Biomedical subjects

Yue Meng

Publications and source records attributed to Yue Meng.

5 recordsLinked to original sources

PubMed2024

The secreted micropeptide C4orf48 enhances renal fibrosis via an RNA-binding mechanism.

Renal interstitial fibrosis is an important mechanism in the progression of chronic kidney disease (CKD) to end-stage kidney disease. However, we lack specific treatments to slow or halt renal fibrosis. Ribosome profiling identified upregulation of a secreted micropeptide, C4orf48 (Cf48), in mouse diabetic nephropathy. Cf48 RNA and protein levels were upregulated in tubular epithelial cells in human and experimental CKD. Serum Cf48 levels were increased in human CKD and correlated with loss of kidney function, increasing CKD stage, and the degree of active interstitial fibrosis. Cf48 overexpression in mice accelerated renal fibrosis, while Cf48 gene deletion or knockdown by antisense oligonucleotides significantly reduced renal fibrosis in CKD models. In vitro, recombinant Cf48 (rCf48) enhanced TGF-β1-induced fibrotic responses in renal fibroblasts and epithelial cells independently of Smad3 phosphorylation. Cellular uptake of Cf48 and its profibrotic response in fibroblasts operated via the transferrin receptor. RNA immunoprecipitation-sequencing identified Cf48 binding to mRNA of genes involved in the fibrotic response, including Serpine1, Acta2, Ccn2, and Col4a1. rCf48 binds to the 3'UTR of Serpine1 and increases mRNA half-life. We identify the secreted Cf48 micropeptide as a potential enhancer of renal fibrosis that operates as an RNA-binding peptide to promote the production of extracellular matrix.

Animals↗

PubMed2004

The formation of sp3 bonding in compressed BN.

Attributed to their specific atomic bonding, the soft, graphite-like, hexagonal boron nitride (h-BN) and its superhard, diamond-like, cubic polymorph (c-BN) are important technological materials with a wide range of applications. At high pressure and temperature, h-BN can directly transform to a hexagonal close-packed polymorph (w-BN) that can be partially quenched after releasing pressure. Previous theoretical calculations and experimental measurements (primarily on quenched samples) provided substantial information on the transition, but left unsettled questions due to the lack of in situ characterization at high pressures. Using inelastic X-ray scattering to probe the boron and nitrogen near K-edge spectroscopy, here we report the first observation of the conversion process of boron and nitrogen sp(2)- and p-bonding to sp(3) and the directional nature of the sp(3) bonding. In combination with in situ X-ray diffraction probe, we have further clarified the structure transformation mechanism. The present archetypal example opens two enormous, element-specific, research areas on high-pressure bonding evolutions of boron and nitrogen; each of the two elements and their respective compounds have displayed a wealth of intriguing pressure-induced phenomena that result from bonding changes, including metallization, superconductivity, semiconductivity, polymerization and superhardness.

Boron Compounds↗

PubMed2003

Bonding changes in compressed superhard graphite.

Compressed under ambient temperature, graphite undergoes a transition at approximately 17 gigapascals. The near K-edge spectroscopy of carbon using synchrotron x-ray inelastic scattering reveals that half of the pi-bonds between graphite layers convert to sigma-bonds, whereas the other half remain as pi-bonds in the high-pressure form. The x-ray diffraction pattern of the high-pressure form is consistent with a distorted graphite structure in which bridging carbon atoms between graphite layers pair and form sigma-bonds, whereas the nonbridging carbon atoms remain unpaired with pi-bonds. The high-pressure form is superhard, capable of indenting cubic-diamond single crystals.

Journal Article↗

PubMed1998

Manganese-Mediated Carbon-Carbon Bond Formation in Aqueous Media: Chemoselective Allylation and Pinacol Coupling of Aryl Aldehydes.

The use of manganese as a mediator for allylations and pinacol couplings in aqueous media was investigated. The combination of manganese and copper is found to be a highly effective mediator for the allylation of aryl aldehydes in water. Such a combination is found to be more reactive than other previously reported metals in aqueous media. No reaction was observed with either manganese or copper alone as the mediator. Only a catalytic amount of copper is required for the proceeding of the reaction. The uses of Cu(0), Cu(I), and Cu(II) as the copper source are all effective. The use of a catalytic amount of manganese combined with a stoichoimetric amount of copper led to the failure of the reaction. Allyl chloride is found to be more effective than allyl bromide for the corresponding reaction. The use of substituted allyl halides gave a mixture of regio- and diastereoisomers. Aromatic aldehydes reacted chemoselectively in the presence of aliphatic aldehydes. An exclusive selectivity was also observed when both an aliphatic and an aromatic aldehyde functionalities are present in the same molecule. In the presence of acetic acid or ammonium chloride, manganese was found to effect the pinacol-coupling reaction in water. The reaction proceeds selectively with aryl aldehydes.

Journal Article↗

PubMed1998

Regio- and Diastereoselective Allenylation of Aldehydes in Aqueous Media: Total Synthesis of (+)-Goniofufurone(1).

The regio- and diastereoselectivities of metal-mediated allenylation of carbonyl compounds were investigated in aqueous media. Different metal mediators showed varied regioselectivities on product formation during propargylation-allenylation reactions of carbonyl compounds with simple propargyl bromide. Under the standard reaction conditions, the use of indium provided the highest regioselectivity, with a preference of formation of the homopropargyl alcohol. The use of tin and bismuth as the metal mediator provided slightly lower selectivities with the same preference. The use of zinc and cadmium as the mediators further lowered the product selectivity. The reactions of an aliphatic aldehyde with simple propargyl bromide showed a lower selectivity than the reaction of an aromatic aldehyde in most cases, except for the use of tin or zinc (where comparable selectivities were observed). On the other hand, the reaction of terminal-substituted propargyl bromides with aldehydes mediated by indium showed a high regioselectivity in forming allenylation products. The indium-mediated allenylation of carbonyl compounds bearing an alpha-hydroxyl group also proceeded with a high diastereoselectivity, forming syn-diols predominantly in aqueous ethanol. The high diastereoselectivity in allenylation of alpha-hydroxyl-substituted aldehydes was attributed to the chelation effect exhibited by the alpha-hydroxyl substitutent. Through the use of this highly diastereoselective allenylation, (+)-goniofufurone was synthesized from D-glucurono-6,3-lactone.

Journal Article↗