Dancr-BRG1 regulates Nfatc1 transcription and Pgc1ß-dependent metabolic shifts in osteoclastogenesis.

Long non-coding RNA (lncRNA) serves as a vital regulator of bone metabolism, but its role in pathologically overactive osteoclast differentiation remains elusive. Here, we identify lncRNA Dancr (Differentiation Antagonizing Non-protein Coding RNA) as a critical suppressor of osteoclastogenesis and bone resorption, which is down-regulated in response to estrogen deficiency. Global or osteoclast-specific Dancr Knockout mice display significant trabecular bone deterioration and enhanced osteoclast activity, but minimal alteration of bone formation. Moreover, the bone-targeted delivery of Dancr by Adeno-associated viral remarkably attenuates ovariectomy-induced osteopenia in mice. Mechanistically, Dancr establishes a direct interaction with Brahma-related gene 1 to prevent its binding and preserve H3K27me3 enrichment at the nuclear factor of activated T cells 1 and proliferator-activated receptor gamma coactivator 1-beta promoters, thereby maintaining appropriate expression of osteoclastic genes and metabolic programs during osteoclastogenesis. These results demonstrate that Dancr is a key molecule maintaining proper osteoclast differentiation and bone homeostasis under physiological conditions, and Dancr overexpression constitutes a potential strategy for treating osteoporosis.

Lignin-derived carbon nanosheets boost electrochemical reductive amination of pyruvate to alanine.

Efficient and sustainable amino acid synthesis is essential for industrial applications. Electrocatalytic reductive amination has emerged as a promising method, but challenges such as undesired side reactions and low efficiency persist. Herein, we demonstrated a lignin-derived catalyst for alanine synthesis. Carbon nanosheets (CNSs) were synthesized from lignin via a template-assisted method and doped with nitrogen and sulfur to boost reductive amination and suppress side reactions. The resulting N,S-co-doped carbon nanosheets (NS-CNSs) exhibited outstanding electrochemical performance. It achieved a maximum alanine Faradaic efficiency of 79.5%, and a yield exceeding 1,199 µmol h-1 cm-2 on NS-CNS, with a selectivity above 99.9%. NS-CNS showed excellent durability during long-term electrolysis. Kinetic studies including control experiments and theoretical calculations provided further insights into the reaction pathway. Moreover, NS-CNS catalysts demonstrated potential in upgrading real-world polylactic acid plastic waste, yielding value-added alanine with a selectivity over 75%.

Association between gut microbiota and bone metabolism: Insights from bibliometric analysis.

Gut microbiota has been reported to participate in bone metabolism. However, no article has quantitatively and qualitatively analyzed this crossing field. The present study aims to analyze the current international research trends and demonstrate possible hotspots in the recent decade through bibliometrics. We screened out 938 articles meeting the standards from 2001 to 2021 in the Web of Science Core Collection database. Bibliometric analyses were performed and visualized using Excel, Citespace, and VOSviewer. Generally, the annual number of published literatures in this field shows an escalating trend. The United States has the largest number of publications, accounting for 30.4% of the total. Michigan State University and Sichuan University have the largest number of publications, while Michigan State University has the highest average number of citations at 60.00. Nutrients published 49 articles, ranking first, while the Journal of Bone and Mineral Research had the highest average number of citations at 13.36. Narayanan Parameswaran from Michigan State University, Roberto Pacifici from Emory University, and Christopher Hernandez from Cornell University were the three professors who made the largest contribution to this field. Frequency analysis showed that inflammation (148), obesity (86), and probiotics (81) are keywords with the highest focus. Moreover, keywords cluster analysis and keywords burst analysis showed that "inflammation", "obesity", and "probiotics" were the most researched topics in the field of gut microbiota and bone metabolism. Scientific publications related to gut microbiota and bone metabolism have continuously risen from 2001 to 2021. The underlying mechanism has been widely studied in the past few years, and factors affecting the alterations of the gut microbiota, as well as probiotic treatment, are emerging as new research trends.

Aerobic Oxidative Cleavage of C(OH)-C Bonds to Produce Aromatic Aldehydes Catalyzed by CuI -1,10-phenanthroline Complex.

Effective cleavage and functionalization of C(OH)-C bonds is of great importance for the production of value-added chemicals from renewable biomass resources such as carbohydrates, lignin and their derivatives. The efficiency and selectivity of oxidative cleavage of C(OH)-C bonds are hindered by their inert nature and various side reactions associated with the hydroxyl group. The oxidative conversion of secondary alcohols to produce aldehydes is particularly challenging because the generated aldehydes tend to be over-oxidized to acids or the other side products. Noble-metal based catalysts are necessary to get satisfactory aldehyde yields. Herein, for the first time, the efficient aerobic oxidative conversion of secondary aromatic alcohols into aromatic aldehydes is reported using non-noble metal catalysts and environmentally benign oxygen, without any additional base. It was found that CuI -1,10-phenanthroline (Cu-phen) complex showed outstanding performance for the reactions. The C(OH)-C bonds of a diverse array of aromatic secondary alcohols were effectively cleaved and functionalized, selectively affording aldehydes with excellent yields. Detailed mechanism study revealed a radical mediated pathway for the oxidative reaction. We believe that the findings in this work will lead to many explorations in non-noble metal catalyzed oxidative reactions.

Rational polyelectrolyte nanoparticles endow preosteoclast-targeted siRNA transfection for anabolic therapy of osteoporosis.

Targeted transfection of siRNA to preosteoclasts features the potential of anti-osteoporosis, yet challenge arises from the development of satisfied delivery vehicles. Here, we design a rational core-shell nanoparticle (NP) composed of cationic and responsive core for controlled load and release of small interfering RNA (siRNA) and compatible polyethylene glycol shell modified with alendronate for enhanced circulation and bone-targeted delivery of siRNA. The designed NPs perform well on transfection of an active siRNA (siDcstamp) that interferes Dcstamp mRNA expression, leading to impeded preosteoclast fusion and bone resorption, as well as promoted osteogenesis. In vivo results corroborate the abundant siDcstamp accumulation on bone surfaces and the enhanced trabecular bone mass volume and microstructure in treating osteoporotic OVX mice by rebalancing bone resorption, formation, and vascularization. Our study validates the hypothesis that satisfied transfection of siRNA enables preserved preosteoclasts that regulate bone resorption and formation simultaneously as potential anabolic treatment for osteoporosis.

A Genetic Variant of the ROBO3 Gene is Associated With Adolescent Idiopathic Scoliosis in the Chinese Population.

STUDY DESIGN: A case-control association study. OBJECTIVES: This study aimed to reveal whether mutations within roundabout receptor 3 ( ROBO3 ) gene were related to adolescent idiopathic scoliosis (AIS) in Chinese Han population and to investigate the functional role of ROBO3 in the pathogenesis and progression of AIS. SUMMARY OF BACKGROUND DATA: ROBO3 is essential for the regulation of hindbrain axonal cell migration and midline crossing. Studies have demonstrated that ROBO3 homozygous mutations are associated with horizontal gaze palsy with progressive scoliosis. However, whether and how ROBO3 contributed to the development of scoliosis remains unclear. MATERIALS AND METHODS: Whole exome sequencing was performed in 135 AIS patients and 267 healthy controls to evaluate the differences of single nucleotide polymorphism variants within ROBO3 . Then the identified variant of ROBO3 was genotyped in another cohort included 1140 AIS patients and 1580 controls. Moreover, paraspinal muscles were collected from 39 AIS patients and 45 lumbar disk herniation patients for the measurement of ROBO3 mRNA expression. The χ 2 test, Fisher exact test or the Student t test were used to compare intergroup data. Pearson correlation was used to determine the association between ROBO3 expression and clinical phenotypes. RESULTS: A significant association was identified between the gene variant (rs74787566) of ROBO3 and the development of AIS through exome sequencing. The genotyping cohort demonstrated a higher frequency of allele A in AIS patients compared to controls (7.89% vs . 4.30%, P <0.001, odds ratio=1.87). In addition, the expression of ROBO3 in paraspinal muscles was inversely correlated with the Cobb angle ( P =0.043, r2 =0.1059). CONCLUSION: A significant association was identified between the gene variant (rs74787566) of ROBO3 and the development of AIS. The reduced expression of ROBO3 could result in the progression of curve magnitude in patients with AIS. Further studies are needed to verify the functional role of ROBO3 in the development of AIS. LEVEL OF EVIDENCE: Level III.

Synthesis of d-Gluconic Acetal Surfactants and Their Foaming Behaviors.

Sugars are natural and environmentally benign substances, which can offer various hydroxyl groups. The understanding of details of the hydroxyl interactions in the hydrophilic groups of sugar-based surfactants, as well as the related properties, is still indistinct. Here, novel d-gluconic acetal surfactants with bicyclic and monocyclic structures in the head group were designed and synthesized. The obtained surfactant with a bicyclic architecture exhibited excellent foamability and a multistimulus-responsive behavior toward foam stabilization. In addition, the control of foamability from defoaming and foaming could be achieved by changing pH values or bubbling gas of CO2/N2. To explore the structural effects such as hydroxyl groups and rigidity of the head group on the properties of sugar-based surfactants, another kind of amphiphilic molecule with various OH- groups and a monocycle in the head group was designed for comparison. These two series of amphiphilic molecules both exhibited good surface activity. However, only the d-gluconic acetal surfactant with a bicyclic structure and a smaller number of OH- groups exhibited excellent foamability. Further studies showed that the foam behaviors were attributed to the conformation and arrangement of the surfactant molecule at the surface layer with the assistance of hydrogen bonds formed by hydroxyl groups and H2O molecules. In addition, the surfactant could provide an environmentally friendly foamer in many potential applications.

How high-fat diet affects bone in mice: A systematic review and meta-analysis.

High-fat diet (HFD) feeding for mice is commonly used to model obesity. However, conflicting results have been reported on the relationship between HFD and bone mass. In this systematic review and meta-analysis, we synthesized data from 80 articles to determine the alterations in cortical and trabecular bone mass of femur, tibia, and vertebrae in C57BL/6 mice after HFD. Overall, we detected decreased trabecular bone mass as well as deteriorated architecture, in femur and tibia of HFD treated mice. The vertebral trabecula was also impaired, possibly due to its reshaping into a more fragmentized pattern. In addition, pooled cortical thickness declined in femur, tibia, and vertebrae. Combined with changes in other cortical parameters, HFD could lead to a larger femoral bone marrow cavity, and a thinner and more fragile cortex. Moreover, we conducted subgroup analyses to explore the influence of mice's sex and age as well as HFD's ingredients and intervention period. Based on our data, male mice or mice aged 6-12 weeks old are relatively susceptible to HFD. HFD with > 50% of energy from fats and intervention time of 10 weeks to 5 months are more likely to induce skeletal alterations. Altogether, these findings supported HFD as an appropriate model for obesity-associated bone loss and can guide future studies.

Highly efficient C(CO)-C(alkyl) bond cleavage in ketones to access esters over ultrathin N-doped carbon nanosheets.

Selective oxidative cleavage of the C(CO)-C bond in ketones to access esters is a highly attractive strategy for upgrading ketones. However, it remains a great challenge to realize this important transformation over heterogeneous metal-free catalysts. Herein, we designed a series of porous and ultrathin N-doped carbon nanosheets (denoted as CN-X, where X represents the pyrolysis temperature) as heterogeneous metal-free catalysts. It was observed that the fabricated CN-800 could efficiently catalyze the oxidative cleavage of the C(CO)-C bond in various ketones to generate the corresponding methyl esters at 130 °C without using any additional base. Detailed investigations revealed that the higher content and electron density of the graphitic-N species contributed to the excellent performance of CN-800. Besides, the high surface area, affording active sites that are more easily accessed, could also enhance the catalytic activity. Notably, the catalysts have great potential for practical applications because of some obvious advantages, such as low cost, neutral reaction conditions, heterogeneous nature, high efficiency, and broad ketone scope. To the best of our knowledge, this is the first work on efficient synthesis of methyl esters via oxidative esterification of ketones over heterogeneous metal-free catalysts.

Highly effective and chemoselective hydrodeoxygenation of aromatic alcohols.

Effective hydrodeoxygenation (HDO) of aromatic alcohols is very attractive in both conventional organic synthesis and upgrading of biomass-derived molecules, but the selectivity of this reaction is usually low because of the competitive hydrogenation of the unsaturated aromatic ring and the hydroxyl group. The high activity of noble metal-based catalysts often leads to undesired side reactions (e.g., saturation of the aromatic ring) and excessive hydrogen consumption. Non-noble metal-based catalysts suffer from unsatisfied activity and selectivity and often require harsh reaction conditions. Herein, for the first time, we report chemoselective HDO of various aromatic alcohols with excellent selectivity, using porous carbon-nitrogen hybrid material-supported Co catalysts. The C-OH bonds were selectively cleaved while leaving the aromatic moiety intact, and in most cases the yields of targeted compounds reached above 99% and the catalyst could be readily recycled. Nitrogen doping on the carbon skeleton of the catalyst support (C-N matrix) significantly improved the yield of the targeted product. The presence of large pores and a high surface area also improved the catalyst efficiency. This work opens the way for efficient and selective HDO reactions of aromatic alcohols using non-noble metal catalysts.

Bioinspired antifouling Fe-based amorphous coating via killing-resisting dual surface modifications.

Fe-based amorphous coatings with outstanding corrosion resistance are promise for marine applications. However, these coatings encounter a great challenge of biofouling in marine environments. Inspired by the unique micro-nano hierarchical structure of shark skin with excellent antifouling properties, in this paper, we construct a bioinspired Fe-based amorphous coating with killing-resisting dual-effect via proper surface modifications, i.e., the modification with micro-patterned nanostructured Cu2O fibers (killing effect), followed by the modification with superhydrophobic surface (resisting effect). As a result, the modified amorphous coating exhibits impressive antifouling properties, achieving 98.6% resistance to Nitzschia closterium f. minutissima, 87% resistance to Bovine serum albumin protein and 99.8% resistance to Pseudomonas aeruginosa, respectively. The remarkable antifouling performance is attributed to a synergistic antifouling mechanism from both resisting effect and killing effect, wherein the superhydrophobic surface provides a barrier to resist protein adsorption, while the patterned nanostructured Cu2O fibers supply Cu+ ions to kill bacterial cells. In addition, the modified amorphous coating also exhibits excellent mechanical robustness, which ensures the durability of the Fe-based amorphous coating in practical services. This work may promote the development of new durable metal-based coatings integrated with anti-fouling and anti-corrosion properties.

Robust selenium-doped carbon nitride nanotubes for selective electrocatalytic oxidation of furan compounds to maleic acid.

Selective oxidation of biomass-derived furan compounds to maleic acid (MA), an important bulk chemical, is a very attractive strategy for biomass transformation. However, achieving a high MA selectivity remains a great challenge. Herein, we for the first time successfully designed and fabricated Se-doped graphitic carbon nitride nanotubes with a chemical formula of C3.0N-Se0.03. The prepared C3.0N-Se0.03 was highly efficient for electrocatalytic oxidation of various biomass-derived furan compounds to generate MA. At ambient conditions, the MA yield could reach 84.2% from the electro-oxidation of furfural. Notably, the substituents on the furan ring significantly affected the selectivity to MA, following the order: carboxyl group > aldehyde group > hydroxyl group. Detailed investigation revealed that Se doping could tune the chemical structure of the materials (e.g., C3.0N-Se0.03 and g-C3N4), thus resulting in the change in catalytic mechanism. The excellent performance of C3.0N-Se0.03 originated from the suitable amount of graphitic N and its better electrochemical properties, which significantly boosted the oxidation pathway to MA. This work provides a robust and selective metal-free electrocatalyst for the sustainable synthesis of MA from oxidation of biomass-derived furan compounds.

Dehydroxyalkylative halogenation of C(aryl)-C bonds of aryl alcohols.

We herein report Cu mediated side-directed dehydroxyalkylative halogenation of aryl alcohols. C(aryl)-C bonds of aryl alcohols were effectively cleaved, affording the corresponding aryl chlorides, bromides and iodides in excellent yields. Aryl alcohols could serve as both aromatic electrophilic and radical synthetic equivalents during the reaction.

Synthesis of thioethers, arenes and arylated benzoxazoles by transformation of the C(aryl)-C bond of aryl alcohols.

Transformation of aryl alcohols into high-value functionalized aromatic compounds by selective cleavage and functionalization of the C(aryl)-C(OH) bond is of crucial importance, but very challenging by far. Herein, for the first time, we report a novel and versatile strategy for activation and functionalization of C(aryl)-C(OH) bonds by the cooperation of oxygenation and decarboxylative functionalization. A diverse range of aryl alcohol substrates were employed as arylation reagents via the cleavage of C(aryl)-C(OH) bonds and effectively converted into corresponding thioether, arene, and arylated benzoxazole products in excellent yields, in a Cu based catalytic system using O2 as the oxidant. This study offers a new way for aryl alcohol conversion and potentially offers a new opportunity to produce high-value functionalized aromatics from renewable feedstocks such as lignin which features abundant C(aryl)-C(OH) bonds in its linkages.

Nitrogen Dioxide Catalyzed Aerobic Oxidative Cleavage of C(OH)-C Bonds of Secondary Alcohols to Produce Acids.

Stable organic nitroxyl radicals are an important class of catalysts for oxidation reactions, but their wide applications are hindered by their steric hinderance, high cost, complex operation, and separation procedures. Herein, NO2 in DMSO is shown to effectively catalyze the aerobic oxidative cleavage of C(OH)-C bonds to form a carboxylic group, and NO2 was generated in situ by decomposition of nitrates. A diverse range of secondary alcohols were selectively converted into acids in excellent yields in this transition-metal-free system without any additives. Preliminary results also indicate its applicability to depolymerize recalcitrant macromolecular lignin. Detail studies revealed that NO2 from nitrates promoted the reaction, and NO2 served as hydrogen acceptor and radical initiator for the tandem oxidative reaction.

Ambient Reductive Amination of Levulinic Acid to Pyrrolidones over Pt Nanocatalysts on Porous TiO2 Nanosheets.

Construction of N-substituted pyrrolidones from biomass-derived levulinic acid (LA) via reductive amination is a highly attractive route for biomass valorization. However, realizing this transformation using H2 as the hydrogen source under mild conditions is still very challenging. Herein, we designed porous TiO2 nanosheets-supported Pt nanoparticles (Pt/P-TiO2) as the heterogeneous catalyst. The prepared Pt/P-TiO2 was highly efficient for reductive amination of LA to produce various N-substituted pyrrolidones (34 examples) at ambient temperature and H2 pressure. Meanwhile, Pt/P-TiO2 showed good applicability for reductive amination of levulinic esters, 4-acetylbutyric acid, 2-acetylbenzoic acid, and 2-carboxybenzaldehyde. Systematic studies indicated that the strong acidity of P-TiO2 and the lower electron density of the Pt sites as well as the porous structure resulted in the excellent activity of Pt/P-TiO2.

Stepwise degradation of hydroxyl compounds to aldehydes via successive C-C bond cleavage.

Stepwise degradation of hydroxyl compounds to aldehydes via successive cleavage of C-C bonds was achieved by using a bimetallic catalytic system (PdCl2 + CuCl) without any ligands and additives. The broad applicability is expanded to a diverse range of aromatic, aliphatic, primary and secondary alcohols, as well as lignin model compounds.

Selective catalytic transformation of lignin with guaiacol as the only liquid product.

Guaiacol is an important feedstock for producing various high-value chemicals. However, the current production route of guaiacol relies heavily on fossil resources. Using lignin as a cheap and renewable feedstock to selectively produce guaiacol has great potential, but it is a challenge because of its heterogeneity and inert reactivity. Herein, we discovered that La(OTf)3 could catalyze the transformation of lignin with guaiacol as the only liquid product. In the reaction, La(OTf)3 catalyzed the hydrolysis of lignin ether linkages to form alkyl-syringol and alkyl-guaiacol, which further underwent decarbonization and demethoxylation to produce guaiacol with a yield of up to 25.5 wt%, and the remaining residue was solid. In the scale-up experiment, the isolated yield of guaiacol reached up to 21.2 wt%. To our knowledge, this is the first work to produce pure guaiacol selectively from lignin. The bio-guaiacol may be considered as a platform to promote lignin utilization.

Transformation of alcohols to esters promoted by hydrogen bonds using oxygen as the oxidant under metal-free conditions.

One-pot oxidative transformation of alcohols into esters is very attractive, but metal-based catalysts are used in the reported routes. We discovered that the basic ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM] OAc) could effectively catalyze this kind of reaction using O2 as an oxidant without any other catalysts or additives. The oxidative self-esterification of benzylic alcohols or aliphatic alcohols and cross-esterification between benzyl alcohols and aliphatic alcohols could all be achieved with high yields. Detailed study revealed that the cation with acidic proton and basic acetate anion could simultaneously form multiple hydrogen bonds with the hydroxyl groups of the alcohols, which catalyzed the reaction very effectively. As far as we know, this is the first work to carry out this kind of reaction under metal-free conditions.

Synthesis of Hierarchical Porous Metals Using Ionic-Liquid-Based Media as Solvent and Template.

It was found that nanodomains existed in the ionic liquid (IL)-based ternary system containing IL 1-ethyl-3-methylimidazole tetrafluoroborate (EmimBF4 ), IL 1-decyl-3-methylimidazole nitrate (DmimNO3 ) and water, and the size distribution of the domains varied continuously with the composition of the solution. A strategy to synthesize hierarchical porous metals using IL-based media as solvent and template is proposed, and the hierarchical porous Ru and Pt metals were prepared by the assembly of metal clusters of about 1.5 nm using this new method. It is demonstrated that the metals have micropores and mesopores, and the size distribution is tuned by controlling the composition of the solution. Porous Ru was used for a series of hydrogenation reactions. It has an outstanding catalytic performance owing to its special morphology and structure.