors have shown significant promise for photodetection due to their low effective carrier masses and long carrier lifetimes. However, achieving balanced detection across a broad spectrum-from X-rays to infrared-within a single perovskite photodetector presents challenges. These challenges stem from conflicting requirements for different wavelength ranges, such as the narrow bandgap needed for infrared detection and the low dark current necessary for X-ray sensitivity.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Organoid Research Center, Institute of Translational Medicine, Shanghai University, Shanghai 200444, People's Republic of China.
Osteoporosis (OP) is a systemic skeletal disorder characterized by decreased bone mineral density and a heightened risk of fractures. Therapies for OP have primarily focused on balancing bone formation and bone resorption, but enhancing the remineralization of osteoporotic bone is also a key strategy for effective repair. Recent insights into biomineralization mechanisms have highlighted the essential role of mineral-containing extracellular vesicles (EVs) secreted by osteoblasts in promoting bone marrow mesenchymal stromal/stem cell (BMSC) differentiation and initiating matrix mineralization.
View Article and Find Full Text PDFMicrobiome
January 2025
Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, China.
Background: The widespread selective pressure of antibiotics in the environment has led to the propagation of antibiotic resistance genes (ARGs). However, the mechanisms by which microbes balance population growth with the enrichment of ARGs remain poorly understood. To address this, we employed microcosm cultivation at different antibiotic (i.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Organic Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, Iran.
Boehmite nanoparticles and NaY nanozeolite were synthesized by co-precipitation and hydrothermal methods, respectively, and characterized by XRD, FT-IR, TG-DTA, BET, and SEM techniques. XRD and BET analyses demonstrated the formation of boehmite nanoparticles with a surface area of 350 m/g and high crystallinity NaY nanozeolite with a surface area of 957 m/g. In order to evaluate the effect of the content of the mesoporous boehmite nanoparticles on the catalytic performance of the Residue Fluid Catalytic Cracking (RFCC) catalyst, alumina active matrix-based and silica inactive matrix-based catalysts were prepared.
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