Feasibility and efficacy evaluation of metallic biliary stents eluting gemcitabine and cisplatin for extrahepatic cholangiocarcinoma

BACKGROUND

Effective endoscopic management is fundamental for the treatment of extrahepatic cholangiocarcinoma (ECC). However, current biliary stents that are widely used in clinical practice showed no antitumor effect. Drug-eluting stents (DESs) may achieve a combination of local chemotherapy and biliary drainage to prolong stent patency and improve prognosis.

AIM

To develop novel DESs coated with gemcitabine (GEM) and cisplatin (CIS)-coloaded nanofilms that can maintain the continuous and long-term release of antitumor agents in the bile duct to inhibit tumor growth and reduce systemic toxicity.

METHODS

Stents coated with different drug-eluting components were prepared by the mixed electrospinning method, with poly-L-lactide-caprolactone (PLCL) as the drug-loaded nanofiber membrane and GEM and/or CIS as the antitumor agents. Four different DESs were manufactured with four drug-loading ratios (5%, 10%, 15%, and 20%), including bare-loaded (PLCL-0), single-drug-loaded (PLCL-GEM and PLCL-CIS), and dual-drug-loaded (PLCL-GC) stents. The drug release property, antitumor activity, and biocompatibility were evaluated in vitro and in vivo to confirm the feasibility and efficacy of this novel DES for ECC.

RESULTS

The in vitro drug release study showed the stable, continuous release of both GEM and CIS, which was sustained for over 30 d without an obvious initial burst, and a higher drug-loaded content induced a lower release rate. The drug-loading ratio of 10% was used for further experiments due to its ideal inhibitory efficiency and relatively low toxicity. All drug-loaded nanofilms effectively inhibited the growth of EGI-1 cells in vitro and the tumor xenografts of nude mice in vivo; in addition, the dual-loaded nanofilm (PLCL-GC) had a significantly better effect than the single-drug-loaded nanofilms (P < 0.05). No significant differences in the serological analysis (P > 0.05) or histopathological changes were observed between the single-loaded and drug-loaded nanofilms after stent placement in the normal porcine biliary tract.

CONCLUSION

This novel PLCL-GEM and CIS-eluting stent maintains continuous, stable drug release locally and inhibits tumor growth effectively in vitro and in vivo. It can also be used safely in normal porcine bile ducts. We anticipate that it might be considered an alternative strategy for the palliative therapy of ECC patients.

[Artesunate attenuate chronic graft-versus-host disease by regulating Th17/Treg balance]

目的

探讨青蒿琥酯抗慢性移植物抗宿主病（cGVHD）的作用及可能机制。

方法

将B10D2小鼠的骨髓细胞和脾脏细胞混合悬液通过尾静脉输入近交系雌性BALB/c小鼠体内建立cGVHD模型，分别予青蒿琥酯（实验组）和丙酮腹腔（对照组）注射治疗。观察两组小鼠的cGVHD临床表现、生存时间和组织病理学改变；应用流式细胞术分析小鼠外周血和脾脏Th17和Treg细胞比例；免疫磁珠分选BALB/c小鼠脾脏CD4⁺T细胞，分别予丙酮和青蒿琥酯进行干预72 h，流式细胞术分析两组Th17/Treg细胞比例。

结果

①实验组小鼠cGVHD临床症状较对照组明显减轻，生存时间延长[（55.71±6.99）d对（46.57±7.83）d，χ²=5.457，P=0.020]。②实验组小鼠皮肤及肺脏cGVHD病理损伤较轻。③与对照组比较，实验组小鼠外周血、脾脏Th17细胞比例均降低[（0.58±0.19）%对（1.51±0.18）%，t=7.233，P<0.001；（0.71±0.18）%对（1.48±0.38）%，t=3.653，P=0.011]，Treg细胞比例增高[（8.40±0.23）%对（4.45±0.04）%，t=15.680，P<0.001；（10.48±0.48）%对（6.62±0.24）%，t=6.590，P=0.003]，Th17/Treg细胞比值均下降（0.09±0.03对0.34±0.05，t=7.621，P=0.002；0.06±0.02对0.19±0.03，t=6.993，P=0.002）。④体外培养小鼠脾脏CD4⁺T细胞，青蒿琥酯干预组较对照组Th17细胞比例减低[（0.82±0.37）%对（3.39±1.22）%，t=4.044，P=0.007]，Treg细胞比例明显增高[（34.63±1.29）%对（14.28±1.69）%，t=19.119，P<0.001]，Th17/Treg细胞比值下降（0.24±0.09对0.02±0.01，t=4.780，P=0.003）。

结论

青蒿琥酯可通过减少Th17细胞及增加Treg细胞，恢复Th17/Treg平衡，减轻cGVHD的临床与病理学损伤，从而发挥抗cGVHD作用。

[In vivo and in vitro effects of CD137 stimulation on vascular calcification in high fat diet fed ApoE-/- mice]

Objective: To investigate the effect and related mechanism of CD137 stimulation on aortic atherosclerotic plaque calcification in high fat diet fed ApoE^-/- mice and on calcification of vascular smooth muscle cells (VSMCs). Methods: (1) ApoE^-/- mice fed with high fat diet were randomly divided into 3 groups: CD137 activated group (treated by 200 μg CD137 agonist i. p. once per week for 6 weeks, n=5); CD137 inhibited group (anti-CD137 group: 200 μg anti-CD137 antibody + 200 μg CD137 agonist, i. p., once per week for 6 weeks, n=5) and control group (n=5). Von kossa staining was used to observe the calcification of the aortic plaque and VSMCs. Immunohistochemistry was used to observe the expression of BMP-2 and Runx2 which are known mediators of osteogenic differentiation. (2) The mouse aortic VSMCs were obtained by Patch-attaching method. The calcium content was measured by Methylthymol Blue complexone method. The mRNA expressions of bone morphogenetic protein 2 (BMP-2) and Runx2 were measured by real-time fluorescent quantitative PCR (RT-PCR). The protein levels of BMP-2, Runx2 of the VSMCs were determined by Western blot. Results: (1) In vivo, the plaque calcified area in ApoE^-/- mice was significantly larger in CD137-agonist group than that in control group ((1.75±0.33)×10⁴ μm² vs. (0.23±0.07)×10⁴ μm^2,P<0.01), and this effect was significantly reduced by cotreatment with CD137-antagonist ((0.83±0.30)×10⁴ μm² vs. (1.75 ±0.33)×10⁴ μm^2,P<0.05). The levels of BMP-2 and Runx2 were all significantly upregulated in CD137-agonist group than in control group (both P<0.01), again, this effect was blocked by cotreatment with CD137-antagonist (P<0.05). (2) Consistent with the in vivo results, VSMCs calcification was also more serious in CD137-agonist group than in control group, which could be significantly attenuated by cotreatment with CD137-antagonist. In VSMCs, calcium content level in CD137-agonist group was higher than in control group ((0.001 3±0.000 2) mmol/mg protein vs. (0.000 7±0.000 1) mmol/mg protein, P<0.01), which could be significantly reduced by co-treatment with CD137-antagonist ((0.000 9±0.000 2) mmol/mg protein vs. (0.001 3±0.000 2) mmol/mg protein, P<0.01). The mRNA and protein levels of BMP-2 and Runx2 were significantly upregulated in CD137-agonist group compared with the control group (P<0.05), which could be significantly down-regulated by cotreatment with CD-137 antagonist (P<0.05). Conclusion: CD137 activation can promote vascular calcification in high fat diet fed ApoE^-/- mice both in vivo and in vitro.

[CD137-CD137L signaling promotes angiogenesis in atherosclerosis plaque of mice through activating nuclear factor of activated T cells c1]

Objective: To explore whether CD137-CD137L signaling can promote angiogenesis in atherosclerosis plaque via activating nuclear factor of activated T cells c1 (NFATc1). Methods: Apolipoprotein E knock out mice were divided into the following groups: control group (n=5), CD137 activated group(n=5)and CD137 inhibited group (n=5). Immunohistochemistry was performed to detect the expression of CD31 in aortic plaque. Endothelial cells (bEnd.3) were purchased from ATCC and divided into the following groups: control group, IgG isotype control group, CD137 activated group and CD137 inhibited group. Western blot was used to determine total protein and nucleoprotein expression of NFATc1. The expression level of CD137 protein on the surface of endothelial cells was detected by flow cytometry(FCM) and CD137 protein of lysate of endothelial cells was detected by enzyme-linked immunosorbent assay (ELISA). Transwell assay was used to observe the migration ability of endothelial cells.Matrigel tube formation ability of endothelial cells were tested in the following groups: control group, CD137 activated group, silent NFATc1 + CD137 activated group, CD137 inhibited group, and over expressed NFATc1+ CD137 inhibited group. Results: (1) In vivo, the expression level of CD31 was significantly higher in the aortic plaque of CD137 activated group than in control group(1 191±187 vs. 115±30, P<0.05), while which was significantly downregulated in CD137 inhibited group(450±92, P<0.05). (2) The level of nucleoprotein(3.07±0.03 vs. 1.00±0.00, P<0.05) and total protein(2.18±0.30 vs. 1.00±0.00, P<0.05) of NFATc1 were significantly higher in CD137 activated group than in IgG isotype control group. The level of nucleoprotein(0.82±0.04) and total protein(0.84 ± 0.09) of NFATc1 were significantly lower in CD137 inhibited group than in CD137 activated group(both P<0.05). (3) FCM results showed that the fluorescence intensity of CD137 on the cell membrane was significantly higher in endothelial cells stimulated by TNF-α than in normal endothelial cells(5 163±329 vs. 1 660±162, P<0.05). (4) ELISA examination showed that the level of CD137 protein was significantly higher in endothelial cells stimulated by TNF-α than in normal endothelial cells ((573.4±23.7)pg/mg vs.(69.5±16.7)pg/mg, P<0.05). (5) Migration cell number was remarkably higher in CD137 activated group than in IgG isotype control group(1.19±0.13 vs. 1.00±0.00, P<0.05) and significantly lower in CD137 inhibited group(0.82±0.06)than in control group (P<0.05). (6) Values of the formation of the tube length ((5.76±0.18)mm vs. (4.21±0.11)mm, P<0.05) and branch number (29.38±1.28 vs. 21.13±0.96, P<0.05) were both significantly higher in CD137 activated group than in the control group. The formation of the tube length ((1.90±0.11)mm) and branch number(8.91±0.72)were significantly lower in silent NFATc1 + CD137 activated group than in the CD137 activated group (both P<0.05). The formation of the tube length((1.28±0.34)mm) and branch number(5.07±0.35)were also significantly decreased in the CD137 inhibited group compared with the CD137 activated group (both P<0.05). Compared with the CD137 inhibited group, the formation of the tube length((4.82±0.09)mm) and branch number(24.44±1.05) in the over expressed NFATc1+ CD137 inhibited group was increased (both P<0.05). Conclusion: CD137 can promote the angiogenesis in atherosclerosis plaque by activating NFATc1.

Mesenchymal stem cell as salvage treatment for refractory chronic GVHD

Refractory chronic GVHD (cGVHD) is an important complication after allogeneic hematopoietic SCT and is prognostic of poor outcome. MSCs are involved in tissue repair and modulating immune responses in vitro and in vivo. From April 2005 to October 2008, 19 patients with refractory cGVHD were treated with MSCs derived from the BM of volunteers. The median dose of MSCs was 0.6 × 10(6) cells per kg body weight. Fourteen of 19 patients (73.7%) responded well to MSCs, achieving a CR (n=4) or a PR (n=10). The immunosuppressive agent could be tapered to less than 50% of the starting dose in 5 of 14 surviving patients, and five patients could discontinue immunosuppressive agents. The median duration between MSC administration and immunosuppressive therapy discontinuation was 324 days (range, 200-550 days). No patients experienced adverse events during or immediately after MSC infusion. The 2-year survival rate was 77.7% in this study. Clinical improvement was accompanied by the increasing ratio of CD5+CD19+/CD5-CD19+ B cells and CD8+CD28-/CD8+CD28+ T cells. In conclusion, transfusion of MSCs expanded in vitro, irrespective of the donor, might be a safe and effective salvage therapy for patients with steroid-resistant, cGVHD.

M(1)-like muscarinic acetylcholine receptors regulate fast-spiking interneuron excitability in rat dentate gyrus

Cholinergic transmission through muscarinic acetylcholine receptors (mAChRs) plays a key role in cortical oscillations. Although fast-spiking (FS), parvalbumin-expressing basket cells (BCs) are proposed to be the cellular substrates of gamma oscillations, previous studies reported that FS nonpyramidal cells in neocortical areas are unresponsive to cholinergic modulation. Dentate gyrus (DG) is an independent gamma oscillator in the hippocampal formation. However, in contrast to other cortical regions, the direct impact of mAChR activation on FS BC excitability in this area has not been investigated. Here, we show that bath-applied muscarine or carbachol, two mAChR agonists, depolarize DG BCs in the acute brain slices, leading to action potential firing in the theta-gamma bands in the presence of blockers of ionotropic glutamate and gamma-aminobutyric acid type A receptors at physiological temperatures. The depolarizing action persists in the presence of tetrodotoxin, a voltage-gated Na(+) channel blocker. In voltage-clamp recordings, muscarine markedly reduces background K(+) currents. These effects are mimicked by oxotremorine methiodide, an mAChR-specific agonist, and largely reversed by atropine, a non-selective mAChR antagonist, or pirenzepine, an M(1) receptor antagonist, but not by gallamine, an M(2/4) receptor antagonist. Interestingly, in contrast to M(1)-receptor-mediated depolarization, M(2) receptor activation by the specific agonist arecaidine but-2-ynyl ester tosylate down-regulates GABA release at BC axons-the effect is occluded by gallamine, an M(2) receptor antagonist. Overall, muscarinic activation results in a net increase in phasic inhibitory output to the target cells. Thus, cholinergic activation through M(1)-like receptor enhances BC activity and promotes the generation of nested theta and gamma rhythms, thereby enhancing hippocampal function and associated performance.