Structural Diversity of Four Metal–Organic Frameworks Based on Linear Homo/Heterotrinuclear Nodes with Furan-2,5-dicarboxylic Acid: Crystal Structures and Luminescent and Magnetic Properties

Four new homo- and heterometallic metal–organic frameworks (MOFs) based on linear homo/heterotrinuclear nodes, namely, {[NH₂(CH₃)₂]₂­[Co₃(FDA)₄­(CH₃OH)₂]}_<i>n</i> (<b>1</b>), {[NH₂(CH₃)₂]₂­[Co₃(FDA)₄]­·2DMF}_<i>n</i> (<b>2</b>), {[Gd₂Co­(FDA)₄(H₂O)₄]·2H₂O}_<i>n</i> (<b>3</b>), and {[Dy₂Co­(FDA)₄(glycol)₂]·2H₂O}_<i>n</i> (<b>4</b>) (H₂FDA = furan-2,5-dicarboxylic acid), were obtained under solvothermal conditions and characterized by single crystal X-ray diffraction, magnetic susceptibility, and luminescence measurements. The building blocks of four MOFs are linear trinuclear clusters stabilized by carboxylic groups, but the three-dimensional frameworks are different. MOFs <b>1</b> and <b>2</b> are both <b>pcu</b> nets with a point symbol of (4¹².6³), whereas MOFs <b>3</b> and <b>4</b> exhibit <b>3,10T9</b> and <b>tfz-d</b> nets with the point symbols of (4¹⁸.6²⁴.8³)­(4³)₂ and (4³)₂(4⁶.6¹⁸.8⁴), respectively. Magnetic susceptibility measurements indicate that there are antiferromagnetic interactions in <b>1</b>–<b>3</b>, while <b>4</b> displays interesting ferromagnetic interactions between Co­(II) and Dy­(III) ions. Luminescence investigation of <b>4</b> shows intense and characteristic emission bands of Dy­(III) ions in the solid state

Di-, tri-, and tetranuclear cobalt, copper, and manganese complexes bridged by <i>μ</i>-hydroxyl groups of tetradentate Schiff base ligands: structures, magnetic properties, and antitumor activities

<div><p>[Co₂(HL^<b>1</b>)₂(H₂O)₂](NO₃) (<b>1</b>), [Cu₂(H_<b>2</b>L^<b>1</b>)(HL^<b>1</b>) (CH₃COO)]·H₂O (<b>2</b>), [Cu₄(HL^<b>1</b>)₄(C₂H₅OH)]·C₂H₅OH·H₂O (<b>3</b>), and [Mn₃(HL^<b>2</b>)₂(CH₃OH)₂(CH₃COO)₄]·2(CH₃OH)·H₂O (<b>4</b>) {<b>H</b>_<b>3</b><b>L</b>^<b>1</b><b> </b>= 2-ethyl-2-(2-hydroxybenzylideneamino)propane-1,3-diol, <b>H</b>_<b>3</b><b>L</b>^<b>2</b><b> </b>= 2-ethyl-2-[(2-hydroxynaphthalene-1-yl)methyleneamino]propane-1,3-diol} have been synthesized and characterized by IR spectra, elemental analyses, single-crystal X-ray diffraction, TGA, XRD, and magnetic measurements. Compound <b>1</b> possesses mixed-valence dinuclear {Co₂(<i>μ</i>₂-O)₂} with Co(II) and Co(III) ions linked through <i>μ</i>₂-hydroxyl of Schiff base ligands. Compound <b>2</b> displays a binuclear structure with {Cu₂(<i>μ</i>₂-O)(<i>η</i>²-COO)} containing one <i>μ</i>₂-hydroxyl and a single <i>syn–syn</i> acetate bridge. Compound <b>3</b> is tetranuclear with a cube-shaped {Cu₄(<i>μ</i>₃-O)₄} core constructed by four Cu(II) centers and four <i>μ</i>₃-hydroxyls of Schiff base ligands. Compound <b>4</b> displays a linear trinuclear {Mn₃(<i>μ</i>₂-O)₂(<i>η</i>²-COO)₂} structure in which the terminal Mn(III) and the central Mn(II) ions are linked by a <i>μ</i>₂-hydroxyl of Schiff base and two <i>syn–syn</i> acetate bridges. The results show that terminal hydroxyl groups of Schiff base ligands play an important role in assembling polynuclear compounds. Magnetic properties and antitumor activities of these compounds were investigated. The antitumor activities reveal that <b>1</b> and <b>2</b> are more effective antitumor agents for K-562 and HL-60, respectively.</p></div

MiR-155 positively regulates the mRNA levels of T-bet and IFN-γ and negatively regulates the mRNA levels of GATA-3 and IL-4.

<p>Pre-miR-ctrl, pre-miR-155, anti-miR-ctrl, and anti-miR-155 were transfected into CD4⁺ T cells, which were then activated by anti-CD3 and anti-CD28. A. The mRNA levels of T-bet and IFN-γ were detected by RT-PCR 3 days after transfection and the collective results are shown, respectively. B. The mRNA levels of GATA3 and IL-4 were detected by RT-PCR 3 days after transfection and the collective results are shown, respectively. All results are shown as mean ± SD. Data represent more than three independent experiments. *p<0.05, **p<0.01.</p

MiR-155 regulates Treg and Th17 cells differentiation as well as Foxp3 and RORγt expression.

<p>Pre-miR-ctrl, pre-miR-155, anti-miR-ctrl, and anti-miR-155 were transfected into CD4⁺ T cells, which were then activated and polarized. A and B. The frequencies of Treg and Th17 cells in CD4⁺ T cells were determined by flow cytometry 4 days later. Treg (A) and Th17 (B) cells were gated with CD4⁺CD25⁺Foxp3⁺ and CD4⁺IL-17⁺, respectively. Representative FACS pictures from a single case are shown. And the percentages of positive cells in CD4⁺ T cells are shown in each panel. The collective results of three independent experiments are shown in the histograms as mean ± SD. C and D. The mRNA levels of Foxp3 (C) and RORγ-t (D) were detected by RT-PCR 3 days after transfection and activation. Relative expression of them were collectively analysed and the results are shown as mean ± SD. Data represent three independent experiments. *p<0.05, **p<0.01.</p

MiR-155 regulates JAK/STAT but not TGF-β/SMAD signaling pathway.

<p>4 days after pre-miR-ctrl, pre-miR-155, anti-miR-ctrl, and anti-miR-155 were transfected, activated CD4⁺ T cells were collected. Whole-cell lysates were prepared and the transcripts involved in Treg and Th17 cells differentiation were detected by western blotting. A. First, protein lysates were immunoblotted with SOCS1 and SOCS3, and β-actin served as the internal reference. Then, protein lysates were immunoblotted with p-STAT5/p-STAT3 and the total proteins, STAT5/STAT3. B. Finally, protein lysates were immunoblotted with p-SMAD5/p-SMAD2 and the total proteins, SMAD5/SMAD2. Representative images from one of three independent experiments are shown.</p

The purity of CD4⁺ T cells and the GFP-transfection efficiency in CD4⁺ T cells.

<p>A. CD4⁺ T cells were purified by magnetic cell sorting (MACS). The purity of CD4⁺ T cells was determined by flow cytometry and a typical FACS picture is shown. B. 2.5 µg pmaxGFP® Vector was transfected into 1×10⁷ CD4⁺ T cells by necleofection. The GFP-transfection efficiency was detected by fluorescence microscopy 8 h later and a typical 20× image (top) is shown. Same slide of CD4⁺ T cells was detected sequentially by light microscopy and the 20× image (bottom) is also shown. Both the purity and the transfection efficiency were checked in every independent experiment.</p

SOCS1-TP^miR-155 inhibits the function of miR-155 during Treg and Th17 cells differentiation.

<p>A. Sequences of mmu-miR-155, 3′-UTR SOCS1, and SOCS1-TP^miR-155 are shown in the schematic. As shown, seed sequences of mmu-miR-155 complementary to 3′-UTR SOCS1, whereas sequences of SOCS1-TP^miR-155 completely complementary to 3′-UTR SOCS1 and over-lapped the binding site of miR-155 in the 3′ UTR of SOCS1. B. The percentages of Treg and Th17 were determined by flow cytometry 4 days after SOCS1-TP^miR-155 and control-TP^miR-155 (shown in the figures as SOCS1-TP and control-TP, respectively) were transfected. Treg and Th17 cells were gated with CD4⁺CD25⁺Foxp3⁺ and CD4⁺IL-17⁺, respectively. Typical FACS pictures from a single case are shown in the left. The collective results of three independent experiments are shown in the right as mean ± SD. C. 4 days after SOCS1-TP^miR-155 and control-TP^miR-155 were transfected, the levels of IL-17A, IL-10, and TGF-β1 in cell culture supernatant were quantified by ELISAs and the collective results are shown as mean ± SD. D. 4 days after SOCS1-TP^miR-155 and control-TP^miR-155 were transfected, the levels of the transcripts involved in Treg and Th17 cells differentiation were also detected by western blotting. Data represent three independent experiments. *p<0.05, **p<0.01.</p

MiR-155 regulates the secreting of IL-17A, but not the secreting of IL-10 and TGF-β1.

<p>Pre-miR-ctrl, pre-miR-155, anti-miR-ctrl, and anti-miR-155 were transfected into CD4⁺ T cells, which were then activated and polarized. A–C. The mRNA levels of IL-17A (A), IL-10 (B) and TGF-β1 (C) were detected by RT-PCR 3 days after transfection and the collective results are shown in the left figures, respectively. While the levels of these cytokines in cell culture supernatant were detected by ELISAs 4 days after transfection and the collective results are shown in the right figures, respectively. All results are shown as mean ± SD. Data represent three independent experiments. *p<0.05, **p<0.01.</p

Multipoint Interactions Enhanced CO₂ Uptake: A Zeolite-like Zinc–Tetrazole Framework with 24-Nuclear Zinc Cages

A zeolite-like microporous tetrazole-based metal–organic framework (MOF) with 24 nuclear zinc cages was synthesized and characterized. It exhibits high CO₂ adsorption capacity up to 35.6 wt % (8.09 mmol/g) and excellent CO₂/CH₄ selectivity at 273 K/1 bar, being among the highest values known to date. Theoretical calculations based on simulated annealing techniques and periodic DFT revealed that CO₂ is predominantly located around the inner surface of the cages through multipoint interactions, in particular, around the aromatic tetrazole rings. Importantly, it is the first time that multipoint interactions between CO₂ molecules and frameworks resulting in high CO₂ uptake are observed

Multipoint Interactions Enhanced CO₂ Uptake: A Zeolite-like Zinc–Tetrazole Framework with 24-Nuclear Zinc Cages

A zeolite-like microporous tetrazole-based metal–organic framework (MOF) with 24 nuclear zinc cages was synthesized and characterized. It exhibits high CO₂ adsorption capacity up to 35.6 wt % (8.09 mmol/g) and excellent CO₂/CH₄ selectivity at 273 K/1 bar, being among the highest values known to date. Theoretical calculations based on simulated annealing techniques and periodic DFT revealed that CO₂ is predominantly located around the inner surface of the cages through multipoint interactions, in particular, around the aromatic tetrazole rings. Importantly, it is the first time that multipoint interactions between CO₂ molecules and frameworks resulting in high CO₂ uptake are observed