22 research outputs found
CCN3 and bone marrow cells
CCN3 expression was observed in a broad variety of tissues from the early stage of development. However, a kind of loss of function in mice (CCN3 del VWC domain -/-) demonstrated mild abnormality, which indicates that CCN3 may not be critical for the normal embryogenesis as a single gene. The importance of CCN3 in bone marrow environment becomes to be recognized by the studies of hematopoietic stem cells and Chronic Myeloid Leukemia cells. CCN3 expression in bone marrow has been denied by several investigations, but we found CCN3 positive stromal and hematopoietic cells at bone extremities with a new antibody although they are a very few populations. We investigated the expression pattern of CCN3 in the cultured bone marrow derived mesenchymal stem cells and found its preference for osteogenic differentiation. From the analyses of in vitro experiment using an osteogenic mesenchymal stem cell line, Kusa-A1, we found that CCN3 downregulates osteogenesis by two different pathways; suppression of BMP and stimulation of Notch. Secreted CCN3 from Kusa cells inhibited the differentiation of osteoblasts in separate culture, which indicates the paracrine manner of CCN3 activity. CCN3 may also affect the extracellular environment of the niche for hematopoietic stem cells
Copper-catalyzed carbon-heteroatom bond formations : asymmetric hydroamination and continuous-flow aromatic Finkelstein reaction
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Chemistry, 2019Cataloged from PDF version of thesis.Includes bibliographical references.The studies presented in this dissertation are regarding the development of new methods for copper-catalyzed carbon-heteroatom bond formations, including asymmetric hydroamination and continuous-flow aromatic Finkelstein reaction. The first part of this dissertation focuses on the development of copper-catalyzed asymmetric hydroamination reactions to access various classes of enantioenriched amines. This includes the development of a broadly applicable hydroamination protocol for the synthesis of enantioenriched N-arylamines (Chapter 1) and 1,2- diamines (Chapter 2). The second part of this dissertation describes the development of copper-catalyzed aromatic Finkelstein reaction under continuous-flow conditions (Chapter 3). Part I. Chapter 1.A Modified System for the Synthesis of Enantioenriched N-Arylamines through Copper-Catalyzed Hydroamination Despite significant recent progress in copper-catalyzed enantioselective hydroamination chemistry, the synthesis of chiral N-arylamines, which are frequently found in natural products and pharmaceuticals, has not been realized. Initial experiments with N-arylhydroxylamine ester electrophiles were unsuccessful and instead, their reduction, in the presence of copper hydride (CuH) catalysts, was observed. We detail key modifications of our previously reported hydroamination protocols that led to broadly applicable conditions for the enantioselective net addition of secondary anilines across the double bond of styrenes, 1,1 -disubstituted alkenes, and terminal alkenes. NMR studies suggest that suppression of the undesired reduction pathway is the basis for the dramatic improvements in yield under this new protocol. Chapter 2.Regio- and Enantioselective Synthesis of 1,2-Diamine Derivatives by Copper- Catalyzed Hydroamination A highly regio- and enantioselective synthesis of 1,2-diamines using [gamma]-substituted allylic pivalamides via copper-catalyzed hydroamination is reported. The N-pivaloyl group is essential, both in facilitating the hydrocupration step and in suppressing the unproductive [beta]-elimination from the alkylcopper intermediate. This synthetic approach enables an efficient construction of chiral, differentially protected, vicinal diamines under mild conditions with broad functional group tolerance. Part II. Chapter 3. Rapid and Efficient Copper-Catalyzed Finkelstein Reaction of (Hetero)Aromatics under Continuous-Flow Conditions A general, rapid, and efficient method for the copper-catalyzed Finkelstein reaction of (hetero)aromatics has been developed using continuous flow to generate a variety of aryl iodides.The described method can tolerate a broad range of functional groups, including N-H and O-H groups. Additionally, in lieu of isolation, the aryl iodide products in solution can be directly used in two distinct multistep continuous-flow processes (amidation or Mg-I exchange/nucleophilic addition) to demonstrate the flexibility of this method.by Saki Ichikawa.Ph. D.Ph.D. Massachusetts Institute of Technology, Department of Chemistr
A Modified System for the Synthesis of Enantioenriched N -Arylamines through Copper-Catalyzed Hydroamination
Despite significant recent progress in copper-catalyzed enantioselective hydroamination chemistry, the synthesis of chiral N-arylamines, which are frequently found in natural products and pharmaceuticals, has not been realized. Initial experiments with N-arylhydroxylamine ester electrophiles were unsuccessful and, instead, their reduction in the presence of copper hydride (CuH) catalysts was observed. Herein, we report key modifications to our previously reported hydroamination methods that lead to broadly applicable conditions for the enantioselective net addition of secondary anilines across the double bond of styrenes, 1,1-disubstituted olefins, and terminal alkenes. NMR studies suggest that suppression of the undesired reduction pathway is the basis for the dramatic improvements in yield under the reported method. A Modified System for the Synthesis of Enantioenriched N-Arylamines through Copper-Catalyzed HydroaminationSaki Ichikawa, Dr. Shaolin Zhu, and Prof. Dr Stephen L. BuchwaldDepartment of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, United StatesAbstractDespite significant recent progress in the copper-catalyzed enantioselective hydroamination chemistry, the synthesis of chiral N-arylamines, which are frequently found in natural products and pharmaceuticals, has not been realized. Initial experiments with N-arylhydroxylamine ester electrophiles were unsuccessful and, instead, their reduction in the presence of copper hydride (CuH) catalysts was observed. Herein, we report key modifications to our previously reported hydroamination methods that lead to broadly applicable conditions for the enantioselective net addition of secondary anilines across the double bond of styrenes, 1,1-disubstituted olefins, and terminal alkenes. NMR studies suggest that suppression of the undesired reduction pathway is the basis for the dramatic improvements in yield under the reported protocol.A modified systemAn efficient method for the preparation of enaptioenriched N-arylamines was developed by making key modifications to a previously reported hydroamination. The reaction is mediated by a copper(I)-hydride (CuH) catalyst, and wide range of olefins and N-arylhydroxylamines are compatible under the optimized conditions. Key to the successful development of this method was the addition of tBuOH and PPh3 to the reaction mixture. Keywords: hydroamination; copper; enantioenriched N-arylamines; asymmetric synthesisNational Institutes of Health (U.S.) (NIH R01-GM58160)National Institutes of Health (U.S.) (NIH R35-GM122483
Regio- and Enantioselective Synthesis of 1,2-Diamine Derivatives by Copper-Catalyzed Hydroamination
A highly regio- and enantioselective synthesis of 1,2-diamine derivatives from Îł-substituted allylic pivalamides using copper-catalyzed hydroamination is reported. The N-pivaloyl group is essential, in both facilitating the hydrocupration step and suppressing an unproductive ÎČ-elimination from the alkylcopper intermediate. This approach enables an efficient construction of chiral differentially protected vicinal diamines under mild conditions with broad functional group tolerance. ©2019 American Chemical Society.National Institute of Health (R35-GM122483)National Institute of Health (R01-GM58160)NIH (Grant no. GM58160-17S1
Differential organ-specific inflammatory response to progranulin in high-fat diet-fed mice
Abstract Progranulin (PGRN) has been reported to bind tumor necrosis factor (TNF) receptor and to inhibit TNFα signaling. We evaluated the effect of augmentation of TNFα signaling by PGRN deficiency on the progression of kidney injury. Eight-week-old PGRN knockout (KO) and wild-type (WT) mice were fed a standard diet or high-fat diet (HFD) for 12 weeks. Albuminuria, markers of tubular damage, and renal mRNA levels of inflammatory cytokines were higher in HFD-fed KO (KO-HFD) mice than in HFD-fed WT (WT-HFD) mice. Body weight, vacuolization in proximal tubules, and systemic and adipose tissue inflammatory markers were lower in the KO-HFD mice than in the WT-HFD mice. The renal megalin expression was lower in the KO mice than in the WT mice regardless of the diet type. The megalin expression was also reduced in mouse proximal tubule epithelial cells stimulated with TNFα and in those with PGRN knockdown by small interfering RNA in vitro. PGRN deficiency was associated with both exacerbated renal inflammation and decreased systemic inflammation, including that in the adipose tissue of mice with HFD-induced obesity. Improved tubular vacuolization in the KO-HFD mice might partially be explained by the decreased expression of megalin in proximal tubules
Iron-Catalyzed Directed Alkylation of Aromatic and Olefinic Carboxamides with Primary and Secondary Alkyl Tosylates, Mesylates, and Halides
Alkenes, arenes, and heteroarenes
possessing an 8-quinolylamide
group as the directing group are alkylated with primary and secondary
alkyl tosylates, mesylate, and halides in the presence of FeÂ(acac)<sub>3</sub>/diphosphine as a catalyst and ArZnBr as a base. The reaction
proceeds stereospecifically for alkene substrates and takes place
without loss of regiochemical integrity of the starting secondary
tosylate, but with loss of the stereochemistry of the chiral center
Long-Term Diet Supplementation with Lactobacillus paracasei K71 Prevents Age-Related Cognitive Decline in Senescence-Accelerated Mouse Prone 8
This study aimed to assess the suppressive effect of long-term diet supplementation with Lactobacillus strains on cognitive decline in the senescence-accelerated mouse prone 8 (SAMP8) model. For 43 weeks, fourteen-week-old female SAMP8 mice were fed a standard diet containing 0.05% (w/w) Lactobacillus casei subsp. casei 327 (L. 327) or Lactobacillusparacasei K71 (L. K71) derived from rice grains and sake lees, respectively. SAMP8 mice that were fed a L. K71-supplemented diet had better cognitive performance compared with the control and L. 327 groups in the Barnes maze and passive avoidance tests. An ELISA analysis revealed that the levels of serotonin were elevated in the serum and brain tissue of L. K71-fed mice. The protein expression levels of brain-derived neurotrophic factor (BDNF), cAMP response element binding protein (CREB), and phosphorylated CREB were evaluated using western blot. Long-term administration of L. K71 resulted in increased protein expression of BDNF and CREB phosphorylation in the hippocampus. These results suggest that prolonged intake of a diet supplemented with a Lactobacillus strain derived from sake lees may prevent age-dependent cognitive decline by upregulating BDNF expression in the hippocampus
Suppression of CH4 Emission by Rice Straw Removal and Application of BioâEthanol Production Residue in a Paddy Field in Akita, Japan
To elucidate the effects of rice straw removal and rice strawâbased bioâethanol production residue application on rice growth and methane (CH4) emission from a paddy field, a lysimeter experiment with three treatments (application of rice straw after harvesting (the riceâstraw plot); removal of rice straw and the application of bioâethanol production residue (the Etâresidue plot); removal of rice straw (the noâapplication plot)) was conducted over three years. Though the grain yields in the Etâresidue and noâapplication plots tended to be slightly higher than that in the ricestraw plot, there were no significant differences among the plots (530â546 gâmâ2). Suppression of CH4 emission by the treatments was found clearly in the early part of the growing season. The total CH4 emissions during the riceâgrowing season (unit: gâCâmâ2âperiodâ1) followed the order of the noapplication plot (11.9) < the Etâresidue plot (14.6) < the riceâstraw plot (25.4), and a significant difference was found between the noâapplication and riceâstraw plots. Consequently, bioâethanol production from rice straw and a following application of its residue to paddy fields is considered to be a promising technology which can obtain new sustainable energy and suppress CH4 emission without any inhibition on rice growth
Safe and Effective Delivery of Small Interfering RNA with Polymer- and Liposomes-Based Complexes
We developed binary and ternary complexes based on polymers and liposomes for safe and effective delivery of small interfering RNA (siRNA). Anti-luciferase siRNA was used as a model of nucleic acid medicine. The binary complexes of siRNA were prepared with cationic polymers and cationic liposomes such as polyethylenimine (PEI), polyamidoamine (PAMAM) dendrimer, poly-L-arginine (PLA), trimethyl[2,3-(dioleoxy)-propyl]ammonium chloride (DOTMA), and cholesteryl 3ÎČ-N-(dimetylaminnoethyl)carbamate hydrochloride (DC-Chol). The ternary complexes were constructed by the addition of Îł-polyglutamic acid (Îł-PGA) to the binary complexes. The complexes were approximately 54-153 nm in particle size. The binary complexes showed a cationic surface charge although an anionic surface charge was observed in the ternary complexes. The polymer-based complexes did not show a silencing effect in the mouse colon carcinoma cell line expressing luciferase regularly (Colon26/Luc cells). The binary complexes based on liposomes and their ternary complexes coated by Îł-PGA showed a significant silencing effect. The binary complexes showed significant cytotoxicity although the ternary complexes coated by Îł-PGA did not show significant cytotoxicity. The ternary complexes coated by Îł-PGA suppressed luciferase activity in the tumor after their direct injection into the tumors of mice bearing Colon26/Luc cells. Thus, we have newly identified safe and efficient ternary complexes of siRNA for clinical use
Beneficial effects of tonsillectomy plus steroid pulse therapy on inflammatory and tubular markers in patients with IgA nephropathy
Background: IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis worldwide. Tonsillectomy plus steroid pulse therapy has been able to induce clinical remission in early-stage IgAN. However, its possible effect on systemic and local cytokines and tubular markers has not been fully investigated.
Methods: We obtained serum and urine samples from 38 patients just before renal biopsy and third steroid pulse therapy. Markers of tubular damage such as N-acetyl-ÎČ-d-glucosaminidase, and kidney injury molecule-1 and inflammation such as interleukin (IL)-6, monocyte chemotactic protein (MCP)-1, intercellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule (VCAM)-1 were measured by immunoassay.
Results: Before renal biopsy, only urinary inflammatory markers, except MCP-1, were associated with glomerular (proteinuria) and/or tubular damage markers. Proteinuria, hematuria, and estimated glomerular filtration rate dramatically improved after therapy. In addition, levels of serum IL-6 and ICAM-1 and all urinary markers declined significantly; however, serum MCP-1 and VCAM-1 levels did not. None of the urinary markers correlated with the serum inflammatory markers.
Conclusion: Tonsillectomy plus steroid pulse therapy for patients with IgAN might be useful for improving not only glomerular damage marker but also tubular damage markers through the improvement of local renal inflammation