Month: October 2022

Liu, Tao; Chen, Gang; Sun, Dawei; Lei, Minghui; Li, Yongqiang; Zhou, Changming; Li, Xiaodong; Xue, Wei; Wang, Hong; Liu, Chunjun; Xu, Jiang published the artcile< Exosomes containing miR-21 transfer the characteristic of cisplatin resistance by targeting PTEN and PDCD4 in oral squamous cell carcinoma>, Application In Synthesis of 6823-69-4, the main research area is exosome miR21 anticancer cisplatin resistance oral squamous cell carcinoma; cisplatin resistance; exosome; miR-21; oral squamous cell carcinoma.

Resistance to chemotherapy remains a major obstacle for the effective treatment of oral squamous cell carcinoma (OSCC). Evidence for the involvement of exosomes as important regulators of cisplatin chemoresistance in OSCC is still poorly understood. Our objective of this study was to explore the roles for exosomes in modulating key cellular pathways mediating response to chemotherapy. We first developed the cisplatin-resistant cell lines (HSC-3-R and SCC-9-R) and found that the conditioned media from cisplatin-resistant OSCC cells enhanced the chemoresistance of parental OSCC cell. The release of exosomes was blocked by inhibitor (GW4869) and exosomes were found to be involved in the chemoresistance of parental OSCC cell transferred from resistant cells. The exosomes derived from resistant cells and parental cells were isolated. Then, the isolated exosomes were characterized and quantified by electron microscopy, qNano anal., and western blot anal. Exosomes derived from cisplatin-resistant OSCC cells were found to enhance the chemoresistance of OSCC cell and decrease the DNA damage signaling in response to cisplatin. It was also found that exosomes derived from cisplatin-resistant OSCC cells transferred miR-21 to OSCC parental cells and induced cisplatin resistance by targeting phosphatase and tensin homolog and programmed cell death 4. Furthermore, the roles of cisplatin-resistant OSCC cells-derived exosomes in vivo were confirmed by s.c. xenograft mouse model.Collectively, the results suggest that exosomes released from cisplatin-resistant OSCC cells transmit miR-21 to induce cisplatin resistance of OSCC cells.

Acta Biochimica et Biophysica Sinica published new progress about Antitumor agents. 6823-69-4 belongs to class imidazoles-derivatives, and the molecular formula is C30H30Cl2N6O2, Application In Synthesis of 6823-69-4.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Shin, Yeonoh; Hedglin, Mark; Murakami, Katsuhiko S. published the artcile< Structural basis of reiterative transcription from the pyrG and Pyrbi promoters by bacterial RNA polymerase>, HPLC of Formula: 452-06-2, the main research area is gene transcription pyrG Pyrbi bacteria RNA polymerase crystal structure.

Reiterative transcription is a non-canonical form of RNA synthesis by RNA polymerase in which a ribonucleotide specified by a single base in the DNA template is repetitively added to the nascent RNA transcript. We previously determined the X-ray crystal structure of the bacterial RNA polymerase engaged in reiterative transcription from the pyrG promoter, which contains eight poly-G RNA bases synthesized using three C bases in the DNA as a template and extends RNA without displacement of the promoter recognition σ factor from the core enzyme. In this study, we determined a series of transcript initiation complex structures from the pyrG promoter using soak-trigger-freeze X-ray crystallog. We also performed biochem. assays to monitor template DNA translocation during RNA synthesis from the pyrG promoter and in vitro transcription assays to determine the length of poly-G RNA from the pyrG promoter variants. Our study revealed how RNA slips on template DNA and how RNA polymerase and template DNA determine length of reiterative RNA product. Lastly, we determined a structure of a transcript initiation complex at the pyrBI promoter and proposed an alternative mechanism of RNA slippage and extension requiring the σ dissociation from the core enzyme.

Nucleic Acids Research published new progress about Bacillus subtilis. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, HPLC of Formula: 452-06-2.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Volpe, Andrea; Natali, Mirco; Graiff, Claudia; Sartorel, Andrea; Tubaro, Cristina; Bonchio, Marcella published the artcile< Novel iridium complexes with N-heterocyclic dicarbene ligands in light-driven water oxidation catalysis: photon management, ligand effect and catalyst evolution>, Recommanded Product: 5-Bromo-1-methyl-1H-imidazole, the main research area is imidazolylidene silver dicarbene complex transmetalation cyclopentadienyl iridium chloride; iridium imidazolylidene dicarbene complex preparation catalyst water oxidation kinetics; crystal structure imidazolylidene cyclopentadienyliridium dicarbene complex; mol structure imidazolylidene cyclopentadienyliridium dicarbene complex.

Ir complexes [IrClCp*diNHC]PF6, with N-heterocyclic dicarbene (diNHC) and pentamethylcyclopentadienyl (Cp*) ligands, were studied in light driven H2O oxidation catalysis within the Ru(bpy)32+/S2O82- cycle (bpy = 2,2′-bipyridine). In particular, the effect of different diNHC ligands was evaluated by employing the complex 1a (diNHC = 1,1′-dimethyl-3,3′-ethylenediimidazol-2,2′-diylidene) and the novel and structurally characterized 2 (diNHC = 1,1′-dimethyl-3,3′-ethylene-5,5′-dibromodiimidazol-2,2′-diylidene) and 3 (diNHC = 1,1′-dimethyl-3,3′-ethylene-dibenzimidazol-2,2′-diylidene). The presented results include: (i) a photon management anal. of the 1a/Ru(bpy)32+/S2O82- system, revealing two regimes of O2 evolution rate, being dependent on the light intensity at low photon flux, where the system reaches an overall quantum yield up to 0.17 ± 0.01 (quantum efficiency 34 ± 2%), while being independent of light intensity at high photon flux thus indicating a change of limiting step; (ii) a trend of O2 evolution activity that follows the order 1a > 2 > 3 both under low and high photon flux conditions, with the reactivity that is favored by the electron donating nature of the diNHC ligand, quantified from the carbene C chem. shift; (iii) an analogous trend also in the bimol. rate constants of electron transfer kET from the Ir species to photogenerated Ru(bpy)33+, with kET values in the range 4.2-6.1 × 104 M-1 s-1, thus implying a significant reorganization energy to the Ir sphere; (iv) the evolution of 1a, as the most active Ir species in the series, to mononuclear Ir species with lower mol. weight and originating from oxidative transformation of the organic ligand scaffold, as proven by converging UV-visible, MALDI-MS and 1H-NMR evidences. These results can be used for the further design and engineering of novel catalysts.

Dalton Transactions published new progress about Carbene complexes Role: CAT (Catalyst Use), PRP (Properties), SPN (Synthetic Preparation), USES (Uses), PREP (Preparation) (cyclopentadienyl Ir complexes). 1003-21-0 belongs to class imidazoles-derivatives, and the molecular formula is C4H5BrN2, Recommanded Product: 5-Bromo-1-methyl-1H-imidazole.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Wickhorst, Peter Jonas; Ihmels, Heiko; Paululat, Thomas published the artcile< Studies on the Interactions of 3,11-Difluoro-6,8,13-trimethyl-8H-quino[4,3,2-kl]acridinium and Insulin with the Quadruplex-Forming Oligonucleotide Sequence a2 from the Insulin-Linked Polymorphic Region>, Quality Control of 452-06-2, the main research area is interaction quadruplex oligonucleotide sequence insulin linked polymorphic region; DNA recognition; ILPR; spectroscopic methods.

Recently, several quadruplex-DNA-forming sequences have been identified in the insulin-linked polymorphic region (ILPR), which is a guanine-rich oligonucleotide sequence in the promoter region of insulin. The formation of this non-canonical quadruplex DNA (G4-DNA) has been shown to be involved in the biol. activity of the ILPR, specifically with regard to its interplay with insulin. In this context, this contribution reports on the investigation of the association of the quadruplex-forming ILPR sequence a2 with insulin as well as with the well-known G4-DNA ligand 3,11-difluoro-6,8,13-trimethyl-8H-quino[4,3,2-kl]acridinium (1), also named RHPS4, by optical and NMR spectroscopy. CD- and NMR-spectroscopic measurements confirmed the preferential formation of an antiparallel quadruplex structure of a2 with four stacked guanine quartets. Furthermore, ligand 1 has high affinity toward a2 and binds by terminal π stacking to the G1-G11-G15-G25 quartet. In addition, the spectroscopic studies pointed to an association of insulin to the deoxyribose backbone of the loops of a2.

Molecules published new progress about Absorption. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Quality Control of 452-06-2.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

He, Yanping; Zhou, Yibo; Chen, Da; Liu, Juewen published the artcile< Global Folding of a Na+-Specific DNAzyme Studied by FRET>, Name: 7H-Purin-2-amine, the main research area is DNAzymes; FRET; aptamers; protein folding; sodium.

Recently, a few RNA-cleaving DNAzymes have been isolated with excellent specificity for Na+, and some of them contain a Na+-binding aptamer. This metal recognition mechanism is different from that of most previously reported DNAzymes. When using 2-aminopurine (2AP) as a probe, interesting local folding induced by Na+ was recently observed In this work, FRET was used to probe the global folding of the Ce13d DNAzyme; one of the Na+-specific DNAzymes. FRET pairs were at different locations, which yielded a total of five constructs to probe the three-way junction structure with a large loop. With endlabeled DNAzymes, the global structure appears to be quite rigid with little folding upon adding up to 200 mM monovalent metal ions, although some minor differences were observed between Li+, Na+, and K+. This lack of significant conformational change is also consistent with CD spectroscopy data. The loop was then labeled with an internal tetramethylrhodamine fluorophore at the G14 position, and its cleavage activity was partially retained. A clear Na+-dependent folding was observed with spectral crossover. From a biosensing standpoint, global folding based sensors are unlikely to work due to the overall rigid structure of the DNAzyme. Therefore, the best way to use this DNAzyme to discriminate Na+ from K+ is based on cleavage activity, followed by probing local folding, whereas global folding is the least effective for metal discrimination.

ChemBioChem published new progress about 452-06-2. 452-06-2 belongs to class imidazoles-derivatives, and the molecular formula is C5H5N5, Name: 7H-Purin-2-amine.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Tong, Ying; Ye, Chao; Ren, Xing-Sheng; Qiu, Yun; Zang, Ying-Hao; Xiong, Xiao-Qing; Wang, Jue-Jin; Chen, Qi; Li, Yue-Hua; Kang, Yu-Ming; Zhu, Guo-Qing published the artcile< Exosome-Mediated Transfer of ACE (Angiotensin-Converting Enzyme) From Adventitial Fibroblasts of Spontaneously Hypertensive Rats Promotes Vascular Smooth Muscle Cell Migration>, Recommanded Product: p-Benzenediacrylanilide, 4′,4′′-di-2-imidazolin-2-yl-, dihydrochloride, the main research area is ACE fibroblast exosome vascular smooth muscle cell migration hypertension; captopril; exosomes; fibroblasts; hypertension; vascular remodeling.

Migration of vascular smooth muscle cells (VSMCs) is pivotal for vascular remodeling in hypertension. Vascular adventitial fibroblasts (AFs) are important in the homeostasis of vascular structure. This study is designed to investigate the roles of AF exosomes (AFE) in VSMC migration and underling mechanism. Primary VSMCs and AFs were obtained from the aorta of spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. VSMC migration was evaluated with Boyden chamber assay and wound healing assay. AFE from WKY rats and SHR were isolated and identified. AFE from SHR promoted but AFE from WKY rats had no significant effect on VSMC migration. The effects of AFE on VSMC migration were prevented by an exosome inhibitor GW4869, an AT1R (Ang II [angiotensin II] type 1 receptor) antagonist losartan, or an inhibitor of ACE (angiotensin-converting enzyme) captopril. ACE contents and activity were much higher in AFE from SHR than those from WKY rats. There were no significant difference in Ang II and AT1R mRNA and protein levels between AFE from SHR and AFE from WKY rats. AFE from SHR increased Ang II and ACE contents and ACE activity in VSMCs of WKY rats and SHR. The changes of Ang II contents and ACE activity were prevented by captopril. ACE knockdown in AFs reduced ACE contents and activity in AFE from SHR and inhibited AFE-induced migration of VSMCs of WKY rats and those of SHR. These results indicate that exosomes from AFs of SHR transfer ACE to VSMCs, which increases Ang II levels and activates AT1R in VSMCs and thereby promotes VSMC migration.

Hypertension published new progress about Angiotensin AT1 receptors Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 6823-69-4 belongs to class imidazoles-derivatives, and the molecular formula is C30H30Cl2N6O2, Recommanded Product: p-Benzenediacrylanilide, 4′,4′′-di-2-imidazolin-2-yl-, dihydrochloride.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Kunz, Peter C.; Klaeui, Wolfgang published the artcile< Zinc and cobalt(II) complexes of tripodal nitrogen ligands of the tris[2-substituted imidazol-4(5)-yl]-phosphane type. Biomimetic hydrolysis of an activated ester>, Category: imidazoles-derivatives, the main research area is tris imidazolyl phosphine ligand preparation zinc cobalt complexation; biomimetic ester hydrolysis zinc enzyme; nitrophenyl pyridine carboxylate hydrolysis kinetics zinc cobalt imidazolylphosphine catalyzed.

Novel tris[2-substituted imidazol-4(5)-yl]phosphane (4-TIPR) ligands 2b (R = Ph) and 2c (R = tBu) were prepared as model ligands for the tris(histidine) motif found in many zinc enzymes. They readily form cobalt and zinc nitrato and chloro complexes in protic solvents. The steric requirements of the substituents R in 4(5)-position of the 4-TIPR ligands (R = iPr (2a), Ph (2b), tBu (2c)) is discussed on the basis of their UV/VIS spectra. Zinc complexes of 2a and 2c were studied due to their ability to promote the hydrolysis of the activated ester 4-nitrophenyl pyridine-2-carboxylate (pNpic).

Collection of Czechoslovak Chemical Communications published new progress about Enzymes Role: BCP (Biochemical Process), BIOL (Biological Study), PROC (Process) (model). 36947-69-0 belongs to class imidazoles-derivatives, and the molecular formula is C7H12N2, Category: imidazoles-derivatives.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Kusama, Hitoshi; Konishi, Yoshinari; Sugihara, Hideki published the artcile< Data mining assisted by theoretical calculations for improving dye-sensitized solar cell performance>, Application of C4H5BrN2, the main research area is data mining theor calculation dye sensitized solar cell performance.

Data mining using exptl. data and information generated from theor. calculations is proposed to study dye-sensitized solar cells, which are complex systems. This method led to new knowledge about the influence of imidazole derivatives as additives in an electrolytic solution on the cell performance. It was found that the solar energy conversion efficiency is strongly correlated to the Mulliken charge of the carbon atom at position 4 in the imidazole group. This result indicates that data mining assisted by theor. calculations should facilitate the rate that cell performance is improved.

Solar Energy Materials & Solar Cells published new progress about Density functional theory (GGA, PBE-functional, DNP). 1003-21-0 belongs to class imidazoles-derivatives, and the molecular formula is C4H5BrN2, Application of C4H5BrN2.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Hu, Haifeng; Wang, Dong; Li, Lihong; Yin, Haiyang; He, Guoyu; Zhang, Yonghong published the artcile< Role of microRNA-335 carried by bone marrow mesenchymal stem cells-derived extracellular vesicles in bone fracture recovery>, Application In Synthesis of 6823-69-4, the main research area is microRNA335 mesenchymal stem cell extracellular vesicle bone fracture.

Mesenchymal stem cells (MSCs) have the potential to reduce healing time and treat nonunion in fracture patients. In this study, bone marrow MSCs-derived extracellular vesicles (B-EVs) were firstly extracted and identified. CD9-/- and normal mice were enrolled for the establishment of fracture models and then injected with B-EVs. Osteoblast differentiation and fracture recovery were estimated The levels of osteoblast-related genes were detected, and differentially expressed microRNAs (miRs) in B-EVs-treated normal fracture mice were screened and verified. The downstream mechanisms of miR were predicted and assessed. The loss-of functions of miR-335 in B-EV and gain-of-functions of VapB were performed in animal and cell experiments to evaluate their roles in bone fracture. Collectively, B-EVs promoted bone fracture recovery and osteoblast differentiation by releasing miR-335. miR-335 downregulation in B-EVs impaired B-EV functions in fracture recovery and osteoblast differentiation. miR-335 could target VapB, and VapB overexpression reversed the effects of B-EVs on osteoblast differentiation. B-EV treatment activated the Wnt/β-catenin pathway in fracture mice and osteoblasts-like cells. Taken together, the study suggested that B-EVs carry miR-335 to promote bone fracture recovery via VapB and the Wnt/β-catenin pathway. This study may offer insights into bone fracture treatment.

Cell Death & Disease published new progress about Angiogenesis. 6823-69-4 belongs to class imidazoles-derivatives, and the molecular formula is C30H30Cl2N6O2, Application In Synthesis of 6823-69-4.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem

Deng, Chun-Lei; Hu, Cheng-Biao; Ling, Sheng-Tao; Zhao, Na; Bao, Li-Hui; Zhou, Feng; Xiong, Ye-Cheng; Chen, Tao; Sui, Bing-Dong; Yu, Xiao-Rui; Hu, Cheng-Hu published the artcile< Photoreceptor protection by mesenchymal stem cell transplantation identifies exosomal MiR-21 as a therapeutic for retinal degeneration>, Application In Synthesis of 6823-69-4, the main research area is retinal degeneration mesenchymal stem cell transplantation MiR21 exosome.

Abstract: Photoreceptor apoptosis is recognized as one key pathogenesis of retinal degeneration, the counteraction of which represents a promising approach to safeguard visual function. Here, we discovered that intravitreal MSCT counteracted photoreceptor apoptosis and alleviated retinal morphol. and functional degeneration in a mouse model of photoreceptor loss induced by N-methyl-N-nitrosourea (MNU). Notably, therapeutic efficacy of MSCT and EXOT on MNU-induced retinal degeneration was long-lasting as photoreceptor preservance and retinal maintenance were detected even after 1-2 mo post to injection for only once. More importantly, using a natural occurring retinal degeneration model caused by a nonsense mutation of Phosphodiesterase 6b gene (Pde6bmut), we confirmed that MSCT and EXOT prevented photoreceptor loss and protected long-term retinal function. In deciphering therapeutic mechanisms regarding potential exosome-mediated communications, we identified that miR-21 critically maintained photoreceptor viability against MNU injury by targeting programmed cell death 4 (Pdcd4) and was transferred from MSC-derived exosomes in vivo for functional regulation. Further experiments revealed that miR-21 mediated therapeutic effects of EXOT on MNU-induced photoreceptor apoptosis and retinal dysfunction. These findings uncovered the efficacy and mechanism of MSCT-based photoreceptor protection, indicating exosomal miR-21 as a therapeutic for retinal degeneration.

Cell Death & Differentiation published new progress about Apoptosis. 6823-69-4 belongs to class imidazoles-derivatives, and the molecular formula is C30H30Cl2N6O2, Application In Synthesis of 6823-69-4.

Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem