Inhibition of Shp2 suppresses mutant EGFR-induced lung tumors in transgenic mouse model of lung adenocarcinoma

Epidermal growth factor receptor (EGFR) mutants drive lung tumorigenesis and are targeted for therapy. However, resistance to EGFR inhibitors has been observed, in which the mutant EGFR remains active. Thus, it is important to uncover mediators of EGFR mutant-driven lung tumors to develop new treatment strategies. The protein tyrosine phosphatase (PTP) Shp2 mediates EGF signaling. Nevertheless, it is unclear if Shp2 is activated by oncogenic EGFR mutants in lung carcinoma or if inhibiting the Shp2 PTP activity can suppress EGFR mutant-induced lung adenocarcinoma. Here, we generated transgenic mice containing a doxycycline (Dox)-inducible PTP-defective Shp2 mutant (tetO-Shp2CSDA). Using the rat Clara cell secretory protein (CCSP)-rtTA-directed transgene expression in the type II lung pneumocytes of transgenic mice, we found that the Gab1-Shp2 pathway was activated by EGFR^L858R in the lungs of transgenic mice. Consistently, the Gab1-Shp2 pathway was activated in human lung adenocarcinoma cells containing mutant EGFR. Importantly, Shp2CSDA inhibited EGFR^L858R-induced lung adenocarcinoma in transgenic animals. Analysis of lung tissues showed that Shp2CSDA suppressed Gab1 tyrosine phosphorylation and Gab1-Shp2 association, suggesting that Shp2 modulates a positive feedback loop to regulate its own activity. These results show that inhibition of the Shp2 PTP activity impairs mutant EGFR signaling and suppresses EGFR^L858R-driven lung adenocarcinoma.     

Adjuvant treatment with tumor-targeting Salmonella typhimurium A1-R reduces recurrence and increases survival after liver metastasis resection in an orthotopic nude mouse model

Colon cancer liver metastasis is often the lethal aspect of this disease. Well-isolated metastases are candidates for surgical resection, but recurrence is common. Better adjuvant treatment is therefore needed to reduce or prevent recurrence. In the present study, HT-29 human colon cancer cells expressing red fluorescent protein (RFP) were used to establish liver metastases in nude mice. Mice with a single liver metastasis were randomized into bright-light surgery (BLS) or the combination of BLS and adjuvant treatment with tumor-targeting S. typhimurium A1-R. Residual tumor fluorescence after BLS was clearly visualized at high magnification by fluorescence imaging. Adjuvant treatment with S. typhimurium A1-R was highly effective to increase survival and disease-free survival after BLS of liver metastasis. The results suggest the future clinical potential of adjuvant S. typhimurium A1-R treatment after liver metastasis resection.     

Role of promyelocytic leukemia (PML) protein in tumor suppression

The promyelocytic leukemia (PML) gene encodes a putative tumor suppressor gene involved in the control of apoptosis, which is fused to the retinoic acid receptor alpha (RARalpha) gene in the vast majority of acute promyelocytic leukemia (APL) patients as a consequence of chromosomal translocations. The PMLRARalpha oncoprotein is thought to antagonize the function of PML through its ability to heterodimerize with and delocalize PML from the nuclear body. In APL, this may be facilitated by the reduction to heterozygosity of the normal PML allele. To determine whether PML acts as a tumor suppressor in vivo and what the consequences of deregulated programmed cell death in leukemia and epithelial cancer pathogenesis are, we crossed PML(-/-) mice with human cathepsin G (hCG)-PMLRARalpha or mammary tumor virus (MMTV)/neu transgenic mice (TM), models of leukemia and breast cancer, respectively. The progressive reduction of the dose of PML resulted in a dramatic increase in the incidence of leukemia, and in an acceleration of leukemia onset in PMLRARalpha TM. By contrast, PML inactivation did not affect neu-induced tumorigenesis. In hemopoietic cells from PMLRARalpha TM, PML inactivation resulted in impaired response to differentiating agents such as RA and vitamin D3 as well as in a marked survival advantage upon proapoptotic stimuli. These results demonstrate that: (a) PML acts in vivo as a tumor suppressor by rendering the cells resistant to proapoptotic and differentiating stimuli; (b) PML haploinsufficiency and the functional impairment of PML by PMLRARalpha are critical events in APL pathogenesis; and (c) aberrant control of programmed cell death plays a differential role in solid tumor and leukemia pathogenesis.     

黄芪总黄酮联合顺铂对Lewis荷瘤小鼠抗癌作用的研究

本研究旨在分析黄芪总黄酮(total flavonoids of Astragalus membranaceus, TFA)联合顺铂对Lewis荷瘤小鼠的抗癌作用及机制,动物实验获得山西大学伦理委员会的批准(SXULL2018012)。肿瘤重量、肿瘤体积变化曲线、抑瘤率等药效学指标以及脏器指数分析显示黄芪总黄酮对顺铂的抗肿瘤作用具有增效减毒作用;进一步采用网络药理学技术预测黄芪总黄酮的作用靶点,结果显示毛蕊异黄酮葡萄糖苷可能是抑制肺癌的主要活性成分,细胞肿瘤抗原p53 (TRP53)、与Ras相关的C3肉毒毒素底物1 (RAC1)、受体酪氨酸蛋白激酶erbB-2 (ERBB2)、血管内皮生长因子A (VEGFA)、信号转导子和转录激活子3 (STAT3)等靶点可能与黄芪总黄酮对顺铂的增效减毒作用相关;血清IL-6含量以及肿瘤组织STAT3、p53蛋白的表达水平结果显示,黄芪总黄酮可能通过IL-6/STAT3通路来抑制肿瘤生长; UPLC-MS血清代谢组学分析结果提示,与肺癌相关的代谢通路包括鞘脂代谢通路、视黄醇代谢通路、甘油磷酸代谢通路、原代胆汁酸生物合成通路,黄芪总黄酮可回调成分相对...     

Interferon-Stimulated Gene 15 Knockout in Mice Impairs IFNα-Mediated Antiviral Activity

Type I interferon (IFN) plays an important role in the host defense against viral infection by inducing expression of interferon-stimulated genes (ISGs). In a previous study, we found that porcine interferon-stimulated gene 15 (ISG15) exhibited antiviral activity against PRV in vitro. To further investigate the antiviral function of ISG15 in vivo, we utilized ISG15 knockout (ISG15^-/-) mice in this study. Here, we demonstrate that ISG15^-/- mice were highly susceptible to PRV infection in vivo, as evidenced by a considerably reduced survival rate, enhanced viral replication and severe pathological lesions. However, we observed no significant difference between female and male infected WT and ISG15^-/- mice. Moreover, ISG15^-/- mice displayed attenuated antiviral protection as a result of considerably reduced expression of IFNβ and relevant ISGs during PRV replication. Furthermore, excessive production of proinflammatory cytokines may be closely related to encephalitis and pneumonia. In further studies, we found that the enhanced sensitivity to PRV infection in ISG15^-/- mice might be caused by reduced phosphorylation of STAT1 and STAT2, thereby inhibiting type I IFN-mediated antiviral activity. Based on these findings, we conclude that ISG15 is essential for host type I IFN-mediated antiviral response.     

In Vitro and In Vivo Evaluation of Antidiabetic Properties and Mechanisms of Ficus tikoua Bur.

In folk medicine, Ficus tikoua (F. tikoua) has been used to treat diabetes for a long time, but there is a rare modern pharmacological investigation for its antidiabetic effect and mechanisms. Our study aimed to evaluate its hypoglycemic effect using in vitro and in vivo experimental models and then explore the possible mechanisms. In the ethanol extracts and fractions of F. tikoua, n-butanol fraction (NBF) exhibited the most potent effect on inhibiting α-glucosidase activity (IC₅₀ = 0.89 ± 0.04 μg/mL) and promoting glucose uptake in 3T3-L1 adipocytes. Further animal experiments showed that NBF could play an antidiabetic role by ameliorating random blood glucose, fasting blood glucose, oral glucose tolerance, HbA1c level, and islets damage in diabetic mice. Then, the activities of the five subfractions of NBF (NBF1-NBF5) were further evaluated; NBF2 showed stronger α-glucosidase inhibition activities (IC₅₀ = 0.32 ± 0.05 μg/mL) than NBF. Moreover, NBF2 also possessed the ability to promote glucose uptake, which was mediated via P13K/AKT and AMPK pathways. This study demonstrated that F. tikoua possesses antidiabetic efficacy in vitro and in vivo and provided a scientific basis for its folk medicinal use. NBF2 might be potential natural candidate drugs to treat diabetes mellitus. It is the first time the antidiabetic activity and the potential mechanisms of NBF2 were reported.     

The olfactory working memory capacity paradigm: A more sensitive and robust method of assessing cognitive function in male 5XFAD mice

The olfactory working memory capacity (OWMC) paradigm is able to detect cognitive deficits in 5XFAD mice (an animal model of Alzheimer's disease [TG]) as early as 3 months of age, while other behavioral paradigms detect cognitive deficits only at 4–5 months of age. Therefore, we aimed to demonstrate that the OWMC paradigm is more sensitive and consistent in the early detection of declines in cognitive function than other commonly used behavioral paradigms. The prefrontal cortex (PFC), retrosplenial cortex (RSC), subiculum (SUB), and amygdala (AMY) of 5XFAD mice were harvested and subjected to immunostaining to detect the expression of β-amyloid (Aβ). Additionally, we compared the performance of 3-month-old male 5XFAD mice on common behavioral paradigms for assessing cognitive function (i.e., the open field [OF] test, novel object recognition [NOR] test, novel object location [NOL] test, Y-maze, and Morris water maze [MWM]) with that on the OWMC task. In the testing phase of the OWMC task, we varied the delay periods to evaluate the working memory capacity (WMC) of wild-type (WT) mice. Significant amyloid plaque deposition was observed in the PFC, RSC, SUB, and AMY of 3-month-old male 5XFAD mice. However, aside from the OWMC task, the other behavioral tests failed to detect cognitive deficits in 5XFAD mice. Additionally, to demonstrate the efficacy of the OWMC task in assessing WMC, we varied the retention delay periods; we found that the WMC of WT mice decreased with longer delay periods. The OWMC task is a sensitive and robust behavioral assay for detecting changes in cognitive function.     

Toll样受体4在C3H/HeJ小鼠军团菌感染模型中作用

目的 探讨Toll样受体4（TLR4）在军团菌感染中作用。方法 用C3H/HeJ小鼠、C3H/HeN小鼠作为实验动物,实验设C3H/HeJ、C3H/HeN染菌组及C3H/HeN对照组,染菌组气管注射军团菌悬液建立军团菌感染模型,对照组气管注射无菌生理盐水;观察主要脏器系数及肺组织病理改变,流式细胞术测定各组小鼠外周血单个核细胞（PBMC）中TLR4蛋白表达量变化。结果 肺组织病理切片显示染菌组均有炎性细胞浸润并出现肺泡血管出血现象;与C3H/HeN对照组比较,染菌72 h C3H/HeJ、C3H/HeN染菌组小鼠肺脏、脾脏脏器系数均升高,差异有统计学意义（P<0.05）;染菌12 h时,C3H/HeJ染菌组小鼠PBMC 中TLR4蛋白表达量为（48.31±5.22）,低于C3H/HeN染菌组的（113.70±17.74）（P<0.05）,C3H/HeN染菌组与C3H/HeN对照组TLR4蛋白表达量差异无统计学意义（P>0.05）。结论 TLR4基因突变使小鼠对军团菌反应性降低,但TLR4对军团菌的抗感染作用机制仍需进一步研究。     

白藜芦醇对小鼠脂代谢及相关蛋白表达影响

目的探讨白藜芦醇（RSV）对高脂饲料喂养的C57BL/6J小鼠脂代谢及肝脏沉默信息调节因子1（SIRT1）及肝X受体α（LXRα）表达影响。方法雄性C57BL/6J小鼠30只,分为对照组、高脂组和RSV干预组（n=10）,对照组和高脂组分别喂饲基础饲料和高脂饲料,RSV干预组在喂饲高脂饲料同时给予RSV灌胃,第16周测定血清甘油三酯（TG）、总胆固醇（TC）、低密度脂蛋白胆固醇（LDL-C）和高密度脂蛋白胆固醇（HDL-C）含量,分离小鼠肝脏,测定TG、TC含量以及SIRT1、LXRα蛋白表达水平。结果与对照组比较,高脂组小鼠血清TG、TC、LDL-C含量[分别为（1.25±0.25）、（4.29±0.59）、（1.59±0.20）mmol/L]和肝脏TG、TC含量[分别为（5.78±1.69）、（2.69±1.20）mmol/L]升高,肝脏SIRT1、LXRα蛋白表达水平[分别为（0.36±0.03）、（0.78±0.07）]下降（P<0.05）;与高脂组比较,RSV干预组小鼠血清TG、TC、LDL-C含量[分别为（0.91±0.15）、（3.65±0.36）、（1.39±0.11）mmol/L]和肝脏TG、TC含量[分别为（4.63±1.70）、（1.65±0.89）mmol/L]明显下降,肝脏SIRT1、LXRα蛋白表达水平[分别为（0.41±0.05）、（0.88±0.09）]明显升高（P<0.05）。结论白藜芦醇可有效改善高脂饲料喂养C57BL/6J小鼠脂代谢异常,其机制可能与促进肝脏SIRT1及LXRα表达有关。     

Moxibustion treatment increases the survival rate of lung infection of patients bed-ridden due to osteoporotic fracture of the spine via regulation of the inflammatory responses

IntroductionThis study aimed to investigate the potential role of moxibustion (MOX) in the treatment of lung infection in patients bed-ridden due to osteoporotic fracture of the spine.Methods96 senile patients with pulmonary infection who were bed-ridden due to osteoporotic fracture of the spine were grouped into a MOX (–) group and a MOX (+) group. An animal model was established as a SHAM group, a PRIMED group, a MOX 15’ group and a MOX 30’ group.ResultsFor the patients’ study, we found that the survival rate was higher for patients who received MOX. Moreover, tumor necrosis factor-α, interleukin (IL) 1β, IL-6 and IL-18 were down-regulated while IL-10 was up-regulated by MOX. MOX time-dependently increased the survival while reducing the bacteria left in infected mice.ConclusionsMoxibustion significantly alleviated the inflammatory responses, thus leading to a better survival rate of patients bed-ridden due to osteoporotic fracture of the spine.