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Frugivory evolved multiple times in mammals, including bats. However, the cellular and molecular components driving it remain largely unknown. Here, we used integrative single-cell sequencing on insectivorous and frugivorous bat kidneys and pancreases and identified key cell population, gene expression and regulatory element differences associated with frugivorous adaptation that also relate to human disease, particularly diabetes. We found an increase in collecting duct cells and differentially active genes and regulatory elements involved in fluid and electrolyte balance in the frugivore kidney. In the frugivorous pancreas, we observed an increase in endocrine and a decrease in exocrine cells and differences in genes and regulatory elements involved in insulin regulation. Combined, our work provides novel insights into frugivorous adaptation that also could be leveraged for therapeutic purposes.

ApoL6 is a new LD-associated protein containing an apoprotein-like domain, expressed mainly in adipose tissue, specifically in adipocytes. ApoL6 expression is low in fasting but induced upon feeding. ApoL6 knockdown results in smaller LD with lower triglyceride (TAG) content in adipocytes, while ApoL6 overexpression causes larger LD with higher TAG content. We show that ApoL6 effect in adipocytes is by inhibition of lipolysis. While ApoL6, Perilipin 1 (Plin1) and HSL can form a complex on LD, C-terminal domain of ApoL6 directly interacts with Plin1, to compete with Plin1 binding to HSL through Plin1 N-terminal domain, thereby keeping HSL in a “stand by” status. Thus, ApoL6 ablation decreases WAT mass, protecting mice from diet-induced obesity, while adipose overexpression increases WAT mass to bring obesity and insulin resistance with hepatosteatosis, making ApoL6 a potential future target against obesity and diabetes.

Over 500 noncoding genomic loci are associated with obesity. The majority of these loci reside near genes that are expressed in the hypothalamus in specific neuronal subpopulations that regulate food intake, hindering the ability to identify and functionally characterize them. Here, we carried out integrative single-cell analysis (RNA/ATAC-seq) on both mouse and human male and female hypothalamus to characterize genes and regulatory elements in specific cell subpopulations. Utilizing both transcriptome and regulome data, we identify over 30 different neuronal and non-neuronal cell subpopulations and a shared core of transcription factors that regulate cell cluster-specific genes between mice and humans. We characterize several sex-specific differentially expressed genes and the regulatory elements that control them in specific cell subpopulations. Overlapping cell-specific scATAC peaks with obesity-associated GWAS variants, identifies potential obesity-associated regulatory elements. Using reporter assays and CRISPR editing, we show that many of these sequences, including the top obesity-associated loci (FTOandMC4R), are functional enhancers whose activity is altered due to the obesity-associated variant and regulate known obesity genes. Combined, our work provides a catalog of genes and regulatory elements in hypothalamus cell subpopulations and uses obesity to showcase how integrative single-cell sequencing can identify functional variants associated with hypothalamus-related phenotypes.

Fat distribution differences between males and females are a major risk factor for metabolic disease, but their genetic etiology remains largely unknown. Here, we establish ADGRG6 as a major factor in adipogenesis and gender fat distribution. Deletion of ADGRG6 in human adipocytes impairs adipogenesis due to reduced cAMP signaling. Conditionally knocking out Adgrg6 in mouse adipocytes or deleting an intronic enhancer associated with gender fat distribution generates males with female-like fat deposition, which are protected against high-fat-diet-induced obesity and have improved insulin response. To showcase its therapeutic potential, we demonstrate that CRISPRi targeting of the Adgrg6 promoter or enhancer prevents high-fat-diet-induced obesity. Combined, our results associate ADGRG6 as a gender fat distribution gene and highlight its potential as a therapeutic target for metabolic disease.

Background:\ud The novel coronavirus disease (COVID-19) vaccines may help control the current pandemic but would require immunization levels that would achieve herd immunity. This study aimed to quantify current COVID-19 vaccine acceptance rates, as well as characterize the determinants, enablers and barriers to vaccine acceptability across the globe by synthesizing published evidence.\ud \ud Methods:\ud A systematic review and meta-analysis of studies was performed on studies assessing the acceptability of a COVID-19 vaccine published between November 1st, 2019, and November 30th, 2020. PubMed, Embase and Cochrane central were searched for eligible studies. Data extracted from retained studies was analyzed using STATA statistical software. A quantitative and narrative synthesis was produced.\ud \ud Results:\ud A total of 35 eligible articles (38 studies) involving a total of 70,997 participants across 7 regions and 35 countries were included. All studies were cross-sectional survey designs. The pooled vaccine acceptance rate across 32 studies was 71% (95% CI: 66 – 76%, p2= 99.4%, range: 29-97%). The pooled vaccine acceptance rate of parents for their children across 4 studies was 52% (95% CI: 37-67%, p2= 99.1%). Vaccine uptake was significantly higher among males (N=13 studies), older age groups (N=7), and healthcare providers (N=2). Enablers of vaccine uptake included perceived individual susceptibility to COVID-19 infection (N=11), prior influenza vaccination (N=7) and high vaccine effectiveness (N=6). The most common barriers to vaccine uptake were general negative attitudes towards vaccines/vaccine hesitancy (N=8), concerns over vaccine safety and efficacy (N=6), vaccine side effects (N=5), and misinformation or conspiracy beliefs around the experimental COVID-19 vaccines (N=2).\ud \ud Conclusions:\ud There is a good acceptance of COVID-19 vaccines globally despite wide variations across countries. Public health campaigns may benefit from capitalising on identified enablers and dispelling important barriers with regards to vaccine safety.

(1,3)-β-D-Glucan synthase (GS) catalyzes formation of the linear (1,3)-β-D-glucan in the fungal cell wall, and is a target of clinically approved antifungal antibiotics. The catalytic subunit of GS, FKS protein, does not exhibit significant sequence homologies to other glycosyltransferases, and thus a significant ambiguity remains about its catalytic mechanism. One of the major technical barriers in studying GS is the absence of activity assay methods that allow characterization of the lengths and amounts of (1,3)-β-D-glucan due to its poor solubility in water and organic solvents. Here, we report a successful development of a novel GS activity assay based on size-exclusion chromatography coupled with pulsed-amperometric detection and radiation counting (SEC-PAD-RC), which allows for the simultaneous characterization of the amount and length of the polymer product. The assay revealed that the purified yeast GS produces glucan with a length of 6,550 ± 760 mer, consistent with the reported degree of polymerization of (1,3)-β-D-glucan isolated from intact cells. Pre-steady state kinetics analysis revealed a highly efficient but rate-determining chain elongation rate of 51.5 ± 9.8 sec(−1), which represents the first observation of chain elongation by a nucleotide-sugar dependent polysaccharide synthase. Coupling the SEC-PAD-RC method with substrate analog mechanistic probes provided the first unambiguous evidence that GS catalyzes non-reducing end polymerization. Based on these observations, we propose a detailed model for the catalytic mechanism of GS. The approaches described here can be used to determine the mechanism of catalysis of other polysaccharide synthases.

SUMMARY Brown adipose tissue harbors UCP1 to dissipate chemical energy as heat. However, the transcriptional network that governs the thermogenic gene program is incompletely understood. Zc3h10, a CCCH-type zinc finger protein, has recently been reported to bind RNA. However, we report here that Zc3h10 functions as a transcription factor to activate UCP1 not through the enhancer region, but by binding to a far upstream region of the UCP1 promoter. Upon sympathetic stimulation, Zc3h10 is phosphorylated at S126 by p38 mitogen-activated protein kinase (MAPK) to increase binding to the distal region of the UCP1 promoter. Zc3h10, as well as mutant Zc3h10, which cannot bind RNA, enhances thermogenic capacity and energy expenditure, protecting mice from diet-induced obesity. Conversely, Zc3h10 ablation in UCP1+ cells in mice impairs thermogenic capacity and lowers oxygen consumption, leading to weight gain. Hence, Zc3h10 plays a critical role in the thermogenic gene program and may present future targets for obesity therapeutics., Graphical Abstract, In Brief Zc3h10 is a RNA-binding protein. Here, Yi et al. report Zc3h10 is a transcription factor that activates UCP1 and other BAT genes. Cold/β3 stimulation causes phosphorylation of Zc3h10 at S126 by p38 MAPK to increase its binding to targets genes and, thus, promotes thermogenic capacity and energy expenditure.

A novel well-defined precatalyst for ammonia-selective catalytic reduction of NOx (NH3-SCR), namely, [W(CtBu)(CH2tBu)3]/CeO2, was prepared by surface organometallic chemistry and then characterized. Due to the high dispersion of the active phase, this catalyst showed excellent activity after calcination at 500 °C, described by up to 99% conversion of NOx, high N2 selectivity, broad operation temperature window (225–500 °C), and extremely high durability for the selective catalytic reduction of NOx with NH3.

Brown adipose tissue is a metabolically beneficial organ capable of dissipating chemical energy into heat, thereby increasing energy expenditure. Here, we identify Dot1L, the only known H3K79 methyltransferase, as an interacting partner of Zc3h10 that transcriptionally activates the UCP1 promoter and other BAT genes. Through a direct interaction, Dot1L is recruited by Zc3h10 to the promoter regions of thermogenic genes to function as a coactivator by methylating H3K79. We also show that Dot1L is induced during brown fat cell differentiation and by cold exposure and that Dot1L and its H3K79 methyltransferase activity is required for thermogenic gene program. Furthermore, we demonstrate that Dot1L ablation in mice using UCP1-Cre prevents activation of UCP1 and other target genes to reduce thermogenic capacity and energy expenditure, promoting adiposity. Hence, Dot1L plays a critical role in the thermogenic program and may present as a future target for obesity therapeutics.

SUMMARY Adipocytes arise from the commitment and differentiation of adipose precursors in white adipose tissue (WAT). In studying adipogenesis, precursor markers, including Pref-1 and PDGFRα, are used to isolate precursors from stromal vascular fractions of WAT, but the relation among the markers is not known. Here, we used the Pref-1 promoter-rtTA system in mice for labeling Pref-1+ cells and for inducible inactivation of the Pref-1 target Sox9. We show the requirement of Sox9 for the maintenance of Pref-1+ proliferative, early precursors. Upon Sox9 inactivation, these Pref-1+ cells become PDGFRα+ cells that express early adipogenic markers. Thus, we show that Pref-1+ cells precede PDGFRα+ cells in the adipogenic pathway and that Sox9 inactivation is required for WAT growth and expansion. Furthermore, we show that in maintaining early adipose precursors, Sox9 activates Meis1, which prevents adipogenic differentiation. Our study also demonstrates the Pref-1 promoter-rtTA system for inducible gene inactivation in early adipose precursor populations., In Brief The relationship among Sox9+, Pref-1+, and PDGFRα+ WAT precursors has not been studied. Gulyaeva et al. show that Pref-1+ cells are early adipose precursors and, upon Sox9 inactivation, they become PDGFRα+ cells at a later stage of the adipogenic pathway. In maintaining Pref-1+ adipose precursors, Sox9 activates Meis1, which prevents adipogenic differentiation., Graphical Abstract

Brown adipose tissue (BAT) is a metabolically beneficial organ capable of burning fat by dissipating chemical energy into heat, thereby increasing energy expenditure. Moreover, subcutaneous white adipose tissue can undergo so-called browning/beiging. The recent recognition of the presence of brown or beige adipocytes in human adults has attracted much attention to elucidate the molecular mechanism underlying the thermogenic adipose program. Many key transcriptional regulators critical for the thermogenic gene program centering on activating the UCP1 promoter, have been discovered. Thermogenic gene expression in brown adipocytes rely on co-ordinated actions of a multitude of transcription factors, including EBF2, PPARγ, Zfp516 and Zc3h10. These transcription factors probably integrate into a cohesive network for BAT gene program. Moreover, these transcription factors recruit epigenetic factors, such as LSD1 and MLL3/4, for specific histone signatures to establish the favorable chromatin landscape. In this review, we discuss advances made in understanding the molecular mechanism underlying the thermogenic gene program, particularly epigenetic regulation.

White adipose tissue (WAT) is the primary energy storage organ and its excess contributes to obesity, while brown adipose tissue (BAT) and inducible thermogenic (beige/brite) adipocytes in WAT dissipate energy via UCP1 to maintain body temperature. Adipose tissues can develop during embryogenesis and after birth depending on anatomical origin. In adipose tissue, differentiation of adipose precursors to adipocytes is governed by transcription factors such as PPARγ, C/EBPβ, Zfp423, and Sox9 and this process is tightly regulated by secreted factors including Pref-1 and Wnt. Additionally, thermogenic gene activation in brown and beige adipocytes relies on common transcriptional machinery that includes PRDM16, Zfp516, Zc3h10, and LSD1, play an important role in regulating the thermogenic gene program. These transcription factors actions are also regulated by metabolites that acts as agonists or cofactor. With the presence of BAT-like tissues in human adults, increasing thermogenic activity these tissues may help to combat obesity.

Mitomycins make up a group of antitumor natural products that are biosynthesized from aminohydroxybenzoic acid (AHBA) and N-acetylglucosamine (GlcNAc). While the biosynthetic gene cluster was reported two decades ago, the mechanism by which the two building blocks, AHBA and GlcNAc, are coupled during biosynthesis remained uncharacterized. Here we report evidence that AHBA is first loaded onto an MmcB acyl carrier protein (ACP) by a MitE acyl ACP synthetase, followed by a transfer of GlcNAc from UDP-GlcNAc by MitB. The results suggest that the early steps of mitomycin biosynthesis proceed via intermediates linked to MmcB.

Brown adipose tissue (BAT) is highly metabolically active tissue that dissipates energy via UCP1 as heat, and BAT mass is correlated negatively with obesity. The presence of BAT/BAT-like tissue in humans renders BAT as an attractive target against obesity and insulin resistance. Here, we identify Aifm2, a NADH oxidoreductase domain containing flavoprotein, as a lipid droplet (LD)-associated protein highly enriched in BAT. Aifm2 is induced by cold as well as by diet. Upon cold or β-adrenergic stimulation, Aifm2 associates with the outer side of the mitochondrial inner membrane. As a unique BAT-specific first mammalian NDE (external NADH dehydrogenase)-like enzyme, Aifm2 oxidizes NADH to maintain high cytosolic NAD levels in supporting robust glycolysis and to transfer electrons to the electron transport chain (ETC) for fueling thermogenesis. Aifm2 in BAT and subcutaneous white adipose tissue (WAT) promotes oxygen consumption, uncoupled respiration, and heat production during cold- and diet-induced thermogenesis. Aifm2, thus, can ameliorate diet-induced obesity and insulin resistance.

Fatty acid and triglyceride synthesis increases greatly in response to feeding and insulin. This lipogenic induction involves coordinate transcriptional activation of various enzymes in lipogenic pathway, including fatty acid synthase and glycerol-3-phosphate acyltransferase. Here, we show that JMJD1C is a specific histone demethylase for lipogenic gene transcription in liver. In response to feeding/insulin, JMJD1C is phosphorylated at T505 by mTOR complex to allow direct interaction with USF-1 for recruitment to lipogenic promoter regions. Thus, by demethylating H3K9me2, JMJD1C alters chromatin accessibility to allow transcription. Consequently, JMJD1C promotes lipogenesis in vivo to increase hepatic and plasma triglyceride levels, showing its role in metabolic adaption for activation of the lipogenic program in response to feeding/insulin, and its contribution to development of hepatosteatosis resulting in insulin resistance., In response to insulin, liver cells increase de novo lipogenesis via the transcription factors USF-1 and SREBP. Here the authors show that USF-1 recruits JMJD1C, after its phosphorylation by mTOR, to lipogenic promoters where JMJD1C demethylates histone H3, contributing to lipogenesis by an epigenetic mechanism.

Condensation of liquid water in the porous washcoat layer of exhaust gas catalysts limits their conversion efficiency during the cold-start of an internal combustion engine (ICE). The evaporation kinetics also determine the functionality of the catalyst. In this work, we study water evaporation in the washcoat layers using in-situ X-ray tomographic microscopy with high temporal and spatial resolution. A novel in-situ heating setup is developed, able to reproduce real-world conditions in terms of temperature and gas speed. It is demonstrated that with a voxel size of 0.4 μm, satisfactory data quality can be achieved with a total acquisition time for tomographic volumes of 0.5 s. Thanks to the high temporal and spatial resolution, the water evaporation in a Al2O3 washcoat layer can be described under representative conditions. We find that the time evolution of the evaporation follows an exponential-like behavior and water starts to evaporate from the macroscopic washcoat cracks.

Adipose tissue mass and adiposity change throughout the lifespan. During aging, while visceral adipose tissue (VAT) tends to increase, peripheral subcutaneous adipose tissue (SAT) decreases significantly. Unlike VAT, which is linked to metabolic diseases, including type 2 diabetes, SAT has beneficial effects. However, the molecular details behind the aging-associated loss of SAT remain unclear. Here, by comparing scRNA-seq of total stromal vascular cells of SAT from young and aging mice, we identify an Aging-dependent Regulatory Cell (ARC) population that emerges only in SAT of aged mice and humans. ARC express adipose progenitor markers but lacks adipogenic capacity; they secrete high levels of pro-inflammatory chemokines, including Ccl6, to inhibit proliferation and differentiation of neighboring adipose precursors. We also found Pu.1 to be a driving factor for ARC development. We identify an ARC population and its capacity to inhibit differentiation of neighboring adipose precursors, correlating with aging-associated loss of SAT.

The product water of polymer electrolyte fuel cells (PEFCs) has to pervade the gas diffusion layer (GDL) and can lead to shortages of educt gas diffusion pathways to the catalyst layer hence to significant performance losses. Here we report on efforts made to enable subsecond and submicron operando X-ray tomographic microscopy (XTM) over a wide range of cell operating temperatures. The short XTM scan times allow to quantify the contributions of capillary-fingering and phase-change-induced flow on the overall water transport inside the cathode GDL at two different cell operating temperatures of 40 °C and 80 °C during a current ramp-up process. The results suggest that phase-change-induced water transport dominates the initial increase of saturation levels at typical automotive PEFC operating temperatures of about 80 °C, whereas capillary-fingering driven transport dominates the development of saturation from the beginning to stagnating stage at 40 °C.

Climate change may affect the internal defense system (IDS) of freshwater snails, and as a result their capacity to transmit disease. We examined effects of short-term exposure to supra- and sub-optimal temperatures or starvation on 3 parameters of the IDS of the schistosome-resistant Salvador strain of Biomphalaria glabrata — hemocyte concentrations, cell division in the amebocyte-producing organ (APO), and resistance to infection with Schistosoma mansoni. Adult snails were exposed to 1 of 3 temperatures, 20 °C, 27 °C (controls), or 33 °C, for 1 or 2 weeks, with food. A fourth group was maintained at 27 °C, but without food. Compared to the controls, starved snails had significantly higher hemocyte counts at both 1 and 2 weeks, although mitotic activity in the APO was significantly lower at both time periods. Exposure to 20 °C or 33 °C for 1 or 2 weeks did not affect hemocyte numbers. However, APO mitotic activity in snails exposed to 20 °C was significantly higher at both 1 and 2 weeks, whereas mitotic activity in snails exposed to 33 °C was significantly lower at 1 week but normal at 2 weeks. None of the treatments altered the resistance phenotype of Salvador snails. In a follow-up experiment, exposure to 33 °C for 4–5 h, a treatment previously reported to both induce expression of heat shock proteins (Hsps) and abrogate resistance to infection, caused immediate upregulation of Hsp 70 and Hsp 90 expression, but did not alter resistance, and Hsp expression levels returned to baseline after 2 weeks at 33 °C. Results of this study indicate that abnormal environmental conditions can have both stimulatory and inhibitory effects on the IDS in adult B. glabrata, and that some degree of acclimation to abnormal temperatures may occur.

Theloderma is a widely distributed yet little-known genus of camouflaged tree frogs found throughout Southeast Asia. One member, T. phrynoderma, known only from the moist evergreen forest of the Karen Hills of Myanmar, is redescribed from two recently collected specimens and examination of type specimens. To date the only information available about T. phrynoderma is Boulenger’s brief 1893 description of two type specimens collected in 1888, and phylogenetic analyses to test its placement among other species of Theloderma is lacking due to an absence of specimens. In the present study, we compared two individuals collected in 2009 and 2010 from the Tanintharyi Nature Reserve to the type specimens of T. phrynoderma and proposed that they are also members of this species. We then used two mitochondrial genes (12S and 16S rRNA) and two nuclear genes (rhodopsin and tyrosinase) to infer the phylogenetic relationship of the putative T. phrynoderma to other members of Rhacophoridae, with a special emphasis on Theloderma. The recently collected individuals are of the same species within Theloderma but distinct from all other DNA sequenced congeners. The species redescription is based on a comparison of the newly found reference specimens with the lectotype and paralectotype. In addition, using a combination of morphological characters we provide a more complete diagnosis. The species is distinct from other congeners by a combination of the following characters: a mid-body size (female 44 mm SVL; male mean 41.3 mm SVL); tympanum diameter to eye diameter (70%); partial webbing between fingers; rugose skin with clumped, white-tipped calcified tubercles throughout the dorsal surface; webbing between fingers; distinct darker brown inverted V-marking between its shoulders; absence of vomerine teeth; and absence of vocal sacs.

An intensive in situ and operando IR study on NOx adsorption over potassium (K) loaded zirconia-titania NSR catalyst in comparison to a barium (Ba) loaded one is reported. Based on in situ IR experiments, NOx adsorption under heated environment was confirmed to favor potassium bidentate nitrate species rather than ionic nitrate species observed for Ba-loaded NSR catalyst (previously published). Complementary operando IR experiments revealed different mechanisms for NOx adsorption over the two NOx storage materials (NSMs): initial simultaneous NO2− and NO3− formation over K loaded catalyst while over Ba-loaded one, NO2− is first accumulated before being converted to NO3−. Isotopic labelling in combination with operando experiments identified distinct dynamic behaviors regarding the exchange between nitrogen containing species on surface and in gas phase. This work provides beneficial inputs for advanced catalyst converter design, for example with zone-coated washcoat that contains more than one catalyst formulations.