胰岛素样细胞生长因子-1、碱性成纤维细胞生长因子及转化生长因子α对人表皮干细胞增殖的影响

目的表皮干细胞是组织工程化皮肤的"种子细胞"。文中研究碱性成纤维细胞生长因子(basic fibroblast growthfactor,bFGF)、胰岛素样细胞生长因子-1(insulin-like growth factor-1,IGF-1)和转化生长因子α(transforming growth factorα,TGFα)对人表皮干细胞增殖的影响。方法采用两步酶消化法和Ⅳ型胶原差速贴壁相结合的方法获得人原代表皮干细胞,将表皮干细胞分为A组(K-SFM)、B组(K-SFM+bFGF)、C组(K-SFM+IGF-1)及D组(K-SFM+TGFα)进行培养。比较不同组之间表皮干细胞的克隆形成率、生长增殖、生长曲线和细胞周期等指标。结果 B组、C组及D组培养的表皮干细胞在细胞增殖、细胞克隆率方面检测结果均明显高于A组(P<0.05);流式细胞仪检测B组、C组与A组及D组处于G0/G1细胞比例比较差异有统计学意义(P<0.05)。结论 IGF-1、bFGF及TGF-α均对表皮干细胞的增殖有促进作用,IGF-1及bFGF对表皮干细胞表型的维持有较好的作用。

VEGF和IGF-1在代谢性酸中毒诱导的新生大鼠视网膜细胞中的表达

目的了解代谢性酸中毒诱导新生大鼠视网膜病变的发展进程,探讨其发生与血管内皮生长因子(VEGF)和胰岛素样细胞生长因子-1(IGF-1)的关系。方法模型组新生Sprague-Daw ley大鼠80只,从出生后第2天开始按535 mg.kg-1的剂量管饲NH4C l(质量浓度为50 mg.m l-1),每天2次,连续7 d,然后进入恢复期;另选未行管饲的80只新生大鼠作为对照组。两组大鼠分别于出生后第3、5、8、10、13、20天处死。取出双眼进行视网膜铺片和二磷酸腺苷酶染色,对视网膜血管进行评估;视网膜切片经常规HE染色定量反映视网膜血管增生情况;用免疫组化方法进行VEGF和IGF-1测定。结果模型组大鼠在出生后第3、5、8、10、13、20天新生血管(NV)发生率分别为0、7%、24%、59%、23%、0。HE染色可见实验组10 d龄鼠有较多突破视网膜内界膜的血管内皮细胞核,平均每张切片有(14.67±2.16)个。而对照组未见或极少见突破内界膜的血管内皮细胞核,每张仅(0.87±0.75)个,两者比较差异有统计学意义(t=18.47,P<0.000 1)。出生后第10、13天,模型组鼠VEGF的蛋白水平比对照组明显升高,差异有统计学意义(P<0.05)。出生后第8天,模型组大鼠视网膜IGF-1的蛋白水平比对照组明显下降,差异有统计学意义(P<0.05)。结论代谢性酸中毒可能损害了正在发育的视网膜血管而引起新生血管;视网膜新生血管的发生与VEGF和IGF-1的异常表达有关。

骨质疏松骨折愈合过程中IGF-I mRNA的基因表达

目的 探讨骨质疏松性骨折愈合过程中IGF ImRNA基因表达的细胞定位及基因表达模式。方法 利用去势SD大鼠造成Ⅰ型骨质疏松及其骨折模型 ,通过原位杂交及斑点杂交的方法 ,检测正常及骨质疏松性骨折骨痂局部IGF ImRNA的基因表达。结果 骨质疏松骨折与正常骨折愈合过程中IGF ImRNA基因表达的细胞定位无差别 ;骨质疏松骨折愈合过程中IGF ImRNA表达在骨折后第 9天 ,且较正常组高。结论 IGF I在骨质疏松骨折愈合中起重要的调节作用。

新疆90例贲门癌中IGF-IR、bcl-2、PCNA的表达及其意义

目的:探讨胰岛素样生长因子-Ⅰ受体(IGF-IR)、细胞凋亡相关基因-2(bcl-2)及增殖细胞核抗原(PCNA) 的异常表达在新疆3个不同民族贲门癌发生发展中的作用及其病理生物学意义,为此病的防治提供实验资料。方法:应用免疫组化LSAB法检测90例贲门腺癌和21例非癌组织的IGF-IR、bcl-2、PCNA蛋白的阳性表达情况。结呆:(1)IGF-IR、bcl-2蛋白、PCNA在90例贲门腺癌中的检出率分别为84．44％(69/90)、87．78％(79/90)、97．78％ (88/90),在贲门非癌良性组织中的阳性检出率分别为47．62％(10/21)、52．38％(11/21)、0％(0/21)。IGF-IR、bcl- 2、PCNA的阳性率在癌和非癌组织间均具有统计学的差异(P<0．01)。(2)哈萨克族(哈族)、维吾尔族(维族)、汉族各民族之间IGF-IR、bcl-2、PCNA阳性率的差异均无统计学意义(P>0．05)。(3)IGF-IR、bcl-2、PCNA在贲门腺癌不同分化程度中阳性率的差异均无统计学意义(P>0．05)。(4)贲门腺癌中bcl-2,与IGF-IR间、bcl-2与PC- NA间无相关关系(P>0．05)。结论:(1)IGF-IR蛋白、癌基因bcl-2和PCNA的异常表达在贲门癌变过程中具有重要作用。(2)贲门癌组织中IGF-IR、bcl-2、PCNA表达在肿瘤不同分化程度和不同民族间无显著差别。

Reactivation of the insulin-like growth factor-Ⅱsignaling pathway in human hepatocellular carcinoma

Constitutive activation of the insulin-like growth factor (IGF)-signaling axis is frequently observed in human hepatocellular carcinoma(HCC).Especially the over- expression of the fetal growth factor IGF-Ⅱ,IGF-Ⅰ receptor(IGF-IR),and cytoplasmic downstream effectors such as insulin-receptor substrates(IRS)contribute to proliferation,anti-apoptosis,and invasive behavior. This review focuses on the relevant alterations in this signaling pathway and independent in vivo models that support the central role IGF-Ⅱsignaling during HCC development and progression.Since this pathway has become the center of interest as a target for potential anti-cancer therapy in many types of malignancies,various experimental strategies have been developed,including neutralizing antibodies and selective receptor kinase inhibitors,with respect to the specific and efficient reduction of oncogenic IGF-Ⅱ/IGF-IR-signaling.

Expression and significance of tumor-related genes in HCC

AIM: To investigate the expression and clinical significance of DEK, cyclin D1, insulin-like growth factor Ⅱ (IGF-Ⅱ), glypican 3 (GPC3), ribosomal phosphoprotein 0 (rpPO) mRNA in hepatocellular carcinoma (HCC) and its paraneoplastic tissues. METHODS: The expression of mRNAs of DEK, cyclin D1, IGF-Ⅱ, GPC3 and rpP0 mRNA was detected in HCC and its paraneoplastic tissues by multiplex RT-PCR. RESULTS: By the simplex RT-PCR, the overexpression of mRNAs of DEK, cyclin D1, IGF-Ⅱ, GPC3, rpP0 mRNA in HCC and its paraneoplastic tissues was 78.1%, 87.5%, 87.5%, 75.0%, 81.3% and 15.6%, 40.6%, 37.5%, 21.9%, 31.3% respectively (P<0.05). By the multiplex RT-PCR, at least one of the mRNAs was detected in all HCC samples and in 75.0% of paraneoplastic samples (P>0.05). However, all these five mRNAs were found in 68.8% of HCC samples, but only in 9.4% of paraneoplastic tissues (P<0.05). The positive expression of mRNAs of DEK, cyclin D1, IGF-Ⅱ, GPC3, rpP0 in well- and poorly-differentiated HCC was 89.0%, 66.7%, 66.7%, 66.7%, 77.8% and 73.9%, 95.7%, 95.7%, 95.7%, 82.6%, respectively (P>0.05). The expression of these genes in HCCs with α-feto protein (AFP) negative and positive was 90.0%, 80.0%, 90.0%, 90.0%, 90.0% and 72.7%, 86.3%, 77.3%, 90.9%, 68.2% respectively (P>0.05). CONCLUSION: The expression of DEK, cyclin D1, IGF-Ⅱ, GPC3, rpP0 mRNA in HCC is much higher in HCC than in its paraneoplastic tissues. Multiplex RT-PCR assay is an effective, sensitive, accurate, and cost-effective diagnostic method of HCC.

Insulin-like growth factor binding protein-5 influences pancreatic cancer cell growth

AIM： To investigate the functional significance of insulin-like growth factor binding protein-5 （IGFBP-5） overexpression in pancreatic cancer （PaC）.METHODS： The effects of IGFBP-5 on cell growth were assessed by stable transfection of BxPC-3 and PANC-1 cell lines and measuring cell number and DNA synthesis. Alterations in the cell cycle were assessed by flow cytometry and immunoblot analyses. Changes in cell survival and signal transduction were evaluated after mitogen and phosphatidylinositol activated protein kinase 3-kinase （PI3K） inhibitor treatment.RESULTS： After serum deprivation, IGFBP-5 expression increased both cell number and DNA synthesis in BxPC-3 cells, but reduced cell number in PANC-1 cells. Consistent with this observation, cell cycle analysis of IGFBP-5-expressing cells revealed accelerated cell cycle progression in BxPC-3 and G2/M arrest of PANC-1 cells. Signal transduction analysis revealed that Akt activation was increased in BxPC-3, but reduced in PANC-1 cells that express IGFBP-5. Inhibition of PI3K with LY294002 suppressed extracellular signal-regulated kinase-1 and -2 （ERK1/2） activation in BxPC-3, but enhanced ERK1/2 activation in PANC-1 cells that express IGFBP-5. When MEK1/2 was blocked, Akt activation remained elevated in IGFBP-5 expressing PaC cells; however, inhibition of PI3K or MEK1/2 abrogated IGFBP-5-mediated cell survival.CONCLUSION： These results indicate that IGFBP-5 expression affects the cell cycle and survival signal pathways and thus it may be an important mediator of PaC cell growth.

Feeder-free maintenance of hESCs in mesenchymal stem cell-conditioned media： distinct requirements for TGF-β and IGF-Ⅱ

A paracrine regulation was recently proposed in human embryonic stem cells （hESCs） grown in mouse embryonic fibroblast （MEF）-conditioned media （MEF-CM）, where hESCs spontaneously differentiate into autologous fibroblastlike cells to maintain culture homeostasis by producing TGF-β and insulin-like growth factor-lI （IGF-Ⅱ） in response to basic fibroblast growth factor （bFGF）. Although the importance of TGF-β family members in the maintenance of pluripotency of hESCs is widely established, very little is known about the role of IGF-Ⅱ. In order to ease hESC cul- ture conditions and to reduce xenogenic components, we sought （i） to determine whether hESCs can be maintained stable and pluripotent using CM from human foreskin fibroblasts （HFFs） and human mesenchymal stem cells （hM- SCs） rather than MEF-CM, and （ii） to analyze whether the cooperation of bFGF with TGF-β and IGF-Ⅱ to maintain hESCs in MEF-CM may be extrapolated to hESCs maintained in allogeneic mesenchymal stem cell （MSC）-CM and HFF-CM. We found that MSCs and HFFs express all FGF receptors （FGFR1-4） and specifically produce TGF-β in response to bFGF. However, HFFs but not MSCs secrete IGF-Ⅱ. Despite the absence of IGF-Ⅱ in MSC-CM, hESC pluripotency and culture homeostasis were successfully maintained in MSC-CM for over 37 passages. Human ESCs derived on MSCs and hESCs maintained in MSC-CM retained hESC morphology, euploidy, expression of surface markers and transcription factors linked to pluripotency and displayed in vitro and in vivo multilineage developmental potential, suggesting that IGF-Ⅱ may be dispensable for hESC pluripotency. In fact, IGF-Ⅱ blocking had no effect on the homeostasis of hESC cultures maintained either on HFF-CM or on MSC-CM. These data indicate that hESCs are successfully maintained feeder-free with IGF-Ⅱ-lacking MSC-CM, and that the previously proposed paracrine mechanism by which bFGF cooperates with TGF-β and IGF-Ⅱ in the maintenance of hESCs in MEF-CM may not be fully extrapolated to hESCs maintained in CM from human MSCs.

Apoptosis in Granulosa cells during follicular atresia:relationship with steroids and insulin-like growth factors

It is well known that during mammalian ovarian follicular development, the majority of follicles undergo atresia at various stages of their development. However, the mechanisms controlling this selection process remain unknown. In this study, we investigated apoptosis in granulosa cells during goat follicular atresia by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). The changes in the levels of steroids, insulin-like growth factors (IGFs) and IGF receptors were studied by radioimmunoassay (RIA) and semi-quantitative reverse transcrip-tion-PCR. We found that the percentage of apoptotic granulosa cells in the atretic (A) follicles was significantly higher than that in the slightly atretic (SA) and healthy (H) follicles. The level of estradiol and the ratio of estradiol to progesterone in H follicles were significantly higher than those in A follicles. On the other hand, the level of progesterone was not significantly different among these follicle types. We also found that the level of IGF-Ⅰ in H follicles was higher than in SA and A follicles, whereas the amount of IGF-Ⅱ did not vary significantly. The expression of IGF receptor also decreased in A follicles as compared to that in H and SA follicles. These results suggested that estradiol and IGF-Ⅰ might be involved in controlling apoptosis in granulosa cells during follicular atresia.

C-peptide and Diabetic Encephalopathy

With the changes of life style, diabetes and its complications have become a major cause of morbidity and mortality. It is reasonable to anticipate a continued rise in the incidence of diabetes and its complications along with the aging of the population, increase in adult obesity rate, and other risk factors. Diabetic en- cephalopathy is one of the severe microvascular complications of diabetes, characterized by impaired cogni- tive functions, and electrophysiological, neurochemical, and structural abnormalities. It may involve direct neuronal damage caused by intracellular glucose. However, the pathogenesis of this disease is complex and its diagnosis is not very clear. Previous researches have suggested that chronic metabolic alterations, vascular changes, and neuronal apoptosis may play important roles in neuronai loss and damaged cognitive functions. Multiple factors are responsible for neuronal apoptosis, such as disturbed insulin growth factor （IGF） system, hyperglycemia, and the aging process. Recent data suggest that insulin/C-peptide deficiency may exert a primary and key effect in diabetic encephalopathy. Administration of C-peptide partially improves the condition of the IGF system in the brain and prevents neuronal apoptosis in the hippocampus of diabetic patients. Those findings provide a basis for application of C-peptide as a potentially effective therapy for diabetes and diabetic encephalopathy.

Effect of growth hormone on small intestinal homeostasis relation to cellular mediators IGF-I and IGFBP-3

AIM:To evaluate the effects of growth hormone(GH) on the histology of small intestines which might be related to the role of insulin like growth factor(IGF)-I, IGF-binding protein 3(IGFBP-3)and its receptors. METHODS:Twelve week-old adult male Wistar albino rats were divided into two groups.The study group(n =10),received recombinant human growth hormone (rGH)at a dose of 2 mg/kg per day subcutaneously for 14 d and the control group(n=10)received physiologic serum.Paraffin sections of jejunum were stained with periodic acid shift(PAS)and hematoxylin and eosin(HE) for light microscopy.They were also examined for IGF-I, IGFBP-3 and IGF-receptor immunoreactivities.Staining intensity was graded semi-quantitatively using the HS- CORE. RESULTS:Goblet cells and the cells in crypt epitheliawere significantly increased in the study group compared to that of the control group.We have demonstrated an increase of IGF-I and IGFBP-3 immunoreactivities in surface epithelium of the small intestine by GH application.IGF-I receptor immunoreactivities of crypt,villous columnar cells,enteroendocrine cells and muscularis mucosae were also more strongly positive in the study group compared to those of in the control group. CONCLUSION:These findings confirm the important trophic and protective role of GH in the homeostasis of the small intestine.The trophic effect is mediated by an increase in IGF-I synthesis in the small intestine, but the protective effect is not related to IGF-I.

Insulin promotes sinusoidal endothelial cell proliferation mediated by upregulation of vascular endothelial growth factor in regenerating rat liver after partial hepatectomy

AIM： To determine whether insulin could promote sinusoidal endothelial cell （SEC） proliferation mediated by upregulation of vascular endothelial growth factor （VEGF） in regenerating rat liver after partial hepatectomy （PHx）. METHODS： Adult male Sprague-Dawley rats undergoing 70% PHx were injected with insulin （300 MU/kg） or saline via the tail veins every 8 h after surgery for 7 d and killed at 0, 24, 48, 72, 96, 120, 144, and 168 h after surgery. Proliferation of both hepatocytes and SECs was monitored by evaluating the proliferating cell nuclear antigen （PCNA） labeling index （LI）. The expression of VEGF protein was evaluated by immunohistochemistJv. The mRNA expressions of VEGF and its receptors FIt-1 and FIk-1 were evaluated by semi-quantitative reverse transcription-PCR. RESULTS： Insulin markedly increased the expression of VEGF mRNA between 24 and 120 h after hepatectomy compared to controls. Similarly, insulin significantly increased the expression of Fit-1 between 24 and 96 h. However, insulin had no significant effect on FIk-1. Furthermore, the immunohistochemical staining revealed that expression of VEGF protein increased in the insulin groups. Insulin significantly increased the PCNA LI of hepatocytes and SECs compared to controls. CONCLUSION： Exogenous insulin may promote SEC proliferation with an enhanced expression of VEGF and its receptor Fit-1 in regenerating rat liver after PHx.

Effects of ethanol on insulin-like growth factor-Ⅰ system in primary cultured rat hepatocytes: Implications of JNK1/2 and alcoholdehydrogenase

AIM: To evaluate the effects of ethanol on the insulin- like growth factor-Ⅰ (IGF-Ⅰ) system involved in c-Jun N-terminal kinase (JNK1/2) and alcoholdehydrogenase (ADH) activity in primary cultured rat hepatocytes. METHODS: Hepatocytes isolated from male Sprague-Dawley rats were incubated with various concentrations of ethanol for different durations of time. The cells were pretreated with SP600125 (10 μmol/L) and 4-MP (200 μmol/L), and then treated with ethanol (200 mmol/L). We then measured IGF-Ⅰ secretion, IGF-Ⅰ mRNA expression, cell viability and JNK1/2 activity by radioimmunoassay, RT-PCR, MTT assay and Western blot, respectively (n = 6). RESULTS: Ethanol induced the activity of phospho (p)-JNK1/2, reaching a maximum at 60 min and then decreasing at 180 min. The effects of ethanol on the IGF-Ⅰ system were increased at 60 min (secretion: 7.11 ± 0.59 ng/mg protein vs 4.91 ± 0.51 ng/mg, mRNA expression: 150.2% ± 10.2% vs 101.5% ± 11.3%, P = 0.045) and then decreased at 180 min (secretion: 3.89 ± 0.25 ng/mg vs 5.4 ± 0.54 ng/mg protein; mRNA expression: 41.5% ± 10.4% vs 84.7% ± 12.1%, P = 0.04), however cell viability was decreased in a dose- and time-dependent manner. SP600125 blocked the ethanol-induced changes (at 60 min). Additionally, 4-methylpyrazole prevented the ethanol-induced decreases in the IGF-Ⅰ system, cell viability and p-JNK1/2 activity (at 180 min). CONCLUSION: This study suggests that ethanol- induced p-JNK1/2 activation is associated with the IGF-Ⅰ system and cell viability in hepatocytes. Furthermore, alcohol dehydrogenase is involved in the relationship between ethanol-induced inactivation of p-JNK1/2 and the changes of the IGF-Ⅰ system and cell viability.

Effects of IGF-1 and oxLDL on expression of phosphatase PHLPP1 in vascular smooth muscular cells

Objective To investigate the effects of insulin-like growth factor-1 （IGF-1） and oxidized low density lipoprotein （oxLDL） on expression ofphosphatase PHLPP 1 in vascular smooth muscle cells （VSMCs）. Methods Rabbit aortic VSMCs were cultured. VSMCs proliferation ability was determined by measuring cell number and mitochondrial dehydrogenase （MD） activity with MTT assay. Western blot was used to detect the protein expression ofphosphatase PHLPP1. Results IGF-1 （100ug/L） increased cell number and MD activity to 3.02 and 3.59 times of that in control group, oxLDL（501xg/ml） elevated the above two parameters to 2.03 and 2.91 times respectively. Western blot showed that IGF-1 and oxLDL inhibited the expression of PHLPPI to 39.27% and 40.26% of the control group （P〈0.01 ）. Conclusion IGF- 1 and oxLDL may enhance the proliferation of VSMCs by decreasing the expression ofphosphatase PHLPP 1.

Retinoic acid regulated insulin-like growth factor gene expression in cord blood lymphocytes

Objective To explore the immune promotion mechanism of retinoic acid (RA).Methods Reverse Transcription-Polymerase chain reaction (RT-PCR) was used to detect the gene expression of insulin like growth factor Ⅰ (IGF-Ⅰ) and IGF receptors (IGF-IR and IGF-IIR) in vitro, and their regulation by RA in human cord blood lymphocyte (CBL). Results Significant upregulation of IGF-I, IGF-IR and IGF-IIR mRNA was found at 6-24 hours in CBL incubated with physiologic concentrations of RA as compared to those without RA. Conclusion The enhancement of IGF expression may be an important pathway for vitamin A to promote immune cellular functions.

Effect of Acupuncture-moxibustion on the Expression of IGF-1 and SOCS2 in Colonic Mucosa of Rats with Ulcerative Colitis

Objective： To observe the effect of acupuncture-moxibustion on the expression of insulin-like growth factor-I （IGF-I） and suppressor of cytokine signaling-2 （SOCS2） in colonic mucosa of rat models of ulcerative colitis （UC）, and explore the mechanism of acupuncture- moxibustion therapy in treating UC. Methods： The rats were randomized into a normal control （NC） group, a model control （MC） group, an herb-partitioned moxibustion （HPM） group and an electroacupuncture （EA） group, 8 in each group. The rat models of UC were established by immunological methods combined with local stimulation. The rats in the HPM and EA groups were given herb-partitioned moxibustion and electroacupuncture treatments respectively, once every day, lasting for 14 d. The morphological variations of rat＇s colonic mucosa were observed under light microscope; the colonic mucosal mucin was detected by PAS-AB and HID-AB staining methods; the expression of IGF-1 and SOCS2 was assayed by the immunohistochemical method. Results： In the rat models of UC, ulceration and inflammation of the colon were revealed by light microscope. The concentration of colonic mucosal mucin was reduced （P〈0.01）, while the expression of IGF-1 had an increase （P〈0.01）, and the expression of SOCS2 was reduced （P〈0.01）. After HPM or EA treatment, the pathological injuries of colonic mucosa had improved, the concentration of mucin increased （P〈0.01）, the expression of IGF-1 decreased （P〈0.01）, and the expression of SOCS2 increased （P〈0.01）. Conclusion： The secretion of mucosal mucin in rat UC decreased, the expression of IGF-1 was significantly higher, while the expression of SOCS2 was remarkably lower; both HPM and EA can help improve the damage of colonic mucosa in rat UC, and modulate the secretion of mucin, as well as regulate the expression of IGF-1 and SOCS2 in the colonic mucosa.

Labeling of human insulin-like growth factor-I eukaryotic expression vector with green fluorescent protein

Objective: To label human insulin-like growth factor-I （hIGF-I） eukaryotic expression vector with green fluorescent protein （GFP） for the repair of articular cartilage defects. Methods: GFP cDNA was inserted into pcDNA3.1-hIGF-1 to construct the co-expression vector with two multiple cloning sites mammalian expression vector under two cytomegalovirus promoters/enhancers respectively. Recombinant pcGI was transfected into NIH 3T3 cells with the help of lipofectamine. Results: Enzyme digestion and agarose gel electrophoresis analysis revealed that pcGI vector contained correct GFP and hIGF-I cDNA. Expression of （hIGF-1） and GFP was confirmed in transfected NIH 3T3 cells by immunocytochemical analysis and fluorescence microscopy. Conclusions: hIGF-I eukaryotic expression vector has been successfully labeled with GFP.

Effects of insulin-like growth factor-1 on the properties of mesenchymal stem cells in vitro

Objective:To explore the effects of insulin-like growth factor-1(IGF-1) on migration,proliferation and differentiation of mesenchymal stem cells(MSCs).Methods:MSCs were obtained from Sprague-Dawley rats by a combination of gradient centrifugation and cell culture techniques and treated with IGF-1 at concentrations of 5-20 ng/ml.Proliferation of MSCs was determined as the mean doubling time.Expression of CXC chemokine receptor 4(CXCR4) and migration property were determined by flow cytometry and transwell migration essay,respectively.mRNA expression of GATA-4 and collagen II was determined by reverse transcription-polymerase chain reaction(RT-PCR).Results:The mean doubling time of MSC proliferation was decreased,and the expression of CXCR4 on MSCs and migration of MSCs were increased by IGF-1,all in a dose-dependent manner,while the optimal concentration of IGF-1 on proliferation and migration was different.IGF-1 did not affect the expression of GATA-4 or collagen II mRNA.Conclusions:IGF-1 dose-dependently stimulated the proliferation of MSCs,upregulated the expression of CXCR4,and accelerated migration.There was no apparent differentiation of MSCs to cardiomyocytes or chondrocytes after culturing with IGF-1 alone.

Tumor targeted mesoporous silica-coated gold nanorods facilitate detection of pancreatic tumors using Multispectral optoacoustic tomography

Multispectral optoacoustic tomography （MSOT） is an emerging imaging technology that offers several advantages over traditional modalities, particularly in its ability to resolve optical contrast at depth on the microscopic scale. While potential applications include the early detection of tumors below clinical thresholds set by current technology, the lack of tumor-specific contrast agents limits the use of MSOT imaging. Therefore, we constructed highly stable nano-contrast agents by coating gold nanorods （GNRs） with either polyacrylic acid （PAA） or amine- functionalized mesoporous silica （MS）. Syndecan-1, which has been shown to target insulin-like growth factor 1 receptor （IGF1-R） （upregulated in pancreatic tumors）, was conjugated on the surface of PAA-coated GNRs （PAA-GNRs） or MS-coated GNRs （MS-GNRs） to create tumor-targeted nanoparticles. In vitro, tumor targeting of nanoparticles was assessed with flow cytometry. In S2VP10L cells （positive for IGF1-R）, the syndecan-1 MS-GNRs （Syndecan-MS-GNRs） demonstrated an increase in OA signal, 10x, compared to syndecan-1 PAA- GNRs （Syndecan-PAA-GNRs）. Minimal binding was observed in MiaPaca-2 cells （negative for IGF1-R）. In vivo, tumor specific targeting of Syndecan-MS-GNRs was evaluated using a murine orthotopic pancreatic cancer model. The Syndecan- MS-GNRs demonstrated significantly greater accumulation within pancreatic tumors than in off-target organs such as the liver. Mice implanted with the IGF1-R negative MiaPaca-2 cells did not demonstrate specific tumor targeting. In summary, we report that targeted nano-contrast agents （Syndecan-MS-GNRs） can successfully detect orthotopic pancreatic tumors with minimum off-target binding in vivo using MSOT.