IL-35 over-expression increases apoptosis sensitivity and suppresses cell growth in human cancer cells

Interleukin (IL)-35 is a novel heterodimeric cytokine in the IL-12 family and is composed of two subunits: Epstein-Barr virus-induced gene 3 (EBI3) and IL-12p35. IL-35 is expressed in T regulatory (Treg) cells and contributes to the immune suppression function of these cells. In contrast, we found that both IL-35 subunits were expressed concurrently in most human cancer cell lines compared to normal cell lines. In addition, we found that TNF-α and IFN-γ stimulation led to increased IL-35 expression in human cancer cells. Furthermore, over-expression of IL-35 in human cancer cells suppressed cell growth in vitro, induced cell cycle arrest at the G1 phase, and mediated robust apoptosis induced by serum starvation, TNF-α, and IFN-γ stimulation through the up-regulation of Fas and concurrent down-regulation of cyclinD1, survivin, and Bcl-2 expression. In conclusion, our results reveal a novel functional role for IL-35 in suppressing cancer activity, inhibiting cancer cell growth, and increasing the apoptosis sensitivity of human cancer cells through the regulation of genes related to the cell cycle and apoptosis. Thus, this research provides new insights into IL-35 function and presents a possible target for the development of novel cancer therapies.     

Placenta mesenchymal stem cell accelerates wound healing by enhancing angiogenesis in diabetic Goto-Kakizaki (GK) rats

Multipotent mesenchymal stem cells have recently emerged as an attractive cell type for the treatment of diabetes-associated wounds. The purpose of this study was to examine the potential biological function of human placenta-derived mesenchymal stem cells (PMSCs) in wound healing in diabetic Goto-Kakizaki (GK) rats. PMSCs were isolated from human placenta tissue and characterized by flow cytometry. A full-thickness circular excisional wound was created on the dorsum of each rat. Red fluorescent CM-DiI-labeled PMSCs were injected intradermally around the wound in the treatment group. After complete wound healing, full-thickness skin samples were taken from the wound sites for histological evaluation of the volume and density of vessels. Our data showed that the extent of wound closure was significantly enhanced in the PMSCs group compared with the no-graft controls. Microvessel density in wound bed biopsy sites was significantly higher in the PMSCs group compared with the no-graft controls. Most surprisingly, immunohistochemical studies confirmed that transplanted PMSCs localized to the wound tissue and were incorporated into recipient vasculature with improved angiogenesis. Notably, PMSCs secreted comparable amounts of proangiogenic molecules, such as VEGF, HGF, bFGF, TGF-β and IGF-1 at bioactive levels. This study demonstrated that PMSCs improved the wound healing rate in diabetic rats. It is speculated that this effect can be attributed to the PMSCs engraftment resulting in vascular regeneration via direct de novo differentiation and paracrine mechanisms. Thus, placenta-derived mesenchymal stem cells are implicated as a potential angiogenesis cell therapy for repair-resistant chronic wounds in diabetic patients.     

The cytoplasmic domain of neuropilin-1 regulates focal adhesion turnover

Though the vascular endothelial growth factor coreceptor neuropilin-1 (Nrp1) plays a critical role in vascular development, its precise function is not fully understood. We identified a group of novel binding partners of the cytoplasmic domain of Nrp1 that includes the focal adhesion regulator, Filamin A (FlnA). Endothelial cells (ECs) expressing a Nrp1 mutant devoid of the cytoplasmic domain (nrp1^cytoΔ/Δ) migrated significantly slower in response to VEGF relative to the cells expressing wild-type Nrp1 (nrp1^+/+ cells). The rate of FA turnover in VEGF-treated nrp1^cytoΔ/Δ ECs was an order of magnitude lower in comparison to nrp1^+/+ ECs, thus accounting for the slower migration rate of the nrp1^cytoΔ/Δ ECs.     

Flavonoids as receptor tyrosine kinase FLT3 inhibitors

The Fms-like tyrosine kinase 3 (FLT3), a receptor tyrosine kinase, is involved in the proliferation, differentiation and apoptosis of hematopoietic cells. FLT3 is highly overexpressed in acute myeloid leukemia (AML) of the majority of patients. Screening for flavonoids including flavones, flavanones, flavonols, and flavanonols disclosed that luteolin was potent FLT3 enzyme inhibitor. Furthermore, luteolin suppressed cell proliferation in MV4;11 cells with constitutively activated FLT3.     

Discovery of a small-molecule inhibitor and cellular probe of Keap1–Nrf2 protein–protein interaction

A high-throughput screen (HTS) of the MLPCN library using a homogenous fluorescence polarization assay identified a small molecule as a first-in-class direct inhibitor of Keap1–Nrf2 protein–protein interaction. The HTS hit has three chiral centers; a combination of flash and chiral chromatographic separation demonstrated that Keap1-binding activity resides predominantly in one stereoisomer (SRS)-5 designated as ML334 (LH601A), which is at least 100× more potent than the other stereoisomers. The stereochemistry of the four cis isomers was assigned using X-ray crystallography and confirmed using stereospecific synthesis. (SRS)-5 is functionally active in both an ARE gene reporter assay and an Nrf2 nuclear translocation assay. The stereospecific nature of binding between (SRS)-5 and Keap1 as well as the preliminary but tractable structure–activity relationships support its use as a lead for our ongoing optimization     

Therapeutic and pharmacokinetic characterizations of an anti-amyloidogenic bis-styrylbenzene derivative for Alzheimer’s disease treatment

Alzheimer’s disease drug discovery regarding exploration into the molecules and processes has focused on the intrinsic causes of the brain disorder correlated with the accumulation of amyloid-β. An anti-amyloidogenic bis-styrylbenzene derivative, KMS80013, showed excellent oral bioavailability (F = 46.2%), facilitated brain penetration (26%, iv) in mouse and target specific in vivo efficacy in acute AD mouse model attenuating the cognitive deficiency in Y-maze test. Acute toxicity (LD₅₀ >2000 mg/kg) and hERG channel inhibition (14% at 10 μM) results indicated safety of KMS80013.     

人参皂甙Rb1对心力衰竭大鼠蛋白激酶R样内质网激酶途径的影响

目的探讨人参皂甙Rbl（Gs—Rbl）改善阿霉素所致心力衰竭（HF）效应是否与调整蛋白激酶R样内质网激酶（PERK）通路有关。方法阿霉素（Adr）诱导的HF大鼠随机分为HF组（n=15）和Gs．Rbl组（70rng／kg／d,n=17）,另随机选取同龄大鼠作为对照组（n=10）。干预结束并进行心脏超声检查后,TUNNEL检测心肌细胞凋亡率（AR）,Western blot和Rt-PCR检测葡萄糖调节蛋白78（GRP78）、PERK、p-PERK、真核细胞起始因子2-（elF2a）、p-elF2a、C／EBP同源蛋白（CHOP）和cleavedcaspase-12。结果1．Adr干预成功构建HF模型,Gs—Rbl显著提高左室射血分数（LVEF）和降低心肌细胞AR（P〈O．01）;2．HF组GRP78mRNA和蛋白均显著高于对照组,Gs—Rbl显著低于HF组和对照组二组的表达（P〈0．01）;3．Gs—Rbl显著降低HF大鼠PERK和p-PERK表达（P〈0．01）;4．HF导致elF2amRNA和蛋白、p-elF2a显著升高,Gs—Rbl显著下调三者的表达（P〈O．01）;5．HF组CHOPmRNA和蛋白显著高于对照组,Gs—Rbl组显著抑制其表达（P〈0．01）;6．Gs—Rbl显著抑制阿霉素所致的caspase-121TIRNA和cleaved caspase-12蛋白表达（P〈0．01）。结论Gs—Rbl通过调节PERK内质网通路介导其改善HF效应。