Low-intensity laser irradiation stimulates bone nodule formation via insulin-like growth factor-I expression in rat calvarial cells

BACKGROUND AND OBJECTIVE: We previously reported that low-intensity laser irradiation stimulated bone nodule formation through enhanced cellular proliferation and differentiation. However, the mechanisms of irradiation are unclear. Thus, we attempted to determine the responsibility of insulin-like growth factor (IGF)-I for the action observed. STUDY DESIGN/MATERIALS AND METHODS: Osteoblast-like cells were isolated from fetal rat calvariae and cultured with rat recombinant (r) IGF-I, IGF-I-antibody (Ab), and/or the cells were irradiated once (3.75 J/cm(2)) with a low-intensity Ga-Al-As laser (830 nm). The number and area of bone nodules formed in the culture were analyzed, and IGF-I expression was also examined. RESULTS: Treatment with rIGF-I significantly stimulated the number and area of bone nodules. This stimulatory effect was quite similar to those by laser irradiation, and this stimulation was abrogated dose-dependently by treatment with IGF-I-Ab. Moreover, laser irradiation significantly increased IGF-I protein and gene expression. CONCLUSION: The stimulatory effect of bone nodule formation by low-intensity laser irradiation will be at least partly mediated by IGF-I expression.     

Binding and internalization of insulin and insulin-like growth factors by isolated brain microvessels

Isolated brain capillaries were used as a model system to test for binding and internalization of insulin and insulin-like growth factors (IGF) I and II. At 37 degrees C, the maximum specific binding of the 125I-labeled peptides was 48.0 +/- 0.8%/mg capillary protein for IGF I, 40.6 +/- 1.4% for IGF II, and 15.1 +/- 0.6% for insulin. The concentration of unlabeled peptide needed to cause a 50% decrease in the maximum binding (ID50) was 22 ng/ml (2.9 nM), 25 ng/ml (3.3 nM), and 7 ng/ml (1.2 nM) for IGF I, IGF II, and insulin, respectively. Unlabeled insulin competed poorly for the IGF I receptor, requiring 5000 ng/ml (667 nM) to cause a 50% reduction in binding, and did not compete at all for the IGF II receptor at concentrations up to 10(5) ng/ml (17.8 microM). The IGF I receptor was further characterized by reduced polyacrylamide gel electrophoresis of the disuccinimidyl suberate cross-linked 125I-labeled IGF I receptor. The gel showed a distinct band at 133,000 Mr that was abolished by 0.6 microgram/ml (80 nM) unlabeled IGF I but not by 10.0 micrograms/ml (1780 nM) unlabeled insulin. Peptide internalization was monitored by the acidwash technique. Only 22% of the bound IGF I was internalized, but 50% of the insulin and 43% of the IGF II were acid resistant. Capillaries prelabeled with internalized 125I-insulin could then export radioactivity into fresh, insulin-free media in a time- and temperature-dependent manner. However, high-performance liquid chromatography (HPLC) and trichloroacetic acid (TCA) analysis of the released material showed that it consisted mostly of degraded peptide.(ABSTRACT TRUNCATED AT 250 WORDS)     

Regulation of plasminogen activator and plasminogen activator inhibitor production by growth factors and cytokines in rat calvarial cells

Summary Fetal rat osteoblast-enriched calvarial cells were used to study the effects of various growth factors and cytokines on plasminogen activator (PA) and plasminogen activator inhibitor (PAI) activities and the possible relationship of these effects to bone resorption. Confluent cultures were exposed to various factors under serum-free conditions, and levels of PA and PAI activities were examined in both conditioned medium (CM) and cell layer using the¹²⁵I-fibrin plate assay, fibrin zymogram, and reverse fibrin zymogram. According to the¹²⁵I-fibrin plate assay or zymogram, incubation of cells with acidic fibroblast growth factor (aFGF), basic FGF (bFGF), epidermal growth factor (EGF), and platelet-derived growth factor (PDGF) elevated the PA activity in the CM as well as in the cell layer extract. Incubation with interleukin 1α (IL-1α), tumor necrosis factor α (TNFα), and insulin-like growth factor I (IGF-I) produced no change in PA activity in either CM or cell layer. Addition of transforming growth factor β (TGFβ) to calvarial cells resulted in nearly undetectable PA activity in CM with the fibrin plate assay but increased PA activity on the fibrin zymogram after PAI was separated from PA by SDS-PAGE. A reverse fibrin zymogram indicated that PAI activity was greatly enhanced in TGFβ-treated CM. TGFβ treatment also increased PA activity in the cell layer of calvarial cells. Treatment of calvarial cells with bFGF and PDGF slightly increased PAI secretion into medium. This increase, however, was not as dramatic as the increase of PA induced by these two agents. IL-1α and TNFα did not change PAI concentration in CM. No detectable PAI activity was found in the cell layer in control and treated groups. The PA found in the CM and cell layer of rat calvarial cells was the urokinase type; the PAI stimulated by TGFβ was the endothelial cell type, PAI-1. The regulation of PA activity by growth factors and cytokines did not correlate with their resorption-stimulating activities. Thus, PA secreted by osteoblasts may not be the only factor involved in the initiation of bone resorption. Delineation of the function of PA and PAI in the physiology of bone tissue awaits further studies.     

Effect of surface roughness on proliferation and alkaline phosphatase expression of rat calvarial cells cultured on polystyrene.

Rough-surfaced substrates made by a variety of methods have been shown to influence osteoblast proliferation and differentiation. The purpose of this study is to confirm the role of surface roughness in promoting osteoblastic differentiation using tissue culture polystyrene as substrate, by excluding factors other than roughness. Immature osteogenic cells derived from fetal rat calvariae were cultured on the plastic cover strips having varied degrees of roughness created by treatment with four kinds of grinding paper of different particle sizes. The proliferation and gene expression of alkaline phosphatase (ALP) and osteocalcin of the calvarial cells increased on the rough-surfaced cover strips. These levels increased in response to the increase in the degree of surface roughness up to 0.8 microm of average roughness and then decreased to the level observed for the smooth surface. These results demonstrate that the surface roughness itself caused increases in osteoblastic proliferation and differentiation in cell cultures.     

Autocrine secretion of transforming growth factor-beta in cultured rat mesangial cells.

Transforming growth factor-beta (TGF-beta) recently has been shown to modulate mesangial cell growth and to stimulate mesangial matrix synthesis by mesangial cells. Here we examined whether mesangial cells expressed TGF-beta mRNA and secreted mature TGF-beta, and we investigated the role of TGF-beta in mesangial cell growth. Cultured rat mesangial cells expressed 2.5 kb TGF-beta mRNA, and removal of fetal calf serum (FCS) for two days decreased the TGF-beta mRNA level, which was then stimulated by re-addition of 17% FCS reaching the maximum at nine hours. 12-O-tetradecanoyl phorbol-13-acetate (TPA), one of the phorbol esters, markedly increased the mRNA level and reached the maximum at six or nine hours. Immunoblot analysis of the conditioned media using specific anti-TGF-beta 1 antibodies revealed single 12.5 kDa proteins, the size compatible with mature TGF-beta subunits. By means of bioassay using CCL-64 cell line, TGF-beta production rate by mesangial cells was estimated to be 22.1 +/- 6.5 (mean +/- SD) ng/10(6) cells/24 hours, 96% of which was in latent forms. Exogenously added TGF-beta inhibited mesangial cell growth at 10 pM or higher. Moreover, addition of anti-TGF-beta neutralizing antibodies augmented mesangial cell growth, indicating that the secreted TGF-beta actually exerted a growth-inhibitory action. In summary, mesangial cells produce and secrete substantial amounts of TGF-beta but mostly in latent forms, and the secreted TGF-beta may regulate mesangial cell growth and differentiation. We conclude that TGF-beta may function as an autocrine factor in mesangial cells.     

Gene expression of insulin-like growth factors I and II in rat membranous osteotomy healing.

Poorly healing mandibular osteotomies can be a difficult problem in reconstructive surgery. Many therapies have been attempted to augment the healing of mandibular fractures, defects, or osteotomies, but these methods have substantial drawbacks or have been ineffective. The difficulty in treating poorly healing bony defects has led to the exploration of gene therapy as a possible approach to supplement or accelerate mandibular fracture healing. To understand at what point the introduction of a suitable gene candidate might be of benefit in mandibular healing, it is imperative to examine the temporal expression of bone growth factors in a model of membranous bone healing. Insulinlike growth factors (IGFs) I and II are two such bone growth factor candidates because of their known potent in vitro as well as in vivo effects on bone formation. In this study the authors demonstrate the temporal pattern of IGF I and IGF II gene expression during mandibular osteotomy healing using a rat model. Their data reveal that IGF I and IGF II were elevated 7 days after a mandibular osteotomy that was held in external fixation. The upregulation of IGF I and IGF II during mandibular bone healing underscores the importance of these growth factors in bone repair. Gene therapy utilizing recombinant viral constructs containing IGFs I and II may be of benefit during mandibular bone healing in an effort to augment clinical scenarios of poor or retarded bony repair.     

Binding of calcitonin and calcitonin gene-related peptide to calvarial cells and renal cortical membranes

Binding of calcitonin (CT) and calcitonin gene-related peptide (CGRP) to rat hemicalvariae and renal membranes was examined in an effort to determine whether CT and CGRP interact with the same bone cell binding site, and to see whether the binding pattern was similar for bone and renal cortex. Specific binding of 125I-salmon CT to rat calvariae was inhibited by unlabeled salmon, porcine, or human CT, but not by rat CGRP. Binding of 125I-rat CGRP to calvariae was inhibited by CGRP and high doses of salmon CT, but not by human or porcine CT. Binding of 125I-salmon CT to renal membranes was inhibited by unlabeled salmon CT or rat CGRP, but no specific binding of 125I-rat CGRP could be detected. The results suggest that separate bone cell receptors for CT and CGRP exist and that CGRP can interact with renal receptors for CT.     

Mitogenic effects of insulin and insulin-like growth factors on PA-III rat prostate adenocarcinoma cells: characterization of the receptors involved.

Four transplantable cell lines (PA-I, II, III, and IV) derived from four Lobund-Wistar (L-W) rats that manifested spontaneous prostate cancer have demonstrated metastatic capacity in visceral organs. Interestingly, PA-III cells, when deposited over the scapula or calvarium of the Lobund-Wistar rat, could produce lytic and blastic reactions on rat skeleton. Since growth factors and growth factor receptors have been implicated in bone remodeling, cancer biology, and metastatic growth of cancer cells, we have examined 1) the effects of insulin and insulin-like growth factors (IGF-I and IGF-II) on the proliferation of PA-III cells; and 2) the presence of specific receptors for these peptides. IGF-I (0.5 to 100 ng/ml), IGF-II (0.5 to 100 ng/ml), and insulin (0.5 to 10 micrograms/ml) stimulated tritiated thymidine uptake and increased the number of PA-III cells in culture. Receptor studies demonstrated the presence of specific bindings sites for IGF-I and II but not for insulin. The number and affinity of the receptor sites were: IGF-I (nb = 675 fmol/100 g protein, Kd = 0.56 nmol) and IGF-II (nb = 225 fmol/100 g protein, Kd = 0.71 nmol). Molecular characterization of IGF binding sites by polyacrylamide gel electrophoresis under denaturing conditions indicated only the presence for the type I IGF receptor. The presence of the IGF-I receptor and the absence of IGF-II and insulin receptors are discussed in relation to the capacity of PA-III cells to produce bone lesions on the L-W rat.     

Metabolic and mitogenic effects of insulin-like growth factor I on rat glomerular mesangial cells cultured under high concentration of glucose

Recent studies indicate the important roles of mesangial cell dysfunction and insulin-like growth factor I (IGF-I) in the development of diabetic nephropathy. In order to know whether hyperglycemia could alter IGF-I action on mesangial cells, we examined mitogenic and metabolic effects of IGF-I on mesangial cells. Mesangial cells revealed to express considerable numbers of receptors specific to IGF-I will relatively small numbers of insulin receptors. The uptake of [3H]-2-deoxy-glucose, [3H]-aminoisobutyric acid (AIB), or [3H]-thymidine into mesangial cells was stimulated by IGF-I at physiological concentrations. Under high concentrations of glucose (55 mM), the stimulation of thymidine uptake by IGF-I was significantly suppressed from 5863 +/- 549 (at 11 mM glucose) to 1731 +/- 146 DPM/100 micrograms/prot. On the contrary, AIB incorporation by IGF-I was significantly enhanced in the cells cultured under high concentration of glucose, as 2.03 +/- 0.03n mol/mg protein/15 min at 55 mM glucose vs 0.59 +/- 0.01 at 11 mM glucose. In conclusion; 1) IGF-I had metabolic and mitogenic effects on rat mesangial cells at physiological concentrations. 2) under excess glucose conditions, mitogenic action of IGF-I on rat mesangial cells was suppressed, while amino acid incorporation was enhanced. These results suggest that modulation of IGF-I effects on mesangial cell by glucose could be associated with mesangial cell dysfunction in diabetes.     

Fibroblast growth factors lead to increased Msx2 expression and fusion in calvarial sutures.

Craniosynostosis, the premature fusion of the skull bones at the sutures, represents a disruption to the coordinated growth and development of the expanding brain and calvarial vault and is the second most common birth defect that affects the craniofacial complex. Mutations in the human homeobox-containing gene, Msx2, have been shown to cause Boston type craniosynostosis, and we have shown that overexpression of Msx2 leads to craniosynostosis in mice. Activating mutations in fibroblast growth factor (FGF) receptors are thought to cause craniosynostosis in Crouzon, Apert, Jackson-Weiss, Beare-Stevenson, and Muenke syndromes. To mimic activated signaling by mutated FGF receptors, we used heparin acrylic beads to deliver FGF ligands to mouse calvaria and demonstrated increased Msx2, Runx2, Bsp, and Osteocalcin gene expression, decreased cell proliferation, and suture obliteration and fusion. FGF2 elicited the greatest increase in Msx2 expression, and FGF1 was most likely to cause suture obliteration and fusion. Of the three sutures studied, the coronal suture exhibited the greatest increase in Msx2 expression and was the most likely to undergo obliteration and fusion. These results are intriguing because the coronal suture is the most commonly affected suture in syndromic craniosynostosis. These results suggest that Msx2 is a downstream target of FGF receptor signaling and that increased FGF signaling leads to osteogenic differentiation by sutural mesenchyme in mouse calvaria. These results are consistent with the hypotheses that increased Msx2 expression and activated signaling by mutated FGF receptors lead to craniosynostosis.     

Vasoactive agents affect growth and protein synthesis of cultured rat mesangial cells.

Mesangial cell (MC) proliferation and extracellular matrix (ECM) formation are hallmarks of chronic glomerular disease. The present in vitro study examined the effects of the vasoactive agents angiotensin II (Ang II), arginine vasopressin (AVP), and serotonin (5-HT) on growth and protein biosynthesis of cultured rat MCs after 72 hours of incubation. AVP and 5-HT (10(-6) M) significantly increased DNA synthesis and growth of quiescent subconfluent MCs to levels of 25 and 45%, respectively, of the optimal stimulatory effect of 10% fetal calf serum (FCS) (both P less than 0.001). The mitogenic effect of Ang II was 10% of the 10% FCS effect (P less than 0.01). ECM production was studied by ELISA assay for fibronectin (FN) secreted into the culture medium (SeFN) and cell-associated FN, that is, intra- and pericellular FN (CaFN). In all incubations, highly significant negative linear relationships were found between the numbers of MCs per well and quantities of both SeFN and CaFN after normalization of the data by logarithmic transformation (SeFN: r values greater than -0.9705; CaFN: r greater than -0.9620; P less than 0.001). Thus, increasing cell densities progressively suppressed ECM formation by MCs. The ECM production was found to be independent of growth activity. AVP significantly increased SeFN (P less than 0.05) and decreased CaFN (P less than 0.001) in subconfluent cultures; Ang II and 5-HT had no effect. Metabolic labeling with 35S-methionine (18 hr, 200 microCi/ml medium) and 2-D electrophoresis of MC lysates resulted in resolution of greater than 500 different radiolabeled intracellular proteins in molecular weight from 110 to 20 Kd over an isoelectric interval of 5.0 to 7.0.(ABSTRACT TRUNCATED AT 250 WORDS)     

软骨终板通透性对体外培养大鼠髓核细胞生物学特性的影响

目的:观察软骨终板营养通路通透性对外培养大鼠髓核细胞生物学特性的影响。方法:4周龄雄性SD大鼠20只,处死后立即手术切取腰段椎间盘(包括邻近的软骨终板),每只6个,随机分为A、B、C 3组,其中A组为正常对照组,B组用骨蜡封闭上软骨终板,C组用骨蜡封闭上、下软骨终板,3组椎间盘在体外进行整体器官培养。于培养前和培养7d、14d时,分别用Mitotracker Green荧光探针和RT-PCR方法评估椎间盘髓核细胞的活力和髓核Ⅱ型胶原及蛋白多糖mRNA的表达;于培养前和培养14d时用免疫组化方法观察髓核蛋白多糖、Ⅱ型胶原和基质金属蛋白酶3(MMP-3)的表达。结果:取材后培养前髓核细胞的荧光强度最高;在体外培养7d,3组髓核细胞的荧光强度较培养前变化均不明显,3组之间无显著性差异(P>0.05);培养14d时A、B、C组荧光强度较培养前分别降低约19%、22%和30%,与培养前比较差异均有显著性(P<0.05),其中C组与A、B两组比较有显著性差异(P<0.05),A、B两组比较差异无显著性(P>0.05)。免疫组织化学观察显示在培养14d时3组髓核蛋白多糖和Ⅱ型胶原的染色强度与培养前比较均有所降低,MMP-3阳性染色增加,蛋白多糖、Ⅱ型胶原和MMP-3染色强度的变化以C组最为明显。3组髓核细胞Ⅱ型胶原和蛋白多糖mRNA的表达在培养7d和14d时均较培养前显著降低(P<0.05),其中7d时3组之间无显著性差异(P>0.05),14d时A、B两组间无显著性差异(P>0.05),C组与A、B组比较有显著性差异(P<0.05)。结论:降低体外培养大鼠椎间盘上下软骨终板的通透性,可在短期内影响髓核细胞的生物学特性,加速椎间盘的退变。     

Proliferative responses of mesangial cells to growth factors during compensatory versus dietary hypertrophy

While the bulk of renal hypertrophy induced by contralateral nephrectomy or a high-protein diet consists of tubular cell growth, there is some evidence suggesting that mesangial cells play a role in this phenomenon. Previous data suggest that this role of mesangial cells is associated with their proliferation. We, therefore, undertook this investigation to assess the proliferative responses of mesangial cells, originating from single remaining kidneys or from kidneys of rats fed a high-protein diet, to epinephrine, endothelin, arginine vasopressin, neo-synephrine, or epidermal growth factor (EGF). All agents significantly enhanced the proliferation of normal mesangial cells, though the responses to neo-synephrine and EGF were significantly lower as compared with the other growth promoters. The mitogenic effects of the first three agents on single kidney mesangial cells were significant, but blunted as compared with control cells. This blunting was not evident in the case of the latter two mitogens. A significant enhancement of proliferation of mesangial cells originating from protein-fed rats was produced by epinephrine, neo-synephrine, and EGF. These effects were statistically not different from those observed in normal mesangial cells. The proliferative response to each of the mitogens used in the study proved highly specific for each mitogen, since it was abolished by respective specific inhibitors. Mesangial cells may play a role in the activation and later in progressive inhibition of renal hypertrophy in vivo.     

Insulin and insulin-like growth factors in central nervous system tumors. Part V: Production of insulin-like growth factors I and II in vitro.

The authors have previously reported the presence of insulin-like growth factor (IGF) receptors in central nervous system (CNS) tumors and the production of IGF's and their binding proteins by CNS tumors in situ. This study was designed to investigate whether CNS tumor cells are capable of autocrine secretion of IGF-I and IGF-II in vitro. Production of IGF's was studied by specific radioimmunoassay of tumor-cell-conditioned serum-free media from 34 CNS tumors: 12 gliomas, 12 meningiomas, and 10 miscellaneous tumors. Normal human serum and cerebrospinal fluid served as controls. Insulin-like growth factor I was detected in five of 12 meningiomas but in none of the gliomas studied. In contrast, IGF-II was detected in four of 12 gliomas and in six of 11 meningiomas studied. Four miscellaneous tumors produced IGF-I and/or IGF-II. These results suggest that CNS tumors differentially produce IGF-I and IGF-II in vitro. Preferential production of IGF's may be an important marker of the tumor-cell differentiation or malignancy and may be useful as a clinical diagnostic tool. These results add further support to the concept that IGF's may play a role in the regulation of the behavior of CNS tumors.     

Effects of endothelial-cell-derived growth factors on cultured astrocytes.

To clarify the participation of endothelial-cell-derived growth factors (ECDGFs) in astrocytosis, the effects of endothelial-cell-conditioned medium (ECCM) derived either from normotensive rats or spontaneously hypertensive, stroke-prone rats (SHRSPs) on proliferation of C6 cells of an established rat glioma cell line were bioassayed. The ECCM from both strains stimulated proliferation of astrocytes, but the ECCM from SHRSPs showed a higher mitogenic activity for astrocytes than that from normotensive rats. Growth-promoting activity of the ECCM derived from SHRSPs showed an increase that was linear to the conditioning time. These results seem to indicate that endothelial cells produce and release factors that promote the growth of astrocytes. It seems also probable that chronic hypertension causes an increase in production and release of such ECDGFs that correlated with astrocytic proliferation.     

Synergistic actions of platelet-derived growth factor and the insulin-like growth factors in vivo.

Topical application of growth factors has been shown to benefit both normal and impaired wound healing. In normal tissue repair, resident cells produce a "cocktail" of various types of growth factors that overlap in function. In vitro studies have proved that growth factor combinations can act synergistically to enhance cellular function beyond that achieved with individual growth factors. To determine whether similar combinations have a synergistic effect in vivo, we applied growth factor combinations topically to full-thickness skin wounds created in genetically diabetic mice. The C57BL/KsJ-db/db mouse is obese and has insulin-resistant diabetes, and it has been proved that this mouse has markedly impaired wound healing. Topical application of platelet-derived growth factor, insulin-like growth factor-I, or insulin-like growth factor-II enhances healing in this model. Marked synergism was found when platelet-derived growth factor and insulin-like growth factor-II were combined to produce augmentation in wound closure beyond that achieved by application of the individual growth factors. The synergistic effect allowed for improved tissue repair at doses of platelet-derived growth factor and insulin-like growth factor-II that were ineffective when applied individually. The addition of insulin-like growth factor-I or insulin to platelet-derived growth factor produced no significant synergism. Because multiple growth factors are released in the wound during the healing process, it is not surprising that their combination further enhances healing. Growth factor combinations should become an important addition to the armamentarium for the treatment of chronic, nonhealing wounds.     

局部植入辛伐他汀诱导自体骨髓间充质干细胞归巢修复大鼠颅骨缺损

目的探讨局部植入辛伐他汀修复大鼠颅骨极限骨缺损的机制,即诱导自体骨髓间充质干细胞（BMSC）归巢。方法辛伐他汀5mg加聚乳酸20mg或单纯聚乳酸20mg分别溶解于200μl丙酮,制备辛伐他汀聚乳酸复合材料或单纯聚乳酸材料。16只SD大鼠尾静脉注射绿色荧光蛋白（GFP）标记的BMSC（GFP-BMSC）作为示踪细胞,48h后制作大鼠颅骨极限缺损模型,并植入辛伐他汀-聚乳酸复合材料（n=8）和单纯聚乳酸材料（n=8）进行修复。2周后经小动物活体荧光成像系统检测缺损处绿色荧光信号,冰冻切片荧光显微镜下观察辛伐他汀组（n=4）和对照组（n=4）缺损处GFP-BMSC归巢。颅骨脱钙后经免疫组化染色检测辛伐他汀组（n=4）和对照组（n=4）缺损处骨形态发生蛋白-2（BMP-2）表达。结果小动物活体荧光成像系统检测显示,辛伐他汀组缺损处有较强的绿色荧光信号,对照组缺损处绿色荧光信号较弱;冰冻切片荧光显微镜下观察发现,辛伐他汀组缺损处较对照组缺损处GFP阳性细胞数量明显增加;免疫组化检测发现,辛伐他汀组BMP-2表达增加。结论局部植入辛伐他汀可诱导自体BMSC归巢至缺损部位并参与修复,其诱导归巢过程可能与BMP-2表达上调有关。     

Cell-free synthesis of rat insulin-like growth factor II

Total RNA extracted from a rat liver cell line (BRL 3A) that synthesizes rat insulin-like growth factor II (IGF-II) was translated in a reticulocyte lysate cell-free system. Incubation of the translation products with antisera to mature rat IGF-II (Mr 8700) selectively immunoprecipitated a Mr 21,600 protein. We propose that this protein represents pre-pro-IGF-II.