Effective delivery of miR-150-5p with nucleus pulposus cell-specific nanoparticles attenuates intervertebral disc degeneration.

BACKGROUND: The use of gene therapy to deliver microRNAs (miRNAs) has gradually translated to preclinical application for the treatment of intervertebral disc degeneration (IDD). However, the effects of miRNAs are hindered by the short half-life time and the poor cellular uptake, owing to the lack of efficient delivery systems. Here, we investigated nucleus pulposus cell (NPC) specific aptamer-decorated polymeric nanoparticles that can load miR-150-5p for IDD treatment. METHODS: The role of miR-150-5p during disc development and degeneration was examined by miR-150-5p knockout (KO) mice. Histological analysis was undertaken in disc specimens. The functional mechanism of miR-150-5p in IDD development was investigated by qRT-PCR assay, Western blot, coimmunoprecipitation and immunofluorescence. NPC specific aptamer-decorated nanoparticles was designed, and its penetration, stability and safety were evaluated. IDD progression was assessed by radiological analysis including X-ray and MRI, after the annulus fibrosus needle puncture surgery with miR-150-5p manipulation by intradiscal injection of nanoparticles. The investigations into the interaction between aptamer and receptor were conducted using mass spectrometry, molecular docking and molecular dynamics simulations. RESULTS: We investigated NPC-specific aptamer-decorated polymeric nanoparticles that can bind to miR-150-5p for IDD treatment. Furthermore, we detected that nanoparticle-loaded miR-150-5p inhibitors alleviated NPC senescence in vitro, and the effects of the nanoparticles were sustained for more than 3 months in vivo. The microenvironment of NPCs improves the endo/lysosomal escape of miRNAs, greatly inhibiting the secretion of senescence-associated factors and the subsequent degeneration of NPCs. Importantly, nanoparticles delivering miR-150-5p inhibitors attenuated needle puncture-induced IDD in mouse models by targeting FBXW11 and inhibiting TAK1 ubiquitination, resulting in the downregulation of NF-kB signaling pathway activity. CONCLUSIONS: NPC-targeting nanoparticles delivering miR-150-5p show favorable therapeutic efficacy and safety and may constitute a promising treatment for IDD.

Highly Efficient Electrosynthesis of Glycine over an Atomically Dispersed Iron Catalyst.

Glycine is a nonessential amino acid that plays a vital role in various biological activities. However, the conventional synthesis of glycine requires sophisticated procedures or toxic feedstocks. Herein, we report an electrochemical pathway for glycine synthesis via the reductive coupling of oxalic acid and nitrate or nitrogen oxides over atomically dispersed Fe-N-C catalysts. A glycine selectivity of 70.7% is achieved over Fe-N-C-700 at -1.0 V versus RHE. Synergy between the FeN3C structure and pyrrolic nitrogen in Fe-N-C-700 facilitates the reduction of oxalic acid to glyoxylic acid, which is crucial for producing glyoxylic acid oxime and glycine, and the FeN3C structure could reduce the energy barrier of *HOOCCH2NH2 intermediate formation thus accelerating the glyoxylic acid oxime conversion to glycine. This new synthesis approach for value-added chemicals using simple carbon and nitrogen sources could provide sustainable routes for organonitrogen compound production.

Manganese-Catalyzed Hydrogenative Desulfurization of Thioamides.

Earth-abundant transition metal catalysis has emerged as an important alternative to noble transition metal catalysis in hydrogenation reactions. However, there has been no Earth-abundant transition metal catalyzed hydrogenation of thioamides reported so far, presumably due to the poisoning of catalysts by sulfur-containing molecules. Herein, we described the first manganese-catalyzed hydrogenative desulfurization of thioamides to amines or imines. The key to success is the use of MnBr(CO)5 instead of commonly-employed pincer-manganese catalysts, together with simple NEt3 and CuBr. This protocol features excellent selectivity on sole cleavage of the C=S bond of thioamides, in contrast to the only known Ru-catalyzed hydrogenation of thioamides, and unprecedented chemo-selectivity tolerating vulnerable functional groups such as nitrile, ketone, aldehyde, ester, sulfone, nitro, olefin, alkyne and heterocycle, which are usually susceptible to common hydride-type reductive protocols.

Mechanochemistry: An Efficient Way to Recycle Thermoset Polyurethanes.

A recycling process of waste thermosetting polyurethane plastics was proposed based on the mechanochemical method, aiming at the three-dimensional network cross-linking structure of thermosetting polyurethane. Orthogonal experimental design was adopted to select three factors of crushing speed, crushing time, and feed amount to determine the best crushing parameters. Then, the waste polyurethane insulation boards were crushed and degraded by the mechanism of regenerative forming with the adjustable speed test machine. Accordingly, the recycled powder was obtained. Finally, nine kinds of polyurethane recycled composite plates were prepared by hot pressing process. The degradation effect of thermosetting polyurethane was analyzed by Fourier transform infrared spectroscopy, scanning electron microscope, and X-ray diffraction. Moreover, the mechanical properties and thermal insulation properties of recycled composite plates were tested and analyzed. The results show that the network cross-linking molecular structure of waste thermosetting polyurethane plastics is destroyed by the effect of mechanochemical action, and methyl and aldehyde groups are decomposed. Therefore, a recycled powder with strong reactivity and plasticity is generated, which improves the activity regeneration ability. After adding thermoplastic resin, the mechanical properties and formability of recycled composite plates are enhanced, with maximum tensile strength up to 9.913 MPa. Correspondingly, the thermal insulation performance of plates is reduced. However, the minimum thermal conductivity can also reach 0.056 W/m·K. This study provides an effective method for the recycling of thermosetting polyurethane plastics.

High Serpin Family A Member 10 Expression Confers Platinum Sensitivity and Is Associated With Survival Benefit in High-Grade Serous Ovarian Cancer: Based on Quantitative Proteomic Analysis.

This study aims to identify differentially expressed proteins related with platinum sensitivity and to find biomarkers for predicting platinum response and survival outcomes in patients with high-grade serous ovarian cancer (HGSOC). Eligible HGSOC patients were divided into platinum-sensitive and platinum-resistant groups according to platinum-free interval (PFI). Tissue protein lysates from tumor tissues were subjected to an in-solution tryptic digest followed by tandem mass tag (TMT) labeling of the resulting peptides and mass spectrometric analysis. Candidate proteins were identified using differentially expressed protein and gene set enrichment analysis (GSEA) and confirmed by immunohistochemistry (IHC), and their survival relevance was evaluated in The Cancer Genome Atlas (TCGA) ovarian cancer cohort. The results showed that there was a significant difference in the protein expression profiling between the two patient groups. In the GSEA model, a gene set of 239 extracellular matrix (ECM)-related proteins was significantly enriched in the platinum-sensitive group [normalized enrichment score (NES) = 3.82, q < 10-5], and this finding was confirmed in TCGA ovarian cancer cohort. Interestingly, an ECM-related gene expression, serpin family A member 10 (SERPINA10), was identified to be significantly positively correlated with overall survival (OS) and progression-free survival (PFS) in TCGA ovarian cancer cohort (all p < 0.05). IHC results demonstrated that HGSOC patients with high SERPINA10 expression had longer PFI than the patients with low SERPINA10 expression (9 vs. 5 months, p = 0.038), and the SERPINA10 expression had an area under the receiver operating characteristic curve (AUC) value of 0.758 (95% CI = 0.612-0.905; p = 0.005) to discriminate the platinum-sensitive group from the platinum-resistant group. In conclusion, the results suggested that SERPINA10 could be a promising biomarker for predicting the response and survival in platinum-based chemotherapy of HGSOC.

Mechanical Properties and Thermal Conductivity of Thermal Insulation Board Containing Recycled Thermosetting Polyurethane and Thermoplastic.

This study used a mechanochemical method to analyze the recycling mechanism of polyurethane foam and optimize the recycling process. The use of mechanochemical methods to regenerate the polyurethane foam powder breaks the C-O bond of the polyurethane foam and greatly enhances the activity of the powder. Based on orthogonal test design, the mesh, proportion, temperature, and time were selected to produce nine recycled boards by heat pressing. Then, the influence of four factors on the thermal conductivity and tensile strength of the recycled board was analyzed. The results show that 120 mesh polyurethane foam powder has strong activity, and the tensile strength can reach 9.913 Mpa when it is formed at 205 °C and 40 min with 50% PP powder. With the help of the low thermal conductivity of the polyurethane foam, the thermal conductivity of the recycled board can reach 0.037 W/m·K at the parameter of 40 mesh, 80%, 185 °C, 30 min. This research provides an effective method for the recycling of polyurethane foam.

Different Roles of TP53 Codon 72 Polymorphism in Type 2 Diabetes and Its Complications: Evidence from a Case-Control Study on a Chinese Han Population.

OBJECTIVE: The purpose of this study was to investigate the relationships between TP53 Pro72Arg (rs1042522) polymorphism and susceptibility to type 2 diabetes (T2DM) and its related complications. METHODS: The TP53 Pro72Arg polymorphism was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 206 T2DM patients and 446 healthy controls. Mitochondrial DNA (mtDNA) content, mtDNA transcriptional level and large-scale mtDNA deletion were evaluated in leukocytes of T2DM patients using fluorescence-based quantitative PCR (FQ-PCR), reverse transcriptase-quantitative PCR (RT-qPCR) and long-range PCR approaches, respectively. The data of our study were processed by GraphPad Prism software (version 7.00). RESULTS: The distribution of TP53 Pro72Arg differed in T2DM patients from the controls, with a moderately increased proportion of TP53 Arg72 variant carriers (Pro/Arg and Arg/Arg genotypes) (88.3% vs 81.2%, p=0.022; OR=1.089, 95% CI=1.018-1.164). T2DM patients with Arg/Arg genotype had significantly decreased prevalences of diabetic neuropathy and retinopathy compared to those without (6.5% vs 19.4%, p=0.018 and 14.8% vs 30.7%, p=0.018, respectively). T2DM patients with Arg/Arg genotype had higher mtDNA content and mtRNA expression level than those who were not Arg/Arg genotype (p<0.05 for all), and we did not observe mtDNA 4977-base pair (bp) deletion mutations in the leukocytes of T2DM patients. CONCLUSION: There was a significant association of the TP53 Pro72Arg polymorphism with susceptibility to T2DM, and the homozygous Arg/Arg genotype of this gene locus might be a protective factor for diabetic complications. Those results suggested that the TP53 Arg72 variant had a different association with type 2 diabetes and its complications, and it might be related to mtDNA maintenance of the TP53 Arg72 variant under hyperglycemia-induced stress.

Umpolung coupling of pyridine-2-carboxaldehydes and propargylic carbonates via N-heterocyclic carbene/palladium synergetic catalysis.

The umpolung cross-coupling reaction of pyridine-2-carboxaldehydes and propargylic carbonates has been developed for the first time through N-heterocyclic carbene/palladium cooperative catalysis with the judicious selection of the palladium catalyst, ligand and N-heterocyclic carbene, giving the propargylic ketones regioselectively.

Manganese-Catalyzed [3 + 2] Cyclization of Ketones and Isocyanates via Inert C-H Activation.

Stoichiometric cyclomanganation of aromatic ketones and further reactions of the thus-formed manganacycles with isocyanates were first reported by Kaesz and Liebeskind in 1975 and 1990, respectively. The buildup of a closed manganese catalytic cycle for the reaction of ketones and isocyanates remains an unsolved problem. Herein, an unprecedented trio of Me2Zn/AlCl3/AgOTf is developed to build up manganese catalysis, which enables the [3 + 2] cyclization of ketones with isocyanates via inert C-H activation to access 3-alkylidene phthalimidines in a straightforward manner unachieved by other transition metal catalyses.

Pathogenic Heteroplasmic Somatic Mitochondrial DNA Mutation Confers Platinum-Resistance and Recurrence of High-Grade Serous Ovarian Cancer.

PURPOSE: Platinum resistance is a primary barrier to improving the survival rate of ovarian cancer. The relationship between mtDNA somatic mutations and response to platinum-based chemotherapy in ovarian cancer has not been well clarified. PATIENTS AND METHODS: Here, we employed the next-generation sequencing (NGS) platform to identify mtDNA mutations of the unrelated high-grade serous ovarian cancer (HGSOC) patients. RESULTS: We identified 569 germline variants and 28 mtDNA somatic mutations, and found the platinum-sensitive relapsed HGSOC patients had more synonymous mutations while the platinum-resistant relapsed HGSOC patients had more missense mutations in the mtDNA somatic mutations. Meanwhile, we found that the HGSOC patients who harbored heteroplasmic pathogenic mtDNA somatic mutations had significantly higher prevalence of both platinum-resistance and relapse than those without (80.0% versus 16.7%, p=0.035). Additionally, we observed that the tumor tissues had significantly higher lactate-to-pyruvate (L/P) ratio than the paired nontumor tissues (p<0.001), and L/P ratio of tumors with any heteroplasmic pathogenic mtDNA mutations was significantly higher than that of the tumors free of pathogenic mtDNA mutations (p=0.025). CONCLUSION: Our findings indicate that these heteroplasmic pathogenic mtDNA somatic mutations may cause decreased respiratory chain activity and lead to the metabolism remodeling that seem to be beneficial for progression of both platinum-based chemotherapy resistance and relapse.

Manganese-Catalyzed Hydroarylation of Unactivated Alkenes.

Transition-metal-catalyzed hydroarylation of unactivated alkenes with strategic use of remote coordinating functional groups has received significant attention recently to address the issues of both low reactivity and poor selectivity. The bidentate 8-aminoquinoline amide group is the most successfully adopted in unactivated alkenes for Pd and Ni catalysis. We describe the first manganese-catalyzed hydroarylation of unactivated alkenes bearing diverse simple functionalities with arylboronic acids. A series of δ- and γ-arylated amides, ketones, pyridines, and amines was accessed with excellent regioselectivity and in high yields. Hydroalkenylation of unactivated alkenes was also shown to be applicable under this manganese-catalysis regime. The method features earth-abundant manganese catalysis, easily available substrates, broad functional-group tolerance, and excellent regioselective control.

Clinicopathological Analysis of Acquired Melanocytic Nevi and a Preliminary Study on the Possible Origin of Nevus Cells.

BACKGROUND: The pathogenesis of acquired melanocytic nevi (AMN) is still unclear, and the origin of nevus cells has not been clarified. OBJECTIVE: To analyze the clinical features and pathological types of AMN and identify the possible origin of nevus cells. METHODS: A retrospective study of 2929 cases of AMN was conducted, and 96 specimens of intradermal and junctional nevi were selected. Immunohistochemical assays were performed to detect the expression of basement membrane component receptor DDR-1 and the molecular markers on epidermal melanocytes, dermal stem cells (DSCs), and hair follicle stem cells. RESULTS: Junctional nevi and compound nevi were prone to occur on glabrous skin, such as the palms, soles, and vulva, and on the extremities in children, whereas intradermal nevi tended to develop on the trunk, head, and face of adults. The immunohistochemical data revealed that both junctional nevi and intradermal nevi expressed the epidermal melanocyte surface markers E-cadherin, DDR-1, and integrin α6 and the DSC molecular markers NGFRp-75 and nestin. CD34 was expressed only in junctional nevi, whereas K19 was not expressed in any type of melanocytic nevi. There was no significant difference in molecular expression at different sites or in different ages of onset. Nestin expression was markedly stronger in the intradermal nevi than in the junctional nevi, but there was no difference between the superficial and deep nevus cell nests of intradermal nevi. CONCLUSION: AMN may have a multicellular origin that commonly follows the mode of Abtropfung. Furthermore, DSCs may partly or independently participate in the formation of nevus cells.

Manganese-Catalyzed Aromatic C-H Allylation of Ketones.

Manganese-catalyzed aromatic C-H allylation of ketones is reported. The reaction proceeded in a monoselective allylation manner to provide various ortho C-H allylated ketones in high yields. With challenging allylic electrophiles bearing substituents at the α-, ß-, or γ-position, excellent SN2' regioselectivity was achieved under mild conditions (rt to 35 °C). Mechanistic studies revealed a possible turnover-limiting C-H bond cleavage step affording a five-membered manganacycle followed by reaction with allylic electrophiles to give the C-H allylation product.

Rhenium-Catalyzed Phthalide Synthesis from Benzamides and Aldehydes via C-H Bond Activation.

The [4 + 1] annulation of benzamides and aldehydes for phthalide synthesis was achieved via rhenium-catalyzed C-H activation, which demonstrates an unprecedented reaction pattern distinct from those of other transition-metal catalyses. The reaction also features readily available starting materials, a wide scope for both electro-rich and electro-deficient substrates, and the elimination of homoannulation byproducts.

Re-Catalyzed Annulations of Weakly Coordinating N-Carbamoyl Indoles/Indolines with Alkynes via C-H/C-N Bond Cleavage.

Described herein are rhenium-catalyzed [3+2] annulations of N-carbamoyl indoles with alkynes via C-H/C-N bond cleavage, which provide rapid access to fused-ring pyrroloindolone derivatives. For the first time, the weakly coordinating O-directing group was successfully employed in rhenium-catalyzed C-H activation reactions, enabled by the unique catalytic trio of Re2 (CO)10 , Me2 Zn and ZnCl2 . Mechanistic studies revealed that aminozinc species plays an important role in the reaction. Based on the mechanistic understanding, a more powerful catalytic trio of Re2 (CO)10 , [MeZnNPh2 ]2 and Zn(OTf)2 was devised and applied successfully in the [4+2] annulations of indolines and alkynes affording pyrroloquinolinone derivatives.

Manganese-Catalyzed Redox-Neutral C-H Olefination of Ketones with Unactivated Alkenes.

Since 1987, stoichiometric cyclomanganation of ketones and subsequent reactions with olefins in the presence of either palladium salts or trimethylamine N-oxide (Me3 N+ O- ) have been reported, but the catalytic versions remain untouched so far. Herein, the first manganese-catalyzed redox-neutral C-H olefination of ketones with unactivated alkenes is described, and shows a distinct reactivity with its parent stoichimetric reactions. Remarkably, mechanistic experiments and DFT calculations uncovers a unique concerted bis-metalation deprotonation (CBMD) mechanism of the Mn-Zn-enabled C-H bond activation.

Manganese-Catalyzed Hydrosilylation Reactions.

Over the past few decades, manganese-catalyzed hydrosilylation of C=O or C=C/C≡C unsaturated bonds have undergone enormous developments. In this focus review, the hydrosilylation reactions of alkenes, alkynes, and carbonyl-containing substrates catalyzed by manganese complexes are summarized. Moreover, the mechanisms of the manganese-catalyzed hydrosilylation are briefly discussed.

A Clinical Study on Axial Symptoms and Imaging Changes in Paraspinal Muscles after Cervical Posterior Open-door Laminoplasty.

OBJECTIVE: This research aimed to gain a better understanding of the relationship between cervical posterior open-door laminoplasty on axial symptoms, the net cross-sectional area of paraspinal muscles, and the degree of pimelosis. METHOD: A retrospective study was conducted on a consecutive series of 37 patients who had underwent cervical posterior open-door laminoplasty + lateral mass fixation and bone graft fusion between January 2015 and July 2015. All patients received postoperative examinations at 6 months and 18 months after the operation. For each follow-up visit, the VAS Rating Scale and ODI Function Index Questionnaire were filled out. Meanwhile, a C-Spine X-ray and MRI of the patients were taken. In the measurements taken with ImageJ 1.51 K Software, the cervical vertebra MRI T2-weighted image cross-section for each segment was measured separately, mainly including the mean T2 signal value of the contour area and the net area of the paraspinal muscles. RESULTS: Differences between VAS and ODI (%) at three different time points were of statistical significance (p < 0.01). Pairwise comparisons of the results showed that VAS and ODI (%) at different times were clearly different (p < 0.01). Differences in the mean T2 signal value and net area at different times were of statistical significance (p < 0.01). Pairwise comparisons of the results indicated that the mean T2 signal value and net area at different times were clearly different (p < 0.01). The corresponding analytical results for VAS, ODI (%), and the mean of the T2 signal value and net area demonstrated that VAS6 months after surgery was positively correlated to the net area of C3/4 and C4/5 (r = 0.352, p < 0.05; r = 0.338, p < 0.05). The analogous analytical results for the mean T2 signal value and net area were of no statistical significance (p > 0.05). CONCLUSIONS: We believe that axial symptoms after cervical spine surgery does not affect the recovery of neurological function. There is a process of acute or subacute enlargement of paraspinal muscles on segments C3/4 and C4/5 after the operation, while the results of the follow-up visits show that there is a gradual process of atrophy in local posterior muscles, which may be related to axial symptoms. The degree of pimelosis of the neck paraspinal muscles may have no relationship with axial symptoms.

Inert C-H Bond Transformations Enabled by Organometallic Manganese Catalysis.

Traditional organic synthesis relies heavily on the transformations of various preinstalled functional groups, such as cross-coupling reactions using organohalides and organometallic reagents. The strategy of C-H activation enables the direct formation of C-C/C-X (X = heteroatom) bonds from inert C-H bonds, which can enhance the atom- and step-economy of organic synthesis. To date, precious metals have overwhelmingly dominated the C-H activation field; however, the rarity and high cost of these metals necessitate the development of more sustainable catalysts. In this regard, catalysts based on manganese are highly desirable owing to the abundant reserve of manganese in the earth's crust and its economic benefits, low toxicity, and potentially unique reactivity. Although the first stoichiometric manganese-mediated C-H activation reaction was reported as early as 1970, manganese-catalyzed C-H activation reactions are largely underdeveloped. How to construct an efficient catalytic cycle for manganese in C-H activation reactions remains as a key issue to be addressed. In this Account, we summarize our recent advances in the manganese-catalyzed transformations of inert C-H bonds. To overcome the challenges associated with building manganese-based catalytic cycles, we developed two novel strategies, namely, synergy between manganese catalysts and bases and between manganese catalysts (with or w/o bases) and acids. By implementing the former strategy, we developed cooperative manganese/base catalytic systems that facilitate a new mode of C-H bond activation by manganese via a redox-neutral base-assisted deprotonation mechanism. As such, the requirement for the tedious preparation of MnR(CO)5 complexes (R = Me, Bn, Ph) in stoichiometric reactions was eliminated, and a series of manganese-catalyzed C-H activation reactions of arenes with various reaction partners having C≡C and C═C bonds were achieved. Through the latter strategy of synergy between manganese catalysts (with or w/o bases) and acids, we disclosed a "dual activation" mode for performing manganese-catalyzed C-H bond transformations, that is, merging C-H activation by manganese catalysts and C-X multiple bond activation by Lewis acids. Consequently, the scope of C-H substrates could be expanded to include challenging ketones and olefinic C-H compounds. Additionally, the range of reaction partners could be significantly broadened to include those bearing more polarized C═O, C═N, and C≡N bonds such as aldehydes, imines, and nitriles. Remarkably, the innate reactivity of different C-H bonds in ketones could be reversed by manganese catalysis, and the reactions could even be carried out at room temperature. Our findings provide guiding information for the future development of manganese-catalyzed C-H activation reactions and beyond. Related important contributions from other groups are mentioned, and the remaining challenges and future perspective in this emerging area are also presented.

Dichotomy of Manganese Catalysis via Organometallic or Radical Mechanism: Stereodivergent Hydrosilylation of Alkynes.

Herein, we disclose the first manganese-catalyzed hydrosilylation of alkynes featuring diverse selectivities. The highly selective formation of E-products was achieved by using mononuclear MnBr(CO)5 with the arsenic ligand, AsPh3 . Whereas using the dinuclear catalyst Mn2 (CO)10 and LPO (dilauroyl peroxide) enabled the reversed generation of Z-products in good to excellent stereo- and regioselectivity. Such a way of controlling the reaction stereoselectivity is unprecedented. Mechanistic experiments revealed the dichotomy of manganese catalysis via organometallic and radical pathways operating in the E- and Z-selective routes, respectively.