Cancer-related malnutrition is a mortal threat to gastric carcinoma patients. However, conventional nutrition treatment is not effective for recovery. Recombinant human GH (rhGH) is widely accepted clinically to treat severe malnutrition caused by non-malignant diseases, but not approved to treat malignant diseases due to the safety concern. To explore the safety of rhGH on gastric cancer, we assessed the effect of rhGH on two tumor-bearing mice models in vivo established by human gastric adenoma cell lines of SGC-7901 and MKN-45. VEGF expression in tumor tissues was detected using immunohistochemistry. The expression of GH receptor (Ghr), Jak-2, Stat3, Vegf, Hif-1α, Fgf, and Mmp-2 was measured by RT-PCR and protein expression of STAT3, phosphorylated STAT3, VEGF, HIF-1α, and MMP-2 was measured by western blotting. The immunocytochemistry results showed that the GHR expression of SGC-7901 was strongly positive (GHR+++), while GHR expression of MKN-45 was regarded as negative (GHR−). After 14 days of rhGH treatment in SGC-7901 (GHR+++) tumor-bearing mice, we found that the tumor growth was significantly increased, and the expressions of downstream factors and VEGF were increased. However, in MKN-45 (GHR−) tumor-bearing mice, tumor growth was not significantly increased by rhGH, but tumor-free body weight was increased especially in high-dose rhGH-treated group (P<0.05). These findings suggest that the level of GHR expression is a key target that influences the effectiveness of rhGH on promoting the growth of gastric cancer and angiogenesis. rhGH may promote the activation of tumor angiogenesis factors through the Jak-2–STAT3 pathway.
Yan Lin, Suyi Li, Peng Cao, Lu Cheng, Ming Quan and Suyu Jiang
Feng Ye, Bingyin Shi, Xiaoyan Wu, Peng Hou, Lei Gao, Xiaodan Ma, Li Xu and Liping Wu
CD40 plays an important role in the pathogenesis of Graves' disease (GD). Inhibition of CD40 expression may be a promising treatment for GD. In this study, we used an animal model to investigate whether lentivirus expressing siRNA for CD40 (LV-CD40-siRNA) could be useful for the therapy of GD. BALB/c mice were injected with PBS alone (PBS group), negative lentivirus (control siRNA group), or LV-CD40-siRNA (CD40 siRNA group), 3 days before being treated with adenovirus expressing human TSHR A subunit (Ad-TSHR289) three times at 3-week intervals to induce GD model. Sera thyroxine (T4) levels were assayed by RIA. The expression of CD40 was detected at the mRNA level by real-time PCR and protein level by flow cytometry. The expression of CD40, CD80, and CD86 was significantly decreased in the CD40 siRNA group (P<0.05), while FOXP3 expression was increased compared to the control siRNA group (P=0.05). Mean T4 levels were decreased 14% in the CD40 siRNA group compared to the control siRNA group. The rate of disease induction was similar among the three groups injected with Ad-TSHR289. LV-CD40-siRNA is a useful tool to inhibit the expression of CD40 in vivo, but it cannot decrease the incidence of hyperthyroidism in a limited period of time.
Xiaoqin Shi, Xinyu Li, Yi Hou, Xuemei Cao, Yuyao Zhang, Heng Wang, Hongyin Wang, Chuan Peng, Jibin Li, Qifu Li, Chaodong Wu and Xiaoqiu Xiao
Parental history with obesity or diabetes will increase the risk for developing metabolic diseases in offspring. However, literatures as to transgenerational inheritance of metabolic dysfunctions through male lineage are relatively scarce. In the current study, we aimed to evaluate influences of paternal hyperglycemia on metabolic phenotypes in offspring. Male SD rats were i.p. injected with streptozotocin (STZ) or citrate buffer (CB, as control). STZ-injected rats with glucose levels higher than 16.7 mM were selected to breed with normal female rats. Offspring from STZ or CB treated fathers (STZ-O and CB-O) were maintained in the identical condition. We monitored body weight and food intake, and tests of glucose and insulin tolerance (GTTs and ITTs), fasting–refeeding and cold exposure were performed. Expression of factors involved in hypothalamic feeding and brown adipose tissue (BAT) thermogenic activity was performed by real-time PCR and Western blot. Adult STZ-O were heavier than CB-O. Impairment of GTTs was observed in STZ-O compared with CB-O at 22 and 32 weeks of age; ITTs results showed decreased insulin sensitivity in STZ-O. Daily food intake and accumulated food intake during 12-h refeeding after fasting were significantly higher in STZ-O. UCP1 levels were downregulated in BAT from STZ-O at room temperature and cold exposure. Finally, STZ-O rats showed suppressed leptin signaling in the hypothalamus as evidenced by upregulated SOCS3, reduced phosphorylation of STAT3, impaired processing POMC and decreased α-MSH production. Our study revealed that paternal hyperglycemia predisposes offspring to developing obesity, which is possibly associated with impaired hypothalamic leptin signaling.
Shiyun Tong, Shumin Yang, Ting Li, Rufei Gao, Jinbo Hu, Ting Luo, Hua Qing, Qianna Zhen, Renzhi Hu, Xuan Li, Yi Yang, Chuan Peng and Qifu Li
Bisphenol-A (BPA) is a common environmental pollutant, and exposure to it is associated with proteinuria and may predict the progression of chronic kidney disease; however, the mechanism is not clear. Neutrophil extracellular traps (NETs) are a DNA skeleton coated with various proteases, and it is associated with various types of autoimmune nephritis. In this study, we examine whether NETs is involved in BPA-induced chronic kidney injury. In vivo, BPA exposure resulted in impaired renal function and altered renal morphology, including glomerular mesangial matrix expansion and increased renal interstitial fibroblast markers. Meanwhile, more dsDNA can be detected in the serum, and the NETs-associated proteins, MPO and citH3 were deposited in the renal system. In vitro, BPA and NETs treatment caused podocyte injury, a loss of marker proteins and disorder in the actin skeleton. After NETs inhibition via DNase administration, BPA-induced injuries were significantly relieved. In conclusion, the increase of NETosis in circulation and the renal system during BPA exposure suggests that NETs may be involved in BPA-induced chronic kidney injury.
Xiufen Chen, Bo Zhou, Jun Yan, Baoshan Xu, Ping Tai, Junxia Li, Shiming Peng, Meijia Zhang and Guoliang Xia
It is proved that epidermal growth factor (EGF)-like factors mediate gonadotropin-induced rodent oocyte maturation via EGF receptor (EGFR). However, the detail kinetics and signal pathway between FSH and EGF/EGFR is not clear in large animals. In the present study, we investigated the roles of EGFR and protein kinase C (PKC) in FSH-induced porcine oocyte meiotic resumption. Porcine cumulus–oocyte complexes were cultured in NCSU37 medium containing 10% porcine follicular fluid and germinal vesicle breakdown (meiotic resumption) was detected after different treatments. The results showed that EGF-like factor amphiregulin (AR) and EGFR mRNA were expressed in porcine cumulus cells, but not oocytes. FSH significantly induced AR mRNA expression with maximum at 4 h and activated EGFR phosphorylation at 8 h. AR (1–100 ng/ml) dose-dependently induced meiosis resumption of porcine oocyte. The specific EGFR inhibitor, AG1478, but not AG43 (the inactive analog of AG1478), completely blocked FSH, EGF, and AR-induced oocyte meiotic resumption; the inhibitory effect of AG1478 on FSH action gradually decreased when the inhibitor was added at 6 h or later and disappeared when it was added at 11 h; EGF reversed the inhibitory effect on FSH when AG1478 was added within 6 h. FSH triggered porcine oocyte meiotic resumption (at 20 h) later than that of EGF and AR (at 18 h). All these results supported that endogenously produced EGFR activator(s), possibly AR (maximum at 4 h) and EGFR activation (began at 6 h and finished within 11 h), in cumulus cells is necessary for FSH-induced porcine oocyte meiotic resumption (began at 18 h). Furthermore, PKC activator PMA mimicked but PKC inhibitor chelerythrine chloride inhibited FSH action, and AG1478 also suppressed PMA-induced porcine oocyte meiotic resumption. These data together suggested that EGFR activation, by PKC signal pathway, participates in FSH-induced porcine oocyte meiotic resumption.
Qiong Lv, Rufei Gao, Chuan Peng, Juan Yi, Lulu Liu, Shumin Yang, Danting Li, Jinbo Hu, Ting Luo, Mei Mei, Ying Song, Chaodong Wu, Xiaoqiu Xiao and Qifu Li
Bisphenol A (BPA), one of the most common environmental endocrine disruptors, is considered to promote hepatic lipid deposition. However, the mechanism has not been fully elucidated. The polarization of Kupffer cells (KCs) plays an important role in hepatic inflammation by promoting pro-inflammatory M1 phenotype (M1KCs), which contributes to dysregulated lipid metabolism. The purpose of this study is to investigate the role of KC polarization in BPA-induced hepatosteatosis in male mice. In this study, we examined hepatic lipid contents and quantified M1KC in BPA-treated CD1 mice, and further explored the interaction between KCs and hepatocytes using conditional HepG2 cell culture. BPA treatment significantly increased hepatic fat contents in CD1 mice, accompanied by increased number of pro-inflammatory M1KCs and enhanced secretion of inflammatory cytokines. Increased lipid contents were also observed in HepG2 cells treated with BPA. Interestingly, higher TG contents were observed in HepaG2 cells treated with conditional media from BPA-treated KCs, compared with those treated with BPA directly. Incubation of KCs with BPA promoted the polarization of KCs to pro-inflammatory M1 dominant subtypes, which was blocked by estrogen antagonist ICI182780. Taken together, our results revealed that M1KCs polarization is involved in BPA-induced hepatic fat deposition, which is possibly associated with the estrogen receptor signaling pathway.
Shu-Fang Xia, Xiao-Mei Duan, Xiang-Rong Cheng, Li-Mei Chen, Yan-Jun Kang, Peng Wang, Xue Tang, Yong-Hui Shi and Guo-Wei Le
The study was designed to investigate the possible mechanisms of hepatic microRNAs (miRs) in regulating local thyroid hormone (TH) action and ultimately different propensities to high-fat diet (HFD)-induced obesity. When obesity-prone (OP) and obesity-resistant (OR) mice were fed HFD for 7 weeks, OP mice showed apparent hepatic steatosis, with significantly higher body weight and lower hepatic TH receptor b (TRb) expression and type 1 deiodinase (DIO1) activity than OR mice. Next-generation sequencing technology revealed that 13 miRs in liver were dysregulated between the two phenotypes, of which 8 miRs were predicted to target on Dio1 or TRb. When mice were fed for 17 weeks, OR mice had mild hepatic steatosis and increased Dio1 and TRb expression than OP mice, with downregulation of T3 target genes (including Srebp1c, Acc1, Scd1 and Fasn) and upregulation of Cpt1α, Atp5c1, Cox7c and Cyp7a1. A stem-loop qRT-PCR analysis confirmed that the levels of miR-383, miR-34a and miR-146b were inversely correlated with those of DIO1 or TRb. Down-regulated expression of miR-383 or miR-146b by miR-383 inhibitor (anti-miR-383) or miR-146b inhibitor (anti-miR-146b) in free fatty acid-treated primary mouse hepatocytes led to increased DIO1 and TRb expressions, respectively, and subsequently decreased cellular lipid accumulation, while miR-34a inhibitor (anti-miR-34a) transfection had on effects on TRb expression. Luciferase reporter assay illustrated that miR-146b could directly target TRb 3′untranslated region (3′UTR). These findings suggested that miR-383 and miR-146b might play critical roles in different propensities to diet-induced obesity via targeting on Dio1 and TRb, respectively.
Dang-Dang Li, Ying-Jie Gao, Xue-Chao Tian, Zhan-Qing Yang, Hang Cao, Qiao-Ling Zhang, Bin Guo and Zhan-Peng Yue
Tryptophan 2,3-dioxygenase (T do 2) is a rate-limiting enzyme which directs the conversion of tryptophan to kynurenine. The aim of this study was to examine the expression and regulation of T do 2 in mouse uterus during decidualization. T do 2 mRNA was mainly expressed in the decidua on days 6–8 of pregnancy. By real-time PCR, a high level of T do 2 expression was observed in the uteri from days 6 to 8 of pregnancy, although T do 2 expression was observed on days 1–8. Simultaneously, T do 2 mRNA was also detected under in vivo and in vitro artificial decidualization. Estrogen, progesterone, and 8-bromoadenosine-cAMP could induce the expression of T do 2 in the ovariectomized mouse uterus and uterine stromal cells. T do 2 could regulate cell proliferation and stimulate the expression of decidual marker Dtprp in the uterine stromal cells and decidual cells. Overexpression of T do 2 could upregulate the expression of Ahr, Cox2, and Vegf genes in uterine stromal cells, while T do 2 inhibitor 680C91 could downregulate the expression of Cox2 and Vegf genes in uterine decidual cells. These data indicate that T do 2 may play an important role during mouse decidualization and be regulated by estrogen, progesterone, and cAMP.
Min Hu, Yuehui Zhang, Jiaxing Feng, Xue Xu, Jiao Zhang, Wei Zhao, Xiaozhu Guo, Juan Li, Edvin Vestin, Peng Cui, Xin Li, Xiao-ke Wu, Mats Brännström, Linus R Shao and Håkan Billig
Impaired progesterone (P4) signaling is linked to endometrial dysfunction and infertility in women with polycystic ovary syndrome (PCOS). Here, we report for the first time that elevated expression of progesterone receptor (PGR) isoforms A and B parallels increased estrogen receptor (ER) expression in PCOS-like rat uteri. The aberrant PGR-targeted gene expression in PCOS-like rats before and after implantation overlaps with dysregulated expression of Fkbp52 and Ncoa2, two genes that contribute to the development of uterine P4 resistance. In vivo and in vitro studies of the effects of metformin on the regulation of the uterine P4 signaling pathway under PCOS conditions showed that metformin directly inhibits the expression of PGR and ER along with the regulation of several genes that are targeted dependently or independently of PGR-mediated uterine implantation. Functionally, metformin treatment corrected the abnormal expression of cell-specific PGR and ER and some PGR-target genes in PCOS-like rats with implantation. Additionally, we documented how metformin contributes to the regulation of the PGR-associated MAPK/ERK/p38 signaling pathway in the PCOS-like rat uterus. Our data provide novel insights into how metformin therapy regulates uterine P4 signaling molecules under PCOS conditions.
Yan-Hong Bu, Yu-Ling He, Hou-De Zhou, Wei Liu, Dan Peng, Ai-Guo Tang, Ling-Li Tang, Hui Xie, Qiu-Xia Huang, Xiang-Hang Luo and Er-Yuan Liao
Insulin receptor substrate 1 (IRS1) is an essential molecule for the intracellular signaling of IGF1 and insulin, which are potent anabolic regulators of bone metabolism. Osteoblastic IRS1 is essential for maintaining bone turnover; however, the mechanism underlying this regulation remains unclear. To clarify the role of IRS1 in bone metabolism, we employed RNA interference to inhibit IRS1 gene expression and observed the effects of silencing this gene on the proliferation and differentiation of and the expression of matrix metallopeptidase (MMP) and tumor necrosis factor receptor superfamily, member 11b (TNFRSF11B) in MC3T3-E1 cells. Our results showed that IRS1 short hairpin RNAs can effectively suppress the expression of IRS1, and inhibit the phosphorylation of AKT in IRS1 pathway; reduce the expression of MMP2, MMP3, MMP13, and MMP14, decrease the expression of TNFRSF11B and RANKL (also known as tumor necrosis factor (ligand) superfamily, member 11), however increase the RANKL/TNFRSF11B ratio; decrease cell survival, proliferation, and mineralization, and impair the differentiation of MC3T3-E1 cells. The downregulation of IRS1 had no effect on the expression of MMP1. Our findings suggest that IRS1 not only promotes bone formation and mineralization but also might play roles in bone resorption partly via the regulation of MMPs and RANKL/TNFRSF11B ratio, thus regulates the bone turnover.